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Digital Camera Patent Abstract
A digital camera with a housing has a digital image device (ICD)
that preferably has a special shape and a flat light sensing surface.
A lens directs light to the light sensing surface and electronics
are connected to the ICD for capturing image data. A memory stores
the image data. An inclinometer in the housing detects an inclination
angle of the housing and is used to correct for various distortions
or otherwise modify the image data. The aspect ratio of the digital
image can also be selected. The ICD is mounted on a yoke for pivoting
about at least one axis passing through the ICD plane to correct
focus by following the Scheimpflug Rule and/or by collecting focus
and distance information for multiple points to create a focus point
landscape used, for example, to tilt the ICD to the best focus solution
for the image.
Digital Camera Patent Claims
1. A digital camera comprising: a housing; an image capture device
in the housing, the image capture device having a selected shape
with a flat light sensing surface laying in an image capture plane
of the image capture device, the selected shape being one of: circular,
oval, polygon with at least about eight sides and cross-shaped,
so that the light sensing surface covers more area than that of
a modified digital image to be created using the image capture device;
a lens having a lens plane and being connected to the housing for
directing light from an actual image plane outside the housing,
onto the light sensing surface; electronic means connected to the
image capture device for capturing image data from the image capture
device corresponding to the light from the actual image to create
a high resolution image file; memory means connected to the electronic
means for storing the high resolution image file; and image modification
means connected to the memory for modifying the high resolution
image file to create the modified digital image.
2. A digital camera according to claim 1, wherein the selected
shape is circular.
3. A digital camera according to claim 1, wherein the selected
shape is cross-shaped.
4. A digital camera according to claim 1, wherein the selected
shape is oval.
5. A digital camera according to claim 1, wherein the selected
shape is polygonal with at least about eight sides.
6. A digital camera according to claim 1, including an inclinometer
in the housing for detecting an inclination angle of the housing
about at least one horizontal axis, the inclinometer being connected
to the image modification means for correcting at least one feature
of the high resolution image file for creating the modified digital
image.
7. A digital camera according to claim 1, including an inclinometer
in the housing for detecting at least a roll inclination angle of
the housing about a horizontal axis extending through the image
capture device and the lens, the inclinometer being connected to
the image modification means for correcting the high resolution
image file for roll of the housing to create the modified digital
image.
8. A digital camera according to claim 1, including yoke means
in the housing for mounting the image capture device for pivoting
about at least one axis passing through the image capture plane,
with respect to the housing.
9. A digital camera according to claim 1, wherein the image modification
means comprises aspect ratio control means connected to the memory
means for modifying the high resolution image file to create the
modified digital image to cover only a selected reduced area of
the light sensing surface having one of a plurality of aspect ratios
and for masking a remaining area of the light sensing surface.
10. A digital camera according to claim 1, including a viewfinder
connected to the electronic means and to the image modification
means for displaying digital images corresponding to modified and
unmodified versions of the high resolution image file.
11. A digital camera according to claim 1, including at least one
of a pitch and roll yoke in the housing for mounting the image capture
device and focus plane control means for controlling at least one
of the pitch and roll of the image capture device with respect to
the housing and the actual image plane to correct the modified digital
image for focus.
12. A digital camera according to claim 1, including at least one
of pitch and roll yoke in the housing for mounting the image capture
device, the image modification means comprising digital convergence
correction means connected to the electronic means for correcting
the digital image for convergences based on at least one of a pitch
and a roll of the image capture device with respect to the housing.
13. A digital camera according to claim 1, including distance sensing
means connected to the electronic means for determining a distance
between the lens and a selected point on the actual image plane.
14. A digital camera according to claim 1, including a distance
sensing means connected to the electronic means for creating focus
readings, and yoke means in the housing for mounting the image capture
device for pivoting about at least one axis passing through the
image capture plane with respect to the housing, the image modification
means operating the yoke means to pivot the image capture device
to a plurality of positions corresponding to a plurality of focus
points in the actual image plane and to take a focus reading at
each focus point to create a focus point landscape and, using the
landscape to pivot the image capture device to a position corresponding
to an optimum focus for the actual image plane.
15. A digital camera comprising: a housing; an image capture device
in the housing, the image capture device having a flat light sensing
surface laying in an image capture device plane which is shaped
to encompass a plurality of different aspect ratios; a lens connected
to the housing for directing light from an actual image plane outside
the housing, onto the light sensing surface of the image capture
device; electronic means connected to the image capture device for
capturing image data from the image capture device corresponding
to the light from the actual image to create a digital image; and
memory means connected to the electronic means for storing the image
data.
16. A digital camera according to claim 15, including an inclinometer
in the housing for detecting an inclination angle of the housing
about at least one horizontal axis.
17. A digital camera according to claim 15, including an inclinometer
in the housing for detecting at least a roll inclination angle of
the housing about a horizontal axis extending through the image
capture device and the lens.
18. A digital camera according to claim 15, including yoke means
in the housing for mounting the image capture device for pivoting
about at least one axis passing through the image capture plane.
19. A digital camera according to claim 15, including aspect ratio
control means connected to the memory means for modifying the image
data to create a modified digital image to cover only a selected
reduced area of the light sensing surface having one of a plurality
of aspect ratios and for masking a remaining area of the light sensing
surface.
20. A digital camera according to claim 15, including a viewfinder
connected to the electronic means and means for displaying digital
images corresponding to modified and unmodified versions of the
image data.
