JP2011247966A - Imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a three-dimensional (3D) image of high quality by surely performing image correction even when an interchangeable lens for 3D photographing is attached.SOLUTION: An imaging apparatus comprises an imaging part and is connectable with the interchangeable lens for stereoscopic photographing so as to be able to form an object image on the imaging part. The imaging apparatus comprises a communicating part for acquiring correction coefficient data from the interchangeable lens. The correction coefficient data permits optical distortion, overlap of images and a brightness error due to the type of the interchangeable lens for the stereoscopic photographing and a performance error to be corrected.

Description

  The present invention relates to an imaging apparatus capable of capturing a three-dimensional image.

  In recent years, portable devices with a photographing function such as a digital camera have overcome various poor photographing scenes by making full use of image processing. In recent years, there has been a 3D (three-dimensional) wave in the movie industry with a sense of realism, and the 3D display devices are also becoming popular following the television industry.

  In consumer photography equipment such as digital cameras, devices capable of 3D photography have been developed. There are a wide variety of proposals for a method of photographing and recording an image including three-dimensional information and reproducing and observing the image. For example, Patent Document 1 discloses an apparatus having a correction unit that corrects an error (tilt) and a positional deviation in the vertical direction of binocular images arranged side by side in accordance with the display unit.

  By the way, in order to enable stereoscopic viewing, it is necessary to capture the right image for the right eye and the left image for the left eye, that is, two images having parallax corresponding to the viewpoints of the left and right eyes. For this reason, two imaging devices, that is, an imaging device that captures a right image and an imaging device that captures a left image are necessary for 3D imaging. Further, there is also an imaging device that provides a 3D image with one imaging device by providing one imaging device and forming optical images from two imaging lenses for the right eye and left eye on the imaging surface of one imaging device. Has been developed.

  In such an imaging apparatus, it is important to display two 3D images in a uniform manner in order to improve the quality of 3D display.

  In view of this, the apparatus disclosed in Patent Document 1 performs correction according to the shift between the left and right images.

Japanese Patent No. 4225768

  However, the apparatus disclosed in Patent Document 1 corrects tilt and positional deviation based on stereoscopic image data. To perform high-precision correction, an enormous amount of calculations and user operations are required. It is. In addition, in the apparatus of Patent Document 1, a method of using focal length information stored in an image file is also disclosed. However, in order to perform high-precision correction, a user explicitly inputs focal length information. There is a need to. Furthermore, the apparatus disclosed in Patent Document 1 has a problem that optical distortion, image overlap, and brightness error peculiar to various interchangeable lenses corresponding to various applications cannot be corrected.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an imaging apparatus capable of performing high-accuracy image correction and obtaining a high-quality 3D image regardless of what 3D imaging interchangeable lens is attached.

  The imaging device of the present invention includes an imaging unit, and in an imaging device to which an interchangeable lens for stereoscopic shooting can be connected so that a subject image can be formed on the imaging unit, optical distortion and image overlap, A communication unit that acquires correction coefficient data capable of correcting an error in brightness from the interchangeable lens;

  According to the present invention, there is an effect that a high-quality 3D image can be obtained by reliably performing image correction regardless of what type of interchangeable lens for 3D shooting is attached.

1 is a block diagram showing a circuit configuration of an imaging apparatus according to a first embodiment of the present invention. Explanatory drawing which shows the external appearance of the imaging device with which the interchangeable lens and the electronic viewfinder were attached. Explanatory drawing which shows the external appearance of the imaging device with which the interchangeable lens and the electronic viewfinder were attached. FIG. 3 is an explanatory diagram showing an example of an optical system employed in the interchangeable lens 12. FIG. 3 is an explanatory diagram showing an example of an optical system employed in the interchangeable lens 12. FIG. 3 is an explanatory diagram showing an example of an optical system employed in the interchangeable lens 12. Explanatory drawing which shows an example of another interchangeable lens. Explanatory drawing for demonstrating the structure of the optical system which looked at FIG. 7 from the upper surface. Explanatory drawing which shows the structure of the optical system which looked at FIG. 7 from the side. Explanatory drawing which shows the relationship between a base line length and the rotation angle of the image imaged on an image pick-up element. The flowchart which shows camera control. 5 is a flowchart showing image correction processing. 12 is a flowchart showing a specific flow of finder control in step S14 in FIG. Explanatory drawing for demonstrating an example of distortion correction. Explanatory drawing for demonstrating a recording process. It is explanatory drawing for demonstrating the control according to an interchangeable lens.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram showing a circuit configuration of an imaging apparatus according to the first embodiment of the present invention. 2 and 3 are explanatory views showing the appearance of an imaging apparatus to which an interchangeable lens and an electronic viewfinder are attached.

  2 and 3, the imaging device 10 has a lens mount (not shown) on the front surface of the imaging device main body 11, and an interchangeable lens 12 is detachably attached thereto. The interchangeable lens 12 is for 3D photography having two imaging lens portions 12R and 12L. An accessory shoe 61 is provided at the upper end of the imaging apparatus main body 11. The electronic viewfinder 13 has an attachment portion 65 for detachably attaching to the accessory shoe 61. A holding portion 66 that holds the two display portions 55R and 55L is rotatably attached to the attachment portion 65.

  The accessory shoe 61 is provided with a contact portion 62 that constitutes a communication portion 23 of the main body circuit portion 20 described later. By attaching the attachment portion 65 of the electronic finder 13 to the accessory shoe 61, the contact portion 62 is attached to the attachment shoe 61. It is electrically connected to a contact portion (not shown) provided at 65. The contact portion 62 of the attachment portion 65 constitutes a communication portion 52 of the electronic finder circuit portion 50 described later.

(Circuit configuration)
The imaging device body 11 of the imaging device 10 includes a body circuit unit 20. As shown in FIG. 1, the main body circuit unit 20 is provided with communication units 22 and 23. On the other hand, the interchangeable lens 12 employed in the present embodiment incorporates an interchangeable lens circuit unit 40. In the present embodiment, various interchangeable lenses can be employed in addition to the interchangeable lens 12 shown in FIGS. 2 and 3, and the interchangeable lens circuit section 40 is built in the interchangeable lens employed in the present embodiment. Has been. An electronic finder circuit unit 50 is built in the electronic finder 13. The interchangeable lens circuit unit 40 and the electronic viewfinder circuit unit 50 are also provided with communication units 42 and 52, respectively. The communication units 22 and 23 of the main body circuit unit 20 can exchange information with each other between the communication unit 42 of the interchangeable lens circuit unit 40 and the communication unit 52 of the electronic viewfinder circuit unit 50. ing.

