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Digital Camera Patent Abstract
A digital camera comprises two photographing systems which are independent
of and substantially identical to each other, and each of which
includes a photographing optical system and an image pickup device.
The photographing optical system is configured to include a photographing
lens, a focusing lens and an aperture stop. The focusing lens of
one of the photographing systems is driven stepwise from a first
predetermined position at which it is to be located when a focusing
position lies at an infinite distance, toward a second predetermined
position at which it is to be located when the focusing position
lies at the closest distance, while the focusing lens of the other
photographing system is driven stepwise from the second predetermined
position toward the first predetermined position every step width.
The contrasts of images formed by the respective photographing systems
are evaluated while the two focusing lenses are being moved, and
a position corresponding to the maximum value of the contrasts is
determined as the focusing position.
Digital Camera Patent Claims
15. A digital camera comprising: a first photographing system and
a second photographing system which respectively pick up an image
of a subject; and a focus adjustment control unit which performs
a focus adjustment when photographing the subject by at least one
of said first photographing system and said second photographing
system, by utilizing both said first photographing system and said
second photographing system.
16. A digital camera according to claim 15, wherein: said first
photographing system includes a first image pickup device which
picks up an image of a subject, a first optical system which forms
the subject image on said first image pickup device, and a first
focus adjustment unit which adjusts a focus for the subject; said
second photographing system includes a second image pickup device
which picks up an image of a subject, a second optical system which
forms the image of the subject on said second image pickup device
and which has a focal depth set shorter than that of said first
optical system, and a second focus adjustment unit which adjusts
the focus for the subject; and when the subject is to be photographed
by said second photographing system, said focus adjustment control
unit controls said first focus adjustment unit so as to perform
the focus adjustment based on said first focus adjustment unit and
thereafter controls said second focus adjustment unit so as to perform
the focus adjustment based on said second focus adjustment unit,
on the basis of a result of the focus adjustment based on said first
focus adjustment unit.
17. A digital camera having a plurality of photographing systems
as defined in claim 16, wherein said second optical system includes
a zoom lens.
18. A digital camera according to claim 16, wherein said first
optical system includes a monofocal lens.
19. A digital camera according to claim 16, further comprising:
a changeover switch which changeovers a photographing system for
photographing the subject, to one of said first photographing system
or said second photographing system; and a display device which
displays images; wherein said focus adjustment control unit controls
said display device so as to display the image formed by one photographing
system determined by said changeover switch, and to display image
information indicative of the image formed by the other photographing
system.
20. A digital camera according to claim 19, further comprising
a recording unit which records the image photographed by said one
photographing system determined by said changeover switch.
21. A digital camera according to claim 16, wherein said first
photographing system and said second photographing system are photographing
systems whose image angles are different from each other.
Digital Camera Patent Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a digital camera, and more
particularly to a digital camera including a display device which
displays an image formed by an image pickup device such as CCD.
[0003] The invention relates to a digital camera having a plurality
of photographing systems, and more particularly to a digital camera
having a plurality of photographing systems which are independently
constructed including a plurality of solid-state image pickup devices
such as CCDs, and which have automatic focusing functions, respectively.
[0004] 2. Description of the Related Art
[0005] In recent years, a large number of digital cameras have
been distributed as imaging apparatuses each having a CCD image
pickup device or the like which is capable of easy photographing.
In its photographing operation, the digital camera reads charges
corresponding to the quantity of light (through photoelectric conversion)
every pixel by the CCD image pickup device or the like, and converts
the charges into image data, whereupon it records a photographed
image as the image data on a recording medium such as magnetic recording
medium.
[0006] In the course from the formation of an image to the recording,
the digital conversion process of the formed image, an image creation
process for displaying the formed image and a recording process
for recording the photographed image are respectively executed as
principal processes every photographing frame.
[0007] Besides, the digital camera of this type has become capable
of photographing a dynamic image, owing to the use of the CCD image
pickup device or the like. It has been proposed to photograph a
dynamic image, for example, in such a way that a plurality of lens
units are arrayed in the direction of an optic axis, and that the
respective lens units are driven to zoom in accordance with photographing
optical systems changed over and selected, so as to form optical
images on the CCD (refer to JP-A No. 10-262175).
[0008] Further, imaging apparatuses etc. each including a plurality
of CCD image pickup devices have been proposed. By way of example,
in a technique disclosed in JP-A No. 11-122536, it has been proposed
to dispose a plurality of CCDs for black-and-white use and for color
use or ones of different device sizes, and a control unit for driving
the CCDs, to divide an optical signal from an optical lens and receive
divided signals by the respective CCDs, and to execute a signal
process by the control unit. In this technique, the CCDs for photographing
are changed over in accordance with the situation of surroundings,
whereby an image corresponding to the circumstances can be obtained.
[0009] The digital camera stated above includes a zoom lever, and
has the zoom function of enlarging or reducing the image of a subject
on the basis of the operation of the zoom lever. There has also
been proposed a camera including two photographing systems, and
two display units which correspond to the respective photographing
systems and which display images obtained by the respective photographing
systems.
[0010] With the prior-art digital camera, however, during telescopic
photographing, only a subject to be photographed can be confirmed
by an optical finder or a display device of liquid crystal or the
like functioning as the optical finder, and the situation of surroundings
cannot be confirmed. This poses, for example, the problem that the
proceeding of a game is not noticed in sports photographing, so
the photographing of a scoring scene or any accident is missed.
[0011] Besides, an autofocusing function in the prior art poses
a problem in case of using a lens of short focal depth, such as
zoom lens, and depending upon the reference position and focal position
of the lens on the occasion of autofocusing. More specifically,
as shown in FIG. 18 by way of example, when contrast at each lens
position is calculated as the lens is moved in the direction of
arrow A in FIG. 18 (as the lens is moved from the side of the longest
focal distance), a distance which the lens is moved till the detection
of the maximum value of the contrast becomes longer than in case
of moving the lens in the opposite direction to the direction of
the arrow A, so that a longer time is expended in searching for
the focal position.
[0012] Besides, in the case of using a lens of short focal depth,
such as zoom lens, it is common that a stepping motor for driving
the focusing lens is driven at intervals of several steps, thereby
to specify a rough focal position range (as rough search), whereupon
the stepping motor is finely driven, thereby to search the specified
rough focal position range for a focus. Even on this occasion, as
in the above, there is the problem that, since a focus search range
is extensive in the rough search, a distance which the lens is moved
becomes long, so a long time is expended in searching for a focal
position.
[0013] Besides, even when the digital camera has the autofocusing
function, a user cannot know which range the image of a subject
is automatically focused on the CCD in, if the image of the subject
has been focused, and so forth.
[0014] Further, it is considered to furnish a camera with two photographing
systems, and two display units which display images obtained by
the respective imaging systems, in correspondence with these respective
imaging systems, and to dispose zoom levers in correspondence with
the respective imaging systems in case of widening or narrowing
an image angle.
[0015] Besides, an autofocusing function in the prior art performs
autofocusing in such a way that, as shown in FIG. 35 by way of example,
the position of a lens focusing in a case where a photographing
distance to a subject is the closest distance previously determined
is set as an initial position, whereupon a lens position at which
a contrast value becomes the maximum value is found as a focusing
position as the lens is driven stepwise every predetermined distance
L from the initial position to the position of the lens focusing
in a case where the photographing distance to the subject is an
infinite distance. Accordingly, there is the problem that, when
the focusing position lies on an infinite distance side as shown
in FIG. 35, a long time is expended on the detection of the focusing
position. With a contrary setting at which the position of the lens
focusing in a case where the photographing distance to the subject
is the infinite distance is set as an initial position, a long time
is expended on the detection of the focusing position when the focusing
position lies on a closest distance side.
SUMMARY OF THE INVENTION
[0016] The present invention has been made in order to solve the
above problems, and has for its first object to provide a digital
camera which can photograph while grasping the situation of surroundings.
[0017] The invention has been made in order to solve the above
problems, and has for its second object to provide a digital camera
having a plurality of photographing systems as can shorten a search
time for a focal position.
[0018] The invention has been made in view of the above facts,
and has for its third object to provide a digital camera which is
capable of recognizing a focus adjustment state.
[0019] The invention has been made in view of the above facts,
and has for its fourth object to provide a digital camera which
can have a simple apparatus construction even when it includes two
photographing systems and is permitted to change the size of the
image of a subject.
[0020] The invention has been made in order to solve the above
problems, and has for its fifth object to provide a digital camera
which can shorten a detection time for a focusing position.
[0021] In order to accomplish the first object, the first aspect
of a digital camera according to a first invention comprises a first
photographing system and a second photographing system which respectively
'photograph a subject; a changeover switch which changeovers a photographing
system for photographing the subject, to one of said first photographing
system and said second photographing system; and a display control
unit which displays an image formed by one photographing system
determined by said changeover switch, and which performs a display
control so as to display information other than the formed image.
[0022] That is, the first photographing system and the second photographing
system respectively photograph the subject.
[0023] The changeover switch changeovers the photographing system
for photographing the subject, to either the first photographing
system or the second photographing system. The display control unit
displays the image formed by one photographing system determined
by the changeover switch, and it performs the display control so
as to display the information other than the formed image.
[0024] Here, in the second aspect, a photographing state of said
second photographing system differs from a photographing state of
said first photographing system; and said display control unit performs
the display control so as to display image information which is
the information other than said formed image, and which represents
an image formed by the other photographing system not being said
photographing system determined by said changeover switch.