21. A digital camera according to claim 15, including at least
one of a pitch and roll yoke in the housing for mounting the image
capture device and focus plane control means for controlling at
least one of the pitch and roll of the image capture device with
respect to the housing and the actual image plane to correct a position
of the image capture device for focusing of the actual image plane.
22. A digital camera according to claim 15, including at least
one of pitch and roll yoke in the housing for mounting the image
capture device, image modification means comprising digital convergence
correction means connected to the electronic means for correcting
the image data for convergences based on at least one of a pitch
and a roll of the image capture device with respect to the housing.
23. A digital camera according to claim 15, including distance
sensing means connected to the electronic means for determining
a distance between the lens and a selected point on the actual image
plane.
24. A digital camera according to claim 15, including distance
sensing means connected to the electronic means for creating focus
readings, and yoke means in the housing for mounting the image capture
device for pivoting about at least one axis passing through the
image capture plane with respect to the housing, and image modification
means operating the yoke means to pivot the image capture device
to a plurality of positions corresponding to a plurality of focus
points in the actual image plane and to take a focus reading at
each focus point to create a focus point landscape and, using the
landscape to pivot the image capture device to a position corresponding
to an optimum focus for the actual image plane.
25. A digital camera comprising: a housing; an image capture device
in the housing, the image capture device having a flat light sensing
surface laying in an image capture device plane; a lens at a lens
plane and connected to the housing for directing light from an actual
image plane outside the housing, onto the light sensing surface
of the image capture device; electronic means connected to the image
capture device for capturing image data from the image capture device
corresponding to the light from the actual image to create a digital
image; memory means connected to the electronic means for storing
the image data; yoke means in the housing for mounting the image
capture device for pivoting about at least one axis passing through
the image capture plane; and drive means connected to the yoke means
for pivoting the image capture device with respect to the lens plane
and the actual image plane so that the actual image plane, the image
capture device plane and the actual image plane intersect along
a line.
26. A digital camera according to claim 25, including image modification
means connected to the memory for modifying the image data to create
a modified digital image which compensates for perspective distortion
of the actual image as viewed through the lens.
27. A digital camera according to claim 25, including an inclinometer
in the housing for detecting an inclination angle of the housing
about at least one horizontal axis.
28. A digital camera according to claim 25, including aspect ratio
control means connected to the memory means for modifying the image
data to create a modified digital image to cover only a selected
reduced area of the light sensing surface having one of a plurality
of aspect ratios and for masking a remaining area of the light sensing
surface.
29. A digital camera according to claim 25, including a viewfinder
connected to the electronic means and means for displaying digital
images corresponding to modified and unmodified versions of the
image data.
30. A digital camera according to claim 25, including at least
one of a pitch and roll yoke in the housing for mounting the image
capture device and focus plane control means for controlling at
least one of the pitch and roll of the image capture device with
respect to the housing and the actual image plane to correct a position
of the image capture device for focusing of the actual image plane.
31. A digital camera according to claim 25, wherein the light sensing
surface of the image capture device is circular.
32. A digital camera according to claim 25, wherein the light sensing
surface of the image capture device is cross-shaped.
33. A digital camera according to claim 25, wherein the light sensing
surface of the image capture device is oval.
34. A digital camera according to claim 25, wherein the light sensing
surface of the image capture device is polygonal with at least eight
sides.
35. A digital camera comprising: a housing; a rectangular image
capture device in the housing, the image capture device having a
flat light sensing surface laying in an image capture device plane;
a lens at a lens plane and connected to the housing for directing
light from an actual image plane outside the housing, onto the light
sensing surface of the image capture device; electronic means connected
to the image capture device for capturing image data from the image
capture device corresponding to the light from the actual image
to create a digital image; memory means connected to the electronic
means for storing the image data; aspect ratio selection means for
mounting the image capture device to the housing for rotating the
image capture device within its plane and to at least two different
positions corresponding to two different aspect ratios; and drive
means connected to the aspect ratio selection means for rotating
the image capture device to the at least two different positions
corresponding to the two different aspect ratios.
36. A digital camera according to claim 35, including image modification
means connected to the memory for modifying the image data to create
a modified digital image which compensates for perspective distortion
of the actual image as viewed through the lens.
37. A digital camera according to claim 35, including an inclinometer
in the housing for detecting an inclination angle of the housing
about at least one horizontal axis.
38. A digital camera according to claim 35, wherein the aspect
ratio selection means and drive means rotate the image capture device
by up to 90 degrees in the housing.
39. A digital camera according to claim 35, including a viewfinder
connected to the electronic means and means for displaying digital
images corresponding to modified and unmodified versions of the
image data.
40. A digital camera according to claim 35, including at least
one of a pitch and roll yoke in the housing for mounting the image
capture device and focus plane control means for controlling at
least one of the pitch and roll of the image capture device with
respect to the housing and the actual image plane to correct a position
of the image capture device for focusing of the actual image plane.
Digital Camera Patent Description
FIELD AND BACKGROUND OF THE INVENTION
[0001] The present invention relates generally to the field of
digital photography, and, in particular, to various new, useful
and interrelated improvements for digital cameras.