  In the present embodiment, as the interchangeable lens 12, a lens for 3D shooting that has two imaging lenses 12R and 12L (see FIG. 2) and can capture a right image and a left image can be employed.

  The lens control unit 41 of the interchangeable lens circuit unit 40 includes a lens information storage unit 43 that stores lens information. The interchangeable lens circuit unit 40 is for 3D photography having two lens units 44R and 44L each including two imaging lenses corresponding to the imaging lenses 12R and 12L. The lens control unit 41 is controlled by the main body circuit unit 20 and can drive the lens units 44R and 44L to control the aperture, focus, zoom, and the like of the imaging lenses 12R and 12L.

  The lens information stored in the lens information storage unit 43 includes lens optical system information. The optical image formed on the image sensor through the lens system has various reproducibility defects such as distortion, image tilt, image shadow that darkens the four corners of the image, overlapping of left and right images, and poor color reproducibility. Arise. In the present embodiment, the lens information includes correction coefficient data for correcting various reproducibility defects such as displacement and deformation of the optical image. That is, the correction coefficient data includes lens type, lens base length, and error information specific to the interchangeable lens.

  The correction coefficient data also includes information such as F number, zooming, and focusing. Furthermore, a lens capable of adjusting the lens system such as the rotation angle and the base line length of the left and right imaging lenses may be adopted as the interchangeable lens, and the changed rotation angle information and the base line length information are also included in the correction coefficient data. In other words, the correction coefficient data includes a fixed value specific to each interchangeable lens to be mounted, a change in lens state after activation of camera control, according to zooming processing, focusing processing, rotation angle and base line length change processing, and the like. And a variable value changed corresponding to

  The communication unit 42 of the lens control unit 41 exchanges information with the communication unit 22 of the main body circuit unit 20 via a predetermined transmission path. When communication with the communication unit 22 of the main body circuit unit 20 is established, the lens control unit 41 can cause the main body circuit unit 20 to transmit lens information read from the lens information storage unit 43 by the communication unit 42. Thereby, the main body circuit unit 20 can acquire various information related to the lens system of the interchangeable lens 12. For example, the optical image of the subject from each of the imaging lenses 12R and 12L forms an image on which area on the imaging surface of the imaging element, which will be described later, what kind of distortion, rotation, etc. have occurred, Information for correcting a defect can be acquired.

  On the other hand, as the electronic viewfinder 13, a 3D display viewfinder capable of displaying the right image and the left image respectively by the display device 55 having the two display portions 55R and 55L can be adopted. As shown in FIG. 2, the electronic viewfinder 13 is provided with display portions 55 </ b> R and 55 </ b> L that are separated from each other, for example, corresponding to the distance between both eyes of a person. The display units 55R and 55L can be configured by an organic EL or LCD.

  A finder information storage unit 53 is provided in the finder control unit 51 of the electronic finder circuit unit 50. The finder information storage unit 53 holds finder information related to the display device 55 of the electronic finder 13.

  The communication unit 52 of the finder control unit 51 transmits and receives information to and from the communication unit 23 of the main body circuit unit 20 through a predetermined transmission path. When communication with the communication unit 23 of the main body circuit unit 20 is established, the finder control unit 51 can cause the communication unit 52 to transmit the finder information stored in the finder information storage unit 53 to the main body circuit unit 20. . Thereby, the main body circuit unit 20 can recognize that the display device 55 has the two display units 55R and 55L.

  When image information is given from the main body circuit unit 20, the finder control unit 51 generates an image signal based on the image information by the display driving unit 54. The main body circuit unit 20 also outputs display control information on how to display on the display device 55, and the display driving unit 54 gives an image signal to the display device 55 based on the display control information for display.

  For example, when 3D display image information is given from the main body circuit unit 20, the display driving unit 54 gives the right image signal to the display unit 55R and gives the left image signal to the display unit 55L based on the display control information. . As a result, a 3D image can be observed by looking through the display portions 55R and 55L of the electronic viewfinder 13 with both eyes of the viewer.

  The main body circuit unit 20 includes an imaging unit 24 configured by an imaging element such as a CCD or a CMOS sensor. The optical image of the subject from the interchangeable lens 12 is formed on the imaging surface of the imaging device that constitutes the imaging unit 24. The imaging unit 24 is driven and controlled by the signal processing and control unit 21. The signal processing and control unit 21 has information on the imaging surface of the imaging element that constitutes the imaging unit 24. The signal processing and control unit 21 outputs a driving signal of the image sensor to the image capturing unit 24 based on the information on the imaging surface and the lens information, and captures an image signal obtained by photoelectric conversion of the optical image by the image sensor. The main body circuit unit 20 is provided with an audio recording unit 25, which collects sound outside the imaging apparatus 10 and outputs an audio signal to the signal processing and control unit 21.

  The signal processing and control unit 21 performs predetermined signal processing, for example, color signal generation processing, matrix conversion processing, and other various digital processing on the image signal obtained by photoelectric conversion of the image sensor. The main body circuit unit 20 can output image information, audio information, and the like compressed by performing an encoding process when recording image signals, audio signals, and the like.

  The signal processing and control unit 21 sets an image region corresponding to the range of incident light from the lens units 44R and 44L on the imaging surface of the imaging unit 24 based on the information on the imaging surface and the lens information. Yes. That is, the signal processing and control unit 21 divides the imaging surface of the imaging unit 24 into a right image region and a left image region according to the incident ranges of incident light from the lens units 44R and 44L, respectively. The signal processing is performed using the image signal from as a right image signal or a left image signal.

  The signal processing and control unit 21 may set an image area according to processing such as aperture and zoom processing as well as imaging surface information and lens information.

  In the present embodiment, the signal processing and control unit 21 includes an image correction unit 21a. The image correction unit 21a is given correction coefficient data from the lens information storage unit 43 of the interchangeable lens circuit unit 40, and corrects the right and left images generated by the signal processing and control unit 21 using the correction coefficient data. It is like that.