[0025] More specifically, in accordance with this aspect, photographing
systems which include a main photographing system and a sub photographing
system are included as the first photographing system and the second
photographing system, and the main photographing system and the
sub photographing system photograph the subject in the photographing
states different from each other (for example, photographing states
of different image angles). For example, the subject can be photographed
in the different photographing states in such a way that the subject
is photographed by employing a plurality of CCD image pickup devices
of different sizes. Incidentally, each of the photographing systems
may consist of a single photographing system, or it may well consist
of the main photographing system and the sub photographing system.
[0026] The changeover switch changeovers the photographing system
for photographing the subject, to either the main photographing
system or the sub photographing system. Besides, the display control
unit displays the image formed by one photographing system determined
by the changeover switch, and it performs the display control so
as to display the image information which represents the image formed
by the other photographing system. The display control may be performed
so as to display the image formed by the other photographing system,
as the image information, or it may well be performed so as to display
the information of, e. g., a region corresponding to the formed
image. Besides, the display control may well be performed so as
to display information other than the formed image, e. g., the operation
menu of the digital camera, as the image information.
[0027] Thus, as the image formed by one photographing system is
displayed, the image information indicative of the image formed
by the other photographing system can also be displayed, so that
the image information indicative of the image which is formed by
the other photographing system and which is other than the image
formed by one photographing system can also be confirmed in photographing.
Accordingly, the subject can be photographed as the situation of
surroundings is grasped.
[0028] Besides, in the third aspect, the digital camera further
comprises a recording unit which records the image formed by said
one photographing system determined by said changeover switch. In
accordance with this aspect, the recording unit is further comprised
in the second aspect, and the recording unit records the image formed
by one photographing system determined by the changeover switch.
Thus, only the image formed by one photographing system is recorded
without recording the image formed by the other photographing system,
so that the recording capacity of the recording unit can be suppressed.
[0029] Moreover, in a case where the image formed by one photographing
system is recorded by the recording unit, a user can record it while
confirming the image information indicative of the image formed
by the other photographing system as displayed by the display control
of the display control unit. Therefore, when the user wants to record
the image formed by the other photographing system, in this case,
he/she can record it easily by altering one photographing system
to the other photographing system through the changeover of the
changeover switch, and he/she is prevented from missing a shutter
chance.
[0030] In accordance with the fourth aspect, in the second aspect
or the third aspect, the first and the second photographing system
are respectively constructed of photographing systems whose image
angles are different from each other. This can be incarnated by
employing, for example, CCD image pickup devices whose sizes are
different, or lens systems of different image angles for the respective
CCD image pickup devices.
[0031] By applying the photographing systems of different image
angles in this manner, the user is permitted to photograph the subject
by, for example, a wide-angle photographing system while confirming
the image formed by a telescopic photographing system.
[0032] By the way, in any of the second through fourth aspects,
aspects as stated below can be performed.
[0033] As the fifth aspect, the display control unit displays the
respective images formed by the main photographing system and the
sub photographing system, on a single display screen.
[0034] In accordance with the fifth aspect, the display control
unit in any of the second through fourth aspects can display the
respective images formed by the main photographing system and the
sub photographing system, on the single display screen. By way of
example, in a case where a telescopic photographing system and a
wide-angle photographing system are included, the image formed by
the wide-angle photographing system can be displayed at the central
part of the image formed by the telescopic photographing system,
or the image formed by the other photographing system can be displayed
as being small at part of the image formed by one photographing
system.
[0035] In the sixth aspect, in any of the second through fourth
aspects, the display control unit has a plurality of display screens,
and image information items which indicate the image formed by one
photographing system and the image formed by the other photographing
system are respectively displayed on the separate display screens.
[0036] That is, in accordance with the sixth aspect, the display
control unit in any of the second through fourth aspects can display
the respective images formed by the plurality of photographing systems,
on the separate display screens. By way of example, the display
screens can be disposed in the number of the photographing systems
so as to display the respective images. On this occasion, by disposing
the display screens of different sizes, the display control may
well be performed so as to display the image formed by the photographing
system determined by the changeover switch, on the larger display
screen. Besides, all the plurality of display screens may well be
equalized in size.
[0037] As the seventh aspect, in each of the above aspects, the
main photographing system and the sub photographing system are constructed
of a single optical system which forms an image of a subject, a
splitting unit which splits the subject image formed by the optical
system, into a plurality of images, and a plurality of image pickup
devices which pick up the subject images split by the splitting
unit.
[0038] In accordance with the seventh aspect, in each of the above
aspects, the plurality of photographing systems (main photographing
system and sub photographing system) are constructed of the single
optical system, the splitting unit and the plurality of image pickup
devices, and the subject image entering the optical system is split
by the splitting unit into the plurality of images, which are formed
on the plurality of image pickup devices. Thus, the subject images
can be photographed by the plurality of photographing systems. It
is possible, for example, to split light entered from one lens,
into two light beams by the splitting unit such as semitransparent
mirror, and to form the images of the light beams on the two image
pickup devices such as CCDs.
[0039] As the eighth aspect, in each of the above aspects, each
of the main photographing system and the sub photographing system
is constructed of an optical system which focuses a subject, and
an image pickup device which forms a subject image focused by the
optical system.
[0040] In accordance with the eighth aspect, in each of the above
aspects, each of the plurality of photographing systems (main photographing
system and sub photographing system) is permitted to construct one
photographing system out of the optical system and the image pickup
device. That is, the photographing systems can be rendered independent
of each other, and various photographing modes such as telescopic,
wide-angle and zooming modes are possible by disposing the plurality
of independent photographing systems in this manner.
[0041] As the ninth aspect, in the first aspect, the first photographing
system and the second photographing system include image pickup
devices which picks up an image of a subject, an optical system
which focuses subject on the image pickup devices, and a focus adjustment
unit which adjusts a focus for the subject, and the display control
unit performs the display control so as to display a focus adjustment
state which indicates a state of the focus adjustment based on the
focus adjustment unit of the photographing system determined by
the changeover switch, as information other than the formed image.
[0042] In order to accomplish the above object, a digital camera
in the first aspect of a second invention comprises a first photographing
system and a second photographing system which respectively photograph
a subject; a changeover switch which changeovers a photographing
system for photographing the subject, to one of said first photographing
system or said second photographing system; and a utilization unit
which utilizes focus adjustment information at the time when a focus
is adjusted when photographing the subject with one photographing
system determined by said changeover switch, for a use other than
the focus adjustment.
[0043] As the second aspect, in the first aspect, said first photographing
system and said second photographing system include image pickup
devices which picks up the image of the subject, an optical system
which forms the image of the subject on said image pickup devices,
and a focus adjustment unit which adjusts a focus for the subject;
and said utilization unit displays the photographed image obtained
by one photographing system determined by said changeover switch,
and displays a focus adjustment state which expresses a state of
the focus adjustment based on said focus adjustment unit of said
one photographing system determined by said changeover switch, on
the basis of the focus adjustment information at the time when the
focus is adjusted when photographing the subject by said one photographing
system.
[0044] More specifically, in this aspect, at least one photographing
system is comprised. The photographing system includes the image
pickup devices which picks up the image of the subject, the optical
system which forms the image of the subject on the image pickup
devices, and the focus adjustment unit which adjusts the focus for
the subject.
[0045] Here, in a prior-art digital camera, a focus for a subject
is adjusted, but a range in which the focusing is to be established,
if the focusing has been established, etc. are not known.
[0046] Therefore, the utilization unit in this aspect displays
the image obtained by the imaging of the photographing system, and
the focus adjustment state expressing the state of the focus adjustment
based on the focus adjustment unit.
[0047] Here, the focus adjustment state may well be. set as at
least one of a focusing range which is that range of the subject
in which the focus is being adjusted, and the adjusted result of
the focus.
[0048] In this manner, the image obtained by the imaging of the
photographing system and the focus adjustment state expressing the
state. of the focus adjustment based on the focus adjustment unit
are displayed, so that the focus adjustment state can be recognized.
[0049] Here, the invention comprises at least one photographing
system, and it may well comprise the first photographing system
which photographs the subject, and the second photographing system
the photographing state of which is different from that of the first
photographing system.
[0050] In the third aspect, when said photographing systems have
been changedover by said changeover switch, said utilization unit
displays an adjusted result of the focus in correspondence with
the image obtained by the photographing of the photographing system
determined by said changeover switch, and it displays a focusing
range being that range of the subject in which the focus is being
adjusted, in correspondence with, at least, the image obtained by
the imaging of the changed over photographing system.
[0051] In this manner, the utilization unit displays the adjusted
result of the focus in correspondence with the image obtained by
the photographing of the photographing system determined by the
changeover switch, and it displays the focusing range being that
range of the subject in which the focus is being adjusted, in correspondence
with, at least, the image obtained by the imaging of the changed
over photographing system, so that the focus adjustment state can
be recognized more.
[0052] Incidentally, it is also allowed to employ such a construction
that the plurality of photographing systems include a first photographing
system, and a second photographing system the photographing state
of which is different from that of the first photographing system,
and that a utilization unit displays an image formed by one photographing
system determined by a changeover switch, while it performs a display
control so as to display image information indicative of an image
formed by the other photographing system.
[0053] In the fourth aspect, said second photographing system has
a focal depth set shorter than that of said first photographing
system; and a focus adjustment control unit is further comprised
for controlling the respective focus adjustment units of said first
photographing system and said second photographing system so that,
when said second photographing system has been determined by said
changeover switch, the focus adjustment unit of said first photographing
system may be controlled so as to perform the focus adjustment based
on the first focus adjustment unit, whereupon the focus adjustment
based on the focus adjustment unit of said second photographing
system is performed on the basis of a focus adjustment result based
on said first focus adjustment unit.