[0002] The most pertinent patents found during the course of a
search conducted in US patent class 348, subclasses 208.2, 208.3,
208.12, 219.1, 222.1, 231.3, 231.6, 239, 275, 311, 315, 340, 345,
351 and 374, were: TABLE-US-00001 U.S. Pat. No. Inventor(s) 4,467,361
Ohno, et al. 4,480,257 Hill 4,866,850 Kelly, et al. 4,988,200 Cohen-Sabban
5,453,784 Krishnan, et al. 5,752,088 Desselle 5,813,333 Ohno 5,897,223
Tritchew, et al. 5,900,909 Parulski, et al. 5,969,760 Ernest, et
al. 6,072,529 Mutze 6,083,353 Iexander 6,201,574 Martin 6,237,235
Feist, et al. 6,304,284 Dunton, et al. 6,310,642 Adair et al. 6,351,720
Hoshina, et al. 6,366,323 Shono 6,406,941 Nakamura 6,466,275 Honey,
et al. 6,537,208 Konno 6,538,691 Macy, et al. 6,574,561 Alexander
6,603,503 Ribera et al. 6,618,093 Levy 6,659,940 Adler 6,665,016
Saitoh 6,670,986 Shoshan, et al. 6,686,954 Kitaguchi, et al. 6,727,954
Okada et al. 6,734,914 Nishimura et al. 6,772,632 Okada and 6,781,622
Sato et al.
[0003] Relevant published US patent applications classified in
the same classes and subclasses were: U.S. patent Publication 2004/0017506
A1 to Livingston disclosing an orientation sensor for a digital
camera comprising gravity sensitive switches such as mercury-filled
switches and a pair of contacts; and U.S. patent Publication 2003/0063200
A1 to Isoyama disclosing an inclination sensor, wherein the detected
inclination is saved to a memory card. During photographing, JPEG
data corresponding to the object image is recorded onto a memory
card in a file format. At that time, the detection result information
indicative of the detection result of the inclination sensor is
read and stored on the same image file.
[0004] Relevant patents may also include patents assigned to photographic
equipment companies such as Sinar, Hasselblad, Leica, Rollei, Mamiya,
Contax, Canon, and Nikon.
[0005] An assignee search for patents issued to these companies
uncovered U.S. Pat. No. 6,734,914 to Nishimura et al. (assigned
to Canon Kabushiki Kaisha).
[0006] U.S. Pat. No. 6,727,954 to Okada et al. (Okada '954) discloses
a rotating image pickup element. The image pickup element comprises
a capsule-shaped unit main body in which opposite ends of a cylinder
are covered by semispherical surfaces. A round window exposes a
taking lens inside the unit main body on a center axis, and an image
pickup device having a CCD arranged behind the taking lens. A U-shaped
support frame pivotally supports the unit main body along a vertical
direction and an L-shaped support frame pivotally supports the unit
main body along a horizontal direction. A driving member rotates
the main body up, down, left and right. Position detecting members
are also provided for detecting the rotational position of the unit
main body in the vertical and horizontal planes. The position detecting
members comprise a magnetic head, an arcuate magnetic scale and
a position detecting circuit.
[0007] Although Okada '954 discloses a rotating unit main body
containing a CCD, a driving member for rotating the unit main body,
and position detecting magnetic and circuit means, it fails to teach
a round CCD mounted in a dual axis yoke and an inclinometer.
[0008] U.S. Pat. No. 6,072,529 to Mutze discloses an electronic
camera comprising an image sensor secured in a holding device mounted
on supports for axial, horizontal and vertical displacements to
fulfill the Scheimpflug condition. Movement of the image sensor
is produced electromechanically.
[0009] This patent, however, only discloses a rectangular CCD and
fails to teach or suggest a round CCD or an inclinometer.
[0010] U.S. Pat. No. 6,686,954 to Kitaguchi et al. discloses a
digital camera deviation correction apparatus comprising a rotation
detection unit which detects the quantity of rotation of the digital
camera and a CCD. The rotation detecting device may be a set of
acceleration sensors and magnetic sensors, or alternatively, gyros.
A position angle calculating unit calculates a change of a positional
angle of the CCD based on the rotation quantity detected by the
rotation detecting unit. A drive control circuit drives a displacement
transmitting element for moving the CCD to correct deviation as
a result of rotation of the camera and CCD. The CCD can be rotated
about the x and y axis via an L-shaped support and a motor.
[0011] U.S. Pat. No. 5,453,784 to Krishnan discloses an imaging
apparatus comprising an imaging array such as a CCD array mounted
on a rotation platform with two rotational degrees of freedom and
pivotally controllable with respect to the optical axis of the lens.
Rotation can be accomplished by a stepper motor.
[0012] U.S. Pat. No. 6,734,914 to Nishimura et al. teaches an image
recording unit for a camera comprising a CCD mounted support means
for rotatably supporting the image recording unit main body. A frictional
driving source drives the image recording unit in arbitrary directions
and comprises electromechanical energy conversion elements which
generate a traveling wave by a supply of different wave signals.
This patent does not teach a motor driven dual axis yoke.
[0013] U.S. Pat. No. 5,969,760 to Ernest, et al. discloses an electronic
still camera comprising mechanically adjustable CCD for affecting
focus. The camera uses a ranging system to determine a distance
to an object. The camera has a micro processor which determines
the proper location of the focal plane based on the measured distance
of the focal plane and signals a motor and an actuation device to
mechanically adjust the location of the sensor with respect to the
lens. Ernest, et al. does not disclose a pivoting CCD.
[0014] U.S. Pat. No. 6,537,208 to Konno similarly discloses a movable
solid state image pickup for an endoscope.
[0015] Round or circular solid state imaging elements (e.g. CCDs)
are disclosed in U.S. Pat. No. 4,988,200 to Cohen-Sabban (see col.
5, lines 1-4), U.S. Pat. No. 4,467,361 to Ohno et al. (see FIG.