  The main body circuit unit 20 is also provided with a clock unit 27 and an operation determination unit 28. The clock unit 27 generates time information used by the signal processing and control unit 21. The operation determination unit 28 generates an operation signal based on a user operation with respect to various switches such as a release switch (not shown) provided in the imaging apparatus 10 and a shooting mode setting, and outputs the operation signal to the signal processing and control unit 21. Yes. The signal processing and control unit 21 controls each unit based on the operation signal.

  The main body circuit unit 20 includes a recording / reproducing unit 26 and a main body display unit 30. The recording / reproducing unit 26 can record image information and audio information from the signal processing and control unit 21 on a recording medium (not shown). For example, a card interface can be employed as the recording / reproducing unit 26, and the recording / reproducing unit 26 can record image information, audio information, and the like on a memory card or the like. Further, the recording / reproducing unit 26 can read out the image information and the audio information recorded on the recording medium and supply them to the signal processing and control unit 21. The signal processing and control unit 21 can decode the image information and audio information from the recording / reproducing unit 26 to obtain an image signal and an audio signal.

  The main body display unit 30 can display the captured image from the imaging unit 24 and the reproduced image from the recording / reproducing unit 26 from the signal processing and control unit 21 to display these images. Further, the main body display unit 30 can be controlled by the signal processing and control unit 21 to display a menu display or the like for operating the imaging device 10.

  The signal processing and control unit 21 can control each unit in the main body circuit unit 20 and can control the interchangeable lens 12 and the electronic viewfinder 13 via the communication units 22 and 23.

  In the present embodiment, the recording / reproducing unit 26 can combine the right image and the left image as one image and record the combined image when recording the 3D image. Further, the recording / reproducing unit 26 can record the right image and the left image as separate images when recording the 3D image.

(interchangeable lens)
4 to 6 are explanatory views showing an example of an optical system employed in the interchangeable lens 12. The examples of FIGS. 5 and 6 are disclosed in Japanese Patent Application Laid-Open Nos. 8-171151 and 2004-4869.

  FIG. 4 shows the positional relationship between the optical system and the imaging element when the imaging device 10 is viewed from above. 4 shows an example in which the interchangeable lens 12 employs a right optical system 81R for the right eye and a left optical system 81L for the left eye as optical systems that constitute the lens portions 44R and 44L, respectively. The imaging device main body 11 is provided with an imaging surface 82a of an imaging element 82 that constitutes the imaging unit 24 facing the optical systems 81R and 81L.

  A left image region is set on the right side in the horizontal direction of the imaging surface 82a of the imaging element 82, and a right image region is set on the left side in the horizontal direction of the imaging surface 82a. The light incident on the imaging lens 12R forms an image on the right image region provided on the left side in the horizontal direction of the imaging surface 82a via the right optical system 81R. Further, the light incident on the imaging lens 12L forms an image on a left image region provided on the right side in the horizontal direction of the imaging surface 82a via the left optical system 81L.

  5 and 6 show other examples of the optical system. The examples of FIGS. 5 and 6 show the optical system when a horizontally long 3D image is captured. FIGS. 5A and 6A show the planar state, and FIGS. 6 (b) shows a state viewed from the lower surface of FIGS. 5 (a) and 6 (a), respectively. 5 and FIG. 6, description will be made assuming that the image sensor 102 is employed as the image sensor of the imaging unit 24 provided in the image pickup apparatus body 11.

  In FIG. 5, the reflecting mirrors 104 and 105 are rotatably attached to a holder 106 fixed to the imaging apparatus main body 11. The reflecting surfaces of the reflecting mirrors 104 and 105 can be rotated on the same plane. A fixed gap is provided between the reflecting mirror 104 and the reflecting mirror 105, and the tip of the partition wall 103 is inserted therein. Therefore, when the partition wall 103 is rotated, the reflecting mirrors 104 and 105 are rotated accordingly.

  The reflecting mirror 111 and the reflecting mirror 104, which are a pair of reflecting optical systems, are reflected from the reflecting surface of the reflecting mirror 111 after light from the subject (right subject image) is incident on the reflecting mirror 111, and then reflected. After being incident on the mirror 104, it is optically arranged sequentially from the incident side so that it is reflected by the reflecting surface of the reflecting mirror 104 and imaged on the upper imaging surface 102a. At this time, the reflecting surface of the reflecting mirror 104 and the reflecting surface of the reflecting mirror 111 are preferably substantially parallel to the extent that an image can be formed on the imaging surface 102a. Further, with respect to the reflecting mirror 112 and the reflecting mirror 105, which are another pair of reflecting optical systems, light from the subject (the subject image on the left side) receives the lower imaging surface 102a as in the case of the reflecting mirror 111 and the reflecting mirror 104. Are sequentially arranged optically from the incident side.

  The convex lens 109 is disposed between the reflecting mirror 111 and the reflecting mirror 104, and is used to form a subject image from the right side on the upper imaging surface 102a via the reflecting mirror 104. Accordingly, the convex lens 109 is disposed along the optical axis of the light emitted from the reflecting mirror 111. Similarly to the convex lens 109, the convex lens 110 is disposed between the reflecting mirror 112 and the reflecting mirror 105. Although a reflecting mirror is used in the reflecting optical system, a prism or other reflecting optical element may be used instead of the reflecting mirror. Further, although the convex lenses 109 and 110 are shown as single lenses, it goes without saying that they can be constituted by a plurality of lenses. Further, the reflecting mirror 111 and the convex lens 109 may be a prism having a convex surface that has the functions of the reflecting mirror 111 and the convex lens 109.

  Further, the interval S between the left and right optical axes 113 and 114 on the incident side shown in FIG. 5A is selected to be a predetermined value in consideration of the size and distance of the subject with reference to the human eye width. In order to form an object on the optical axes 113 and 114 at the center of the imaging surface 102a, the optical axes 115 and 116 passing through the convex lenses 109 and 110 are in a horizontal line H as shown in FIG. It is inclined with respect to the predetermined angle θ. This angle θ is calculated from the equation tan θ = a / S. In this way, by arranging the convex lenses 109 and 110 between the two reflecting mirrors 104 and 111 and 105 and 112, respectively, it becomes possible to project a subject having a wide angle of view in the horizontal direction on the imaging surface 102a. .

