JP4536893B2 - camera - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a camera including light receiving means and a focus optical system including an optical member that operates in association with a focus detection operation.
[0002]
[Prior art]
Conventionally, a main mirror having a semi-transmissive portion for guiding the light beam that has passed through the photographing lens to the finder optical system, and a sub mirror for guiding the light beam that has passed through the semi-transmissive portion of the main mirror to the focus detection device, A camera is proposed that is configured to move the main mirror and sub mirror to a fixed position in the imaging optical path and stop at this position during viewfinder observation, and to move the main mirror and sub mirror out of the imaging optical path during imaging. ing.
[0003]
In this type of camera, when the number of operations of the main mirror and the sub mirror increases, the members related to the driving of the main mirror and the sub mirror wear, and accordingly, the stationary positions of the main mirror and the sub mirror at the time of focus detection change. There has been a problem that the focus position detected by the focus detection device and the focus position of the imaging plane are shifted due to a change in the optical path length of the light beam guided to the detection device.
[0004]
Therefore, in Japanese Patent Laid-Open No. 9-54243, the relationship between the accumulated number of operations of the optical member and the focus detection signal correction amount is stored in advance, and at the time of focus detection, the accumulated number of operations at that time and the accumulated operation count stored in advance. A camera that corrects a focus detection signal based on a relationship between focus detection signal correction amounts has been proposed.
[0005]
FIG. 14 is a block diagram showing the main part of the camera disclosed in the Japanese Patent Laid-Open No. 9-54243.
[0006]
In FIG. 1, reference numeral 101 denotes a photographic lens, 101a denotes an optical axis of the photographic lens, and 102 denotes an image recording medium on which a subject image that has passed through the photographic lens 101 is formed. Reference numeral 103 denotes a main mirror having a semi-transmissive portion that is provided so as to be movable out of the photographing optical path at the time of photographing. It leads to the optical system. On the other hand, the remaining light beam that has passed through the semi-transmissive portion of the main mirror 103 is reflected downward by the sub-mirror 107 configured to be movable in synchronization with the operation of the main mirror 103, and consists of a pair of photoelectric conversion element arrays. The light is guided to a well-known phase difference type focus detection device 108 including an image sensor, a pair of secondary imaging lenses, a diaphragm having a pair of openings, a field lens, and the like.
[0007]
Here, the focus detection principle of the phase difference method will be described with reference to FIG. In addition, the part which attached | subjected the same symbol as FIG. 14 has the same function. Further, in FIG. 15, the main mirror 103 and the sub mirror 107 are omitted, and the field lens 115, the diaphragm 116 having a pair of openings, a pair of secondary imaging lenses 117, a pair of pairs are omitted in order to eliminate the complexity of the drawing. An image sensor 118 composed of a photoelectric conversion element array or the like is developed on the optical axis 101a of the photographing lens.
[0008]
The light beam emitted from one point on the optical axis 101a passes through the photographing lens 101, and then forms an image on the primary imaging surface 102a that is optically conjugate with the image recording medium 102. An image is formed on the image sensor 118 at a predetermined interval via the secondary imaging lens 117. The field lens 115 is arranged so that the pupil 101 b of the photographing lens 101 and the entrance pupil of the pair of secondary imaging lenses 117, that is, the vicinity of the stop 116, correspond to the pair of openings of the stop 116. Thus, the pupil 101b of the photographing lens 101 is divided in the vertical direction in the figure.
[0009]
With such a configuration, for example, when the photographic lens 101 is extended to the left in the figure and a light beam forms an image to the left from the image recording medium 102, the pair of images on the image sensor 118 are displaced in the direction of the arrow in the figure. To do. By detecting the relative shift amount of the pair of images by the image sensor 118, it is possible to adjust the focus of the photographing lens 101. The same applies to the case where the photographing lens 101 is retracted to the right in the drawing. The same applies to object points other than the optical axis 101a of the photographing lens 101.
[0010]
The focus detection device 108 having the above principle is used to detect the focus of the photographing lens 101.
[0011]
Returning to FIG. 14, reference numeral 109 denotes a microcomputer that processes and controls various operations of the camera. The ROM 109b, the RAM 109c, and the EEPROM 109d (programmable ROM capable of electrically erasing) in which programs related to the CPU 109a and the focus detection processing operation are stored. ). 110 is a focus detection circuit connected to the image sensor 118, 111 is a mirror driving means for moving the main mirror 103 out of the imaging optical path, 112 is a mirror driving circuit for driving the mirror driving means 111, and 113 is imaging. A lens driving unit 114 for adjusting the focus of the lens 101, and a lens driving circuit 114 for driving the lens driving unit 113.
[0012]
The EEPROM 109d built in the microcomputer 109 stores in advance the relationship between the cumulative number of operations of the main mirror 103 and the focus detection signal correction amount based on experimental data, and the main mirror 103 up to the present stored in the RAM 109b. , The focus obtained by the focus detection device 108 and the focus detection circuit 110 in accordance with the focus detection processing operation stored in the ROM 109c based on the relationship between the integration operation count stored in the EEPROM 109d and the focus detection signal correction amount. Correct the detection signal. Therefore, when the cumulative number of operations of the main mirror 103 and the sub mirror 107 increases, the members that hold the main mirror 103 and the sub mirror 107 movably wear, and accordingly, the stationary positions of the main mirror and the sub mirror at the time of focus detection. The focus position detected by the focus detection device 108 and the focus detection circuit 110 deviates from the focus position on the image recording medium 102 due to the change in the optical path length of the focus detection optical system. Since the focus detection signal is corrected based on the number of integration operations 103, high-precision focus detection can be realized.
[0013]
[Problems to be solved by the invention]
However, for example, when the main mirror 103 is operated in a short-time intensive manner and when the main mirror 103 is operated after an appropriate time interval, the main mirror 103 and the sub-mirror 107 are connected even if the number of integrated operations is the same. The degree of wear and the degree of fatigue of the members to be held are different, and the shift of the focus detection signal associated therewith is also different. Nevertheless, in the above-described conventional example, the focus detection signal is uniformly corrected according to the number of cumulative operations of the main mirror 103, and therefore, appropriate correction of the focus detection signal cannot be expected.
[0014]
Further, the degree of wear and the degree of fatigue differ depending on the manufacturing error and assembly error of individual parts, and there is a problem that an appropriate focus detection signal cannot be corrected.
