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Digital Camera Patent Abstract
A control method of a digital camera includes: displaying a moving
image on a screen based on charges stored in an image sensor by
an electronic shutter with a shutter curtain opened; detecting illuminance
of the shutter curtain with the shutter curtain closed; setting
a still image exposure period based on the detected illuminance
of the shutter curtain; exposing the image sensor in the still image
exposure period with the shutter curtain opened; and storing a still
image in a recording medium based on the charges stored in the image
sensor in the still image exposure period.
Digital Camera Patent Claims
1. A control method of a digital camera comprising; displaying a
moving image on a screen based on charges stored in an image sensor
by an electronic shutter with a shutter curtain opened; detecting
illuminance of the shutter curtain with the shutter curtain closed;
setting a still image exposure period based on the detected illuminance
of the shutter curtain; exposing the image sensor in the still image
exposure period with the shutter curtain opened; and storing a still
image in a recording medium based on the charges stored in the image
sensor in the still image exposure period.
2. The control method according to claim 1, wherein the displaying
process includes: storing the charges in photodiodes of the image.
sensor; transferring the charges, which belong to a plurality of
fields being different from each other and constituting one frame,
from the photodiodes to a vertical element of the image sensor in
time-division manner; transferring the charges in every field from
the vertical element to a horizontal element of the image sensor;
transferring the charges in every field from the horizontal element
to a detecting element of the image sensor; generating pixel signals
corresponding to the charges transferred to the detecting element
in every field; and generating a plurality of continuous frames
based on each pixel signal while displaying each frame as the moving
image.
3. The control method according to claim 2, wherein the charges
in a plurality of cells of the vertical element are transferred
to and accumulated in each of cells of the horizontal element.
4. The control method according to claim 1, wherein the displaying
process includes: storing the charges in photodiodes of the image
sensor; transferring the charges, which belong to a plurality of
fields being different from each other and constituting one frame,
from the photodiodes to a vertical element of the image sensor in
time-division manner; transferring the charges in every field from
the vertical element to a horizontal element of the image sensor;
transferring the charges in every field from the horizontal element
to a detecting element of the image sensor; generating pixel signals
corresponding to the charges transferred to the detecting element
in every field; and generating each frame based on each pixel signal
while displaying each frame as the moving image.
5. The control method according to claim 4, wherein the charges
in a plurality of cells of the vertical element are transferred
to and accumulated in each of cells of the horizontal element.
6. A digital camera comprising; an image sensor; a shutter curtain,
adapted to expose and shield the image sensor; a display controller,
operable to display a moving image on a screen based on charges
stored in the image sensor by an electronic shutter with the shutter
curtain opened; and a still image recorder, operable to detect illuminance
of the shutter curtain with the shutter curtain closed, to set a
still image exposure period based on the illuminance, to expose
the image sensor in the still image exposure period with the shutter
curtain opened, and to store a still image in a recording medium
based on the charges stored in the image sensor in the still image
exposure period.
7. The digital camera according to claim 6, wherein the image sensor
includes a first controller, operable: to store the charges in photodiodes
of the image sensor; to transfer the charges, which belong to a
plurality of fields being different from each other and constituting
one frame, from the photodiodes to a vertical element of the image
sensor in time~ivision manner; to transfer the charges in every
field from the vertical element to a horizontal element of the image
sensor; and to transfer the charges in every field from the horizontal
element to a detecting element of the image sensor, and the display
controller includes a second controller, operable: to generate pixel
signals corresponding to the charges transferred to the detecting
element in every field; to generate a plurality of continuous frames
based on each pixel signal; and to display each frame as the moving
image.
8. The digital camera according to claim 7, wherein the charges
in a plurality of cells of the vertical element are transferred
to and accumulated in each of cells of the horizontal element.
9. The control method according to claim 6, wherein the image sensor
includes a first controller, operable: to store the charges in photodiodes
of the image sensor; to transfer the charges, which belong to a
plurality of fields being different from each other and constituting
one frame, from the photodiodes to a vertical element of the image
sensor in time-division manner; to transfer the charges in every
field from the vertical element to a horizontal element of the image
sensor; and to transfer the charges in every field from the horizontal
element to a detecting element of the image sensor, and the display
controller includes a second controller, operable: to generate pixel
signals corresponding to the charges transferred to the detecting
element in every field; to generate each frame based on each pixel
signal; and to display each frame as the moving image.
10. The control method according to claim 9, wherein the charges
in a plurality of cells of the vertical element are transferred
to and accumulated in each of cells of the horizontal element.
Digital Camera Patent Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a digital camera and a
control method thereof and more specifically, to a digital camera
using a shutter curtain which operates mechanically and using an
area image sensor which does not have a structure for a high-speed
draft mode, and a control method thereof.
[0002] A CCD area image sensor which divides electric charges stored
in photodiodes into charges of a plurality of divided fields to
transfer them is known (refer to, for example, JP-A-818875 and Japanese
Patent No. 3009041). By dividing electric charges stored in photodiodes
into charges of a plurality of divided fields to transfer them,
the area of the vertical CCD can be reduced. As a result, since
the area of the photodiodes can be increased, this becomes advantageous
from the viewpoint of the saturated amount of signals. A digital
camera provided with an electronic viewfinder is often mounted with
an area image sensor corresponding to a high-speed draft mode, with
a function of selectively reading charges at regular intervals from
a plurality of photodiodes, which are arrayed along the vertical
CCD, in order to increase the frame rate of a moving image which
is displayed in real time on the electronic viewfinder. Since the
area image sensor corresponding to a high-speed draft mode is provided
with a dedicated control signal line for reading the charges stored
in the photodiodes at one time by thinning out them according to
a rule capable of forming a color image, pixels in a vertical direction
from all pixels can be thinned out and read out. As a result, since
a grainy image representing a whole image, that is, an image having
a low resolution can be read, the frame rate of a moving image can
be increased by reading the grainy image in a short time.
[0003] However, since a digital camera provided with a high-resolution
CCD image sensor which is not corresponding to the high-speed draft
mode cannot increase the frame rate of a moving image, it has a
difficulty in realizing a moving image display function by the electronic
viewfinder. In a digital camera provided with a high-sensitivity
and high-resolution CCD image sensor, exposure is often by a shutter
curtain which operates mechanically.