[0054] When the second photographing system has been determined
by the changeover switch, that is, when the subject is to be photographed
by the second photographing system, note must be taken of the fact
that the second optical system is set shorter in the focal depth
than the first optical system. On account of this fact, in case
of adjusting the focus by the second focus adjustment unit, a focal
distance range in which the focus adjustment is performed by the
second focus adjustment unit of the second photographing system
is broader than in the first photographing system, so that a longer
time is expended on a search for the focus in the focus adjustment.
[0055] Therefore, the focus adjustment control unit controls the
respective focus adjustment units of the first photographing system
and the second photographing system so that, after the focus adjustment
unit of the first photographing system is controlled so as to perform
the focus adjustment based on the first focus adjustment unit, the
focus adjustment based on the focus adjustment unit of the second
photographing system may be performed on the basis of the focus
adjustment result based on the first focus adjustment unit.
[0056] More specifically, when the subject is to be photographed
by the second photographing system, the first focus adjustment unit
is controlled by the focus adjustment control unit so as to perform
the focus adjustment, and a rough focal distance is specified by
the focus adjustment based on the first focus adjustment unit. Thereafter,
the second focus adjustment unit is controlled so as to perform
the focal adjustment based on this unit, in order to search, for
example, the range of the specified rough focal distance for a focal
position on the basis of the result of the focus adjustment based
on the first focus adjustment unit. That is, after the rough focal
position is specified by the first photographing system of narrower
focal distance range (longer focal depth), the focus adjustment
based on the second photographing system is performed on the basis
of the specified rough focal position. Therefore, as compared with
a case where a focal distance is specified by only the second photographing
system of wider focal distance range (shorter focal depth), the
search for the focal position can be made in the narrower range,
and hence, a time period required for the focus search can be rendered
shorter.
[0057] Incidentally, the second optical system can employ a zoom
lens. Since the focal depth of the zoom lens is short, a long time
is expended on the focus adjustment. In this regard, the time period
for the focus adjustment based on the second photographing system
can be shortened in such a way that the rough focal position is
specified by the first photographing system which is longer in the
focal depth than the zoom lens.
[0058] Besides, the first optical system can employ a monofocal
lens. Since the monofocal lens has a long focal depth, a focal search
can be made in a short time in specifying the rough focal position,
by employing the monofocal lens for the first optical system.
[0059] In the fifth aspect, said first photographing system includes
a first image pickup device which picks up an image of a subject,
a first monofocal optical system which forms the image of the subject
on said first image pickup device, and a first focus adjustment
unit which adjusts a focus for the subject, while said second photographing
system includes a second image pickup device which picks up an image
of a subject, a second variable-focus optical system whose focus
is variable and which forms an image of the subject on said second
image pickup device, and a second focus adjustment unit which adjusts
the focus for the subject; said digital camera further comprises
a single image-angle alteration unit by which an alteration of an
image angle is instructed; and in a case where said first photographing
system has been determined by said changeover switch and where the
alteration of the image angle has been instructed by said image-angle
alteration unit, said utilization unit submits image data obtained
by said first photographing system, to image processing so as to
correspond to an image whose image angle is altered in correspondence
with the instruction of said image-angle alteration unit, while
in a case where said second photographing system has been determined
by said changeover switch and where the alteration of the image
angle has been instructed by said image-angle alteration unit, said
utilization unit utilizes the focus adjustment information by adjusting
said second variable-focus optical system through said second focus
adjustment unit so as to alter the image angle in correspondence
with the instruction of said image-angle alteration unit.
[0060] That is, the digital camera according to the invention comprises
the first photographing system and the second photographing system.
The first photographing system includes the first image pickup device
which picks up the image of the subject, the first monofocal optical
system which forms, the image of the subject on the first image
pickup device, and the first focus adjustment unit which adjusts
the focus for the subject.
[0061] The second photographing system includes the second image
pickup device which picks up the image of the subject, the second
variable-focus optical system whose focus is variable and which
forms the image of the subject on the second image pickup device,
and the second focus adjustment unit which adjusts the focus for
the subject.
[0062] The changeover switch changeovers the photographing system
for photographing the subject, to the first photographing system
or the second photographing system. The image-angle alteration unit
serves to instruct the alteration of the image angle, and the invention
comprises the single image-angle alteration unit.
[0063] In the case where the first photographing system has been
determined by the changeover switch and where the alteration of
the image angle has been instructed by the image-angle alteration
unit, the utilization unit submits the image data obtained by the
first photographing system, to the image processing so as to alter
the image angle in correspondence with the instruction of the image-angle
alteration unit.
[0064] Besides, in the case where the second photographing system
has been determined by the changeover switch and where the alteration
of the image angle has been instructed by the image-angle alteration
unit, the utilization unit adjusts the second variable-focus optical
system through the second focus adjustment unit so as to alter the
image angle in correspondence with the instruction of the image-angle
alteration unit.
[0065] In this manner, the alterations of the image angles of the
first and second photographing systems can be instructed by the
single image-angle alteration unit, so that the apparatus can be
rendered simple in construction.
[0066] Meanwhile, in the case where the second photographing system
has been determined by the changeover switch and where the alteration
of the image angle has been instructed by the image-angle alteration
unit, the utilization unit adjusts the second variable-focus optical
system. In this regard, in a case where the second variable-focus
optical system has been instructed to alter the image angle in excess
of an adjustable range, by the image-angle alteration unit through
the second focus adjustment unit, the image angle cannot be altered
by the adjustment of the second variable-focus optical system.
[0067] In the sixth aspect, therefore, in a case where said second
variable-focus optical system has been instructed to alter the image
angle in excess of an adjustable range by said image-angle alteration
unit through said second focus adjustment unit said utilization
unit submits image data obtained by said second photographing system
to image processing so as to correspond to an image whose image
angle is altered in correspondence with the instruction of said
image-angle alteration unit.
[0068] In the seventh aspect, a display device which displays images
is further comprised, and said image-angle control unit controls
said display device so as to display the images which are respectively
obtained by said first photographing system and said second photographing
system, regardless of a changeover state based on said changeover
switch.
[0069] In the eighth aspect, a display device which displays images
is further comprised, and said image-angle control unit controls
said display device so as to display only the image obtained by
said first photographing system, in a case where said first photographing
system has been determined by said changeover switch, and to display
the images respectively obtained by said first photographing system
and said second photographing system, in a case where said second
photographing system has been determined by said changeover switch.
[0070] In the ninth aspect, said optical system of said second
photographing system has a focal depth set shorter than that of
said optical system of said first photographing system; and in a
case where said second photographing system has been determined
by said changeover switch, the image-angle control unit controls
the respective focus adjustment units of said first photographing
system and said second photographing system so that, after said
focus adjustment unit of said first photographing unit is controlled
so as to perform the focus adjustment based on said first focus
adjustment unit, the focus adjustment based on said focus adjustment
unit of said second photographing system may be performed on the
basis of a result of the focus adjustment based on said first focus
adjustment unit.
[0071] More specifically, when the subject is to be photographed
by the second. photographing system, the first focus adjustment
unit is controlled by the control unit so as to perform the focus
adjustment based on the first focus adjustment unit, and a rough
focal distance is specified. Thereafter, the second focus adjustment
unit is controlled so as to perform the focal adjustment based on
this unit, in order to search, for example, the range of the specified
rough focal distance for a focal position on the basis of the result
of the focus adjustment based on the first focus adjustment unit.
That is, after the rough focal position is specified by the first
photographing system of narrower focal distance range (longer focal
depth), the focus adjustment based on the second photographing system
is performed on the basis of the specified rough focal position.
Therefore, as compared with a case where a focal distance is specified
by only the second photographing system of wider focal distance
range (shorter focal depth), the search for the focal position can
be made in the narrower range, and hence, a time period required
for the focus search can be rendered shorter.
[0072] Incidentally, a zoom lens can be employed as the second
variable-focus optical system. Since the focal depth of the zoom
lens is short, a long time is expended on the focus adjustment.
In this regard, the time period for the focus adjustment based on
the second photographing system can be shortened in such a way that
the rough focal position is specified by the first photographing
system which is longer in the focal depth than the zoom lens.
[0073] Besides, a monofocal lens can be employed as the first monofocal
optical system. Since the monofocal lens has a long focal depth,
a focal search can be made in a short time in specifying the rough
focal position, by employing the monofocal lens for the first optical
system.
[0074] In order to accomplish the above object, a digital camera
in the first aspect of a third invention comprises a first photographing
system and a second photographing system which respectively pick
up an image of a subject; and a focus adjustment control unit which
performs a focus adjustment when photographing the subject by at
least one of said first photographing system and said second photographing
system, by utilizing both said first photographing system and said
second photographing system.
[0075] In the second aspect, said first photographing system includes
a first image pickup device which picks up an image of a subject,
a first optical system which forms the image of the subject on said
first image pickup device, and a first focus adjustment unit which
adjusts a focus for the subject, while said second photographing
system includes a second image pickup device which picks up an image
of a subject, a second optical system which forms the image of the
subject on said second image pickup device and which has a focal
depth set shorter than that of said first optical system, and a
second focus adjustment unit which adjusts the focus for the subject;
and when the subject is to be photographed by said second photographing
system, said focus adjustment control unit controls said first focus
adjustment unit so as to perform the focus adjustment based on said
first focus adjustment unit and thereafter controls said second
focus adjustment unit so as to perform the focus adjustment based
on said second focus adjustment unit, on the basis of a result of
the focus adjustment based on said first focus adjustment unit.