[0015]
(Object of invention)
The first object of the present invention is to calculate a change in position relative to these fixed positions due to an increase in the number of operations of the optical member, mirror member or sub-mirror, and to change the optical path length of the focus detection optical system due to this change in position. Therefore, it is an object of the present invention to provide a camera capable of appropriately correcting a shift between the in-focus position and the in-focus position on the imaging surface and performing highly accurate focus detection.
[0016]
A second object of the present invention is to provide a camera capable of performing highly accurate focus adjustment.
[0017]
A third object of the present invention is to provide a camera capable of calculating focus information in many focus detection areas without occupying an effective range used for focus detection of an optical member, a mirror member, or a submirror. It is something to be offered.
[0018]
A fourth object of the present invention is to provide a camera capable of detecting a predetermined image with light receiving means with higher accuracy.
[0019]
[Means for Solving the Problems]
In order to achieve the first object, the invention according to claim 1 is a light receiving means comprising a plurality of photoelectric conversion elements, and at the time of focus detection, is moved from outside the photographing optical path to a fixed position within the photographing optical path, In a camera having an optical member that guides the light beam that has passed through the photographing lens onto the light receiving means, the light beam enters the effective range of the optical member that is used to guide the light beam to the light receiving means. An image forming unit for forming a predetermined image is provided on the light receiving unit, and an arithmetic unit for calculating a positional change of the optical member with respect to the fixed position is provided based on a light amount distribution related to the predetermined image on the light receiving unit. A camera.
[0020]
Similarly, in order to achieve the first object, the invention according to claim 2 is a light receiving means comprising a plurality of photoelectric conversion elements, and is moved from the outside of the photographing optical path to a fixed position within the photographing optical path at the time of focus detection. In a camera having an optical member that guides the light flux that has passed through the photographing lens onto the light receiving means, the light flux is incident within an effective range of the optical member that is used to guide the light flux to the light receiving means. And providing an image forming portion for forming a predetermined image on the light receiving means, and based on each output output from the plurality of photoelectric conversion elements constituting the light receiving means by forming the predetermined image, The camera is provided with calculation means for calculating a change in position of the optical member with respect to the fixed position.
[0021]
Similarly, in order to achieve the first object, the invention according to claim 3 is a light receiving means comprising a plurality of photoelectric conversion elements, and is moved from outside the photographing optical path to a fixed position within the photographing optical path at the time of focus detection. In a camera having a mirror member that guides the light flux that has passed through the photographing lens onto the light receiving means, the light flux is incident within an effective range of the mirror member that is used to guide the light flux to the light receiving means. And providing an image forming portion for forming a predetermined image on the light receiving means, and based on each output output from the plurality of photoelectric conversion elements constituting the light receiving means by forming the predetermined image, The camera is provided with calculation means for calculating a positional change of the mirror member with respect to the fixed position.
[0022]
Similarly, in order to achieve the first object, the invention according to claim 4 includes a light receiving means including a plurality of pairs of photoelectric conversion elements and a fixed position in the photographing optical path from the outside of the photographing optical path at the time of focus detection. In a camera for detecting focus information by a phase difference method, having a sub-mirror that guides the light beam that has been moved and passed through the photographic lens onto the light-receiving unit, the sub-mirror is used to guide the light beam to the light-receiving unit. An image forming unit that forms a predetermined image on the light receiving unit when the luminous flux enters the effective range is provided, and the plurality of photoelectric elements that constitute the light receiving unit by forming the predetermined image. The camera is provided with calculation means for calculating a position change of the submirror with respect to the fixed position based on each output output from the conversion element.
[0023]
In order to achieve the second object, the invention according to claim 7 comprises a focus adjusting means for converting the focus information obtained by the focus detecting means into a driving amount of the photographing lens and performing focus adjustment. The camera according to claim 6 is provided.
[0024]
In order to achieve the third object, the invention according to claim 11 is characterized in that at least one or more of the image forming portions are provided in the vicinity of an end of the optical member. A camera.
[0025]
Similarly, in order to achieve the third object, the invention according to claim 12 is the camera according to claim 3, wherein at least one of the image forming portions is provided in the vicinity of an end of the mirror member. Is.
[0026]
Similarly, in order to achieve the third object, the invention according to claim 13 is the camera according to claim 4, wherein at least one of the image forming portions is provided in the vicinity of an end of the sub mirror. It is.
[0027]
In order to achieve the fourth object, the invention according to claim 14 is the camera according to any one of claims 1 to 4, wherein the image forming portion has a linear shape. is there.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail based on illustrated embodiments.
[0029]
(First embodiment)
FIG. 1 is a block diagram showing a main part of a camera according to each embodiment of the present invention. Portions having the same functions as those in FIG. 14 are given the same reference numerals, and detailed descriptions thereof are omitted.
[0030]
In FIG. 1, a part of the light beam that has passed through the photographic lens 101 is reflected upward in the figure by a main mirror 103 having a semi-transmissive portion, and is guided to a finder optical system that includes a focus plate 104, a pentaprism 105, and an eyepiece lens 106. It is burned. On the other hand, the remaining light beam that has passed through the semi-transmissive portion of the main mirror 103 is reflected downward in the figure by the sub-mirror 107 and guided to the focus detection device 108 that employs a known phase difference method.
[0031]
The light beam reflected downward in the figure by the sub-mirror 107 forms an image once on the imaging surface of the taking lens 101, that is, the primary imaging surface 102a that is optically conjugate with the image recording medium 102, and the field mask. 1. After passing through the pupil 101b of the taking lens 101 and the field lens 115 that forms the entrance pupil of the secondary imaging lens, the total reflection mirror 2 converts the optical path to the left in the figure. Thereafter, a pair of subject images are formed on the image sensor 118 including a pair of photoelectric conversion element arrays via the infrared cut glass 3, the diaphragm 116 having a pair of openings, and the secondary imaging lens 117 having a pair of exit surfaces. is doing.
[0032]
Here, the main mirror 103 is provided so as to be rotatable about a main mirror rotation shaft 103a. The main mirror 103 is stationary at the position shown in FIG. 1 at the time of focus detection, and retracts out of the photographing optical path at the time of photographing. It is comprised by. The same applies to the sub mirror 107. In addition, the incident surface of the secondary imaging lens 117 has a concave shape so that the light beam is not refracted excessively, and a good image without distortion can be obtained over a wide range on the image sensor 118.