SUMMARY
[0004] It is therefore an object of the invention to provide a
digital camera and its control method capable of controlling exposure
of a still image by a shutter curtain which operates mechanically
to display a moving image in real time and capable of increasing
the frame rate of a moving image, even if an area image sensor does
not have a structure for a high-speed draft mode.
[0005] In order to achieve the object, according to the invention,
there is provided a control method of a digital camera comprising:
[0006] displaying a moving image on a screen based on charges stored
in an image sensor by an electronic shutter with a shutter curtain
opened;
[0007] detecting illuminance of the shutter curtain with the shutter
curtain closed;
[0008] setting a still image exposure period based on the detected
illuminance of the shutter curtain;
[0009] exposing the image sensor in the still image exposure period
with the shutter curtain opened; and
[0010] storing a still image in a recording medium based on the
charges stored in the image sensor in the still image exposure period.
[0011] With this configuration, by storing the charges in the image
sensor by the electronic shutter with the shutter curtain opened,
the moving image can be displayed in real time on the screen on
the basis of the charges stored in the image sensor. By setting
the still image exposure period on the basis of the detected illuminance
of the shutter curtain in its closed state, and opening the shutter
curtain in the still image exposure period, exposure of a still
image can be controlled by the mechanical shutter curtain.
[0012] The displaying process may include: storing the charges
in photodiodes of the image sensor; transferring the charges, which
belong to a plurality of fields being different from each other
and constituting one frame, from the photodiodes to a vertical element
of the image sensor in time-division manner; transferring the charges
in every field from the vertical element to a horizontal element
of the image sensor; transferring the charges in every field from
the horizontal element to a detecting element of the image sensor;
generating pixel signals corresponding to the charges transferred
to the detecting element in every field; and generating a plurality
of continuous frames based on each pixel signal while displaying
each frame as the moving image.
[0013] In this case, by using the pixel signals of one field for
generation of pixel signals of a plurality of continuous frames,
and by overlapping the pixel signals of one field with a plurality
of frames, even if the image sensor does not have a structure for
a high-speed draft mode, the frame rate of the moving image of a
digital camera can be increased.
[0014] The charges in a plurality of cells of the vertical element
may be transferred to and accumulated in each of cells of the horizontal
element.
[0015] In this case, by accumulating the charges for a plurality
of cells of the vertical element in each cell of the horizontal
element and transferring charges of each cell of the horizontal
element to the detecting element, the number of times of transfer
of charges by the vertical element can be reduced. As a result,
the frame rate of a moving rate of a digital camera can be increased.
[0016] The displaying process may include: storing the charges
in photodiodes of the image sensor; transferring the charges, which
belong to a plurality of fields being different from each other
and constituting one frame, from the photodiodes to a vertical element
of the image sensor in time-division manner; transferring the charges
in every field from the vertical element to a horizontal element
of the image sensor; transferring the charges in every field from
the horizontal element to a detecting element of the image sensor;
generating pixel signals corresponding to the charges transferred
to the detecting element in every field; and generating each frame
based on each pixel signal while displaying each frame as the moving
image.
[0017] In this case, a frame of a monotone image can be generated
on the basis of the charges of photodiodes corresponding to some
color components of all the color components. Accordingly, even
if a digital camera is not provided with dedicated signal lines
for a high-speed draft mode, the frame rate can be increased by
transmitting, to control signal lines for detecting time-divided
charges of photodiodes in every field, control signals for detecting
charges of the photodiodes for one field in every frame, and displaying
each frame of a monotone moving image on the screen on the basis
of the charges of the photodiodes for one field.
[0018] The charges in a plurality of cells of the vertical element
may be transferred to and accumulated in each of cells of the horizontal
element.
[0019] In order to achieve the object, according to the invention,
there is also provided a digital camera comprising:
[0020] an image sensor;
[0021] a shutter curtain, adapted to expose and shield the image
sensor;
[0022] a display controller, operable to display a moving image
on a screen based on charges stored in the image sensor by an electronic
shutter with the shutter curtain opened; and
[0023] a still image recorder, operable [0024] to detect illuminance
of the shutter curtain with the shutter curtain closed, [0025] to
set a still image exposure-period based on the illuminance, [0026]
to expose the image sensor in the still image exposure period with
the shutter curtain opened, and [0027] to store a still image in
a recording medium based on the charges stored in the image sensor
in the still image exposure period.
[0028] The image sensor may include a first controller, operable:
to store the charges in photodiodes of the image sensor; to transfer
the charges, which belong to a plurality of fields being different
from each other and constituting one frame, from the photodiodes
to a vertical element of the image sensor in time-ivision manner;
to transfer the charges in every field from the vertical element
to a horizontal element of the image sensor; and to transfer the
charges in every field from the horizontal element to a detecting
element of the image sensor. The display controller may include
a second controller, operable: to generate pixel signals corresponding
to the charges transferred to the detecting element in every field;
to generate a plurality of continuous frames based on each pixel
signal; and to display each frame as the moving image.
[0029] The charges in a plurality of cells of the vertical element
may be transferred to and accumulated in each of cells of the horizontal
element.
[0030] The image sensor may include a first controller, operable:
to store the charges in photodiodes of the image sensor, to transfer
the charges, which belong to a plurality of fields being different
from each other and constituting one frame, from the photodiodes
to a vertical element of the image sensor in time-division manner;
to transfer the charges in every field from the vertical element
to a horizontal element of the image sensor; and to transfer the
charges in every field from the horizontal element to a detecting
element of the image sensor. The display controller may include
a second controller, operable: to generate pixel signals corresponding
to the charges transferred to the detecting element in every field;
to generate each frame based on each pixel signal; and to display
each frame as the moving image.
[0031] The charges in a plurality of cells of the vertical element
are transferred to and accumulated in each of cells of the horizontal
element
[0032] In addition, the order of respective operations of the method
as set forth in claims is not limited to the described order unless
there are technical impediments. For example, the operations may
be executed in an arbitrary order or may be executed at the same
time. Further, the respective functions of a plurality of units
installed in the present invention are implemented by hardware resources
whose functions are specified by their own construction, software
resources whose functions are specified by programs, or combinations
of the hardware and software resources. Further, the respective
functions of the plurality of units are not limited to those which
are implemented by software resources physically independent from
each other. Further, the present invention can be specified not
only as an invention of a program but also as an invention of a
recording medium in which the program is recorded.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] FIGS. 1A to 1C are views showing the appearance of a digital
still camera according to a first embodiment.
