JPH0540036A - Focus detecting device - Google Patents

Abstract

PURPOSE:To obtain a highly accurate focus detecting device, the optical adjustment of which can be performed easily and which is high in mass-productivity. CONSTITUTION:Photoelectron arrays 105 and 106 are arranged in parallel in a photoelectric conversion section 201. Images of the same object are formed on the arrays 105 and 106 by means of a focus detecting optical system. The image outputs of the arrays 105 and 106 are stored in a data memory means 203 in a microcomputer 203 after A/D conversion. An image deviation computing means 205 computes the relative deviation between both image outputs. A correction data storing means 207 stores correction data for correcting the output of the computing means 205. A correction computing means 206 corrects the correction data stored in the storing means 207, converts the corrected data into a defocusing amount (deviation between the object and a prescribed image formation of a photographing lens), and sends the defocusing amount to a display driving means 208. The driving means 208 displays the focus adjusted state based on the defocusing amount and drives the photographing lens to a focused position.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a focus detecting device for detecting relative displacement of optical images of substantially the same object formed on a pair of photoelectric element arrays. In particular, it is used for focus detection devices such as cameras and distance measuring devices. 2. Description of the Related Art FIG. 1A shows an optical system of a focus detecting device such as a general camera. A subject 100 is a taking lens 1
By 01, an image is formed in the vicinity of the field lens 102. The primary image of the subject 100 is formed as a secondary image on the first and second photoelectric element arrays 105 and 106 by the first and second re-imaging lenses 103 and 104, respectively.
The relative positional relationship of the secondary images on the arrays 105 and 106 is detected from the image output of the arrays. In order to perform such focus detection with high accuracy, each point of the light image distributed on the photoelectric element array 105 and each corresponding point of the light image distributed on the photoelectric element array 106 are combined. It is necessary that they are relatively completely coincident with each other at the time of focusing and that the corresponding points are deviated by the same amount according to the amount of non-focusing when they are out of focus. Of course, it is also possible to determine that the corresponding points at the time of focusing deviate by a certain amount. However, the above condition is not satisfied due to aberrations or insufficient adjustment of the focus detection optical system including the field lens 102 and the re-imaging lenses 103 and 104. When focused, as shown in FIG. 1B, the image points 107a, 1a of the center point 100a of the subject 100
08a forms an image at the same position (for example, the center) of each of the arrays 105 and 106, but the image point 107 of the peripheral point 100b.
b and 108b are imaged relatively displaced. Therefore, there is a difference between the focus detection result based on the point images 107a and 108a and the focus detection result based on the point images 107b and 108b, and correct focus detection cannot be performed. In order to remove such a difference in the relative position between each array and the optical image on it (hereinafter referred to as a position shift) depending on the position of the array, a focus detection optical system with extremely small aberration is adopted. In addition, the optical adjustment must be performed very carefully, which leads to an increase in the cost of the focus detection optical system and a significant decrease in mass productivity. The above-mentioned problems are not limited to the pupil division type focus detection device of FIG. 1, but in a device for photoelectrically detecting a pair of optical images of the same object and performing distance measurement or focus detection from their relative positions, photoelectric image displacement. This is common when performing detection.
An object of the present invention is to provide a focus detection device (distance measuring device) capable of reliable focus adjustment even for a subject having a depth. An embodiment of the present invention will be described below with reference to the drawings. In FIG. 2, a pair of photoelectric element arrays 105 and 106 each composed of an image sensor such as a CCD are juxtaposed in the photoelectric conversion unit 201. An image of the same subject is formed on each photoelectric element array by the same focus detection optical system as in FIG. The image outputs a1 ... aN from the array 105 are A / D converted sequentially by the A / D converter 202 in time series and stored in the data memory means 204 in the microcomputer 203. Similarly, the image outputs b1 from the array 106 are exactly the same. ... bN is also stored in the data memory means 204 via the A / D converter 202. The image shift calculation means 205 calculates the relative shift amount between both image outputs, that is, the relative shift amount between the light images on the pair of arrays, based on the pair of image outputs a1 ... aN, b1 ... bN. Of course, the data used for the image shift calculation need not necessarily be the direct image output of the array, but may be the image output obtained by appropriately filtering or sampling these outputs. The correction data storage means 207 stores correction data for correcting the output of the image shift calculation means 205. This correction data is defined as follows.