  In the optical system having such a configuration, the luminous flux of the subject image having parallax is incident on each of the reflection optical systems provided on the left and right, and is reflected by the two reflection surfaces in each of the reflection optical systems. The luminous flux exposes the upper half right image area of the imaging surface 102a divided by the partition wall 103, and the other luminous flux exposes the lower half left image area.

  A 3D image can be obtained by taking out signals from these right image areas as right image signals and taking out signals from the left image area as left image signals.

  In the above configuration, the reflecting mirrors 104 and 105 are rotated to obtain a 3D image of another size. That is, FIG. 6 shows a state in which the reflecting mirrors 104 and 105 are rotated 90 degrees from the state of FIG. In this case, as a matter of course, the position of the convex lens is moved in conjunction with the rotation of the reflecting mirrors 111 and 112.

  FIG. 7 is an explanatory diagram showing another example of an interchangeable lens that can be attached to the lens mount of the imaging apparatus main body 11. FIG. 8 is an explanatory diagram for explaining the configuration of the optical system when FIG. 7 is viewed from the top, and FIG. 9 is an explanatory diagram showing the configuration of the optical system when FIG. 7 is viewed from the side.

  In the optical image formed on the image sensor through the above-described interchangeable lens in FIGS. 4 to 6, distortion not described in FIGS. 4 to 6 occurs. If the distortion is actively used and the resolution of the image sensor is used effectively, the optical system should be configured to form an optical image obliquely with respect to the left and right baselines. Is advantageous. The interchangeable lens of FIG. 7 is configured from such a viewpoint. In the example of FIG. 7, description will be made assuming that the imaging device 205 is disposed in the imaging unit 24. In the description of FIG. 7, “L” and “R” after the reference numerals are used for distinguishing components belonging to the left and right optical paths.

  The interchangeable lens 200 includes left and right objective lens groups 201L and 201R with respect to the left and right optical paths, and first reflection surfaces 202L and 202R and second reflection surface 203L that sequentially reflect light incident from the objective lens groups 201L and 201R. , 203R and a common imaging lens group 204 on which the light reflected by the left and right second reflecting surfaces 203L, 203R is incident. An imaging element 205, which is a common single imaging element, is disposed at the imaging position of the optical image by the imaging lens group 204.

  Field-of-view masks 211L and 211R that pass image-forming light beams centered on chief rays 210L and 210R and restrict unnecessary light are disposed on the incident sides of the left and right objective lens groups 201L and 201R, respectively. Each of the field masks 211L and 211R is configured to have a simple shape that covers substantially the lower side of the left objective lens group 201L and covers the upper side of the right objective lens group 201R.

  As is apparent from the drawing, the reflection directions of the first reflecting surfaces 202L and 202R and the second reflecting surfaces 203L and 203R are such that the left first reflecting surface 202L passes the optical path incident from the left objective lens group 201L to the right objective. The second reflecting surface 203L bends the bent optical path approximately 90 degrees in the same direction as the optical path incident on the left objective lens group 201L, and is bent approximately 90 degrees toward the lens group 201R. Similarly, the right first reflecting surface 202R bends the optical path incident from the right objective lens group 201R to the left objective lens group 201L side by approximately 90 degrees to make a second reflection. The surface 203R bends the bent optical path in a direction substantially parallel to the optical path incident on the right objective lens group 201R and approximately 90 degrees in the same direction. It has a configuration to be incident to 4.

  With such a configuration, the interchangeable lens 200 can arrange the common imaging lens group 204 and the imaging element 205 between the left and right objective lens groups 201L and 201R, and the width in the left and right direction is the left and right objective lens group 201L. , 201R is determined by the distance between the end portions (the distance obtained by adding the aperture of one objective lens group to the base length), and the thickness in the depth direction with respect to the subject is determined by the objective lens groups 201L and 201R and the imaging surface The distance is determined by the distance from the rear end surface of the lens group 204, and the height is equal to or less than the aperture of the objective lens groups 201L and 201R (because the effective area of the objective lens groups 201L and 201R can be trimmed, the height is equal to or less than the aperture). Therefore, it can be made compact.

  Then, the left image of the binocular parallax image that is incident from the left objective lens group 201L, passes through the first reflecting surface 202L and the second reflecting surface 203L in order and is imaged on the image sensor 205 by the imaging lens group 204, Inverted and projected on the lower half of the rectangular imaging surface of the imaging device 205, enters from the right objective lens group 201R, passes through the first reflecting surface 202R and the second reflecting surface 203R in order, and then the imaging lens group 204 picks up the imaging device. The right image of the binocular parallax image formed on 205 is projected upside down on the upper half of the rectangular imaging surface of the imaging element 205.

  Here, the parallax direction of the entire optical system of the interchangeable lens 200 connects between the incident lens surfaces of the left and right objective lens groups 201L and 201R or the points where the left and right principal rays 210L and 210R are incident on the field masks 211L and 211R. The parallax direction of the left and right images (parallax image) projected onto the image sensor 205 is the direction of the straight line BB ′ parallel to the rectangular side of the image sensor 205. As is clear from FIG. 7, in the interchangeable lens 200, the parallax direction AA ′ of the entire optical system and the parallax direction BB ′ of the optical image projected onto the image sensor 205 are parallel. The two left and right images are inclined with respect to the parallax direction AA ′ on the imaging surface.

  This is because the inclination of the first reflecting surfaces 202L and 202R and the second reflecting surfaces 203L and 203R is not simply an inclination around an axis orthogonal to the same plane, but an inclination around two axes. This is because the subject image projected on the element 205 is rotated. Here, the left and right principal rays 210L and 210R are incident from the objective lens groups 201L and 201R, respectively, and sequentially pass through the first reflecting surfaces 202L and 202R and the second reflecting surfaces 203L and 203R. It is defined by the central ray of the light beam reaching the center of each of the left and right images formed on the top.