[0034] FIGS. 2A and 2B are views showing the appearance of the
digital still camera according to the first embodiment.
[0035] FIG. 3 is a block diagram of the digital still camera according
to the first embodiment.
[0036] FIG. 4 is a schematic view of an image sensor related to
the first embodiment.
[0037] FIGS. 5A and 5B are schematic views for explaining a read
method of the image sensor related to the first embodiment.
[0038] FIG. 6 is a flowchart showing the flow of processing in
a photographing mode related to the first embodiment.
[0039] FIGS. 7A to 7D are schematic views showing the operation
of the image sensor related to the first embodiment
[0040] FIG. 8 is a schematic view showing driving signals of the
image sensor related to the first embodiment.
[0041] FIG. 9 is a schematic view for explaining the processing
which generates frame data from pixel signals.
[0042] FIG. 10 is a schematic view for explaining the processing
which generates frame data from pixel signals.
[0043] FIG. 11 is a flowchart showing the operation of the image
sensor in the through image display processing.
[0044] FIG. 12 is a schematic view of a digital still camera according
to a second embodiment.
[0045] FIG. 13 is a flowchart showing the flow of processing in
a photographing mode related to the second embodiment.
DETAIL DESCRIPTION OF PREFERRED EMBODIMENTS
[0046] Hereinafter, a plurality of embodiments of the invention
will be described with reference to the accompanying drawings. The
components of each embodiment to which the same reference numerals
are given correspond to those of other embodiments to which the
reference numerals are given.
[0047] (First Embodiment)
[0048] FIGS. 1A, 1B, 1C and 2A are views showing the appearance
of a digital still camera (DSC) 1 according to a first embodiment
of the invention. FIG. 2B is a view showing that a replaceable lens
unit 2 is mounted to the DSC 1. FIG. 3 is a block diagram showing
the DSC 1.
[0049] In addition, although the DSC 1 is of a compact camera type,
it may be of a single lens reflex camera type.
[0050] In the DSC 1, a plurality of kinds of replaceable lens units
2 can be mounted to a mount 28. Afocus adjusting dial 58 and a diaphragm
adjusting dial 56 are provided outside a lens barrel of each lens
unit 2. When the focus adjusting dial 58 rotates, lenses 60 and
64 move in the direction of an optical axis. A focus can be adjusted
by rotating the focus adjusting dial 58. When the diaphragm adjusting
dial 56 rotates, the aperture of a diaphragm 62 varies. The diaphragm
can be adjusted by rotating the diaphragm adjusting dial 56.
[0051] A first shutter curtain 30 and a second shutter curtain
32 constitute an electrically controlled focal plane shutter. The
first shutter curtain 30 and the second shutter curtain 32 are put
into an operable state by rotating a winding lever 14, and their
mechanical opening and shutoff operations are electrically controlled
by a shutter driving part 70. That is, when the shutter starts to
operate, the first shutter curtain 30 operates first, and shutoff
of the light projected through the lenses within the replaceable
lens unit 2 is opened. Therefore, exposure of the image sensor 72
starts, and this exposure is continued during the period until the
second shutter curtain 32 operates. Then, since the light projected
through the lenses with the completion of the operation of the second
shutter curtain 32 is shut off again, the exposure is completed.
[0052] In addition, the construction of the shutter is not limited
particularly. For example, the shutter may be a shutter in which
electric control is not used for operation of a shutter curtain
or may be a shutter in which the charge storage time of the image
sensor 72 is controlled by a so-called electronic shutter which
controls a substrate voltage, without using the shutter curtain.
[0053] The internal illuminance meter 66 is an optical sensor which
measures the iluminance of the reflected light of the shutter curtain.
The illuminance of the light which is incident on the internal illuminance
meter 66 varies according to the aperture of the diaphragm 62. Therefore,
if the diaphragm adjusting dial 56 rotates, the output value of
the internal illuminance meter 66 also varies. The quantity of the
light projected through the lenses within the replaceable lens unit
2 can be measured according to the output of the internal illuminance
meter 66 which measures the illuminance of the reflected light of
the shutter curtain. The result of this measurement is used for
calculation of shutter speed, that is, an exposure period or the
like of the image sensor 72 by the DSC 1.
[0054] It is noted herein that the surface of the shutter curtain
in a photographing preparatory state is not painted in plain deep
black or pure white, but is painted so that its refractive index
becomes about 18%. As a result, the illuminance of the light projected
through the tens unit 2 can be more exactly measured by the internal
iluminance meter 66. Further, if the intense reflected light is
incident on the shutter curtain, the internal illuminance meter
66 cannot measure the illuminance of the reflected light exactly.
In this case, since a proper exposure period cannot be calculated,
photographing with proper exposure cannot be performed. Thus, by
forming rough minute satin on the surface of the shutter curtain,
the light incident on the shutter curtain is gently diffused on
the surface of the shutter curtain. As a result, since the light
gently diffused on the surface of the shutter curtain is incident
on the internal illuminance meter 66, the illuminance of the light
incident on the internal iliuminance meter 62 can be measured exactly.
Further, as for the photographing of the DSC 1, the refractive index
of a central portion of the shutter curtain is made different from
that of a peripheral portion thereof so that centralized exposure
photographing becomes possible. Specifically, the reflecting quantity
of the shutter curtain is adjusted by, for example, painting the
shutter curtain in deeper color toward the peripheral portion so
that the refractive index of the surface of the shutter curtain
is reduced from the central portion of the shutter curtain toward
the peripheral portion thereof. Further, the internal illuminance
meter 62 is adjusted to output exact illuminance if the reflective
index of the lens unit 2 in its optical path direction by the shutter
curtain becomes about 18%.
[0055] In addition, in a construction which does not use a shutter
curtain, the image sensor 72 can directly detect the illuminance
of the light passed through the lens unit 2 or the internal illuminance
meter 66 can indirectly detect the reflected light of a half mirror.
[0056] FIG. 4 is a schematic view of the image sensor 72. FIGS.
5A and 5B are schematic views for explaining a reading method of
the image sensor 72. The image sensor 72 is a so-alled CCD color
area image sensor composed of photodiodes 720, vertical CCDs 721,
a horizontal CCD 722, a detecting element 723, etc., which are discretely
arranged in a two-dimensional space. The image sensor 72 includes
R. G, and B color filters which are Bayer-arrayed in every photodiode
720, and stores in each photodiode 720 a signal charge showing the
density level of any one of RGB channels in every pixel. In addition,
although the image sensor 72 in which the photodiodes 720 are arrayed
in a tetragonal lattice are illustrated herein, the photodiodes
720 of the image sensor 72 may be arrayed in the shape of a honeycomb.