That is, after the focus detection optical system is temporarily adjusted during the manufacture of the focus detection apparatus, the array 10 in the focused state is obtained.
5, the relative positional deviation amount of each corresponding image point of the optical image on the optical images 5 and 106 is measured, and the relative positional deviation amount of each image point on this array is stored in the storage means 207 as the correction amount. As a specific example, as shown in FIG. 1B, when the position in the array direction of the photoelectric elements of the arrays 105 and 106 is x and the center xo of each array 105 and 106 is the array xo, the array 105 is , 106, it is relatively easy to adjust so that the corresponding image points of the light image at the center xo of the array will coincide when in focus. Therefore, when adjusted in this way, the relative positional deviation amount of each point has the characteristic S (x) indicated by the solid line at the in-focus point and the characteristic Z (x) at the out-of-focus point as shown in FIG. 3, for example. Here, the characteristic S (x) at the time of focusing shows that the relative displacement amount is zero at the array center xo by the above adjustment and increases linearly from here to the periphery of the array. The characteristic Z (x) of the focus is translated from the characteristic S (x) by an amount ZT according to the degree of out-of-focus. The position shift S (x) of the in-focus point is stored in the correction data storage unit 207. It is not preferable to store all the values of S (x) for each location x of the array as a method of this storage because the number of stored data increases. Therefore, when the positional shift amount S (x) can be approximated by a straight line passing through the origin xo as shown in FIG. 3, the positional shift amount S (x) can be obtained only by the inclination of the straight line.
Since (x) can be specified, the storage unit 207 may store data indicating this inclination. In this case, the correction data storage means 207 can be extremely simplified, and the value of the potentiometer 401 can be changed to the characteristic straight line S as shown in FIG.
The output of the potentiometer 401 can be input to the microcomputer 203 via the A / D converter 402 by adjusting the inclination of (x). The correction data storage means 207 shown in FIG.
You may use ROM like the above (a) which memorize | stored the said inclination. In this ROM, the output terminals P1 to P8 are also connected to the power supply line Vcc and the ground line Et, respectively, and the output terminals P1 to P8 are set according to the data to be stored.
Is processed so that it is connected to only one of the power supply line and the ground line. Further, the correction data storage means 2
A ROM in the microcomputer 203 can be used as 07. When the correction data S (x) is not a straight line but a curved line as shown in FIG. 5, this curved line is approximated by an n-order equation and specified by (n + 1) numerical values. Good. Alternatively, for example, Lagrangian interpolation may be used if correction data for several predetermined positions xi are stored and correction data for intermediate positions are required. Returning to FIG. 2 again, the correction calculation unit 206 corrects the output Z (x) of the image shift calculation unit 205 with the correction data S (x) of the correction data storage unit 207, and specifically, Z (x ) -S (x) is calculated to calculate the corrected image shift amount ZT. The corrected image shift amount ZT is converted to a defocus amount (a shift amount between the subject image and a predetermined image formation of the photographing lens) by the correction calculation unit 206 and sent to the display drive unit 208. This means 208 displays the focus adjustment state based on the defocus amount and drives the taking lens to the in-focus position. This operation will be described below. A pair of arrays 1
Image output from 05 and 106 a1 ... aN, b1 ... b
N is stored in the data memory means 204 after A / D conversion. Image outputs a1 ... aN stored in the data memory means 204 are illustrated in FIG. 6 (a). Image shift calculation means 2
Reference numeral 05 designates this image output as shown in FIG. 6 (b) or (c), for example, five areas X-2, X-1, X0, X.
1 and X2, and image output b1 ... bN in exactly the same way
Is also divided into five regions X-2, X-1, X0, X1, and X2, and the partial output Xi is obtained from the image output of each partial region X1.
The partial image shift amount Z (xi) with respect to the center xi of is calculated individually. The correction calculation means 206 calculates the partial correction amount S (xi) at the location xi from the contents of the correction data storage means 207. This partial correction amount S (xi) is obtained by substituting x = xi into the function S (x) as shown in FIG. Thereafter, the correction calculation unit 206 subtracts the partial correction amount S (xi) from the partial image shift amount Z (xi) to obtain the corrected partial image shift amount Z.
Get T (xi). That is, ZT (xi) = Z (xi)-
Get S (xi). In this way, the correction calculation means 206 obtains the corrected partial image shift amount ZT (xi) for each partial region Xi, and, for example, the simple average ΣZT (xi) / 5 of these values.