[0033]
As shown in FIG. 2, the image sensor 118 includes a pair of photoelectric conversion element arrays formed of a plurality of photoelectric conversion elements, and a pair of photoelectric conversion elements corresponding to a pair of exit surfaces of the secondary imaging lens 117. Rows 4a, 4b and 5a, 5b and 6a, 6b are formed. The pair of photoelectric conversion element arrays 4a, 4b and 5a, 5b and 6a, 6b detect the light quantity distribution relating to the pair of subject images, thereby detecting the focus adjustment state of the photographing lens 101 by well-known phase difference type focus detection. is doing.
[0034]
In the drawing, only the photoelectric conversion element rows 4a and 4b are shown for each pixel, but the other photoelectric conversion element rows 5a, 5b, 6a, and 6b are similarly configured. Further, as shown in the figure, the pair of photoelectric conversion element arrays 4a and 4b are divided into regions (1), (2), and (3), but the other photoelectric conversion element arrays 5a, 5b, and 6a are divided. , 6b are similarly divided.
[0035]
  FIG. 3 is a diagram in which a pair of photoelectric conversion element arrays 4a, 4b and 5a, 5b and 6a, 6b on the image sensor 118 are back projected onto the image recording medium 102 and viewed from the photographing lens 101 side. On the medium 102, the pair of photoelectric conversion element arrays 4a, 4b and 5a, 5b and 6a, 6b are substantially coincident with each other and are shown as 4, 5, 6 in the figure. In FIG. 3, 7a, 7b, 7c,7d isA focus detection frame (not shown) displayed in the viewfinder is back projected onto the image recording medium 102.
[0036]
  Here, as described above, the pair of photoelectric conversion element arrays 4a, 4b, 5a, 5b, 6a, and 6b is divided into regions 1, 2, and 3, respectively. , 5 and 6 are also divided into three corresponding to the divided areas 1, 2 and 3 of the photoelectric conversion element arrays 4a, 4b, 5a, 5b, 6a and 6b. One focus detection area is formed. A focus detection frame is provided corresponding to the focus detection area. Therefore, when the focus detection frame is back-projected onto the image recording medium 102, as shown in FIG. 3, the position 7a is positioned at the position corresponding to the focus detection area. , 7b, 7c,7d isTo position.
[0037]
  With the above configuration, 7a, 7b, 7c,7dBy adjusting the target subject to the focus detection frame in the corresponding finder, the focus adjustment state of the photographing lens can be detected. Of the divided focus detection areas of the focus detection areas 4, 5 and 6, the areas 1 in the photoelectric conversion element arrays 4a, 4b, 6a and 6b corresponding to the focus detection areas indicated by the dotted lines in FIG. 3 is not used for focus detection in the present embodiment.
[0038]
FIG. 4 is a front view of the reflecting surface when the sub mirror 107 shown in FIG. 1 is viewed from the photographing lens 101 side.
[0039]
Patterns 8a and 8b are provided on the reflecting surface side of the sub mirror 107 by means of printing or the like as shown in the figure, and are composed of a black low-reflective paint or the like so that the reflectance becomes as low as possible. ing. Therefore, the subject image formed on the image sensor 118 is a light beam reflected in the area excluding the patterns 8 a and 8 b on the sub mirror 107. The patterns 8a and 8b are positioned at positions on the sub-mirror 107 corresponding to the region (3) so that the patterns 8a and 8b can be detected in the region (3) of the pair of photoelectric conversion element arrays 4a and 4b and 6a and 6b of the image sensor 118, respectively. Is provided.
[0040]
With the configuration as described above, even if the stationary position at the time of focus detection of the sub-mirror 107 that is movably provided along with photographing changes due to an increase in the number of times of cumulative operation, the sub-mirror 107 is provided on the sub-mirror 107. By using the detection results of the patterns 8a and 8b by the image sensor 118, it is possible to correct the shift of the focus detection signal, and it is possible to detect the focus with high accuracy.
[0041]
First, the detection of the patterns 8a and 8b by the image sensor 118 will be described.
[0042]
FIG. 5 is a diagram in which the patterns 8a and 8b on the sub mirror 107 are projected onto the image sensor 118 of FIG. 2 in the initial state where the stationary position of the sub mirror 107 has not changed.
[0043]
A pair of pattern images 9a, 9b and 9c, 9d shown by hatched areas in the figure corresponding to the patterns 8a, 8b are arranged at predetermined intervals on the region (3) of the pair of photoelectric conversion element arrays 4a, 4b and 6a, 6b. Are formed with a gap. Actually, since the reflectance of the patterns 8a and 8b on the sub-mirror 107 is extremely low, no image is formed on the image sensor 118. However, in order to make the region on the image sensor 118 corresponding to the patterns 8a and 8b easy to understand, It is shown as a hatched area. The image actually formed on the image sensor 118 is only the light receiving area of the pair of photoelectric conversion element arrays 4a, 4b and 5a, 5b and 6a, 6b so that the light flux is not guided to other areas. Limited by the field mask 1 of FIG.
[0044]
FIG. 6 is an enlarged view of a main part in which the vicinity of the pattern images 9a and 9b of the photoelectric conversion element arrays 4a and 4b shown in FIG. 5 is enlarged, and the focus of the photographing lens 101 is on the image recording medium 102 as in FIG. Is imaged.
[0045]
  In the figure, reference numerals 10a and 10b denote image signals output from the photoelectric conversion element arrays 4a and 4b based on the light amount distribution relating to the pattern image, and Z₀Is the image interval obtained from the image signals 10a and 10b through a known image interval detection process,RespectivelyShow. Since the pattern 8a on the sub-mirror 107 is away from the primary imaging plane 102, the pair of pattern images 9a and 9b actually formed on the image sensor 118 are blurred images. Therefore, for example, when a subject with uniform and appropriate luminance is detected in the region 3 of the photoelectric conversion element arrays 4a and 4b, the output image signal has a slightly gradual falling curve as indicated by 10a and 10b.
[0046]
  Further, the positions where the pattern images 9a and 9b are formed on the image sensor 118 are also slightly shifted from the optically conjugate positions. However, when a substantially uniform and appropriate subject is detected in the region 3 of the photoelectric conversion element arrays 4a and 4b, the image signal output from the image sensor 118 is flat as shown by 10a and 10b in FIG. The high-intensity part (peak part) and the flat low-intensity part (bottom part) appear remarkably, so that the image interval between the pattern images 9a and 9b is Z₀Then, the image interval Z is detected using a known image interval detection process.₀ Can be detected. This image interval Z₀ Is the image interval in the initial state in which the stationary position of the sub mirror 107 has not changed. It should be noted that the arithmetic filter processing is applied to the image signals 10a and 10b related to the pattern images 9a and 9b.GiveIf the noise component is removed, even if the subject is somewhat uneven, the image interval Z₀Can be detected accuratelyButIs possible.