Further, the color filters of the image sensors 72 may be arrayed
in stripes. Further, the image sensor 72 may be a CMOS area image
sensor.
[0057] Each vertical CCD 721 has four transfer electrodes which
allow a vertical driving signal V1, V2, V3, or V4 to be input to
every cell 721 a. By gradually and sequentially applying vertical
driving signals with mutually different phases to the four transfer
electrodes, a potential well is formed in each cell 721 a of the
vertical CCD 721, and an electric charge bound in the potential
well of each cell 721 a moves to potential wells of sequentially
adjacent cells 721 a one after another. Signal charges transferred
to each cell 721 a from the photodiodes 720 in this way are transferred
to the horizontal CCD 722. Hereinafter, the transfer of signal charges
by the above-described vertical CCD 721 is referred to as "vertical
CCD transfer,"
[0058] The horizontal CCD 722 has two transfer electrodes which
allow a horizontal driving signal Vh1 or Vh2 to be input to every
cell 722a. Different potential wells are formed within the cells
722a of the horizontal CCD 722. In addition, by applying the horizontal
driving signals Vh1 and Vh2 with different phases of 180.degree.
to the two horizontal transfer electrodes, a potential well is formed
in every cell 722a, and an electric charge bound in the potential
well of each cell 722a moves to potential wells of sequentially
adjacent cells 722a one after another Signal charges transferred
to each cell 722a by the vertical CCD 721 in this way are sequentially
transferred to the detecting element 723. Specifically, vertical
signal lines 724 and horizontal signal lines 725 are connected to
transfer electrodes (not shown) of the vertical CCD 721 and the
horizontal CCD 722, respectively. Also, the vertical CCD 721 and
the horizontal CCD 722 are driven by the.vertical driving signals
(refer to V1 to V4 in FIG. 8) and the horizontal driving signals
(refer to Vh1 and Vh2 in FIG. 8), respectively, which are applied
to the above-mentioned signal lines by an image capturing controller
76, thereby transferring signal charges.
[0059] The detecting element 723 converts charges transferred to
the horizontal CCD 722 into pixel signals. Specifically, for example,
the detecting element 723, which is a floating diffusion amplifier,
converts signal charges into voltages values as pixel signals according
to its capacitance. In addition, although the image sensor 72 in
which the vertical CCD 721 are of four-phase driving method is illustrated,
the vertical CCD 721 may be a CCD of arbitrary phase driving method.
Further, although the image sensor 72 in which the horizontal CCD
722 is of two-phase driving method is illustrated, the horizontal
CCD 722 of the image sensor 72 may be a CCD of arbitrary phase driving
method. Further, the detecting element 723 may be a floating gate
amplifier.
[0060] As shown in FIGS. 5A and 5B, the image sensor 72 is an area
image sensor of soclled frame reading method which reads pixel signals
of one frame which are divided into two fields. Since a vertical
CCD for reading in this area image sensor of frame reading method
is used for both a first field and a second field, the area of the
vertical CCD can be reduced. As a result, since the size of the
photodiodes 720 can be increased or the size of the cells 721 a
(refer to FIG. 4) of the vertical COD 721 can be increased, it is
advantageous in that the area image sensor of frame reading method
can increase the saturated amount of signal charges. The image sensor
72 has a shift electrode for controlling transfer of signal charges
from the photodiodes 720 to a vertical CCD 721 between the photodiodes
720 and the vertical CCD 721. A shift signal line 726 and a shift
signal line 727 are connected to this shift electrode so that, during
reading of each field, charge signals showing the density level
of the same channels are transferred to a vertical CCD 721 in each
column. Specifically, for example, in the image sensor 72 having
Bayer-arrayed color filters, the shift signal line 726 and the shift
signal line 727 are alternately connected to a continuous shift
electrode. In this case, in the image sensor 72, a signal charge
showing the density level of a Gchannel or a B-channel is transferred
to the vertical CCD 721 in each column from a photodiode 720 during
reading of the first field (refer to FIG. 5A), and a signal charge
showing the density level of an R-channel or a G-channel is transferred
to a vertical CCD in each column from a photodiode during reading
of the second field (refer to FIG. 5B).
[0061] As such, the image sensor 72 transfers signal charges of
mutually different fields to the vertical CCD 721 in time~ivision
manner to read pixel signals of one frame which is divided into
two fields. In addition, although the image sensor 72 has been described
as the one which reads pixel signals of one frame which is divided
into two fields, it may be an area image sensor which reads pixel
signals of one frame which are divided into three or more fields.
Further, the image sensor 72 may be of full pixel reading method,
if it has color filters which are arrayed in stripes.
[0062] It is noted herein that the image sensor 72 does not have
a structure for a high-speed draft mode, for example, shift signal
lines for selectively transferring signal charges from a plurality
of photodiodes 720 which are arrayed along a vertical CCD 721. Therefore,
in the image sensor 72, the size of the photodiodes 72 can be further
increased, and the size of the vertical CCD 721 cab be increased,
Thus, the saturated amount of signal charges can be increased. Further,
since the area of light-receiving surfaces of the photodiodes 720
can be increased, this is advantageous from the viewpoint of sensitivity
or the like. However, in the image sensor 72, by thinning out signal
charges stored in the photodiodes 720 to transfer them to the vertical
CCD 721 like a high-speed draft mode, the number of times of transfer
of the signal charges required to display one frame by the horizontal
CCD 722 cannot be reduced.
[0063] For example, if all pixels of an area image sensor of 600
million pixels (3008 pixels in the horizontal direction and 2000
pixels in the vertical direction) are read at a reading rate of
25 MHz by a related frame reading method, a reading time of 0.04
Ms per one pixel is required. Therefore, the reading of one field
requires a reading time of at least 120.32 ms (=0.04 .mu.s.times.3008.times.1000).
Accordingly, the reading of one frame requires a reading time of
240.64 ms when the reading time for at least two fields is added
up. That is, if a continuous image is read and displayed using an
area image sensor of 600 million pixels which does not correspond
to the high-speed draft mode (hereinafter referred to as "through
image reading"), only four frames can be read for one second.
Here, the through image is a series of moving images which are obtained
by photographing a photographic subject at predetermined time intervals.