4, element 35A), U.S. Pat. No. 4,480,257 to Hill (see col. 1, lines
9-11; FIG. 4), U.S. Pat. No. 5,813,333 to Ohno (Ohno '333) (see
col. 7, line 63), U.S. Pat. No. 6,310,642 to Adair et al. (col.
7, lines 1-4; FIG. 1b, element 40'), U.S. Pat. No. 6,659,940 to
Adler (see its prior art discussion), and U.S. Pat. No. 6,406,941
to Nakamura (see FIG. 7). However, only Ohno '333 and Nakamura '941
disclose a camera having a round solid state imaging element. Furthermore,
none of these patents teach or suggest use of a round solid state
imaging element in combination with a fully operational and self-contained
digital camera, for capturing an image to a high resolution data
file so that various other useful effects and capacities can be
realized, such as a selectable aspect ratio having maximum lens
coverage and unwanted areas removed.
[0016] U.S. Pat. No. 6,201,574 to Martin and U.S. Pat. No. 6,603,503
to Ribera et al. disclose a spherical CCD.
[0017] Inclinometers are known from U.S. Pat. No. 6,574,561 to
Alexander, U.S. Pat. No. 6,466,275 to Honey et al., U.S. Pat. No.
6,351,720 to Hoshina et al., U.S. Pat. No. 6,237,235 to Feist et
al., U.S. Pat. No. 6,083,353 to Alexander, U.S. Pat. No. 5,897,223
to Tritchew et al., and U.S. Pat. No. 4,866,850 to Kelly et al.,
some disclosed for use with cameras in general, or in combination
with digital cameras.
[0018] U.S. Pat. No. 6,772,632 to Okada discloses an acceleration
sensor which can be used as a clinometer in digital cameras.
[0019] Patents were also uncovered which teach devices in which
orientation information is stored or saved. U.S. Pat. No. 6,304,284
to Dunton et al. discloses a camera system for generating panoramic
images in which orientation information is recorded in memory. A
motion sensor or accelerometer is used to detect the orientation.
A processor reconstructs a panoramic image from recorded images
using the recorded orientation information.
[0020] The remaining patents in the above list disclose other digital
camera enhancements which are distinguishable from the present invention
and which have been cited for general reference.
[0021] The inventor here is a professional photographer and has
discovered several deficiencies in currently known digital cameras
which are addresses by the invention disclosed herein.
SUMMARY OF THE INVENTION
[0022] It is an object of the present invention to provide various
improvements for the digital camera. All of the proposed improvements
relate to image control and correction. The invention relies on
various new combinations of proven optical laws and techniques and
new methods for digitally reading and processing camera parameters
and editing digital image outputs. The inventor has found the new
advancements in technology allow for classical image control techniques
to be modified in new ways and used in conjunction with digital
input and image correction methods to produce a desired output not
possible if relying on classical film camera methods alone, and
not currently know or used in digital cameras or digital photography.
[0023] The digital camera according to one embodiment of the invention
comprises a round Image Capture Device (ICD) mounted in a dual axis
yoke for facilitating pivoting of the ICD about its horizontal axis.
The ICD of the present invention, whether round, rectangular or
otherwise shaped, may be a Charge Coupled Devise (CCD) or any one
of a variety of light sensing, usually semiconductor-bases devices
that are capable of being read using digital technology and are
of presently know type, or future construction.
[0024] The yoke pivots within the camera back housing about its
vertical axis. Each axis is independently controlled by a separate
digital motor. The digital camera also comprises a digital inclinometer
which continuously samples the lens angle with respect to the horizontal
axis and then outputs information to an onboard computer or electronic
circuit means or image modifying means, which send a digital signal
to the digital motor for controlling the axis of the dual axis yoke.
[0025] In use, the round ICD captures the image to a high resolution
data file and permits selection of an aspect ratio that includes
maximum lens coverage and/or removal of unwanted areas. The attached
data file also incorporates information on the camera roll angle
measured by the digital inclinometer. Once this data is saved, it
can be corrected digitally. Pivoting the ICD in relation to the
lens plane adjusts the plane of sharp focus. Convergence results
when the ICD plane is adjusted away from a plane parallel to the
lens plane. A pre-defined convergence correction curve as a function
of the lens angle can be used to correct the resulting convergence
from the adjustment of the plane of sharp focus.
[0026] Other new and useful aspects of the invention, however do
not require a round ICD but may use conventional rectangular ICDs
or specially shaped ICDs such as cross-shaped ICDs or oval ICDs
or even polygonal ICDs of at least eight sides which therefore mimic
a circular ICD.
[0027] Accordingly, another object of the present invention is
to provide a digital camera comprising a housing enclosing a volume,
a digital image capture device (ICD) in the housing, the ICD having
a round, circular, oval, polygon (with at least about eight sides)
or cross-shaped and flat light sensing surface laying in an ICD
plane, a lens connected to the housing for directing light from
an actual image plane outside the housing, onto the light sensing
surface of the ICD, electronic means connected to the ICD for capturing
image data from the ICD corresponding to the light from the actual
image to create a digital image and memory means connected to the
electronic means for storing the image data.
[0028] Another object of the invention is to provide a digital
camera with an inclinometer in the housing for detecting an inclination
angle of the housing about at least one horizontal axis, the inclinometer
being connected to the electronic means for use in correcting at
least one aspect of the digital image.
[0029] A still further object of the invention is to provide a
digital camera including aspect ratio control means connected to
the electronic means for processing data from a selected area of
the light sensing surface having one of a plurality of aspect ratios
and for masking a remaining area of the light sensing surface.