  The left and right principal rays 210L and 210R are defined as described above, whereas the left and right objective lens groups 201L and 201R have optical axes (center axis and rotation axis), respectively (see the optical axis 215L in FIG. 9). The imaging lens group 204 has one optical axis (center axis, rotation axis) (see the optical axis 216L in FIG. 9). Then, when the optical paths at the first reflecting surfaces 202L and 202R and the second reflecting surfaces 203L and 203R are developed to make the left and right optical systems (lens systems) one lens system, the light of the left objective lens group 201L The axis 215L and the optical axis 216L of the imaging lens group 204 coincide to form one optical axis. Further, the optical axis of the right objective lens group 201R and the optical axis of the imaging lens group 204 coincide to form one optical axis. Then, the left and right light beams from the same subject enter the left and right objective lens groups 201L and 201R along the left and right principal rays 210L and 210R, respectively, on the lower half and the upper half of the rectangular imaging surface of the image sensor 205, respectively. The left and right parallax images are inverted and imaged.

  The principal rays 210L and 210R incident on the left and right objective lens groups 201L and 201R do not coincide with the respective optical axes, and the left incident principal ray 210L forms an angle on the upper side of the left optical axis. Is incident on the lower side of the right optical axis. However, in order to form the left and right images, the principal rays 210L and 210R incident on the left and right objective lens groups 201L and 201R are parallel to each other or form an convergence angle corresponding to the distance to the subject in substantially the same plane. For this reason, the optical axes of the left and right objective lens groups 201L and 201R are twisted with respect to each other about the optical axis of the imaging lens group 204, and are in a 180-degree rotational symmetry relationship.

  The first reflecting surfaces 202L and 202R have a size and shape that do not limit the effective luminous flux transmitted through the objective lens groups 201L and 201R, and are approximately 45 degrees in the horizontal direction and several degrees on the image sensor 205 side in the vertical direction. It is inclined and makes the reflected light beam incident on the second reflecting surfaces 203L and 203R. The second reflecting surfaces 203L and 203R are disposed substantially perpendicularly to the second reflecting surfaces 203L and 203R in the horizontal direction and inclined at a minute angle toward the image sensor 205 in the vertical direction. Make the light beam incident. When viewed from the vertical direction, the second reflecting surfaces 203L and 203R are arranged such that the left second reflecting surface 203L intersects with the right and the second reflecting surface 203R intersects with each other from the left and right. The incident light beam is deflected so as to enter the direction of the imaging lens group 204 from above and below. Here, the second reflecting surfaces 203L and 203R constitute a diaphragm member that forms an exit pupil.

  The light beams limited by the field masks 211L and 211R are transmitted through a low-pass filter (not shown) by the imaging lens group 204, and then the left and right eye images are formed in either one of the upper and lower half regions of the image sensor 205. To do. By the action of the field masks 211L and 211R, the upper and lower parallax images are separated and formed in parallel on the image sensor 205 without overlapping each other.

  Thus, in the optical lens 200, the main light beam does not pass through the center of the lens but passes through the asymmetric optical system, so that non-rotationally symmetric distortion occurs. Further, since the mirror arrangement is such that the incident light is horizontal and the image is arranged in the vertical direction, the image is rotated, and the left and right images are inclined. In addition, the image becomes darker at the four corners of the image. Furthermore, the right and left images may overlap due to the size of the field mask. Furthermore, color reproducibility may become poor due to chromatic aberration and color shading.

  These defects are uniquely determined by the configuration of the lens system. Therefore, in the interchangeable lens 200 in FIG. 7 and each of the interchangeable lenses shown in FIGS. 4 to 7, correction coefficient data for correcting various defects in image reproducibility is stored in the lens information storage unit 24. . By using this correction coefficient data, it is possible to generate an image in which the above reproducibility defects are corrected.

  In the interchangeable lens 200, as shown in FIG. 8, the lens and each reflecting surface can be moved or rotated. For example, the objective lens groups 201L and 201R are configured to be rotatable in the R1 direction in FIG. Further, the first reflecting surfaces 202L and 202R are configured to be rotatable in the R2 direction of FIG. Furthermore, the second reflecting surfaces 203L and 203R are movable in the M1 direction in FIG. 8, and the first reflecting surfaces 202L and 202R and the objective lens groups 201L and 201R are optical path lengths between the first and second reflecting surfaces. Is configured to be movable in the direction M2 in FIG.

  Further, the effect of stereoscopic display can be changed by changing the distance between the objective lens groups 201L and 201R (the distance between the first and second reflecting surfaces), that is, the base line length. For example, by making the base line length longer, 3D imaging with increased stereoscopic effect on the wide angle side is possible. In order not to change other requirements such as angle of view and focusing, the base line length is changed without changing the optical path length.

  Note that when the baseline length is changed, the rotation angle of the image also changes. FIG. 10 is an explanatory diagram showing the relationship between the baseline length and the rotation angle of the image formed on the image sensor. 10A shows the left and right images when the baseline length is relatively short, and FIG. 10B shows the left and right images when the baseline length is relatively long. As shown in FIG. 10, the longer the baseline length, the smaller the image rotation.

  As described above, in order to obtain a high-quality 3D image, it is effective to change the baseline length and the convergence angle according to the distance of the subject to be photographed in addition to the angle of view at the time of photographing. Accordingly, it is important to correct a plurality of images by such switching.

  In the present embodiment, as described above, information such as the baseline length is also supplied to the signal processing and control unit 21 by the correction coefficient data included in the lens information, and the image correction unit 21a is based on the correction coefficient data. Thus, it is possible to correct the rotation angle of the left and right images.

(Function)
Next, the operation of the embodiment configured as described above will be described with reference to FIGS. FIG. 11 is a flowchart showing camera control, FIG. 12 is a flowchart showing image correction processing, and FIG. 13 is a flowchart showing a specific flow of finder display control in step S14 in FIG.

  In step S1 of FIG. 11, lens communication is performed. The signal processing and control unit 21 controls the communication unit 22 to perform communication with the communication unit 42 of the lens control 41 of the interchangeable lens circuit unit 40, and the lens information stored in the lens information storage unit 43. Is read. In this way, the correction coefficient data included in the lens information is read into the image processing unit 21 a of the signal processing and control unit 21.

  In the next step S2, the signal processing and control unit 21 determines whether or not the shooting mode is set. Assume that the shooting mode is instructed. In this case, in step S3, the signal processing and control unit 21 performs autofocus control (AF), takes in a signal from the imaging unit 24, performs signal processing, and generates an image signal.