[0047]
Further, since the pattern 8a on the sub mirror 107 is located between the photographing lens and the primary imaging plane 102a, it is not affected by the focus adjustment state (defocusing) of the photographing lens 101, and the image interval Z₀ Is always constant in any focus adjustment state. That is, the image interval Z₀ Depends on the position change of the subject and the optical member.
[0048]
Next, a case where the stationary position is changed due to an increase in the number of operations of the sub mirror 107 will be described.
[0049]
FIG. 7 is an enlarged view of a main part in which a part centering on the sub-mirror 107 in FIG. 1 is enlarged, and parts having the same reference numerals as those in FIG. 1 and the like are parts having the same functions, and details thereof are omitted. .
[0050]
When the cumulative number of operations of the main mirror 103 and the sub mirror 107 that are operated in accordance with the photographing operation of the camera increases, the stationary positions of the main mirror 103 and the sub mirror 107 change due to wear and fatigue of the members constituting these operating mechanisms.
[0051]
  Therefore, for example, as shown in FIG. 7, a case is considered in which the stationary position of the sub mirror 107 changes as indicated by a dotted line 107 'around the sub mirror rotation axis 107a. The main mirror103The change of the stationary position due to the cumulative number of operations is omitted because it has less influence on the focus detection device 108 than the sub mirror 107.
[0052]
When the stationary position of the sub mirror 107 does not change, that is, in the initial state, the optical axis 101a of the taking lens 101 becomes the optical axis 101c whose direction has been changed downward in the figure by the sub mirror 107 after passing through the main mirror 103, thereby detecting focus. Guided to device 108. On the other hand, when the stationary position of the sub mirror 107 is changed to 107 ′ indicated by a dotted line in the figure, the optical axis 101a of the photographing lens 101 passes through the main mirror 103, and the optical path is changed by the sub mirror 107 ′. 'Become. Accordingly, the primary imaging plane 102a also tilts while shifting to the right and upward in the figure as indicated by 102a 'indicated by a dotted line in the figure.
[0053]
  FIG. 8 is an enlarged view of the main part similar to FIG. 6, and the pattern is shown when the sub mirror 107 is displaced to the stationary position 107 'in FIG.8aIs projected onto the image sensor 118. Similar to FIGS. 5 and 6, the focal point of the photographing lens 101 forms an image on the image recording medium 102. Also, in the figure, the parts denoted by the same reference numerals as those in the above figures are parts having the same functions, and the details thereof are omitted.
[0054]
As shown in FIG. 7, the primary imaging surface 102a becomes 102a ', the primary imaging surface moves to the photographing lens 101 side, and the optical path length from the primary imaging surface to the image sensor 118 becomes longer. Therefore, the pair of pattern images 9a and 9b move in the direction in which the image interval is reduced to become 9a ′ and 9b ′ indicated by dotted lines in FIG. Strictly speaking, the movement amounts of the pair of pattern images 10a and 10b are different. Accordingly, the image signals 10a and 10b by the image sensor 118 also become 10a 'and 10b' indicated by dotted lines in the drawing, and the image interval Z after the change of the stationary position of the sub mirror 107 is performed by a known image interval detection process.₁ Is calculated.
[0055]
Here, the image interval Z in the initial state₀ And the image interval Z after the change of the stationary position of the submirror 107₁ From the following equation (1), the image interval deviation amount ΔZ₁ Is calculated.
[0056]
ΔZ₁ = Z₁ -Z₀                                   ………… (1)
This image interval deviation amount ΔZ₁ Is reflected in the focus adjustment amount of the photographic lens 101, high-precision focus detection can be realized even if the stationary position of the sub mirror 107 changes.
[0057]
Up to this point, the pattern 8a on the submirror 107 has been described. However, the same applies to the pattern 8b, and the description thereof is omitted.
[0058]
Next, an actual operation related to the correction of the focus detection signal will be described.
[0059]
FIG. 9 is a block diagram showing the circuit configuration of the camera according to the present embodiment, and parts having the same functions as those in the above figures are given the same reference numerals.
[0060]
A focus detection circuit 110 is connected to the image sensor 118, and the focus detection circuit 110 is further connected to a microcomputer 109, which is a processing device, to specify a light receiving area of the image sensor 118 and to control accumulation of photocharges. . The microcomputer 109 includes a CPU (central processing unit) 109a, a ROM 109b, a RAM 109c, and an EEPROM (electrically erasable programmable ROM) 109d, and executes a focus detection operation according to a program stored in the ROM 109b.
[0061]
  The EEPROM 109d stores optical information of the focus detection optical system in advance during the adjustment process. Further, the microcomputer 109 is connected to a switch SW1 that is turned on by a first stroke of a release button operated by a photographer and a switch SW2 that is turned on by a second stroke. Further, a mirror driving circuit 112 for driving the mirror driving means 111 for retracting the main mirror 103 and the sub mirror 107 out of the photographing optical path at the time of photographing, and a lens for adjusting and moving a focus lens row (not shown) of the photographing lens 101 according to the focus detection state. To drive the driving means 113ofA lens driving circuit 114 is connected to the microcomputer 109.
[0062]
Next, the operation of the microcomputer 109 that proceeds the processing according to the focus detection processing program stored in the ROM 109b will be described with reference to the flowchart of FIG.
[0063]
First, in step # 101, it is determined whether the release button is operated by the photographer and the hand switch SW1 is turned on, and the process proceeds to step # 102 when turned on. In step # 102, photocharge accumulation is started in each region of the image sensor 118 corresponding to at least one focus detection frame (not shown) selected in advance, and the accumulated charges are read out as a pair of image signals. And stored in the RAM 109c. In the subsequent step # 103, the reliability of the image signal is determined. If the reliability does not satisfy the predetermined condition, it is determined that the focus cannot be detected, the process proceeds to step # 104, and the process proceeds when the focus cannot be detected.