[0030] A digital camera is also provided which includes correcting
means for correcting at least one aspect of the digital image connected
to the electronic means and a viewfinder connected to the electronic
means for receiving the digital image in a corrected and in an uncorrected
form so the photographer can see the actual unmodified image or
the image as it would appear after it has been subjected to correction
or modification according to the present invention. The camera may
have at least one of pitch and/or roll gimbal or yoke means in the
housing for mounting the ICD and a mechanical focus plane control
or drive for controlling at least one of the pitch and roll angle
of the ICD with respect to the housing to correct the image plane
for focus (according to the so-called Scheimpflug Rule for example).
[0031] A digital camera of the invention may also include a manual
focus and/or auto-focus means of know design that can be used to
determining a distance between the lens and a selected point or
a matrix of points on the actual image plane.
[0032] A focus point landscape can be created with the ICD divided
into many points and with one focusing scan (that is, the ICD cycled
through its full range of motion once) so all points are focused
at the best position of the ICD. Then the ICD is tilted to the best
angle for the best average focus.
[0033] A further object of the invention is to provide an improved
digital camera with one or more advantages over current digital
cameras and one which is simple in design and rugged in construction.
[0034] The various features of novelty which characterize the invention
are pointed out with particularity in the claims annexed to and
forming a part of this disclosure. For a better understanding of
the invention, its operating advantages and specific objects attained
by its uses, reference is made to the accompanying drawings and
descriptive matter in which a preferred embodiment of the invention
is illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] In the drawings:
[0036] FIG. 1 is a vertical elevation of a round or circular Image
Capture Device (ICD) according to one aspect of the present invention,
illustrating the full lens coverage possible with various standard
aspect ratios created by masking unwanted areas superimposed on
the ICD;
[0037] FIG. 2 is a composite illustrating certain advantages of
the present invention;
[0038] FIG. 3 is a composite illustrating how the present invention
is capable of switching between vertical (image E) and horizontal
(image F) panoramic aspect ratios without physically turning the
camera body;
[0039] FIG. 4 is a user defined correction curve plotting the angle
between the lens plane and vertical in degrees, against a convergence
correction factor in percent and showing how the convergence correction
can be a function of lens angle predefined by the photographer;
[0040] FIG. 5 is a composite illustrating the dynamics between
Plane of Sharp Focus (PSF), the Building Face (BF) of an image and
digital convergence correction;
[0041] FIG. 6 is a diagram illustrating the so-called Scheimpflug
Rule of photography;
[0042] FIG. 7 is a perspective view with underlying areas visible,
of a digital camera of the present invention;
[0043] FIG. 8 is a composite of four side elevational views of
the digital camera of FIG. 7, showing various positions of the ICD
thereof;
[0044] FIG. 9 is a perspective view similar to FIG. 7 of a further
embodiment of the invention; and
[0045] FIG. 10 is a composite view similar to FIG. 8 of the embodiment
of FIG. 9.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0046] In order to simplify this disclosure, the following definitions
are used but may be given broader meaning as would be understood
by those skilled in the art of photography in general, and digital
photography specifically, if any of these terms are used in the
claims: [0047] Convergence: Image distortion, usually seen as converging
of parallel lines, created by not having the film plane (ICD plane)
parallel to the plane of the subject of focus (the actual image
plane). [0048] Data File: A file attached to or part of the High
Resolution Image File that contains information about specific camera
settings and parameters at the time the picture was taken. [0049]
Digital Motor: An extremely accurate positioning motor connected
to one of the axis on the Dual Axis Yoke. Its function is to rotate
the Image Capture Device or ICD to a precise angle. [0050] Dual
Axis Yoke: A fixture that supports the ICD and allows the ICD plane
to be rotated about the vertically and horizontal (or any other)
axis independently. The design is such that the distance between
a point on the lens plane at the center of the lens and a point
on the ICD plane at the center of the ICD will remain constant independent
of a change in ICD angle.
[0051] High Resolution [0052] Image File: The image file captured
by the ICD when the camera shutter is released. A round ICD will
produce a round image. This is ideal for all digital correction
processes of the present invention because all information captured
by the lens is retained.
[0053] Image Capture [0054] Device Plane: The light sensing surface
or plane where the lens image is recorded. Currently, most digital
cameras use a Charge Coupling Device (CCD) to record the image.
In traditional film cameras the film was mounted to this plane.
[0055] Lens Coverage: Size of the total image circle projected by
the lens. [0056] Pitch Inclinometer: An instrument used to measure
and record the camera pitch angle. Output from this instrument is
used to adjust the ICD plane angle when setting the Plane of Sharp
Focus
[0057] Plane of Sharp Focus [0058] (Focus Plane or PSF): A plane
in space, such as the actual image plane to be recorded. When viewed
through the lens, everything that falls on this plane will be in
focus. This plane can be moved toward and away from the lens by
focusing the camera (changing the distance between the lens and
film or ICD planes). The angle of the plane can be changed by tilting
the camera angle, lens angle or film plane angle. The position and
orientation of this plane is given by the Scheimpflug rule (see
The Camera by Ansel Adams). [0059] Roll Inclinometer: An instrument
used to measure and record the camera roll angle. Output from this
instrument is used to correct the Viewfinder Image in real time.