[0076] The first imaging system consists of the first image pickup
device, the first optical system and the first focus adjustment
unit, and the subject image is formed on the first image pickup
device by the first optical system. On this occasion, the focal
position is adjusted by the first focus adjustment unit.
[0077] Besides, the second imaging system similarly consists of
the second image pickup device, the second optical system and the
second focus adjustment unit, and the subject image is formed on
the second image pickup device by the second optical system. On
this occasion, the focal position is adjusted by the second focus
adjustment unit.
[0078] Here, in a case where the subject is to be photographed
by the second photographing system, note must be taken of the fact
that the second optical system is set shorter in the focal depth
than the first optical system. On account of this fact, in case
of adjusting the focus by the second focus adjustment unit, a focal
distance range in which the focus adjustment is performed by the
second focus adjustment unit of the second photographing system
is broader than in the first photographing system, so that a longer
time is expended on a search for the focus in the focus adjustment.
[0079] Therefore, when the subject is to be photographed by the
second photographing system, the first focus adjustment unit is
controlled by the focus adjustment control unit so as to perform
the focus adjustment based on the first focus adjustment unit, and
a rough focal distance is specified. Thereafter, the second focus
adjustment unit is controlled so as to perform the focal adjustment
based on the second focus adjustment unit, in order to search, for
example, the range of the specified rough focal distance for the
focal position on the basis of the result of the focus adjustment
based on the first focus adjustment unit. That is, after the rough
focal position is specified by the first photographing system of
narrower focal distance range (longer focal depth), the focus adjustment
based on the second photographing system is performed on the basis
of the specified rough focal position. Therefore, as compared with
a case where a focal distance is specified by only the second photographing
system of wider focal distance range (shorter focal depth), the
search for the focal position can be made in the narrower range,
and hence, a time period required for the focus search can be rendered
shorter.
[0080] In the third aspect, said second optical system includes
a zoom lens. Accordingly, the rough focal position is specified
by the first photographing system the focal depth of which is longer
than that of the zoom lens, whereby a time period for the focus
adjustment based on the second photographing system can be shortened.
[0081] Besides, said first optical system can employ a monofocal
lens. Since the monofocal lens has a long focal depth, the focus
can be searched for in a short time in specifying the rough focal
position, by employing the monofocal lens for the first optical
system.
[0082] Further, the fourth aspect further comprises a changeover
switch which changeovers a photographing system for photographing
the subject, to one of said first photographing system or said second
photographing system, and a display device which displays images;
and said focus adjustment control unit controls said display device
so as to display the image formed by one photographing system determined
by said changeover switch, and to display image information indicative
of the image formed by the other photographing system.
[0083] Thus, while the image formed by either of the first photographing
system and the second photographing system is being displayed, also
the image information indicative of the image formed by the other
photographing system can be displayed. It is therefore possible
to confirm during photographing, also the image information indicative
of the image which is other than the image formed by one photographing
system and which is formed by the other photographing system. Accordingly,
the photographing can be performed as the situation of surroundings
is grasped.
[0084] Incidentally, the fifth aspect further comprises a recording
unit which records the image photographed by said one photographing
system determined by said changeover switch. Besides, in the sixth
aspect, said first photographing system and said second photographing
system are photographing systems whose image angles are different
from each other.
[0085] By the way, in the seventh aspect, a focal distance is specified
within a predetermined range on the basis of the result of the first
focus adjustment, and the focus adjustment based on the second focus
adjustment unit is controlled so as to proceed only within the predetermined
range.
[0086] Besides, in the eighth aspect, each of the first focus adjustment
unit and the second focus adjustment unit includes a drive unit
which drives a focusing lens included in the corresponding optical
system, and a focus control unit which calculates a contrast value
from image data representing the subject image obtained from the
corresponding image pickup device and which controls the drive unit
on the basis of the contrast value.
[0087] In the ninth aspect, said first photographing system includes
a first image pickup device which picks up a subject, and a first
lens which forms the image of the subject on said first image pickup
device; said second photographing system includes a second image
pickup device which is substantially identical to said first image
pickup device, and a second lens which is substantially identical
to said first lens; and said focus adjustment control unit drives
said first lens so as to move from a first predetermined position
side at which said first lens is to be located in a case where a
focusing position is one end of a predetermined photographing distance
range, toward a second predetermined position side at which said
first lens is to be located in a case where the focusing position
is the other end of the photographing distance range, while it drives
said second lens so as to move from the second predetermined position
side toward the first predetermined position side, and it performs
the focus adjustment on the basis of the image of the subject obtained
by said first image pickup device and the image of the subject obtained
by said second image pickup device.
[0088] In accordance with the ninth aspect, the two photographing
systems which are substantially identical in construction (performance)
are comprised. Each of the photographing systems includes the image
pickup device, and the lens for forming the image of the subject
on the image pickup device.
[0089] The focus adjustment control unit performs the focus adjustment
on the basis of the image of the subject obtained by the first image
pickup device and the image of the subject obtained by the second
image pickup device.
[0090] The focus adjustment control unit executes the focus adjustment
while moving the first lens and the second lens. More specifically,
the first lens is driven so as to move from the first predetermined
position side at which the first lens is to be located in the case
where the focusing position is one end of the predetermined photographing
distance range, toward the second predetermined position side at
which the first lens is to be located in the case where the focusing
position is the other end of the photographing distance range. Besides,
simultaneously therewith, the second lens is driven so as to move
from the second predetermined position side toward the first predetermined
position side. Here, the photographing distance range can be set
as, for example, a range from the infinite distance to the closest
distance. In this case, one end of the photographing distance range
is the position of the infinite distance, and the other end is the
position of the closest distance.
[0091] In this manner, the focus adjustment is executed while the
two lenses are being moved in directions opposite to each other,
so that a time period for the focus adjustment can be sharply shortened.
[0092] In the tenth aspect, said first photographing system includes
a first image pickup device which picks up a subject, and a first
lens which forms the image of the subject on said first image pickup
device; said second photographing system includes a second image
pickup device which picks up a subject, and a second lens which
forms the image of the subject on said second image pickup device,
at least one of said second image pickup device and said second
lens being different from the corresponding one of said first photographing
system; and said focus adjustment control unit drives said first
lens so as to move from a first predetermined position side at which
said first lens is to be located in a case where a focusing position
is one end of a predetermined photographing distance range, toward
a second predetermined position side at which said first lens is
to be located in a case where the focusing position is the other
end of the photographing distance range, while it drives said second
lens so as to move from the second predetermined position side toward
the first predetermined position side, and it performs the focus
adjustment on the basis of the image of the subject obtained by
said first image pickup device and the image of the subject obtained
by said second image pickup device.
[0093] In accordance with this aspect, the two photographing systems
which are different in construction (performance) are comprised.
Each of the photographing systems includes the image pickup device,
and the lens for forming the image of the subject on the image pickup
device. The respective photographing systems are different in, at
least, either of the image pickup devices and the lenses. Such a
difference includes, for example, the case of construction where
the image pickup devices are different in size or the number of
pixels and where the lenses are identical, or the case of construction
where the image pickup devices are identical and where the image
angles of the lenses are different.
[0094] The focus adjustment control unit performs the focus adjustment
on the basis of the image of the subject obtained by the first image
pickup device and the image of the subject obtained by the second
image pickup device.
[0095] The focus adjustment control unit executes the focus adjustment
while moving the first lens and the second lens. More specifically,
the first lens is driven so as to move from the first predetermined
position side at which the first lens is to be located in the case
where the focusing position is one end of the predetermined photographing
distance range, toward the second predetermined position side at
which the first lens is to be located in the case where the focusing
position is the other end of the photographing distance range. Besides,
simultaneously therewith, the second lens is driven so as to move
from the second predetermined position side toward the first predetermined
position side. Here, the photographing distance range can be set
as, for example, a range from the infinite distance to the closest
distance. In this case, one end of the photographing distance range
is the position of the infinite distance, and the other end is the
position of the closest distance.
[0096] In this manner, the focus adjustment is executed while the
two lenses are being moved in directions opposite to each other,
so that a time period for the focus adjustment can be sharply shortened.
[0097] Here, even in a case, for example, where the numbers of
pixels of the first image pickup device and the second image pickup
device are different, no problem is posed on condition that the
sizes thereof are equal. The reason therefor is that the subject
to be imaged by the first image pickup device and the subject to
be imaged by the second image pickup device are substantially identical,
so the focusing positions of the first and second lenses become
substantially identical.
[0098] On the other hand, in a case where the sizes of the first
image pickup device and the second image pickup device are different,
a problem might be posed because the subject to be imaged by the
first image pickup device and the subject to be imaged by the second
image pickup device are different.
[0099] In the eleventh aspect, said first image pickup device has
a size different from that of said second image pickup device; and
said focus adjustment control unit performs the focus adjustment
on the basis of an image of a predetermined focus adjustment area
in the image of the subject formed by said first image pickup device,
and an image of a focus adjustment area having the same image angle
as that of the first-mentioned focus adjustment area, in the image
of the subject formed by said second image pickup device.
[0100] That is, the image angles of the focus adjustment areas
are rendered identical in the two photographing systems. Thus, even
in the case where the sizes of the image pickup devices are different,
the images which are utilized for the focus adjustment become substantially
identical, and hence, the peak positions of AF evaluation values
can be rendered identical.
[0101] In the twelfth aspect, said focus adjustment control unit
may well set an initial position of said first lens at the first
predetermined position and an initial position of said second lens
at the second predetermined position. Thus, in a case where the
focusing position exists on one side of the photographing distance
range, a time period for the focal adjustment can be sharply shortened.