Moreover, this time is purely the time required to read all the
pixels including 3008 pixels in the horizontal direction and 2000
pixels in the vertical direction. Generally, since the time to read
optical black pixels arranged around the image sensor 72, the processing
time to drive the image sensor 72, the high-speed emission transfer
time for noise emission, the exposure time of a photographic subject,
and the like also are required, only two or three frames can be
read practically, and thus the moving posture of a photographic
subject cannot be practically read as a moving image.
[0064] Therefore, in the DSC 1, an image to be displayed as a moving
image does not need to have high resolution. Even if it has low
resolution, a reading method is schemed on the basis of the idea
that higher frame rate brings a better result. First, after a fixed
time of exposure, signal charges for pixels in the first field are
shifted to a vertical CCD 721 by a shift signal. Thereafter, transfer
of the individual signal charges in the vertical CCD 721 is carried
out. At this time, analog accumulative addition of signal charges
for a plurality of cells in the vertical direction is performed
by storing signal charges for a plurality of cells of the vertical
CCD 721 in each cell 722a of the horizontal CCD 722. In addition,
the number of charges to be added up may be for two cells or for
three cells. Then, the signal charges for a plurality of cells of
the vertical CCD 721 are transferred by the horizontal CCD 721.
[0065] The number of reading lines of pixel lines in the vertical
direction can be reduced by adding signal charges for a plurality
of cells of the vertical CCD 721 as such (for example, if addition
for two cells is performed, the number of reading lines become half,
and if addition for four cells is performed, the number of reading
lines becomes one fourth). Therefore, even if a structure for a
high-speed draft mnode is not provided, it is possible to reduce
the number of transfer of signal charges by the horizontal CCD 722,
which is required to display one frame of a through image as a moving
image. At this time, for example, if addition for two cells and
addition for four cells are performed, the number of times of transfer
of signal charges can be reduced to half and one fourth, respectively,
and the frame rate can be increased to twice and quadruple, respectively.
Further, since the apparent sensitivity of the image sensor 72 can
be raised by adding signal charges, the exposure period of the image
sensor 72 during display of a through image can be shortened (for
example, if addition for two cells are performed, the exposure period
is shortened to half, and if addition for four cells is performed,
the exposure period is shortened to one fourth). Accordingly, the
frame rate can be further improved. As a result, the DSC 1 can display
a through image at high speed even if an image sensor 72 with a
large number of pixels, which is capable of photographing a high
resolution of a still image, Further, the SN ratio of signal charges
can also be improved by adding signal charges for a plurality of
cells of the vertical CCD 721. In addition, the moving image may
be a moving image which is recorded by a moving image photographing
function of the DSC 1. Further, the number of signal charges to
be added may be for two cells, for three cells, or for four cells,
or may be changed automatically or manually. Hereinafter, "adding
signal charges for `n` cells of the vertical CCD 721 in each column
to each of the cells 722a of the horizontal CCD 722" is referred
to "n-time pixel addition." The image capturing controller
76 shown in FIG. 3 applies vertical driving signals, horizontal
driving signals, and shift signals to the transfer electrodes of
the vertical CCD 721, the transfer electrodes of the horizontal
CCD 722, and the shift electrode, respectively, via the vertical
signal lines 724, the horizontal signal lines 725, and the shift
signal lines 726 and 727, respectively.
[0066] An analog front end (AFE) 74 is composed of a correlation
double sampling (CDS) circuit 740, an amplifier 742, an analog/digital
(AID) converter 744, an analog black level reproducing circuit (a
circuit which reproduces a reference voltage of optical black by
settling the signal level of black by using pixels, which are optically
masked, in the image sensor 72) which is not shown, etc. The CDS
circuit 740 is a circuit which removes reset noises concluded in
pixel signals output by the image sensor 72. The amplifier 742 is
an amplifier, i.e., a so-called variable gain amplifier to amplify
pixel signals with gains corresponding to the brightness of a photographic
subject. The A/D converter 744 generates digital pixel signals (hereinafter
referred to as pixel data) by performing A/D conversion on pixel
signals. The pixel data output from the AFE 74 is stored in a RAM
100 by an image processing controller 98.
[0067] The image processing controller 98 performs a variety of
image processing on the image data output from the AFE 74, in cooperation
with the RAM 100, a color processing part 102, a resolution converting
part 104, and an image compression/extension part 106.
[0068] The RAM 100 is a volatile memory in which pixel data, etc.
are temporarily stored.
[0069] The color processing part 102 cooperates with the image
processing controller 98, and performs image development processing
on the pixel data output from the AFE 74. The development processing
is processing which generates frame data having density levels of
three RGB channels in every pixel by means of white balance correction,
gradation correction, and demosaic processing which interpolates
the density level of each pixel of pixel data corresponding to a
signal charge of each photodiode 720 on the image sensor 72 between
neighboring pixels, and which finally reproduces the frame data
in the form of an image.
[0070] The resolution converting part 104 cooperates with the image
processing controller 98, and converts the resolution (total number
of pixels) of frame. data to a predetermined resolution. Specifically,
for example, the resolution converting part 104 converts the resolution
of frame data to a resolution corresponding to the photographing
conditions set by a user before photographing, or converts the resolution
of frame data to a resolution corresponding to the screen size of
an LCD 36.
[0071] The compression/extension part 106 cooperates with the image
processing controller 98, and compresses frame data and extends
compressed frame data (for example, the compression/extension part
compresses image data into image data of the JPEG format or extends
data compressed into the JPEG format). In addition, the compression/extension
part can also store frame data in the removable memory 92 without
compressing the frame data.
[0072] A graphic controller 94 cooperates with the image processing
controller 98, and displays an image represented by frame data on
the screen of the LCD 36.
[0073] The above-described functions of the image processing controller
98, the color processing part 102, the resolution converting part
104, the compression/extension part 106, and the graphic controller
94 may be implemented by dedicated circuits, such ASIC and DSP,
or may be implemented by execution of a specific program of a control
section 80.
[0074] The operating part 84 has a power switch 52, a release button
10, a shutter speed dial 12, buttons 40, 42, 44, 46, 48 and 50 for
setting photographing conditions, and a jog dial 22.
[0075] An external interface controller 86 communicably connects
the DSC 1 with external systems, such as a personal computer (PC)
(not shown). A removable memory controller 88 is an input/output
mechanism which transfers
[0076] the data stored in the RAM 100 to the removable memory 92
as a recording medium connected to a card connector 90. In addition,
the recording medium may be built-in memories, such as a flash memory
82.