It is also saved in the Data File and used to correct camera roll
on the High Resolution Image File. [0060] Viewfinder Image: A low
resolution image that is output to a display. This image is used
by the photographer to view composition and adjust focus before
taking a picture. [0061] Vignetting: This occurs when the lens of
a view camera is swung, tilted, or slid and part of the film falls
outside of the lens coverage and does not get exposed (see the Ansel
Adams reference).
[0062] Referring now to the drawings, in which like reference numerals
are used to refer to the same or similar elements, FIG. 7 illustrates
the improved digital camera 10 of the present invention which will
now be described in greater detail after these additional consideration.
[0063] General Design Guidelines:
[0064] 1) Traditional guidelines of view camera photography state
that convergence control (the control of perspective and image distortion)
is accomplished by tilting the film plane while controlling of the
Focus Plane (PSF) is accomplished by tilting the lens plane. Tilting
the lens plane does not affect convergence but it does affect focus
settings and can cause vignetting. Therefore, the traditional method
for attaining the desired amount of convergence control, Focus Plane
angle, and proper focusing range is a time consuming process requiring
tilts at the lens and film plane along with a fundamental understanding
of the Sheimpflug Rule (again see the Ansel Adams reference).
[0065] New technologies for camera position sensing and digital
image processing used in the following design allow for all convergence
corrections to be performed digitally. Current technology allows
image distortion to be corrected digitally therefore all adjustments
to the Focus Plane can be made solely by tilting the Image Capture
Device (ICD) Plane (which replaces the film plane in digital cameras).
By keeping the lens plane fixed, the camera design remains simpler,
vignetting is not an issue and camera focus remains independent
of the ICD Plane angle. The convergence caused by tilting the ICD
is then corrected digitally after the picture has been taken. The
camera sensors used in the following design makes it possible for
correction parameters to be recorded with the image file and used
to correct optical convergence automatically.
[0066] 2) All rotational, convergence and perspective corrections
and image cropping are performed digitally by applying correction
parameters to a High Resolution Image File. The correction parameters
can be saved within the High Resolution Image File or in a corresponding
Data File.
[0067] 3) A digital viewfinder shown at 28 in FIG. 7, is used to
preview the photograph. The viewfinder displays a low resolution
image in one of two modes: uncorrected or corrected. In Uncorrected
Mode, the image is displayed exactly as if it were viewed directly
through the lens, e.g. quadrant G in FIG. 5. In Corrected Mode the
image is displayed as a preview of what the High Resolution Image
File will look like after all correction parameters have been applied,
e.g. quadrant J in FIG. 5.
[0068] Inventions/Improvements:
[0069] Round Image Capture Device (ICD)
[0070] A round ICD shown at 12 in FIGS. 7 and 8, is preferably
used to capture the full Lens Coverage to a High Resolution Image
File. Image aspect ratio is applied to the file by digitally masking
out unwanted areas which will be more fully explained in connection
with FIG. 2. Other ICD shapes can also be used with the aspect ratio
selection feature of the present invention.
[0071] 1) A round ICD is used to record the full lens coverage.
The High Resolution Image File is created using the full lens coverage.
An attached data file includes information on the aspect ratio selection
for that image. This full coverage image can be captured using known
digital camera circuits 30 in FIG. 7 which are electronically connected
to ICD 12, and is stored as the High Resolution Image File in a
memory section 32 of the circuit. According to the invention, the
high resolution image file is modified in various unique ways using
image modifying circuits or means 31 connected to the circuits 30
and memory 32.
[0072] 2) All standard vertical and horizontal aspect ratios are
possible by masking the circular High Resolution Image File. In
this way, any aspect ratio selected will include the maximum amount
of lens coverage (see FIG. 1 for some of the standard aspect ratios
which might be selected). An aspect ratio selector 34 and appropriate
software, firmware or hardware in circuits 30 are provided for this
purpose.
[0073] 3) The digital viewfinder 28 displays the desired composition
in the user-selected aspect ratio.
[0074] 4) Since image formats are selected digitally, there is
never a need to rotate the camera body 24. Also, it is possible
to select a different aspect ratio after the picture has been taken
without losing any lens coverage as will be explained in connection
with FIG. 3.
[0075] 5) Circular image capture allows for rotational correction
without the problem of unwanted "corner cropping" (see
FIG. 2). Unwanted areas of the round image file are permanently
removed after all image corrections have been made to save storage
size for the final digital image file.
[0076] Digital Camera Roll Correction:
[0077] A Digital Inclinometer 26 in FIG. 7, is used to detect the
amount of camera roll about the horizontal axis passing through
the center of lens 20 and ICD 12, when an image is taken. Digital
correction is then applied to the High Resolution Image File.
[0078] 1) Digital Roll Inclinometer 26 (e.g. an AccuStar.RTM. II/DAS
20, Dual Axis Clinometer and FIG. 7) continuously samples camera
roll.
[0079] 2) Rotational image correction is applied to the digital
viewfinder image in real time. In Corrected Mode the viewfinder
image always appears level regardless of camera roll. The viewfinder
28 shows an exact preview of how the High Resolution Image File
will appear after correction.
[0080] 3) The High Resolution Image File is captured with the round
ICD using the full lens coverage. An attached or separate but associated
Data File includes information on the camera roll angle at the time
the picture was taken. Digital image rotation is used to correct
the High Resolution Image File (FIG. 2). The amount of rotational
correction is given by the roll inclinometer reading stored in the
corresponding Data File in memory 32.
[0081] Mechanical Focus Plane Control with Digital Convergence:
Correction
[0082] It is possible to adjust the Plane of Sharp Focus by tilting
the ICD plane in relation to the lens plane. This adjustment causes
convergence of parallel lines which can be corrected digitally.