[0102] In the thirteenth aspect, said focus adjustment control
unit can calculate as a first evaluation value, contrast of the
image of the subject formed by said first image pickup device, and
as a second evaluation value, contrast of the image of the subject
formed by said second image pickup device, and it can move said
first lens and said second lens to a position at which at least
one of the first evaluation value and the second evaluation value
is maximized. Thus, the focus adjustment can be accurately performed
on the basis of the contrasts of the formed images.
[0103] Alternatively, the focus adjustment unit may well be operated
so as to find those positions of the first lens and the second lens
at which the first evaluation value and the second evaluation value
become substantially equal, to set a predetermined range which includes
the middle position between the found positions of the first and
second lenses, and to move the first lens to one end of the predetermined
range and the second lens to the other end thereof.
[0104] The contrast of each formed image is considered to become
the maximum at the focusing position and to decrease more at the
same rate as the position of the corresponding lens comes nearer
to an infinite distance side or a closest distance side with respect
to the focusing position, and the focusing position is considered
to exist at or near the middle position between those positions
of the first and second lenses at which the first and second evaluation
values become substantially equal. Accordingly, the predetermined
range including the middle position is set as a range in which the
focusing position exists, and the first lens is moved to one end
of the predetermined range, while the second lens is moved to the
other end of the predetermined range, whereupon the focus adjustment
is consecutively executed. Thus, a time period for detecting the
focusing position can be shortened still further.
[0105] It is also allowed to employ a construction comprising a
photographing system which includes a first image pickup device
for imaging a subject, a second image pickup device being substantially
identical to said first image pickup device, a branch unit for branching
light entered from the subject, to said first image pickup device
and said second image pickup device, and a lens for forming the
images of the subject on said first image pickup device and said
second image pickup device; and a focus adjustment unit which drives
said first image pickup device so as to move from a first predetermined
position side where said first image pickup device is to be located
when a focusing position is one end of a predetermined photographing
distance range, toward a second predetermined position side where
said first image pickup device is to be located when the focusing
position is the other end of the photographing distance range, and
also drives said second image pickup device so as to move from the
second predetermined position side toward the first predetermined
position side, and which performs a focus adjustment on the basis
of the image of the subject obtained by said first image pickup
device and the image of the subject obtained by said second image
pickup device. Thus, the focus adjustment can be executed on the
basis of the identical images, so that a more accurate focus adjustment
can be effected.
[0106] Besides, it is allowed to employ a construction comprising
a photographing system which includes a first image pickup device
for imaging a subject, a second image pickup device being different
from said first image pickup device, a branch unit for branching
light entered from the subject, to said first image pickup device
and said second image pickup device, and a lens for forming the
images of the subject on said first image pickup device and said
second image pickup device; and a focus adjustment unit which drives
said first image pickup device so as to move from a first predetermined
position side where said first image pickup device is to be located
when a focusing position is one end of a predetermined photographing
distance range, toward a second predetermined position side where
said first image pickup device is to be located when the focusing
position is the other end of the photographing distance range, and
also drives said second image pickup device so as to move from the
second predetermined position side toward the first predetermined
position side, and which performs a focus adjustment on the basis
of the image of the subject obtained by said first image pickup
device and the image of the subject obtained by said second image
pickup device.
[0107] The first image pickup device and the second image pickup
device are different in, at least, one of size and the number of
pixels by way of example, and the focus adjustment can be implemented
as described before. A more accurate focus adjustment can be effected
by sharing the lens in this manner.
[0108] A digital camera according to a fourth invention comprises
at least one photographing system which includes an image pickup
device which picks up an image of a subject, an optical system which
forms an image of the subject on said image pickup device, and a
focus adjustment unit for adjusting a focus for the subject; and
a display unit which displays the picked up an image of said photographing
system, and further displays a focus adjustment state indicated
by said focus adjustment unit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0109] FIGS. 1A and 1B are perspective views each showing the external
appearance of a digital camera according to the first embodiment
of the present invention;
[0110] FIG. 2 is a diagram showing the photographing systems of
the digital camera according to the embodiment of the invention;
[0111] FIG. 3 is a diagram showing a display example of images
formed by the plurality of photographing systems of the digital
camera according to the embodiment of the invention;
[0112] FIG. 4 is a block diagram showing the construction of the
electric system of the digital camera according to the embodiment
of the invention;
[0113] FIG. 5 is a diagram showing another display example of images
formed by the plurality of photographing systems;
[0114] FIG. 6 is a flow chart showing the process of a photographing
operation in the digital camera according to the embodiment of the
invention;
[0115] FIG. 7 is a diagram showing another example of a display
unit which displays images formed.
[0116] FIG. 8 is a diagram showing another construction of the
photographing systems of the digital camera according to the embodiment
of the invention;
[0117] FIG. 9 is a view showing an example of a digital camera
which includes two display screens for displaying images formed;
[0118] FIG. 10 is a diagram showing a display example in the digital
camera which includes the two display screens for displaying the
images formed;
[0119] FIG. 11 is a block diagram showing part of an example of
the construction of an electric system in the case where a plurality
of displays are included;
[0120] FIG. 12 is a diagram showing another method of displaying
images formed by a plurality of photographing systems in the digital
camera according to the embodiment of the invention;
[0121] FIG. 13 is a block diagram showing the schematic construction
of a digital camera according to the second embodiment of the invention;
[0122] FIG. 14 is an image diagram showing an example of the dividing
aspect of a photographing frame in an integration circuit as is
utilized for image corrections and an AF control;
[0123] FIG. 15 is an image diagram showing an example of weighting
factors Wi which are allotted to the respective blocks of the photographing
frame;
[0124] FIG. 16 is a flow chart showing the AF control of the digital
camera according to the embodiment of the invention;
[0125] FIG. 17 is a graph showing an example of the AF control
of the digital camera according to the embodiment of the invention;
[0126] FIG. 18 is a graph showing an example of an AF control in
the prior art;
[0127] FIG. 19 is a block diagram showing the schematic construction
of a digital camera according to the third embodiment of the invention;
[0128] FIG. 20 is part of a flow chart showing the AF control of
the digital camera according to the embodiment of the invention;
[0129] FIG. 21 is the remainder of the flow chart showing the AF
control of the digital camera according to the embodiment of the
invention;
[0130] FIG. 22 is a diagram showing an example in which two display
screens for displaying images formed are included, and focusing
ranges are indicated in the respective screens;
[0131] FIGS. 23A and 23B are diagrams showing a successful focusing
state and an unsuccessful focusing state, respectively;
[0132] FIG. 24 is a diagram showing another display example of
images formed by a plurality of photographing systems;
[0133] FIG. 25 is part of a flow chart showing a photographing
process in a digital camera according to the fourth embodiment of
the invention;
[0134] FIG. 26 is the remainder of the flow chart showing the photographing
process in the digital camera according to the fourth embodiment
of the invention;
[0135] FIG. 27 is a block diagram showing the schematic construction
of a digital camera according to the fifth embodiment of the invention;
[0136] FIG. 28 is a flow chart showing the flow of an AF control
in the fifth embodiment of the invention;
[0137] FIG. 29 is a graph showing the relationship between the
lens positions and contrast values of focusing lenses according
to the fifth embodiment of the invention;
[0138] FIG. 30 is a graph showing the relationship between the
lens positions and contrast values of the focusing lenses according
to the fifth embodiment of the invention;
[0139] FIG. 31 is a flow chart showing the flow of an AF control
in the sixth embodiment of the invention;
[0140] FIG. 32 is a flow chart showing the flow of a focusing-lens
moving process in the sixth embodiment of the invention;
[0141] FIG. 33 is a graph showing the relationship between the
lens positions and contrast values of the focusing lenses according
to the sixth embodiment of the invention;
[0142] FIG. 34 is a schematic constructional diagram showing another
example of a photographing system;
[0143] FIG. 35 is a graph showing the relationship between the
lens positions and the contrast values of the focusing lenses according
to the related art;
[0144] FIG. 36 is a graph showing the relationship between the
lens positions and the contrast values of focusing lenses according
to the seventh embodiment of the invention;
[0145] FIG. 37 is a graph showing the relationship between the
lens positions and the contrast values of the focusing lenses according
to the seventh embodiment of the invention;
[0146] FIG. 38A is a graph showing the relationship between the
lens position and contrast value of the focusing lens of a photographing
system of wide-angle mode, while FIG. 38B is a graph showing the
relationship between the lens position and contrast value of the
focusing lens of a photographing system of telescopic mode; and
[0147] FIG. 39 is a table showing the corresponding relationship
between the focusing positions of the focusing lens of the first
photographing system and those of the focusing lens of the second
photographing system, according to the seventh embodiment of the
invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0148] (First Embodiment)
[0149] Now, an example of the first embodiment of the present invention
will be described in detail with reference to the drawings.
[0150] As shown in FIGS. 1A and 1B, a digital camera 10 has a substantially
box-like body 12, and it is in such a shape that a protrusion (grip
portion) for facilitating the grip of the body 12 is formed on a
left side as viewed from the front. A body tube 15 in which a lens
14 is fitted is disposed on the front central part of the body 12.
A strobe 18 for emitting auxiliary light in cases of photographing
at a low illuminance, etc., and an optical finder 16 for a user
to confirm a photographing range, etc. by the eye are mounted on
the parts of the body 12 above the lens 14.
[0151] Besides, at positions near the strobe 18, there are respectively
provided a strobe light receiving window 38 for guiding strobe light
to a strobe light receiving sensor, which detects the quantity of
light of the strobe light reflected to retrocede from a subject
at the strobe light emission, and an AE light receiving window 40
for guiding light to a built-in AE sensor.