[0077] The flash memory 82 is.a volatile memory which stores image
processing programs to be executed by the control section 80. Image
processing programs and various kinds of data which are necessary
for operation of the DSC 1 can also be stored in the flash memory
82 by downloading over networks from a predetermined server, reading
from the removable memory 92, or the like.
[0078] The control section 80 has a CPU 78, a RAM 81, and a flash
memory 82.
[0079] The control section 80 executes the control programs stored
in the flash memory 82 to control respective parts of the DSC 1,
and also functions as a display control unit and a still image recording
unit. The RAM 81 is a volatile memory is which temporarily stores
control programs and various kinds of data.
[0080] FIG. 6 is a flowchart showing the flow of processing in
a through image photographing mode of the DSC 1. The processing
shown in FIG. 6 is started when the DSC 1 transits to the through
image photographing mode, and the processing is repeated until the
DSC 1 transits from the through image photographing mode to any
mode other than the through image photographing mode.
[0081] First, the control section 80 opens the first shutter curtain
30 and the second shutter curtain 32 in cooperation with the shutter
driving part 70 (refer to Step S100). Hereinafter, the expression
"open the first shutter curtain 30 and the second shutter curtain
32" is referred to as "open the shutter curtain."
[0082] In Step S102, the control section 80 displays a through
image on the screen of the LCD 36. Specifically, the control section
80 makes signal charges stored in the photodiodes 720 for a predetermined
period of exposure using an electronic shutter with the shutter
curtain opened, and reads pixel signals according to these signal
charges from the image sensor 72. Then, the control section 80 generates
frame data from the read pixel signals, and performs pixel interpolation
procession for each of R, G and B, white balancing processing, color
reproduction processing, gamma correction processing, and verticaland-horizontal-size
reducing processing, etc. on this frame data, thereby displaying
an image for one frame represented by the frame data after the various
kinds of processing. The control section 80 repeats the series of
processing to display a through image as a moving image on the LCD
36. The detailed description thereof will be made below.
[0083] In Step S104, the control section 80 determines whether
or not the release button 10 has been pushed. If the release button
10 is pushed, the control section 80 executes processing (refer
to Step S106 to Step S118) for photographing a still image of a
photographic subject.
[0084] In Step S106, the control section 80 closes the first shutter
curtain 30 and the second shutter curtain 32 in cooperation with
the shutter driving part 70 (hereinafter referred to as "dose
the shutter curtain"), and then performs charge of the shutter
for the next shutter operation, preparation of the image sensor
72 for the next photographing, etc.
[0085] In Step S108, the control section 80 detects the illuminance
of curtain surface reflected light reflected by the first shutter
curtain 30 or the second shutter curtain 32. Specifically, the control
section 80 reads output signals of the internal illuminance meter
66, thereby detecting the illuminance of the light which is transmitted
through the diaphragm 62 of the lens unit 2 and reflected by the
shutter curtain.
[0086] In Step S110, the control section 80 sets an optimal exposure
period (a proper period in which the shutter curtain is to be opened)
under photographing conditions according to the illuminance of the
curtain surface reflected light. Specifically, the control section
80 sets an exposure period on the basis of output signals of the
internal illuminance meter 66.
[0087] In Step S112 to Step S114, the control section 80 opens
the shutter curtain only for the exposure period set in Step S110.
Specifically, the control section 80 performs preparation for exposure
of the image sensor 72 prior to the opening of the shutter curtain
(for example, emission processing of charges stored in the individual
photodiodes 720 of the image sensor 72 and emission processing of
charges remaining in the vertical CCDs 721 and the horizontal CCD)
722). Then, if preparation for the exposure of the image sensor
72 is made, the control section 70 opens the shutter curtain in
cooperation with the shutter driving part 70 (refer to Step S112),
and closes the shutter curtain after the set exposure period has
elapsed from when the shutter curtain has been opened (refer to
Step S114). As a result, the image sensor 72 is exposed to the light
from a photographic subject only for the exposure period.
[0088] In Step S116 to Step S118, the control section 80 generates
a still image, Specifically, the control section 80 makes the charges
remaining in the vertical CCDs 721 and the horizontal CCD 722 of
the image sensor 72 emitted, and thereafter reads pixel signals
of a first field and pixel signals of a second field sequentially
from the image sensor 72 (refer to Step S116). Then, the control
section 80 performs development processing on the read pixel signals
of the first field and the read pixel signals of the second field
in cooperation with the color processing part 102, thereby generating
frame data from the pixel signals of the first field and the pixel
signals of the second field. Moreover, the control section 80 performs
resolution conversion processing, compression processing (for example,
compressing processing according to the JPEG standard), and the
like on the frame data, in cooperation with the resolution conversion
part 104, the compressionl/extension part 106, the image processing
controller 98, and the removable memory controller 88, and stores
the frame data in the removable memory 92, etc. (refer to Step S118)
as a still image (for example, a still image of the JPEG format).
[0089] FIGS. 7A to 7D are schematic views showing the operation
of the image sensor 72 in the through image display processing.
FIG. 8 is a schematic view showing driving signals output by the
image capturing controller 76 in the through image display processing.
FIGS. 7A to 7D respectively show states of the image sensor 72 at
t1 to t4 of FIG. 8. FIG. 9 is a schematic view showing the processing
which generates frame data from pixel signals in the through image
display processing. Hereinafter, the through image processing will
be described while the processing which reads pixel signals of a
first field from the image sensor 72, and generates frame data for
one frame from the read pixel data of the first field, and its previously
read pixel signals of the second field is specifically described.
[0090] First, the control section 80 transfers signal charges of
a first field to the individual cells 721a of the vertical CCD 721
from the photodiodes 720 (refer to waveforms of Vsh at t1 shown
in FIG. 7A and FIG. 8). At this time signal charges showing the
density level of the same channels, specifically, signal charges
showing the density level of G channels, or signal charges showing
the density level of B channels are transferred to all the cells
721a of the vertical CCD 721 in each column from the corresponding
photodiodes 721.