[0083] 1) The photographer selects whether the Plane of Sharp Focus
will remain vertical, or, in rare cases such as for aerial photography,
horizontal. Another possibility within the present invention is
to provide the camera with a view screen that is pressure sensitive
and to allow the photographer to manually select three desired points
on the image displayed on the view screen. The ICD is then moved
through a focus cycle and the three selected points are used to
determine the final best tilt angle for the ICD.
[0084] 2) Adjusting the angle of the Plane of Sharp Focus is accomplished
by digitally controlling the ICD plane angle using horizontal and/or
vertical motors 16, 18 to drive a yoke. The ICD 12 is mounted in
a Dual Axis Yoke 14 which carry motors 16, 18. It is noted that
the term yoke or gimbal as used here is meant to include a mounting
mechanism that can pivot the ICD or its holder about at least one
axis that is generally transverse to the axis passing through the
centers of the ICD and the camera lens. This transverse axis may
be vertical or horizontal or may be at 45 degrees or at any other
angle to the vertical or horizontal. The only requirement is that
the ICD can be pivoted, rotated or tilted with respect to the digital
camera body as will become clearer in the following. In the preferred
embodiment illustrated here, the ICD pivots in the yoke about its
horizontal axis via motor 16. The yoke pivots within the camera
back housing about its vertical axis via motor 18 (FIG. 7). Each
axis is independently controlled by a digital motor controller in
circuits 30. One motor rotates the plane about the vertical axis.
The other motor rotates the plane about the horizontal axis (see
FIG. 8 for example of the resulting motion).
[0085] 3) The lens angle from horizontal can be calculated automatically
by a Pitch Inclinometer which is also in inclinometer 26. The inclinometer
outputs information to an onboard computer in circuits 30, which
sends a signal to the Digital Motor that controls the horizontal
axis of the Dual Axis Yoke to rotate the ICD plane in relation to
the lens plane (FIG. 7). The angle between these planes defines
the Plane of Sharp Focus and can be calculated using a formula which
will be explained in connection with FIG. 6. The angle of the Plane
of Sharp Focus is governed by the Sheimpflug Rule (see the Ansel
Adams reference).
[0086] 4) Optionally, distance sensing means such as the know through-the-lens
auto-focus method is used to determine the distance between the
camera lens and multiple points in the frame or actual image plane
being viewed. This data is then processed by the onboard computer
to determine the best ICD plane angle for keeping all objects in
focus. Such auto-focus method involves selecting two adjacent groups
of pixels on the ICD and moving the lens through one or more focus
cycles. When maximum contrast between the two pixel groups is detected,
the lens position is assumed to be at the point of best focus since
at the point the sharpest focus would result in the maximum contrast.
Since the distance between the ICD and the lens is known, and the
focal length of the lens is know, a simple calculation performed
in the circuits of the camera will give the distance to the actual
image.
[0087] By testing multiple points across the actual image plane
being viewed, in a rectilinear matrix for example, a Focus Landscape
can be created that identifies and stores the focus distance for
each point in memory 32. This focus landscape can be used for various
purposes, such as calculating the best tilt and roll angle for the
ICD 12 using yoke 14 and motors 16, 18 for best or average focus
of the frame. An auto-average function can be stored in the circuits
30 for achieving this best positioning for ICD 12.
[0088] 5) When the lens plane and ICD plane are moved from parallel,
optical convergence is introduced. Parallel lines appear to converge.
The photographer can select the amount of convergence correction
desired. One such method is to predefine a convergence correction
curve as a function of lens angle (see FIGS. 4 and 5). The camera
will then, in real time, digitally correct for convergence in the
View Finder Image. When the picture is taken, a Convergence Correction
Factor is saved in the Data File and then applied to the High Resolution
Image File.
[0089] FIG. 1 shows, in a vertical elevational view, a circular
Image Capture Device or ICD of the present invention with a number
of aspect ratios that are possible according to the present invention,
including but not limited to the standard aspect ratios of: 1:2--Panoramic
Vertical; 4:5--Large Format; 1:1--Square; 2:3--35 mm and 4:1--Panoramic
Horizontal. In this regard it is noted that statistically the best
aspect ratio for a horizontal image is 2:3 or the hardware aspect
ratio for 35 mm cameras which are ergonomically designed for horizontal
images. About 75% of all images taken, however, are vertical so
that most of the time the 35 mm camera is being held at the wrong
orientation for its design, namely vertically or sideways. Further,
the best aspect ratio for a vertical image is not 3:2 (as provided
by the hardware-dictated, side-ways held 35 mm or usual digital
camera) but is 4:3, which is not available at all in cameras of
known design. The software solution of the present invention thus
not only avoids having to turn the camera body, but its flexibility
allows for the best possible aspect ratio for any image orientation.
[0090] FIG. 2 illustrates certain advantages of the present invention
where the upper left quadrant A shows a picture recorded by a rectangular
ICD at an angle from the horizontal, the roll angle being recorded
in a data file; the upper right quadrant B shows the picture where
digital roll correction is applied to the image file but corner
cropping affects the rectangular image when it is rotated; the lower
left quadrant C illustrates a picture recorded by a circular ICD
at an angle from the horizontal and the angle of roll recorded in
a data file; and the lower right quadrant D shows the picture with
digital roll correction applied and no corner cropping because of
the full lens coverage possible with an image file that is round.