  If the shooting mode is instructed, the signal processing and control unit 21 determines whether or not an electronic viewfinder is connected in step S4.

  Now, it is assumed that the electronic finder is not connected to the accessory shoe 61 of the imaging apparatus main body 11. In this case, the signal processing and control unit 21 outputs the generated image signal to the main body display unit 30 to display the captured image (step S5).

  Next, the signal processing and control unit 21 determines whether or not an instruction to start shooting is instructed in step S6. If the start of photographing has not been instructed, the signal processing and control unit 21 determines whether or not a power-off operation has been performed in step S19. If the power-off operation has not been performed, the processing is performed in step S2. Return to. If a power off operation is performed, the power is turned off in step S20.

  If it is determined in step S6 that the user has instructed to start shooting, the signal processing and control unit 21 performs moving image shooting (step S7). In FIG. 11, in the display mode on the main body display unit 30, it has been described that moving image shooting is performed by an instruction to start shooting, but still image shooting may be performed.

  When an instruction to end shooting is given, the signal processing and control unit 21 proceeds from step S8 to step S9 to perform image correction and image file creation. That is, the signal processing and control unit 21 performs image correction simultaneously with shooting.

  In step S41 of FIG. 12, the image correction unit 21a captures a variable value of correction coefficient data that has changed along with the change of the state of the interchangeable lens after the start of camera control. In step S42, the image correction unit 21a cuts out and reads out image data of an area necessary for correcting distortion and the like of the image area of the left image based on the acquired correction coefficient data. Next, in step S43, the image correction unit 21a corrects the left image based on the correction coefficient data.

  For example, the image correction unit 21a corrects a left image corresponding to the subject by correcting non-rotationally symmetric distortion, optical distortion of multiple 3D images, image overlap, and brightness error. FIG. 14 is an explanatory diagram for explaining an example of distortion correction. FIG. 14A shows the left and right images of each frame formed on the imaging surface of the imaging device obtained by moving image shooting. In the example of FIG. 14, the left image (L) and the right image (R) are formed on the left and right of the imaging surface of the image sensor. FIG. 14B shows an example in which the four corners of the left and right images are distorted. In step S42, the image correction unit 21a corrects the distortion and obtains the left image shown in FIG.

  The image correction unit 21a corrects the tilt of the image. Also, the alignment adjustment is performed so that the left and right images are correct vertically and horizontally and no distortion occurs. Further, the image correction unit 21a corrects the blurring of the image that darkens the four corners of the image. In addition, when the left and right images overlap, the image correction unit 21a performs a removal process for removing the overlapping region. The image correction unit 21a also corrects an image with poor color reproducibility using the correction coefficient data to obtain an image with excellent color reproducibility.

  In step S44, the image correction unit 21a cuts out and reads out image data of an area necessary for correcting distortion or the like of the image area of the right image based on the acquired correction coefficient data. Next, in step S45, the image correction unit 21a corrects the right image based on the correction coefficient data. Even when the right image is corrected, the same processing as that of the left image is performed.

  The error between the plurality of 3D images is caused not only by the type and manufacturing error of the photographing lens but also by the conditions at the time of photographing. Therefore, this is corrected to obtain a high-quality stereoscopic image.

  The signal processing and control unit 21 performs a recording process on the image corrected by the image correction unit 21a. In this case, the signal processing and control unit 21 combines the left and right images into one image and records them, or records the left and right images as separate images.

  FIG. 15 is an explanatory diagram for explaining the recording process. FIG. 15A shows a state in which the left image L and the right image R are arranged side by side and synthesized as one image. This corresponds to a so-called side-by-side recording method, and schematically shows a state of reading and recording for each pixel column from the left and right images. At this time, the size information of each 3D frame is sent to enable separation.

  FIG. 15B shows that the left image L and the right image R are separate images. When the composite image in the state of FIG. 15A is recorded, the display device that displays the reproduced image recognizes that the left and right images are arranged on the left and right of each image, and for the stereoscopic display. Process. In addition, when each image in the state of FIG. 15B is recorded, the display device that displays the reproduced image captures the left image and the right image and performs processing for stereoscopic display.

This is a schematic diagram assuming a frame sequential method in which a left and right image is sequentially read out and recorded or reproduced for each frame in the case of a moving image. Also at this time, the size information of each 3D frame is sent to enable separation.
In order to control frame sequential and side-by-side, information to that effect is also prepared.

  In order to obtain a stereo image corresponding to these methods, it is essential to obtain a uniform image by eliminating an optical error factor as in the present invention.

  The signal processing and control unit 21 performs encoding processing on the generated left and right images and transfers image information from the recording / reproducing unit 26 to the recording medium. The transferred image information is made into a file.

  Next, in step S2, it is determined that the playback mode has been instructed. In this case, the signal processing and control unit 21 shifts the processing from step S10 to step S11, reads the information of the list of files recorded in the recording / reproducing unit 26, and displays the file list display on the main body display unit 30. Display.

  When the user selects a file at the time of displaying the file list (step S12), the signal processing and control unit 21 reads the selected file through the recording / playback unit 26, performs a decoding process, Play an audio signal. The signal processing and control unit 21 gives the reproduced image signal and audio signal to the main body display unit 30 for display (step S13).

  If an end operation is performed when the file list is displayed, the signal processing and control unit 21 moves the process from step S12 to step S14 and ends the playback mode.

  In the present embodiment, an example in which image correction is performed during recording has been described. However, image correction may be performed during playback without performing image correction during recording. That is, in this case, the signal processing and control unit 21 provides header areas or auxiliary data recording areas for the left and right image files captured by the imaging unit 24, and correction coefficient data read from the interchangeable lens in these areas. Corresponding to record. Then, at the time of reproduction, image correction may be performed by the image correction processing of FIG. 12 using the correction coefficient data read corresponding to the left and right image data.

  When the signal processing and control unit 21 determines in step S4 in FIG. 11 that the electronic viewfinder is connected, the process proceeds to step S15 to perform image correction and viewfinder display control.