[0152] On the upper surface of the body 12, a power source switch
20 and a release switch 22 are respectively disposed on a right
side as viewed from the front and on the left side (at a position
corresponding to the grip portion). The right side surface of the
body 12 as viewed from the front is provided with a slot 24 into
which a memory card (not shown) can be loaded.
[0153] Besides, on the right side surface of the digital camera
10, there are disposed a USB (Universal Serial Bus) terminal 42
to which a USB cable is connected, the USB cable serving to externally
transfer image data that are stored in a built-in memory included
in the digital camera 10 or the memory card loaded in the slot 24,
and a portable telephone terminal 44 which is used when the digital
camera 10 is connected with a portable telephone in externally transmitting
the image data stored in the built-in memory or the memory card,
through the portable telephone.
[0154] Further, an AC adapter connection port 28 to which an AC
adapter for obtaining a supply voltage from an AC power source is
connected is provided under the portable telephone terminal 44,
whereby the AC power source can be connected to the digital camera
10.
[0155] Besides, as shown in FIG. 1B, a color display 26 which includes
a transmissive type liquid crystal (which may well be a semi-transmissive
type one) is disposed on the rear surface of the body 12. The display
26 is constructed having a backlighting unit made of a fluorescent
lamp, an LED or the like. Incidentally, the display 26 also has
the function of the optical finder 16.
[0156] Disposed on the right side of the rear surface of the body
12 are a select (SELECT) switch 34, a menu (MENU) switch 30, an
execute/view change (EX/VIEW CHG) switch 32 and a cancel (CANCEL)
switch 36. Incidentally, the select switch 34 is a switch for selecting
any of modes on a menu screen or the like displayed by depressing
the menu switch 30, and the selected mode is executed by the execute/view
change switch 32. Besides, the cancel switch 36 is a switch for
canceling any of the various modes.
[0157] Further, a photographing mode changeover switch 82 for changing
over photographing modes, and a tele/wide changeover switch 25 are
disposed on the rear surface of the body 12. The static image photographing
mode for photographing a static image, and the dynamic image photographing
mode for photographing a dynamic image are changed over by manipulating
the photographing mode changeover switch 82, while a tele-mode (telescopic
mode) and a wide-mode (wide-angle mode) are changed over by manipulating
the tele/wide changeover switch 25. Incidentally, the tele/wide
changeover switch 25 corresponds to changeover means in the invention.
[0158] Meanwhile, the photographing systems of the digital camera
10 according to this embodiment include two image pickup devices
50A, 50B of different sizes as shown in FIG. 2A subject image entered
from a lens 14 is split by a semitransparent mirror 86 being split
means, and the split images are respectively formed on the two image
pickup devices 50A, 50B. Incidentally, the larger image pickup device
50A is used for the wide-mode, and the smaller image pickup device
50B for the tele-mode.
[0159] By the way, the two image pickup devices 50A, 50B, the lens
14 and the semitransparent mirror 86 correspond to photographing
systems including a main photographing system and a sub photographing
system in the invention.
[0160] Besides, as shown in FIG. 3 byway of example, the subject
images formed by the respective image pickup devices 50A, 50B are
composited and displayed on the screen of the display 26 so as to
be respectively confirmable. Incidentally, FIG. 3 shows an example
in which the image formed by the smaller image pickup device 50B
is displayed at the central part of the image formed by the larger
image pickup device 50A. In this case, both the images may well
be composited so that the image formed by the smaller image pickup
device 50B may correspond onto the image formed by the larger image
pickup device 50A. Also, a frame or the like may well be displayed
as image information at that position on the image formed by the
larger image pickup device 50A which corresponds to the image formed
by the smaller image pickup device 50B.
[0161] Shown in FIG. 4 is the construction of the electric system
of the digital camera 10.
[0162] The two image pickup devices 50A, 50B each including an
area CCD sensor or the like are arranged at positions which correspond
to the focal positions of the lens 14 inside the body 12. As stated
above, light reflected from a subject and entering the lens 14 is
split in two by the semitransparent mirror 86, and the split light
beams are respectively focused on the photosensitive faces of the
image pickup devices 50A, 50B.
[0163] Each of the image pickup devices 50A, 50B outputs as image
signals, analog signals which represent the quantities of light
respectively received by a large number of photoelectric conversion
cells that are arrayed in the shape of a matrix on the photosensitive
face. Each of the image pickup devices 50A, 50B is driven at timings
synchronized with timing signals which are generated by a timing
signal generation unit 52 connected to a drive circuit 46, thereby
to output the image signals.
[0164] An aperture stop 48 is arranged between the lens 14 and
the image pickup devices 50A, 50B. The aperture stop 48 may be constructed
of a single aperture stop whose aperture is continuously alterable,
or it may well be constructed of a plurality of aperture stops which
have different apertures and which are changed over.
[0165] A strobe control circuit 54 which controls the light emission
of the strobe 18, is further connected to the timing signal generation
unit 52. In a case where a low illuminance has been detected or
where an instruction for the light emission has been given by the
user, the strobe 18 is controlled to emit light at a timing synchronized
with a timing signal generated by the timing signal generation unit
52.
[0166] A sampling unit 56, an A/D converter 58, a signal processing
unit 60, a memory 62 and a compression/decompression unit 64 are
successively connected to the signal output end of the image pickup
device 50. They are respectively connected to a system bus 68, and
they are collectively controlled by a system control unit 70 connected
to the system bus 68.
[0167] The sampling unit 56 samples the image signals outputted
from the image pickup device 50, at timings synchronized with timing
signals generated by the timing signal generation unit 52, and it
amplifies the sampled signals and then outputs them to the A/D converter
58. The sampling unit 56 is constructed including a CDS (Correlated
Double Sampling) unit, not shown. When an image pickup device of,
for example, CCD type is employed, the CDS unit basically includes
a clamp circuit which clamps various noise ascribable to the image
pickup device, by a timing signal from the timing signal generation
unit 52, and a sample-and-hold circuit which holds an analog voltage
signal by a timing signal. The CDS unit removes a noise component,
and sends the image signal as an analog output signal to the A/D
converter 58. The image signal outputted from the sampling unit
56 is converted by the A/D converter 58 into digital image data,
which is inputted to the signal processing unit 60. In the signal
processing unit 60, the inputted image data is submitted to various
processes such as color correction, .gamma. correction and Y/C conversion.
The image data outputted from the signal processing unit 60 is temporarily
stored in the memory 62 such as RAM. After being compressed by the
compression/decompression unit 64, the image data is stored in the
built-in memory 84 or the memory card 80 loaded in the slot 24.
Incidentally., the built-in memory 84 or the memory card 80 corresponds
to record means in the invention.
[0168] Although not shown here in FIG. 4, a sampling unit, an A/D
converter and a signal processing unit are connected to the signal
output end of the image pickup device 50B, similarly to the output
end of the image pickup device 50A. Signal processing as stated
above is executed by the signal processing unit, and likewise to
the above, image data is temporarily stored in the memory 62, compressed
by the compression/decompression unit 64 and is thereafter stored
in the built-in memory 84 or the memory card 80 loaded in the slot
24.
[0169] Besides, a display driver 27 for driving the display 26
is also connected to the system bus 68. Thus, the display 26 is
permitted to display an image based on the image data obtained by
imaging, and it is submitted to a display control by the display
driver 27 so as to display various display aspects. By way of example,
it is allowed to employ the aspect as shown in FIG. 3 in which the
image formed by the wide-mode image pickup device 50A is displayed
on the whole area, while the image formed by the tele-mode image
pickup device 50B is displayed substantially at the central part
(in this case, the respective images formed may be composited, or
the frame or the like may well be displayed on the position of the
wide-mode image corresponding to the telescopic-mode image). It
is also allowed to employ an aspect as shown in FIG. 5 in which
an image formed by one image pickup device is displayed on the whole
area, while an image formed by the other image pickup device is
displayed to be small at a corner. Incidentally, FIG. 5 shows an
example in which the image formed by the tele-mode image pickup
device 50B is displayed on the whole area, while the image formed
by the wide-mode image pickup device 50A is displayed to be small
at the corner.
[0170] By the way, the display driver 27 and the display 26 correspond
to display control means in the invention.
[0171] Further connected to the system bus 68 is an input/output
interface (I/F) 76 to which the USB terminal 42, the portable telephone
terminal 44 and various operating switches (such as the menu switch
30, execute/view change switch 32, select switch 34, cancel switch
36 and photographing mode changeover switch 82) 74 including the
release switch 22 and the tele/wide changeover switch 25 are connected.
Thus, controls complying with the manipulations of the various operating
switches 74 are performed.
[0172] More specifically, in a case where the user has given the
instruction of storing image data in the built-in memory 84 or the
memory card 80 loaded in the slot 24, through the manipulation of
the release switch 22 by way of example, the system control unit
70 reads out the image data temporarily stored in the memory 62
and transfers it to the compression/decompression unit 64. Thus,
the image data is compressed by the compression/decompression unit
64 and is thereafter stored in the built-in memory 84 or the memory
card 80. By the way, in accordance with the mode of photographing,
the image data is sometimes stored in the built-in memory 84 or
the memory card 80 without being compressed.
[0173] Besides, in a case where the user has given the instruction
of reproducing (displaying) an image which is represented by image
data stored in the built-in memory 84 or the memory card 80 loaded
in the slot 24, the image data is read out from the built-in memory
84 or the memory card 80 loaded in the slot 24, and the read-out
image data is expanded by the compression/decompression unit 64
and is thereafter temporarily stored in the memory 62. Subsequently,
the image is displayed (reproduced) on the display 26 by using the
image data temporarily stored in the memory 62.