[0064]
On the other hand, if the reliability of the focus detection signal satisfies the predetermined condition, the process proceeds from step # 103 to step # 105, and after correcting the pair of image signals by the aberration of the focus detection optical system, the specific frequency component is removed. Executes digital filter calculation processing. In the next step # 106, a known image interval detection process is performed on the pair of image signals, thereby calculating an image shift amount from the image interval at the time of focusing and the current image interval. The image interval at the time of focusing differs for each focus detection area described with reference to FIG. 3, and the image interval at the time of focusing in each focus detection area is stored in the EEPROM 109d in advance. Thereafter, various corrections such as correction of the image interval due to temperature are performed, and the focus adjustment amount of the photographing lens 101 in the focus detection frame selected previously is calculated.
[0065]
Next, in step # 107, the driving amount of the focus lens (not shown) of the photographing lens 101 is calculated from the calculated focus adjustment amount, and the lens driving device 113 is driven by the driving amount calculated through the lens driving circuit 114. The focus of the photographic lens 101 is adjusted. Then, in the next step # 108, it is determined whether or not the focus adjustment state after driving the lens is within the in-focus range. If it is determined that it is within the in-focus range, the process proceeds to step # 109. If it is determined that it is not within the focal range, the process returns to the focus detection process in step # 102.
[0066]
Proceeding to step # 109, here, the photocharge accumulated in the region (3) of the pair of photoelectric conversion element arrays 4a, 4b and 6a, 6b of the image sensor 118 onto which the patterns 8a and 8b shown in FIG. 5 are projected. Are read out as a pair of image signals and stored in the RAM 109. Here, two pairs of image signals relating to the patterns 8a and 8b are stored. In the next step # 110, the reliability of the pair of image signals is determined, and the reliability of one or both of the pair of image signals satisfies a predetermined condition. If it is determined, the process proceeds to step # 111. If it is determined that the reliability does not satisfy the predetermined condition, the process immediately proceeds to step # 116, and the pattern detection process is terminated.
[0067]
Here, as described with reference to FIG. 5, as a reliability determination method, image signals related to the patterns 8a and 8b when a subject with uniform and appropriate luminance is detected are stored in the EEPROM 109d in advance during the manufacturing process. In addition, a method of determining based on the correlation amount between the image signal and the image signal at the time of pattern detection can be considered.
[0068]
When the process proceeds to step # 111 assuming that the reliability of the image signal satisfies the predetermined condition, a digital filter calculation process for removing the specific frequency component is performed after correcting the pair of image signals by the aberration of the focus detection optical system. Do. In the next step # 112, first, a known image interval detection process is performed on the pair of image signals determined to have reliability satisfying a predetermined condition, and the image interval is calculated. Next, from the initial image interval stored in the EEPROM 109d in the manufacturing process in advance, the image interval shift amount is calculated by the above equation (1), and at the same time, the total number of detections is calculated. The number of times of integration detection here means the number of times of integration up to the present when the predetermined condition is satisfied in the reliability determination in step # 110, and 1 when the next step # 112 is passed. It is rewritten to the value increased by times.
[0069]
Here, the image interval deviation amount by the pattern 8a when the cumulative number of detections is n is expressed as ΔZ._an, The image interval deviation amount by the pattern 8b is ΔZ_bnThen, the representative image interval deviation amount ΔZ by the following equation (2):_n Is calculated.
[0070]
ΔZ_n = (ΔZ_an+ ΔZ_bn) / 2 ......... (2)
However, the image interval deviation amount ΔZ is determined based on the result of the reliability determination in step # 110._anOr image interval deviation amount ΔZ_bnIf only one of these is calculated, the calculated image interval deviation amount is represented by the representative image interval deviation amount ΔZ regardless of the above equation (2)._n And
[0071]
In the next step # 113, the representative image interval deviation amount ΔZ_n And the number n of integrated detections at that time is stored in the EEPROM 109d. Then, in the next step # 114, it is determined whether or not the integrated detection count n is equal to or greater than the threshold value m. If the accumulated detection number n is equal to or greater than the threshold value m, the process proceeds to step # 115. move on. Here, the threshold value m is provided in order to eliminate the influence of slight variations in the stationary position for each operation of the sub mirror 107 and variations in the pattern detection signal depending on the subject. This is because high-precision focus detection can be realized by using and correcting. When the number of integrated detections n is extremely small compared to the increase in the number of actuations of the sub mirror 107 and is unlikely to reach the threshold value m, the value of the threshold value m is changed according to the number of actuations of the sub mirror 107. It is desirable to make corrections at appropriate timing.
[0072]
Proceeding to step # 115, here, a plurality of representative image interval deviation amounts ΔZ stored in the EEPROM 109d at step # 113 above.₁ , ΔZ₂ , ..., ΔZ_m Then, an image interval correction amount is derived from this, and this image interval correction amount is multiplied by a coefficient corresponding to each focus detection region to calculate an image interval correction amount for each focus detection region. Therefore, the image interval correction amount is set to ΔZ_C For example, the coefficient in the focus detection area corresponding to the focus detection frame 7a in FIG._FP1 Then, the image interval correction amount ΔZ for each focus detection area_FP1CIs calculated by the following equation (3).
[0073]
ΔZ_FP1C= C_FP1 × ΔZ_C                           ………… (3)
Image interval correction amount ΔZ for each focus detection area_FP1CBased on the above, the image interval at the time of focusing in the initial state stored in the EEPROM 109d in advance is corrected, and the integrated detection number n stored in step # 113 is reset to zero.
[0074]
Now, the image interval at the time of focusing on the initial state in the focus detection area corresponding to the focus detection frame 7a is set to Z._FP1 Then, the image interval Z according to the following equation (4):_FP1 Is rewritten, and the deviation of the image interval accompanying the change in the stationary position of the sub mirror 107 is corrected from the next focus detection.
[0075]
Z_FP1 = Z_FP1 + ΔZ_FP1C                          ………… (4)
Similarly, the image interval shift is corrected in the focus detection areas corresponding to the other focus detection frames 7b to 7e.
[0076]
The coefficient C corresponding to the focus detection area_FP1 Is a constant estimated from experimental results of experimentally measuring a change in the stationary position accompanying an increase in the number of actuations of the submirror 107, and is determined in advance. Therefore, the correction of the image interval shift accompanying the change in the stationary position of the sub mirror 107 is performed every m times of detection (m is a threshold value). Here, the image interval correction amount ΔZ_C The coefficient C corresponding to the focus detection area_FPAs shown in FIG. 7, assuming that the stationary position of the sub mirror 107 changes around the sub mirror rotation axis 107a, the change in the optical path length of the focus detection optical system differs depending on the light beam reflection position on the sub mirror 107, as shown in FIG. It is.