  In the finder display control, the signal processing and control unit 21 performs image correction of the right and left images in step S23. The image correction in step S23 is the same processing as in FIG. 12, and the image correction unit 21a corrects the distortion and the like of the right image and the left image based on the correction coefficient data.

  Next, in step S24, the signal processing and control unit 21 performs right and left image enlargement / reduction processing and frame image generation processing. The image sizes of the right image and the left image depend on the size of the imaging surface of the imaging device of the imaging unit 24 and the incident range by the optical system. For this reason, it is conceivable that the image sizes of the right and left images are different from the image sizes of the display units 55R and 55L of the electronic viewfinder 13. Therefore, the signal processing and control unit 21 performs enlargement / reduction processing according to the image sizes of the right and left images in accordance with the image sizes of the display units 55R and 55L. In addition, a frame image corresponding to the aspect ratio of the right and left images and the display image is generated and superimposed on the enlarged and reduced right and left images.

  The signal processing and control unit 21 supplies the generated right and left image signals to the finder control unit 51 of the electronic finder 13 via the communication units 23 and 52. The finder control unit 51 controls the display driving unit 54 to provide the right image signal to the display unit 55R and the left image signal to the display unit 55L (step S25), and returns the processing to the main routine. Thus, 3D display based on the subject optical image captured through the optical lens 12 is performed on the display device 55 of the electronic viewfinder 13.

  Here, it is assumed that the user instructs to capture a still image while observing the 3D display. Then, the signal processing and control unit 21 shifts the processing from step S16 in FIG. 11 to step S18 to perform still image shooting. That is, the signal processing and control unit 21 corrects the right and left still images at the shooting instruction timing, compresses them, and causes the recording / reproducing unit 26 to record them on the recording medium (step S9). Further, the signal processing and control unit 21 causes the right and left still images after the image correction to be displayed on the display units 55R and 55L for a certain period of time.

  Further, it is assumed that the user gives an instruction to capture a moving image while observing the 3D display. In this case, the signal processing and control unit 21 moves from step S16, S17 to step S7 to perform moving image shooting.

  As described above, in this embodiment, communication with the interchangeable lens is performed, and lens information including correction coefficient data is automatically acquired, so that distortion or the like according to the state of the lens system of the interchangeable lens is obtained. Image reproducibility defects can be automatically corrected. Image correction is performed using the actual state information of the interchangeable lens, not the lens control information held in the main body circuit unit 20, and high-accuracy image correction is possible.

  In addition, the correction coefficient data includes state information such as zooming, focusing, rotation angle information, and baseline length that has changed since the start of camera control, so that reliable image correction is possible regardless of camera operation. Further, by using correction coefficient data such as the rotation angle information and the baseline length, the rotation angle of the image can be automatically corrected.

  Note that the interchangeable lens may hold correction coefficient data itself for zooming, focusing, rotation angle information, and baseline length, and coefficient correction data for correcting the initial correction coefficient according to the change in the state of the interchangeable lens. May be. In this case, the image correction unit corrects the correction coefficient data with the coefficient correction data, and then performs image correction using the corrected correction coefficient data.

  A 2D lens may be used as an interchangeable lens. Therefore, as shown in FIG. 16, a flow that allows only the 3D-compatible body to use the 3D interchangeable lens may be adopted.

  When the main circuit unit 20 is turned on, the signal processing and control unit 21 requests the interchangeable lens circuit unit 40 to transmit lens information. In response to this, the interchangeable lens circuit unit 40 transmits lens information to the main body circuit unit 20. Further, the lens control unit 41 of the interchangeable lens circuit unit 40 transmits a command instructing the use prohibition state to the main body circuit unit 20.

  When the body circuit unit 20 recognizes from the lens information that the lens is a 3D lens and includes data for image correction, the body circuit unit 20 generates a use permission request command in response to the command for instructing the use prohibition state, and the interchangeable lens. Transmit to the circuit unit 40.

  The interchangeable lens circuit unit 40 changes the use permission flag of the main body circuit unit to a use permission state, and transmits a command instructing use permission to the main body circuit unit 20. Thereby, the main body circuit unit 20 performs lens control of the interchangeable lens and performs image correction using the correction coefficient data on the captured image from the imaging unit 24.

  When the main body circuit unit is a circuit that does not support 3D, the main body circuit unit does not perform lens control and image correction even when a command for instructing use is received from the interchangeable lens circuit unit 40.

  Moreover, it is possible to set it as the following aspects as an interchangeable lens for stereo photography.

  An optical system for stereo photography can be used as an interchangeable lens. When a stereo imaging optical system is used for an interchangeable lens, it is preferable to provide correction parameters relating to image correction (including numerical data that enables calculation of correction parameters). In this case, it is preferable to increase the memory in the camera body and reduce the number of firmware ups on the WEB.

  Although only the two-lens lens has been described here, it is needless to say that the present invention can also be applied to a lens that captures images from more viewpoints or a system that obtains a 3D image by dividing one lens region.

(Appendix 1)
In an imaging apparatus that includes an imaging unit and is capable of connecting an interchangeable lens for stereoscopic shooting so that a subject image can be formed on the imaging unit.
A communication unit for acquiring correction coefficient data from the interchangeable lens, each of which is capable of correcting displacement of a plurality of subject images formed on the imaging unit, which occurs in a direction rotating with respect to a principal ray from the subject;
An imaging apparatus having

(Appendix 2)
An interchangeable lens device that can be attached to and detached from a camera body having an image sensor,
The interchangeable lens device has a plurality of light incident surfaces, and a stereo imaging optical system that forms a plurality of parallax images having parallax corresponding to the positions of the plurality of light incident surfaces on the imaging element;
A correction parameter storage unit that stores correction parameters used when electrically correcting an image by the stereo imaging optical system;
An interchangeable lens apparatus for stereo photography, comprising: a communication unit that enables communication with the camera body when the correction parameter stored in the storage unit is connected to the camera body.

(Appendix 3)
The stereo imaging optical system is
The exchange for stereo imaging according to appendix 2, wherein a direction connecting each principal ray incident on each light incident surface when attached to the camera body is parallel to a direction in which pixels of the imaging element are arranged. Lens device.