[0091] Next, the control section 80 adds up signal charges for
a plurality of cells of the vertical CCD 721 in each column, in
each cell 722a of the horizontal CCD 722. Specifically, for example,
when signal charges for two cells of the vertical CCD 721 in each
column are added up, the control section 80 makes the vertical CCD
721 transfer signal charges for two cells of the vertical CCD 721
to each cell 722a of the horizontal CCD 722, without driving the
horizontal CCD 722 (refer to waveforms of Vh at t1 to t5 shown in
FIG. 8). Waveforms V1 to V4 at t1 to t3 shown in FIGS. 7B and 7C
and FIG. 8 show vertical driving signals for transferring a signal
charge in the first cell, and Waveforms V1 to V4 at t4 to t5 shown
in FIG. 7D and FIG. 8 show vertical driving signals for transferring
a signal charge in the second cell. As a result, signal charges
for two cells of the vertical CCD 721 in each column are stored
in each cell 722a of the horizontal CCD 722. In addition, signal
charges showing the density level of the same channels are transferred
to the vertical CCD 721 in each column as described above, signal
charges showing the density level of different channels are not
mixed in each cell 722a of the horizontal CCD 722 by the pixel addition.
However, even if signal charges showing the density level of mutually
different channels are mixed in the pixel addition, generation of
a monotone through image is possible. Therefore, signal charges
showing the density level of different channels may be transferred
to the vertical CCD 721 in each column. However, even if signal
charges showing the density level of mutually different channels
are mixed in the pixel addition, for example, a monotone through
image is displayed, signal charges showing the density level of
different channels may be transferred to the vertical CCD 721 in
each column.
[0092] Next, the control section 80 makes the horizontal CCD 722
transfer the signal charges after the pixel addition to the detecting
element 723 (refer to waveforms of Vh at t5 to t6 shown in FIG.
8), and makes the detecting element 723 convert the signal charges
into pixel signals. That is, the horizontal CCD 722 clears off charges
only once whenever charges for two cells of a vertical CCD are stored
in each cell. In the DSC 1, the number of times of transfer of signal
charges of the horizontal CCD 722 can be reduced in this manner,
thereby reducing the number of times of transfer of signal charges
by the vertical CCD 721, which is required for displaying one frame.
Specifically, the number of times of transfer by the vertical CCD
721, which is required for displaying one frame is reduced to one
n-h by n-time pixel addition. As a result, pixel signals required
for displaying one frame can be output at high speed from the image
sensor 72. In addition, when the detecting element 723 is a floating
diffusion amplifier, the control section 80 may transfer signal
charges for a plurality of cells of the vertical CCD 722 to the
detecting element 723, thereby making the detecting element 723
convert signal charges into pixel signals after addition of the
signal charges by the detecting element 723.
[0093] Noise removal by the AFE 74, brightness adjustment, A/D
conversion, etc. are performed on the pixel signals read from the
image sensor 72. Specifically, the brightness adjustment is performed
when the control section 80 controls the gain of the amplifier 742
according to the brightness of a photographic subject. The control
section 80-determines the brightness of a photographic subject,
for example, from a pixel signal read before a pixel signal to be
adjusted. In addition, the adjustment of the brightness of a through
image may be performed by setting a multiple for pixel addition
in every field or in every frame according to the brightness of
a photographic subject, with the exposure period being kept constant.
When the above-described adjustment of the brightness by the amplifier
724 and the above-described adjustment of the brightness by the
pixel addition are utilized together, pixel signals subjected to
the pixel addition show that a photographic subject is brighter
than the actual brightness of the photographic subject. Therefore,
determination of the brightness of a photographic subject based
on pixel signals requires consideration of a multiple for pixel
addition.
[0094] Next, the control section 80 stores pixel data output from
the AFE 74 in the RAM 100 in cooperation with the image processing
controller 98. It is noted herein that the vertical resolution of
a frame represented by the pixel data output from the AFE 74 is
reduced in the vertical direction by addition of signal charges
Therefore, the control section 80 thins out pixels of the image
data in the horizontal direction or adds up pixel values, which
are continuous in the horizontal direction, according to the number
of addition of the signal charges in the vertical direction, thereby
reducing the vertical resolution of a frame represented by the pixel
data output from the AFE 74. As a result, distortion of a frame
represented by the pixel data output from the AFE 74 is corrected,
and the resolution of the frame is reduced. By reducing the amount
of information of the pixel data as such, the amount of processing
to be performed on the image data afterwards can be reduced.
[0095] Next, the control section 80 generates frame data for one
frame from previously read pixel data of a second field and currently
read pixel data (refer to FIG. 9) in cooperation with the color
processing part 102. Then, the control section 80 makes a frame
represented by the frame data, which has been converted into frame
data with a resolution corresponding to the screen size of the LCD
36, displayed on the LCD 16 in cooperation with the resolution converting
part 104, the image processing controller 98 and the graphic controller
94. Meanwhile, the currently read pixel data is used for generation
of the next frame data, along with pixel data to be read next time,
as shown in FIG. 9. That is, in the DSC 1, a through image is displayed
on the LCD 36 while the pixel data read from the image sensor 72
is used for generation of frame data for two continuous frames.
In addition, generation of the pixel data of the field and generation
of the frame data are performed in the same period.
[0096] By using the pixel data read from the image sensor 72 for
the generation of frame data for two continuous frames, the frame
rate can be increased as compared with a case (refer to FIG. 10
in which the pixel data is used for generation of frame data for
one frame. In addition, when the image sensor 72 is an image sensor
which reads pixel signals of one frame which is divided into a plurality
of (three or more) fields, the pixel data read from the image sensor
72 may be used for generation of frame data for a plurality of continuous
frames according to the number of the divided fields. Further, the
DSC 1 may be controlled so as to be able to be switched between
a frame generating mode shown in FIG. 9 and a frame generating mode
shown in FIG. 10.
[0097] Furthermore, the DSC 1 may read the first field and the
second field alternately, and generate one frame of a monotone through
image from image signals for one field whenever it reads one field.
The frame of a monotone through image as a monotone moving image
can be generated on the basis of signal charges showing the density
level of some channels among all the channels. For example, the
frame of a monotone through image can be generated on the basis
of signal charges showing the density level of a G channel of RGB
channels. Therefore, the frame of a continuous monotone through
image can be generated from image signals of a first field and image
signals of a second field, which are continuous, on the basis of
image signals of G channels commonly included in the first field
and the second field. Here, the image signals of G channels means
image signals correlated to the signal charges showing the density
level of the G channels. As a result, since the number of times
of reading of fields required for generating one frame can be reduced,
even if a structure for a high-speed draft mode is not provided,
the frame rate of a through image can be increased. In addition,
the DSC 1 may read either a first field or a second field continuously,
and may not need to read the other field at all during display of
a monotone through image. In this case, the DSC 1 generates one
frame of a monotone through image from image signals for one field
whenever it reads either the first field or the second field.