[0077]
Next, the process proceeds to step # 116, where it is determined whether or not the switch SW2 that is turned on by the second stroke of the release button has been operated by the photographer. If the switch SW2 is turned on, the process proceeds to step # 117, where the switch is turned on. If not, wait at this step. Thereafter, when the switch SW2 is turned on, the process proceeds to step # 117, where the mirror driving means 111 is driven via the mirror driving circuit 112, thereby retracting the main mirror 103 and the sub mirror 107 out of the photographing optical path and opening / closing a shutter (not shown). The shooting operation is executed by.
[0078]
As described above, according to the first embodiment, the stationary position of the sub mirror 107 changes due to the wear of the rotation support member and the member for regulating the stationary position due to an increase in the number of operations of the sub mirror 107. Even if the in-focus position of the taking lens 101 and the in-focus position obtained by the focus detection calculation are shifted due to the change in the optical path length of the focus detection optical system, the image interval shift due to the patterns 8a and 8b provided on the sub mirror 107 is detected. Thus, the focus detection result can be corrected according to the detection result, and high-precision focus detection that is not affected by the number of operations of the optical members constituting the focus detection optical system can be realized. In addition, since the patterns 8a and 8b are detected after the photographing lens 101 is focused, the focusing speed is not reduced.
[0079]
The image displacement direction of the pattern images 9a to 9d on the image sensor 118 due to a change in the stationary position of the submirror 107 in the rotation direction about the submirror rotation axis 107a, and the image displacement on the image sensor 118 by the phase difference method. The direction (division direction of the pupil 101b of the taking lens by the diaphragm 16) is the same, and the stationary position change in the rotation direction is efficiently detected. However, the two image shift directions are orthogonal to each other. The present invention can also be applied to the case where the division of the pupil 101b is the left-right direction (the vertical direction in FIG. 1).
[0080]
Furthermore, although the description has been made using the phase difference type focus detection device, the present invention can also be applied to a contrast detection method focus detection device. In this case, an image shift from an initial state due to a pattern is detected, and this detection is performed. The focus detection result may be corrected according to the result. Specifically, the contrast detection method is equivalent to the case where only one side of the pair of photoelectric conversion element arrays in the phase difference method is provided. In this case, the absolute position of the image by the initial pattern on the image sensor (where the image is located on the plurality of photoelectric conversion elements) is stored, and the absolute position of the image by the pattern after time is detected, Correction is performed based on the absolute position change amount from the initial state.
[0081]
(Second Embodiment)
The second embodiment of the present invention will be described below. In the second embodiment, in the first embodiment, the number, position, and shape of patterns provided on the sub mirror 107 and the correction of the image interval deviation due to the change in the stationary position of the sub mirror 107 are improved. The other parts are the same as those in the first embodiment, so the description thereof is omitted, and the figures and symbols used in the first embodiment are used as they are as necessary.
[0082]
FIG. 11 is a plan view of the anti-inclined surface of the sub mirror 107 shown in FIG. 1 viewed from the photographing lens side. In the vicinity of the four corners on the anti-inclined surface side of the sub mirror 107, as shown in FIG. 11a, 11b, 11c, and 11d are provided by means such as printing.
[0083]
FIG. 12 is a diagram in which the patterns 11a to 11d on the sub mirror 107 are projected onto the image sensor 118 of FIG. 2 in the initial state where the stationary position of the sub mirror 107 has not changed, and the hatched pattern image 12a in FIG. , 12b, 12c, 12d, 12e, 12f, 12g, 12h.
[0084]
The pattern images 12a to 12h are formed on the areas (1) and (3) of the photoelectric conversion element arrays 4a, 4b, 6a, and 6b that are not used for focus detection in the image sensor 118. The pattern 11a and the pair of pattern images 12a and 12c, the pattern 11b and the pair of pattern images 12b and 12d, the pattern 11c and the pair of pattern images 12e and 12g, and the pattern 11d and the pattern images 12f and 12h, respectively. It is an image corresponding to.
[0085]
FIG. 13 is an enlarged view of a main part in which the photoelectric conversion element arrays 4a and 4b shown in FIG. 12 are enlarged. In the figure, 13a, 13b, 13c and 13d are pattern images output from the photoelectric conversion element arrays 4a and 4b. The signal is ZB1₀ Is the image interval obtained from the image signals 13a and 13c through a known image interval detection process, similarly to ZB2.₀ Indicates the image interval by the image signals 13b and 13d, respectively.
[0086]
  Here, as in the first embodiment, the pattern 11 on the sub-mirror 107 is separated from the primary imaging plane 102a, and thus the pair of pattern images 12a to 12d actually formed on the image sensor 118 are The image is blurred and the positions where the pattern images 12a to 12d are formed on the image sensor 118 are also slightly deviated from the optically conjugate positions. However, if an object with appropriate and uniform brightness is detected, the image intervalZB1 ₀ ,ZB2 ₀  Can be calculated by the image interval detection process. Furthermore, in the present embodiment, the pattern on the sub-mirror 107 has a single line shape, and the pattern image signal has one high-intensity part (peak part) and two flat low-intensity parts. It is possible to detect the image interval with higher accuracy than the first embodiment. In the photoelectric conversion element arrays 6a and 6b, the image interval is calculated based on the same principle. Further, the case where the stationary position of the sub mirror 107 is changed is the same as in the first embodiment.
[0087]
Since the actual camera operation related to focus detection and pattern detection is the same as in the first embodiment described above, the description thereof is omitted. Here, correction of the image interval change due to the change in the stationary position of the submirror 107 is corrected. The part related to is described.
[0088]
First, the number of times of total detection by the patterns 11a, 11b, 11c, and 11d is set to o, p, q, and r, and the image interval image shift amount at that time calculated by the equation (1) of the first embodiment. , ΔZ_ao, ΔZ_bp, ΔZ_cq, ΔZ_drAnd At this time, the minimum number of integration detection times o, p, q, r is set as the integration detection number n, and is stored in the EEPROM 109d. At the same time, image interval deviation amount ΔZ by pattern_ao, ΔZ_bp, ΔZ_cq, ΔZ_drAre stored in the EEPROM 109d.
[0089]
Next, when the integrated detection count n reaches the threshold value m, the image interval is corrected in the same manner as in the first embodiment.