[0091] In FIG. 3, the left image E is a vertical composition including
the center tree, clouds and flowers. The right image F is a horizontal
panoramic composition including both trees and the house. Full lens
capture allows final composition decisions to be made after the
image has been taken without losing lens coverage. Thus, the present
invention with its capacity to switch between vertical (image E)
and horizontal (image F) panoramic, or any other aspect ratio, without
physically turning the camera body, gives the photographer the option
to choose a different aspect ratio or image composition after the
picture has been taken without losing lens coverage, all portions
of the image bounded by any rectangular box within the round ICD
being part of the final composition.
[0092] FIG. 4 shows the convergence correction curve which can
be a function of lens angle predefined by the photographer.
[0093] FIG. 5 shows views on the ICD and visible through the viewfinder
of a digital camera of the present invention, where the upper left
quadrant G is with no ICD rotation, the upper right quadrant H is
with no ICD rotation but with digital correction, the lower left
quadrant I is with the ICD rotated about the horizontal axis, and
J is with ICD Rotation and with digital correction.
[0094] In FIG. 5, quadrant G shows the Plane of Sharp Focus (PSF)
parallel to the lens plane. The Building Face (BF) is only in focus
along a horizontal line directly in front of lens. Parallel lines
show slight convergence reflecting normal perspective. Quadrant
H shows the image with camera settings the same as for quadrant
G but with 100% digital convergence correction so that the converging
lines become parallel. The image, however, remains out of focus
on the top and bottom. In quadrant I of FIG. 5, the PSF aligns with
the building face BF and the parallel line convergence becomes exaggerated.
In quadrant J with 100% digital convergence correction applied to
the image of quadrant H, lens and ICD angles are recorded and saved
in the Data File. This information is used to perform digital convergence
correction.
[0095] Referring to FIG. 6, the Scheimpflug Rule states that the
Lens Plane, film plane in a camera but the ICD Plane for the present
invention, and the Plane of Sharp Focus or PSF, must all converge
on the same line. The angle b between the Lens Plane and the ICD
Plane can be calculated as follows: b=ArcTan(F/D*Tan(a));
[0096] where D is the distance between the center of the lens and
a point in sharp focus directly in front of the lens (which can
be given using the auto- or manual focus method as distance sensing
means for the invention); F is the distance between the Lens Plane
and a point directly in the center of the ICD (a know dimension
of the camera); a is the angle between the Lens plane and the PSF
(which can be supplied by the inclinometer 26); and b is the angle
between the Lens Plane and the ICD plane (which can be supplied
by knowing the yoke 14 tilt position).
[0097] Turning now to FIGS. 7 and 8, digital camera 10 contains
ICD 12, e.g. a CCD, that is preferably round but may be a regular
or irregular polygon of about eight or more sides, a cross, an oval
or ellipse or other shape.
[0098] ICD 12 is mounted for pivoting on the yoke 14, about a horizontal
axis via the horizontal digital motor 16 and about a vertical axis
via the vertical digital motor 18.
[0099] Quadrant K in FIG. 8 shows the ICD 12 rotated 20 degrees
down, while quadrant L shows the ICD 12 rotated 20 degrees up. Quadrant
M in FIG. 8 shows the ICD 12 rotated 20 degrees to the right and
quadrant N shows the ICD 12 rotated 20 degrees up and to the right.
[0100] The image modification means 31 of the invention may be
on-board the camera 10 as shown in FIG. 7, or at some other location,
but may include electronics for the aspect ratio selection means
(FIGS. 1 and 3), the means that achieves the frame selection or
cropping and masking effect (FIG. 2) in conjunction with the inclinometer
26, the controller for the yoke pivoting (FIGS. 5, 6 and 8) whether
used for creating the focus landscape, or, with the inclinometer,
to correct or modify the digital image for convergence, or for focus
according to the Scheimpflug Rule, or for modifying the high resolution
image file to create any other form of the modified digital image.
[0101] In FIGS. 9 and 10 the digital camera body 24 contains a
yoke 14 that comprises an inner yoke hoop that carries the ICD and
which is mounted for pivotal motion to an outer yoke hoop. As shown
in FIG. 10, upper left quadrant, the inner hoop can be driven by
a first digital drive motor with respect to the outer hoop to pivot
the ICD about a horizontal axis, e.g. about 20 degrees counterclockwise,
or in the upper right quadrant, 20 degrees clockwise. For pivoting
about a vertical axis, the outer hoop is drive by a second motor
mounted to the camera housing 24, e.g. 20 degrees to one side as
shown in the lower left quadrant, or both motors can be operated
to tilt or pivot the ICD to one side and counterclockwise as shown
in the lower right quadrant.
[0102] FIG. 9 also illustrates another embodiment of the invention
which includes a further digital motor 36 that is capable of rotating
the ICD around in the inner loop in the direction of the curved
arrow and within the plane of the ICD. In this way a standard rectangular
ICD mounted in the yoke can be rotation 90 degrees in either direction
between horizontal and vertical aspect ratio images, without rotating
the camera body (for a total of up to 180 degrees). This alternate
aspect ratio selection means can be used alone or in combination
with the other features of the invention such as the tilting yoke
features, to produce a digital camera with advanced features but
with a more conventionally shaped ICD. The rotation of the ICD can
also be used to compensate for roll as discussed above so that rotation
of up to 90 or 180 degrees is possible.
[0103] While a specific embodiment of the invention has been shown
and described in detail to illustrate the application of the principles
of the invention, it will be understood that the invention may be
embodied otherwise without departing from such principles. |