[0174] Incidentally, images formed by the image pickup devices
50A, 50B are selectively recorded in the built-in memory 84 or the
memory card 80 in compliance with the manipulations of the tele/wide
changeover switch 25, respectively.
[0175] Next, as the operation of the digital camera 10 constructed
as stated above, a process in the case of photographing a static
image will be described with reference to the flow chart of FIG.
6. Incidentally, the static image photographing is started by changing
over the photographing mode changeover switch 82 to a static image
photographing mode.
[0176] At a step 100, whether or not a photographing mode is the
tele-mode is decided. The decision is given by deciding whether
or not the tele/wide changeover switch 25 is thrown on its telescopic
photographing side.
[0177] In a case where the decision of the step 100 has been affirmed,
the routine shifts to a step 102, at which images represented by
image data from the two image pickup devices 50A, 50B are respectively
displayed on the display 26, while the image represented by the
image data from the tele-mode image pickup device 50B is highlighted.
By way of example, referring to FIG. 3, owing to the drive of the
display 26 by the display driver 27, the image represented by the
image data from the wide-mode image pickup device SOA is displayed,
while the image represented by the image data from the tele-mode
image pickup device 50B is displayed substantially at the central
part of the wide-mode image. Here in the display, the frame part
of the image represented by the image data from the tele-mode image
pickup device 50B is emphasized, or the image represented by the
image data from the wide-mode image pickup device 50A is shaded.
Alternatively, as shown in FIG. 5, the image represented by the
image data from the tele-mode image pickup device 50B is displayed
on the whole screen of the display 26, while the image represented
by the image data from the wide-mode image pickup device 50A is
displayed to be small at a corner. By the way, in the case as shown
in FIG. 3 where the image formed by the tele-mode image pickup device
50B is displayed substantially at the central part of the image
formed by the wide-mode image pickup device 50A, only image information
such as a frame may well be displayed on that position of the image
formed by the wide-mode image pickup device 50A which corresponds
to the image formed by the tele-mode image pickup device 50B, without
displaying the image itself formed by the tele-mode image pickup
device 50B.
[0178] According to the display in FIG. 3 or FIG. 5, both the image
to be recorded (the image formed by one image pickup device) and
the image not to be recorded (the image formed by the other image
pickup device) are displayed, so that the image to be recorded can
be confirmed, while the image not to be recorded can be subsidiarily
confirmed.
[0179] At a step 104, whether or not the release switch 22 has
been turned ON is decided. In a case where the decision has been
negated, the routine returns to the step 100, and the above processing
is repeated.
[0180] In a case where the decision of the step 104 has been affirmed,
the routine shifts to a step 106, at which the image data from the
tele-mode image pickup device 50B is recorded. That is, the image
data from the tele-mode image pickup device 50B is temporarily stored
in the memory 62. Subsequently, the system control unit 70 reads
out the image data temporarily stored in the memory 62 and transfers
it to the compression/decompression unit 64. Thus, the image data
is compressed by the compression/decompression unit 64 and is thereafter
stored in the built-in memory 84 or the memory card 80.
[0181] On the other hand, in a case where the decision of the step
100 has been negated, that is, where the tele/wide changeover switch
25 is thrown on its wide-mode side, the routine shifts to a step
108.
[0182] At the step 108, images represented by image data from the
two image pickup devices 50A, 50B are respectively displayed on
the display 26, while the image represented by the image data from
the wide-mode image pickup device 50A is highlighted. By way of
example, referring to FIG. 3, owing to the drive of the display
26 by the display driver 27, the image represented by the image
data from the wide-mode image pickup device 50A is displayed, while
the image represented by the image data from the tele-mode image
pickup device 50B is displayed substantially at the central part
of the wide-mode image. Here in the display, the frame part of the
image represented by the image data from the wide-mode image pickup
device 50A is emphasized, or a frame corresponding to the image
represented by the image data from the tele-mode image pickup device
50B is made difficult to see (by a frame of dotted line, fine line
or the like). Alternatively, contrariwise to the illustration of
FIG. 5, the image represented by the image data from the wide-mode
image pickup device 50A is displayed on the whole screen of the
display 26, while the image represented by the image data from the
tele-mode image pickup device 50B is displayed to be small at a
corner. By the way, in the case as shown in FIG. 3 where the image
formed by the tele-mode image pickup device 50B is displayed substantially
at the central part of the image formed by the wide-mode image pickup
device 50A, only image information such as a frame may well be displayed
on that position of the image formed by the wide-mode image pickup
device 50A which corresponds to the image formed by the tele-mode
image pickup device 50B, as an inconspicuous display (of, for example,
a dotted line or a fine line), without displaying the image itself
formed by the tele-mode image pickup device 50B.
[0183] According to the display in FIG. 3 or contrary to FIG. 5,
both the image to be recorded (the image formed by one image pickup
device) and the image not to be recorded (the image formed by the
other image pickup device) are displayed, so that the image to be
recorded can be confirmed, while the image not to be recorded can
be subsidiarily confirmed.
[0184] At a step 110, whether or not the release switch 22 has
been turned ON is decided. In a case where the decision has been
negated, the routine returns to the step 100, and the above processing
is repeated.
[0185] In a case where the decision of the step 110 has been affirmed,
the routine shifts to a step 112, at which the image data from the
wide-mode image pickup device 50A is recorded. That is, the image
data from the wide-mode image pickup device 50A is temporarily stored
in the memory 62. Subsequently, the system control unit 70 reads
out the image data temporarily stored in the memory 62 and transfers
it to the compression/decompression unit 64. Thus, the image data
is compressed by the compression/decompression unit 64 and is thereafter
stored in the built-in memory 84 or the memory card 80.
[0186] Subsequently, when the image data has been recorded at the
step 106 or the step 112, the routine shifts to a step 114, at which
whether or not photographing has ended is decided. The decision
is given by deciding, for example, whether or not the power source
switch 20 has been turned OFF, or whether or not the instruction
of a reproduction mode has been given by manipulating the various
switches 74. When the decision has been negated, the routine returns
to the step 100, and the above processing is repeated, and when
the decision of the step 114 has been affirmed, the photographing
process is ended.
[0187] In this manner, with the digital camera 10 according to
this embodiment, the image represented by the image data from the
tele-mode image pickup device 50B and the image represented by the
image data from the wide-mode image pickup device 50A are simultaneously
displayed on the display 26. The image can therefore be photographed
as the situation of surroundings is grasped, in such a way that
the photographing is performed after manipulating the tele/wide
changeover switch 26 in accordance with the circumstances. More
specifically, the tele/wide changeover switch 25 is thrown onto
the side of the main or desired image pickup device, and the image
formed by the main image pickup device is recorded. Since, on this
occasion, the image formed by the other image pickup device than
the main image pickup device is also displayed on the display 26,
the photographing is permitted as the situation of the surroundings
is grasped. Accordingly, a shutter chance can be prevented from
being missed.
[0188] Incidentally, although the photographing process in the
static image photographing mode has been described with reference
to FIG. 6, the image represented by the image data from the tele-mode
image pickup device 50B and the image represented by the image data
from the wide-mode image pickup device 50A are simultaneously displayed
on the display 26, similarly in the photographing of a dynamic image.
[0189] Besides, although in the above embodiment, the images formed
by the two image pickup devices 50A, 50B are displayed in the photographing
operation, images as displayed on the display 26 may well be displayed
by an electronic finer 90 which includes a display device 92 of
liquid crystal or the like, a lens 94, etc. as shown in FIG. 7.
[0190] Next, there will be described a digital camera in a first
modification to the digital camera 10 according to the above embodiment.
In the foregoing embodiment, the two photographing systems are so
constructed that the light entered by the single optical system
(lens 14) is split by the semitransparent mirror 86, and that the
subject images are formed on the two image pickup devices 50A, 50B
whose sizes are different from each other. In the first modification,
as shown in FIG. 8, two photographing systems are constructed independently
of each other in such a way that a wide-angle lens and a telescopic
lens are respectively included as a wide-mode lens 14A and a telescopic
lens 14B, and that two image pickup devices 51A, 51B are disposed
in correspondence with the respective lenses. Incidentally, the
two image pickup devices 51A, 51B may have either equal sizes or
different sizes. Besides, the tele-mode lens 14B may well be a zoom
lens (variable focal-distance lens).
[0191] Even when the two photographing systems are constructed
quite independently of each other in this manner, the same advantage
as in the foregoing embodiment can be attained.
[0192] Further, there will be described a digital camera in a second
modification to the digital camera 10 according to the above embodiment.
Since the images formed by the two image pickup devices 50A, 50B
are displayed on the single display 26 in the foregoing embodiment,
the composition of the images to be displayed is required, and one
image cannot be seen at a part where the two images lie one over
the other. In the second modification, therefore, two displays 26A,
26B of larger and smaller sizes are included so as to respectively
display the individual images, as shown in FIGS. 9 and 10. In this
manner, the images formed by the two image pickup devices are respectively
displayed on the two displays 26A, 26B, whereby processes such as
the composition of the images to be displayed can be omitted, and
both the whole images can be seen.