[0090]
First, a plurality of image interval deviation amounts ΔZ related to the pattern 11a._a1, ΔZ_a2, ..., ΔZ_amAnd the image interval correction amount related to the pattern 11a calculated based on these is ΔZ_aCThen, a plurality of image interval deviation amounts ΔZ stored in the EEPROM 109d_a1, ΔZ_a2, ..., ΔZ_amBased on the image interval correction amount ΔZ_aCIs calculated. Similarly, the image interval correction amounts for the patterns 11b, 11c, and 11d are set to ΔZ, respectively._bC, ΔZ_cC, ΔZ_dCThen, through the same process, the image interval correction amount ΔZ_bC, ΔZ_cC, ΔZ_dCIs calculated.
[0091]
Next, calculation of the image interval correction amount for each focus detection area will be described.
[0092]
In FIG. 12, when attention is paid to the upper photoelectric conversion element arrays 4a, 5a and 6a in the pair of photoelectric conversion element arrays, pattern images 12a, 12b, 12e and 12f by the patterns 11a to 11d on the sub mirror 107 are It is formed in the four corner regions of the upper photoelectric conversion element arrays 4a, 5a, 6a. Therefore, it is possible to interpolate and calculate the image shift amount in the region in between, that is, the region used for focus detection, from the image shift amount in the four corner regions.
[0093]
The same applies to the lower photoelectric conversion element arrays 4b, 5b, and 6b in FIG. 12, and accordingly, the image interval correction amount ΔZ calculated in the previous step._aC, ΔZ_bC, ΔZ_cC, ΔZ_dC, The image interval correction amount in the five focus detection areas in FIG. 3 can be calculated by interpolation.
[0094]
Specifically, the focus detection area corresponding to the focus detection frame 7a in FIG. 3 is the pattern 11a, 11b, and the focus detection area corresponding to the focus detection frame 7b is the pattern 11a, 11c, the focus corresponding to the focus detection frame 7a. Focus detection areas are detected by the patterns 11a and 11b, focus detection areas corresponding to the focus detection frame 7c are detected by the patterns 11a and 11d or patterns 11b and 11c, and focus detection areas corresponding to the focus detection frame 7d are detected by the patterns 11b and 11d. The focus detection area corresponding to the frame 7e is compensated from the image interval correction amount by the patterns 11c and 11d. Therefore, for example, the image interval correction amount for each focus detection region in the focus detection region corresponding to the focus detection region 7a is expressed as ΔZ._FP1CThen, based on the assumption that the image interval correction amount related to the light beam that has passed between the patterns on the submirror 107 is linear, the image interval correction amount ΔZ for each focus detection region_FP1CIs calculated by the following equation (6).
[0095]
ΔZ_FP1C= (ΔZ_aC  + ΔZ_bC) / 2 ............ (6)
Similarly, the image interval correction amount for each focus detection area in the focus detection area corresponding to the focus detection frames 7b, 7c, 7d, and 7e is ΔZ, respectively._FP2C, ΔZ_FP3C, ΔZ_FP4C, ΔZ_FP5CThen, it is calculated by the following formulas (7) to (10), respectively.
[0096]
ΔZ_FP2C= (ΔZ_aC  + ΔZ_cC) / 2 (7)
ΔZ_FP3C= (ΔZ_aC  + ΔZ_dC) / 2 ............ (8)
ΔZ_FP4C= (ΔZ_bC  + ΔZ_dC) / 2 ............ (9)
ΔZ_FP5C= (ΔZ_cC  + ΔZ_dC) / 2 ......... (10)
It should be noted that the image interval correction amount ΔZ for each focus detection area in the above equation (8)._FP3CIs the image interval correction amount ΔZ_bC, ΔZ_dCIt is also possible to calculate using both of the calculation results. By applying this focus detection-specific image interval correction amount to Equation (4) of the first embodiment, it is possible to correct the image interval shift due to the change in the stationary position of the sub mirror 107 with high accuracy.
[0097]
As described above, in the second embodiment, as shown in the equation (3) of the first embodiment, the coefficient corresponding to the focus detection area determined from the experimental result is set._FPIs used for each focus detection area based on the detection results of the patterns 11a to 11d provided in the vicinity of the four corners of the sub-mirror 107, so that the change in the stationary position of the sub-mirror 107 has a large individual difference variation. Even if it does, high-precision correction can be performed.
[0098]
Further, since the pattern on the single line is used as the pattern on the sub mirror 107, it is possible to reduce the calculation error in the image interval calculation process as compared with the first embodiment. If a double-line pattern having a different width is used, the calculation error can be further reduced.
[0099]
In the second embodiment, the five focus detection areas are corrected based on the detection results of the four patterns 11a to 11d. However, even if more focus detection areas are provided, the patterns 11a to 11a are provided. By correcting the detection result of 11d, correction can be performed with high accuracy. Conversely, more accurate correction can be achieved by increasing the number of patterns and interpolating a large number of detection results.
[0100]
According to each of the above embodiments, a pattern is provided within the effective range of the sub-mirror 107 that is an optical member used to guide the light beam to the image sensor 118, and the image sensor 118 detects the light amount distribution related to the pattern. Therefore, even if the relative positional relationship between the sub mirror 107 and the image sensor 118 changes from the initial state due to an increase in the number of operations of the sub mirror 107, the position change is detected by the image sensor 118 detecting the deviation of the light amount distribution related to this pattern. Can know.
[0101]
In addition, since the focus adjustment amount (information regarding focus detection) of the photographic lens 101 is corrected based on the result of detecting the light quantity distribution related to the pattern by the image sensor 118, high accuracy that is not affected by the position change of the sub mirror 107 is obtained. Focus detection can be realized.
[0102]
In addition, since at least one pattern is provided in the vicinity of the end of the sub mirror 107, the effective range used for focus detection of the sub mirror 107 is not greatly occupied, and the pattern detection without disturbing the focus detection area. The light amount distribution can be detected. In addition, more accurate focus detection is possible by performing correction using light quantity distributions related to a plurality of patterns.
[0103]
In the second embodiment, since the shape of the pattern is a linear shape, the calculation error due to the image interval processing calculation can be reduced, and the pattern image interval can be detected with higher accuracy.
[0104]
【The invention's effect】
As described above, according to the first, second, third, or fourth aspect of the present invention, the position change with respect to these fixed positions due to the increase in the number of operations of the optical member, the mirror member, or the sub-mirror is calculated, and this position is calculated. Even if the optical path length of the focus detection optical system changes due to the change, it is possible to provide a camera that can correct the deviation between the focus position and the focus position on the imaging surface appropriately and perform high-precision focus detection It is.