[0098] FIG. 11 is a flowchart showing the through image display
processing which displays a monotone through image.
[0099] First, the control section 80 reads pixel signals of a first
field (refer to Step S200). If pixel signals of a first field have
been read, the control section 80 executes the processing of Step
S202.
[0100] In Step S202, the control section 80 generates monotone
frame data on the basis of only pixel data of G channels of a first
field. Specifically, for example, the control section 80 generates
monotone frame data for one field on the basis of only read pixel
data of G channels in cooperation with the color processing part
102. Since the frame data is generated on the basis of only pixel
signals of a first field, the number of times of field reading required
for generating frame data for one field can be reduced as compared
with a case in which the frame data is generated on the basis of
pixel signals of a plurality of fields. Further, since the frame
data is generated on the basis of only the pixel data of G channels,
the processing amount of the pixel data required for generating
the frame data for one field can be reduced as compared with a case
in which the frame data is generated on the basis of the pixel data
of G channels and pixel data of B channels. As a result, the frame
rate of a through image can be increased. In addition, the monotone
frame data may be generated on the basis of the pixel data of G
channels of a first field and pixel data of B channels of a first
field.
[0101] In Step S204, the control section 80 displays a monotone
image for one field on the LCD 36 on the basis of the frame data.
Specifically, for example, the control section 80 displays a frame
represented by the frame data converted to have a resolution corresponding
to the screen size of the LCD 36, in cooperation with the resolution
converting part 104, the image processing controller 98 and the
graphic controller 94.
[0102] In Step S206, the control section 80 reads pixel signals
of a second field similarly to the processing of Step S200.
[0103] In Step S208, the control section 80 generates frame data
on the basis of the read pixel signals of G channels of the second
field, similarly to the processing of Step S202.
[0104] In Step S210, the control section 80 displays on the LCD
360 the monotone frame generated on the basis of the pixel signals
of G channels of the second field, similarly to the processing of
Step S204.
[0105] By repeating the above-described processing of Step S200
to Step S210, the control section 80 displays a predetermined number
of continuous frames of a monotone through image on the LCD 36.
[0106] In addition, generation of the pixel data of the field and
generation of the frame data are performed in the same period.
[0107] Further, the DSC 1 may display continuous monotone frames
on the LCD 36 on the basis of pixel signals of G channels of a first
field, which have been read continuously by repeating the processing
of Step S200 to Step S204. Besides, the DSC 1 may display continuous
monotone frames on the LCD 36 on the basis of pixel signals of G
channels of a second field, which have been read continuously by
repeating the processing of Step S206 to Step S210. By reading pixel
signals of either the first field or the second field, a time difference
in exposure period between continuous fields can be shortened, and
signal charges can be read from the same photodiode 721 between
the continuous fields. As a result, a high-definition, clear through
image can be displayed on the LCD 36 as compared with a through
image based on the pixel signals of both of first and second fields.
[0108] (Second Embodiment)
[0109] FIG. 12 is a schematic view of a DSC 300 according to a
second embodiment.
[0110] The DSC 300 is a so-called single lens reflex DSC including
a main mirrr 302 and a sub-mirror 304. A central portion of the
main mirror 302 is composed of a half mirror. The sub-mirror 304
is disposed in the vicinity of the center of the main mirror 302
to reflect the light transmitted through the half mirror. Hereinafter,
the central portion of the main mirror 302 is referred to as a half
mirror part. The DSC 300 includes the substantially same components
as those of the DSC 1 according to the first embodiment shown in
FIG. 3.
[0111] When the main mirror 302 and the sub-mirror 304 takes a
posture indicated by a dotted line in shown FIG. 12 (hereinafter
referred to as "mirror-down state"), the light from a
photographic subject which has been transmitted through lenses 60
and 64 and incident on a portion other than the mirror half part
of the main mirror 302 is reflected by the main mirror 302. On the
other hand, the light which has been transmitted through the lenses
60 and 64 and incident on the half mirror part of the main mirror
302 is split into light which is reflected by the surface of the
main mirror and light which is transmitted through the half mirror
part. The beam reflected by the main mirror 302 is guided to an
eyepiece lens by a pentaprism (not shown) which is disposed above
the camera. In contrast, the light from a photographic subject which
has been transmitted through the half mirror part of the main mirror
302 is guided from the main mirror 302 to an AF sensor module (not
shown), which is disposed below the camera, by a portion of the
sub-mirror 304 located on the side of the image sensor 72.
[0112] When the image sensor 302 takes a posture indicated by a
solid line in FIG. 12 (hereinafter referred to as "mirror-up
state"), the sub-mirror 304 is folded until it takes a posture
parallel to the main mirror 302 so as to approach the main mirror
302. In the mirror-up state, the light from a photographic subject
is guided in the direction of the shutter curtains 30 and 32, and
incident on the image sensor 72 when the shutter is opened.
[0113] FIG. 13 is a flowchart showing the flow of processing in
a photographing mode of the DSC 300. The processing shown in FIG.
13 is started when the DSC 300 transits to the photographing mode
and is repeated until the USC 300 transits from the photographing
mode to any mode other than the photographing mode.
[0114] First, the control section 80 determines whether or not
a preview button is pushed (refer to Step S300). Here, the preview
button is an actuator which allows selection of either a mode in
which a subject is photographed while being checked with a through
image as a moving image being displayed on the LCD 36 or a mode
in which a subject is photographed while being checked with an optical
finder.
[0115] When the preview button is pushed, the control section 80
controls the main mirror 302 and the sub-mirror 304 so that they
may take the mirror-up state (refer to Step S302). Then, the control
section 80 executes the substantially same processing as that in
Step S100 and S118. As a result, a photographer can photograph a
subject while checking it with a through image as a moving image
displayed on the LCD 36.
[0116] On the other hand, when the preview button is not pushed,
the control section 80 controls the main mirror 302 and the sub-mirror
304 so that they may take the mirror-down state (refer to Step S304).
Then, since the light from a photographic subject is guided to an
eyepiece lens as described above, a photographer can check the photographic
subject with an optical finder. Then, the control section 80 executes
processing in Step S104. |