[0193] On this occasion, the images to be displayed on the larger
and smaller displays 26A, 26B may well be changed over in accordance
with the tele/wide changeover switch 25, that is, with the image
to-be-recorded. More specifically, the display driver 27 and the
display 26 in FIG. 4 are replaced with a contrivance as shown in
FIG. 11, in which a plurality of (in FIG. 11, two) displays 26A,
26B are disposed, while display drivers 27A, 27B are disposed in
correspondence with the respective displays, and the images (the
image formed by the tele-mode image pickup device 50B and the image
formed by the wide-mode image pickup device 50A) to be displayed
are changed over by a shift device 96 connected to the system bus
68. By way of example, in a case where the image formed by the tele-mode
image pickup device 50B is to be recorded (where the tele-mode has
been selected through the tele/wide changeover switch 25), a changeover
control is performed by the shift device 96 so that, as shown in
FIG. 10, the image formed by the tele-mode image pickup device 50B
may be displayed on the larger display 26A, while the image formed
by the wide-mode image pickup device 50A may be displayed on the
smaller display 26B. Besides, in a case where the image formed by
the wide-mode image pickup device 50A is to be recorded (where the
wide-mode has been selected through the tele/wide changeover switch
25), a changeover control is performed by the shift device 96 so
that, contrariwise to the above, the image formed by the wide-mode
image pickup device 50A may be displayed on the larger display 26A,
while the image formed by the tele-mode image pickup device 50B
may be displayed on the smaller display 26B. Incidentally, the remaining
construction is the same as in the foregoing embodiment and shall
therefore be omitted from description.
[0194] The two displays 26A, 26B of larger and smaller sizes are
included in this manner, whereby as in the foregoing embodiment,
the image to be recorded can be confirmed, while the image formed
by the imaging system which is not to be used can be subsidiarily
confirmed.
[0195] By the way, in the case where the plurality of displays
are included in this manner, information different from the image
formed, such as a menu display, may well be presented on, for example,
the smaller display 26B.
[0196] Besides, a digital camera which includes the two independent
photographing systems and the two displays 26A, 26B may well be
constructed by combining the first modification and the second modification.
[0197] Next, there will be described a digital camera in a third
modification to the digital camera 10 according to the above embodiment.
In the foregoing embodiment, the image formed by the tele-mode image
pickup device 50B and the image formed by the wide-mode image pickup
device 50A are entirely displayed on the single display 26, respectively.
In the digital camera of the third modification, the image formed
by the tele-mode image pickup device 50B is displayed, while only
a predetermined region is displayed as to the image formed by the
wide-mode image pickup device 50A. By way of example, as shown in
FIG. 12, the image formed by the tele-mode image pickup device 50B
is displayed on the upper side of the display 26, while only the
predetermined region 96 of the image formed by the wide-mode image
pickup device 50A is extracted and displayed on the lower side of
the display 26. Incidentally, such changeover of the display can
be implemented by, for example, manipulating the menu switch 30,
select switch 34, execute/view change switch 32 and cancel switch
36 of the various operating switches 74, and a display control can
be performed by the display driver 27.
[0198] In a case, for example, where a horse race is to be photographed
as shown in FIG. 12, only the predetermined belt-like region 96
may be displayed on the display 26 as to the image formed by the
wide-mode image pickup device 50A. Therefore, only the predetermined
region 96 is designated, and the instruction of displaying the predetermined
region 96 on the lower side of the screen of the display 26 is given,
by manipulating the various operating switches 74, whereby substantially
the whole image formed by the wide-mode image pickup device 50A
can be grasped. Moreover, necessary information can be effectively
displayed in a small display area by displaying only the predetermined
region 96 of the image formed by the wide-mode image pickup device
50A, in this manner.
[0199] Incidentally, although the two photographing systems are
included in the above embodiment, they are not restrictive, but
three or four photographing systems, for example, may well be included
so as to simultaneously display formed images on the display 26.
On this occasion, the display 26 may well be provided with display
screens in a number corresponding to that of the photographing systems.
[0200] (Second Embodiment)
[0201] Next, an example of the second embodiment of the invention
will be described in detail.
[0202] Shown in FIG. 13 is a block diagram of a digital camera
according to the embodiment of the invention. The digital camera
210 has two photographing systems (a first photographing system
212A and a second photographing system 212B) independent of each
other, and the respective photographing systems form subject images
on the photosensitive faces of CCDs 218A, 218B through photographing
optical systems 214A, 214B.
[0203] Incidentally, the CCD 218A corresponds to a first image
pickup device in the invention, the CCD 218B to a second image pickup
device in the invention, the photographing optical system 214A to
a first optical system in the invention, and the photographing optical
system 214B to a second optical system in the invention.
[0204] Two imaging systems are respectively constructed of the
first photographing system 212A which is used in ordinary-mode photographing,
and the second photographing system 212B which is used in telescopic-mode
photographing.
[0205] The respective photographing optical systems 214A, 214B
are constructed including photographing lenses 216A, 216B and aperture
stops 217. The photographing lens 216A is made of a monofocal lens,
while the photographing lens 216B is made of a zoom lens (variable
focal-distance lens).
[0206] The subject images formed on the photosensitive faces of
the CCDs 218A, 218B through the respective photographing optical
systems 214A, 214B are converted into signal charges in quantities
corresponding to the quantities of entered lights, by the respective
sensors. The signal charges thus accumulated are read out by CCD
drive pulses impressed from CCD drive circuits 220A, 220B, and are
sequentially outputted from the CCDs 218A, 218B as voltage signals
(analog image signals) corresponding to these signal charges.
[0207] Each of the CCDs 218A, 218B is provided with a shutter drain
through a shutter gate, and the shutter gate is driven by shutter
gate pulses, whereby the accumulated signal charges can be swept
out to the shutter drain. That is, the CCD 218 has a so-called "electronic
shutter function" in which the accumulation time of the charges
accumulated in the sensor (a shutter speed) is controlled by the
shutter gate pulses.
[0208] In CDS circuits 222A, 222B, the signals read out from the
respective CCDs 218A, 218B are submitted to correlated double sampling
(CDS) processes, and they are submitted to color separation processes
into individual color signals R, G and B, the signal levels of which
are adjusted (as white balance pre-processes).
[0209] The image signals having undergone these predetermined analog
signal processes are applied to A/D converters 224A, 224B and are
converted by the A/D converters 224A, 224B into digital signals
R, G and B, which are stored in memories 226A, 226B. Incidentally,
the memories 226A, 226B may be constructed either as a single memory
or as individual memories for the respective photographing systems.
[0210] A timing signal generation circuit (TG) 228 applies appropriate
timing signals to the CCD drive circuits 220A, 220B, the CDS circuits
222A, 222B and the A/D converters 224A, 224B in compliance with
commands from a CPU 230, and the respective circuits are synchronously
driven by the timing signals applied from the timing signal generation
circuit 228.
[0211] The CPU 230 is a control unit (control means) which collectively
controls the various circuits of the digital camera 210. It is connected
through a bus 232 with a gain adjustment circuit 234, a gamma correction
circuit 236, a brightness/color difference signal process circuit
(termed "Y/C process circuit") 238, a compression/decompression
circuit 240, a card interface 244 for a memory card 242, a displaying
driver 248 for driving a display unit 246, and so forth.
[0212] The CPU 230 performs the control of a corresponding circuit
block on the basis of an input signal from an operation unit 250.
It also performs the controls of the zooming operation of the photographing
lens 216B and the autofocusing (AF) operations of the photographing
lenses 216A, 216B, the control of an automatic exposure adjustment
(AE), etc.
[0213] Included in the operation unit 250 are a release button
for giving the instruction of starting the recording of an image,
camera mode selection means, zooming operation means, and various
other input means. These input means are in any of various aspects
such as switch buttons, a dial and a slide type knob, or in an aspect
in which a setting menu or selection items are displayed on a touch
panel or the screen of a liquid-crystal monitor display unit so
as to select a desired item by a cursor. By way of example, an ordinary
mode based on the first photographing system or a telescopic mode
based on the second photographing system can be selected through
the manipulation of the operation unit 250. The operation unit 250
may be disposed on the camera body, or it can also be constructed
as a remote-control transmitter separately from the camera body.
[0214] The CPU 230 executes various calculations such as focus
evaluation calculations and AE calculations, on the basis of the
image signals outputted from the CCDs 218A, 218B, and it controls
drive circuits 252A, 252B for the photographing lenses 216A, 216B
and the aperture stops 217 on the basis of the calculations. More
specifically, motors 254A, 254B are driven, thereby to move the
focusing lenses to focusing positions and to set the aperture stops
217 at appropriate aperture values. The motors 254A, 254B are stepping
motors, and the focusing lens positions are controlled by controlling
the numbers of steps of these motors. Incidentally, the motors 254A,
254B are not restricted to the stepping motors, but they can also
be, for example, DC motors.
[0215] Adopted for the AF control is a contrast AF scheme in which
the focusing lens is moved so as to maximize the high frequency
component of a G signal. More specifically, the focusing lenses
are respectively moved by driving the motors 254A, 254B through
the drive circuits 252A, 252B, until the focusing lenses are located
at positions of maximum contrast values. In the AE control, a subject
brightness (photographing EV) is found on the basis of an integral
value obtained by integrating the R, G and B signals of one frame,
and an aperture value and a shutter speed are determined on the
basis of the photographing EV. Subsequently, the aperture stops
217 are driven through the drive circuits 252A, 252B, and the accumulation
time periods of the charges in the CCDs 218A, 218B are controlled
by electronic shutters so as to afford the determined shutter speeds.
Accordingly, the optimum exposure adjustments are performed, and
the photographing lenses 216A, 216B are automatically focused, merely
by directing these lenses of the digital camera 210 toward a subject.
[0216] In a photographing recording operation, at the "half
depression" of the release button, the above AF operation is
performed, and an accurate photographing EV is found by |