[0105]
According to the seventh aspect of the present invention, a camera capable of performing high-precision focus adjustment can be provided.
[0106]
According to the invention described in claim 11, 12 or 13, the focus information is calculated in many focus detection areas without occupying the effective range used for focus detection of the optical member, mirror member or sub-mirror. It is possible to provide a camera that makes it possible to do this.
[0107]
According to the invention described in claim 14, it is possible to provide a camera capable of detecting a predetermined image by the light receiving means with higher accuracy.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing an optical configuration of a camera according to a first embodiment of the present invention.
2 is a diagram showing a schematic configuration of a light receiving surface of the image sensor of FIG. 1;
3 is a diagram in which a photoelectric conversion element array and a focus detection frame of an image sensor are back-projected on the image recording medium of FIG. 1;
FIG. 4 is a diagram showing a pattern of sub-mirror opposite slopes in the first embodiment of the present invention.
5 is a diagram in which the pattern of FIG. 4 is projected on the light receiving surface of the image sensor of FIG. 1;
6 is a diagram in which the main part of the image sensor of FIG. 5 is omitted from enlargement.
7 is an enlarged view of a main part in which the vicinity of the sub mirror in FIG. 1 is enlarged. FIG.
8 is a diagram in which the main part of the image sensor in FIG. 5 is omitted from enlargement.
FIG. 9 is a block diagram showing a circuit configuration of the camera according to the first embodiment of the present invention.
FIG. 10 is a flowchart showing the operation of the main part of the camera according to the first embodiment of the present invention.
FIG. 11 is a diagram showing a pattern of a sub-mirror opposite slope according to the second embodiment of the present invention.
12 is a diagram in which the pattern of FIG. 11 is projected onto the light receiving surface of an image sensor according to a second embodiment of the present invention.
13 is a diagram in which the main part of the image sensor in FIG. 12 is omitted from enlargement.
FIG. 14 is a schematic diagram illustrating an optical configuration and a circuit configuration of a conventional camera.
FIG. 15 is a diagram illustrating the principle of a phase difference (image shift) method.
[Explanation of symbols]
8a, 8b pattern
101 Photography lens
103 Main mirror
107 Submirror
109 Microcomputer
110 Focus detection circuit
111 Mirror drive means
112 Mirror drive circuit
117 Secondary imaging lens
118 Image sensor

Claims (16)

In a camera having a light receiving means composed of a plurality of photoelectric conversion elements and an optical member that is moved from the outside of the photographing optical path to a fixed position in the photographing optical path at the time of focus detection and guides the light beam that has passed through the photographing lens onto the light receiving means. ,
An image forming part for forming a predetermined image on the light receiving means by providing the light flux is provided within an effective range of the optical member used for guiding the light flux to the light receiving means, and the light receiving means. A camera comprising: a calculation unit that calculates a change in position of the optical member with respect to the fixed position based on a light amount distribution relating to the predetermined image. In a camera having a light receiving means composed of a plurality of photoelectric conversion elements and an optical member that is moved from the outside of the photographing optical path to a fixed position in the photographing optical path at the time of focus detection and guides the light beam that has passed through the photographing lens onto the light receiving means. ,
An image forming portion for forming a predetermined image on the light receiving means by the incidence of the light flux is provided in an effective range of the optical member used for guiding the light flux to the light receiving means. Computation means is provided for calculating a positional change of the optical member with respect to the fixed position based on outputs outputted from the plurality of photoelectric conversion elements constituting the light receiving means when an image is formed. camera. In a camera having a light receiving means composed of a plurality of photoelectric conversion elements and a mirror member that is moved from the outside of the photographing optical path to a fixed position in the photographing optical path at the time of focus detection and guides the light beam that has passed through the photographing lens onto the light receiving means. ,
An image forming portion for forming a predetermined image on the light receiving means by providing the light flux is provided in an effective range of the mirror member used for guiding the light flux to the light receiving means, and Computation means is provided for calculating a positional change of the mirror member with respect to the fixed position based on outputs outputted from the plurality of photoelectric conversion elements constituting the light receiving means when an image is formed. camera. A light receiving means including a plurality of pairs of photoelectric conversion elements; and a sub-mirror that guides a light beam that has been moved from outside the photographing optical path to a fixed position in the photographing optical path and passed through the photographing lens upon focus detection. In a camera that detects focus information by the phase difference method,
An image forming portion for forming a predetermined image on the light receiving means by the incident of the light flux is provided in an effective range of the sub mirror used to guide the light flux to the light receiving means, and the predetermined image And a calculation means for calculating a position change of the sub mirror with respect to the fixed position based on outputs outputted from the plurality of photoelectric conversion elements constituting the light receiving means.   The camera according to claim 1, wherein the predetermined image is formed as a paired image on a pair of photoelectric conversion elements among the plurality of photoelectric conversion elements. .   Focus information is calculated using outputs of a plurality of photoelectric conversion elements other than the plurality of photoelectric conversion elements on which the predetermined image is formed out of the light receiving means, and the calculation is performed on the focus information. 6. The camera according to claim 1, further comprising a focus detection unit that corrects the position change information obtained by the unit and calculates final focus information.   The camera according to claim 6, further comprising a focus adjustment unit that converts focus information obtained by the focus detection unit into a driving amount of the photographing lens and performs focus adjustment.   The arithmetic means obtains a difference between the paired image interval obtained when the camera is used and an image interval stored in advance, and calculates the position change information based on the difference information. The camera according to claim 5, wherein   The camera according to claim 8, wherein the calculation unit calculates the position change information by obtaining the difference information a predetermined number of times.   The camera according to claim 9, wherein the number of times is added when reliability of photoelectric conversion signals of the paired images satisfies a predetermined condition.   The camera according to claim 1, wherein at least one image forming unit is provided in the vicinity of an end of the optical member.   The camera according to claim 3, wherein at least one image forming unit is provided in the vicinity of an end of the mirror member.   The camera according to claim 4, wherein at least one image forming unit is provided in the vicinity of an end of the submirror.   The camera according to claim 1, wherein the shape of the image forming unit is a linear shape.   The camera according to claim 5, wherein an arrangement direction of a pair of images formed by the image forming unit and an arrangement direction of the photoelectric conversion elements forming the pair are the same.   The camera according to claim 5, wherein the alignment direction of the paired images formed by the image forming unit and the alignment direction of the photoelectric conversion elements forming the pair are orthogonal to each other.

Images