(Appendix 4)
The stereo imaging optical system is
A first light guide optical system including a first reflecting surface and a first reflecting surface for guiding a light beam from a subject incident on one of the light beam incident surfaces to the image sensor; The second light guide optical system including a second-first reflection surface and a second-second reflection surface for guiding a light beam from a subject incident on one of the two to the image pickup device. Interchangeable lens device for stereo imaging.

(Appendix 5)
The stereo imaging optical system is
A first objective lens group and a second objective lens group having negative refractive power, which are arranged side by side in the parallax direction with the incident surface facing the subject side, and more than these first and second objective lens groups The interchangeable lens device for stereo imaging according to appendix 4, wherein the imaging lens group has a positive refractive power and is integrally or individually disposed on the image side.

(Appendix 6)
The stereo imaging optical system is configured such that at least two parallax images having the parallax projected on the imaging device are projected side by side in directions different from their parallax directions. The interchangeable lens for stereo imaging according to any one of appendices 2 to 5.
(Appendix 7)
A central ray of a light beam reaching the center of a parallax image projected on the single imaging element through the first objective lens group, the first light guide optical system, and the imaging lens group is a first principal ray, When the central ray of the light beam reaching the center of the parallax image projected on the single image sensor through the second objective lens group, the second light guide optical system, and the imaging lens group is the second principal ray 7. Each of the first objective lens group and the second objective lens group is an optical system that deflects the corresponding first chief ray and second chief ray, respectively. Interchangeable lens for stereo imaging.
(Appendix 8)
The stereo imaging device according to appendix 7, wherein the first chief ray incident on the first objective lens group and the second chief ray incident on the second objective lens group are located in substantially the same plane. interchangeable lens.
(Appendix 9)
The interchangeable lens for stereo imaging according to appendix 6, wherein a direction different from the parallax direction in which parallax images are arranged on the imaging element is a direction intersecting with the parallax direction of the parallax image.
(Appendix 10)
The imaging surface of the imaging device has a rectangular shape having a long side direction and a short side direction, and a parallax image via the first objective lens group and a parallax image via the second objective lens group are The interchangeable lens for stereo imaging according to appendix 5, wherein the interchangeable lens is projected side by side in the short side direction of the image sensor.
(Appendix 11)
The interchangeable lens for stereo imaging according to appendix 2, wherein the correction parameter storage unit stores a correction parameter used for correcting rotation of the plurality of parallax images formed by the stereo imaging optical system.

(Appendix 12)
The interchangeable lens for stereo imaging according to appendix 2, wherein the correction parameter storage unit stores correction parameters used for correcting distortion of the plurality of parallax images formed by the stereo imaging optical system.

(Appendix 13)
The interchangeable lens for stereo imaging according to appendix 2, wherein the correction parameter storage unit stores correction parameters used for correcting shading of the plurality of parallax images formed by the stereo imaging optical system.

(Appendix 14)
The interchangeable lens for stereo imaging according to appendix 2, wherein the correction parameter storage unit stores correction parameters used for correcting chromatic aberration of the plurality of parallax images formed by the stereo imaging optical system.

(Appendix 15)
The stereo correction imaging unit according to appendix 2, wherein the correction parameter storage unit stores a parameter for performing image cropping to avoid a region where the plurality of parallax images formed by the stereo imaging optical system overlap. interchangeable lens.

(Appendix 16)
The interchangeable lens for stereo imaging according to appendix 2, wherein the correction parameter storage unit stores information representing a principal ray interval on an incident surface of the stereo imaging optical system.

(Appendix 17)
The interchangeable lens for stereo imaging according to appendix 2, wherein the correction parameter storage unit stores information indicating an angle formed between principal rays of the stereo imaging optical system.

(Appendix 18)
The interchangeable lens for stereo imaging according to appendix 2, wherein the correction parameter stores information representing a zoom state, a focus state, and an aperture value of the stereo imaging optical system.

(Appendix 19)
The interchangeable lens for stereo imaging according to appendix 2, wherein the stereo imaging optical system is capable of changing an angle between principal rays and / or a distance between principal ray passing positions on a light incident surface. .

    DESCRIPTION OF SYMBOLS 10 ... Imaging device, 11 ... Imaging device main body, 12 ... Interchangeable lens, 13 ... Electronic finder, 20 ... Main body circuit part, 21 ... Signal processing and control part, Image correction part ... 21a, 22, 23, 42, 52 ... Communication Reference numeral 24: Imaging unit 30: Main body display unit 40: Interchangeable lens circuit unit 50: Electronic viewfinder circuit unit

Claims (6)

In an imaging apparatus that includes an imaging unit and is capable of connecting an interchangeable lens for stereoscopic shooting so that a subject image can be formed on the imaging unit.
A communication unit that acquires correction coefficient data from the interchangeable lens that can correct optical distortion and image overlap due to the type of the interchangeable lens for the stereoscopic shooting and an error in the workmanship, image error,
An imaging apparatus having   The imaging apparatus according to claim 1, wherein the correction coefficient data includes at least one of a lens type, a baseline length of the photographing lens, and error information specific to the interchangeable lens. In an imaging apparatus that includes an imaging unit and is capable of connecting an interchangeable lens for stereoscopic shooting so that a subject image can be formed on the imaging unit.
A communication unit for acquiring correction coefficient data from the interchangeable lens, each of which is capable of correcting displacement of a plurality of subject images formed on the imaging unit, which is generated in a direction rotating with respect to a principal ray from the subject;
An imaging apparatus comprising: a recording unit that records the correction coefficient data in association with a captured image captured by the imaging unit.   4. The image pickup apparatus according to claim 3, wherein the correction coefficient data includes at least one of a lens type, a baseline length of the photographing lens, and error information specific to the interchangeable lens. In an imaging apparatus that includes an imaging unit and is capable of connecting an interchangeable lens for stereoscopic shooting so that a subject image can be formed on the imaging unit.
A communication unit that acquires correction coefficient data for correcting a defect in reproducibility of a subject image formed on the imaging unit, which is generated based on a state of a lens system of the interchangeable lens from the interchangeable lens;
An image correction unit that generates an image in which the displacement of the subject image is corrected based on the correction coefficient data acquired by the communication unit.   The imaging apparatus according to claim 5, wherein the communication unit acquires correction coefficient data including a fixed value unique to the interchangeable lens and a variable value generated by a change in the state of the interchangeable lens.

Images