Is calculated as the final image shift amount, converted into a defocus amount, and sent to the display drive unit 208. There are various methods of obtaining the final image shift amount ZT from the partial image shift amount ZT (xi) for each partial region Xi, depending on the purpose, but some examples will be shown below. (A1) Corrected partial image shift amount ZT (xi) as described above
The average value of is the final image shift amount ZT. (A2) The average value of the remaining corrected partial image shift amounts excluding the maximum and minimum corrected partial image shift amounts ZT (xi) is set as the final image shift amount ZT. (A3) When the corrected partial image shift amounts ZT (xi) are arranged in descending order, the central one is set as the final image shift amount ZT. (A4) The corrected partial image shift amount ZT related to the partial region having the maximum information amount E (x) described later is set as the final image shift amount ZT. (A5) The final image shift amount Z is obtained by adding the average value of the corrected partial image shift amounts ZT (xi) regarding a plurality of partial regions having a relatively large amount of information or an average value obtained by weighted addition according to the information amount.
Let T. As an algorithm for calculating the partial image shift from the data of each partial region Xi, for example, means for performing Fourier transform on the image output and comparing the phases (Japanese Patent Laid-Open No. 54-54).
(JP-A-57-45510) or a means for calculating a shift amount that gives a maximum correlation by performing a correlation calculation can be used. When the number of photoelectric conversion elements included in the partial region Xi is small, it is more accurate to use the Fourier transform method. When a deep subject is imaged on the array and the image shift amount is calculated using the image output of the entire area of the array, it is completely unknown which part of the depth subject is automatically focused. Becomes The problem regarding such a depth subject can be solved as follows by calculating the partial image shift amount Z (xi) for each partial region Xi as described above. (B1) If the smallest image shift amount is selected from the plurality of partial image shift amounts Z (xi) and the final image shift amount ZT is obtained based on this, the defocus amount for the closest portion of the depth subject is calculated. On the contrary, by selecting the one having the largest partial image shift amount, the defocus amount for the distant portion can be obtained, and by selecting the intermediate one, the defocus amount for the intermediate distance portion can be obtained. (B2) If some of the plurality of partial image shift amounts Z (xi) have almost the same value, the value is selected, and if the final image shift amount ZT is obtained based on this value, a subject occupying a relatively wide area can be obtained. Can be obtained. (B3) The partial image shift amount in the partial area Xi having the largest information amount described later is selected, and the final image shift amount ZT is selected based on this.
Is obtained, it is possible to obtain the defocus amount for the subject having the most information for focus detection, generally, the subject having the highest contrast. Next, a specific example of calculating the partial image shift amount as described above will be described with reference to a flowchart. Figure 7
In step, the image shift calculation means 205 calculates the partial image shift amount Z (xi) and the information amount E (xi) in each partial region Xi. Here, the information amount E (xi) represents the reliability of the corresponding partial image shift amount Z (xi). The larger the value of this information amount, the higher the accuracy of the corresponding partial image shift amount. Specifically, if the image shift calculation is performed by the phase comparison after the Fourier transform as the information amount, the values related to the amplitude after the Fourier transform (r1, r1 ′ in JP-A-55-98710). , R2, r2 '
Is applicable. ) Can be used, and when the image shift calculation is a correlation method, an autocorrelation value Wm described later can be used. In the step, each of the partial areas Xi
Of the information amount E (xi) is compared with a predetermined threshold value Eth, and the partial area Xi of the information amount E (xj) having a value larger than the threshold value is selected. In step, correction data storage means 2
The partial correction amount S (xj) in the selected partial area xj is calculated from the content S (x) of 07, and the partial image deviation amount Z (xj) in the selected partial area Xj is calculated as the partial image deviation amount Z (xi. ) To choose from. In step, the corrected partial image shift amount ZT (xj) for the selected area Xj is set to ZT (xj) =
It is calculated from Z (xj) -S (xj). In step, the corrected partial image shift amount ZT (x
j) whether the variation is smaller than a predetermined value ΔZ, specifically, whether the difference between the maximum value and the minimum value of the corrected partial image displacement amount ZT (xj) is smaller than a predetermined value. If it is small, the process proceeds to the step because the subject has no depth, and if it is not small, the subject is determined to have the depth and the process proceeds to step. In the step, for example, the above (A1)-
The final displacement amount ZT is obtained by any of the processes in (A5). In the step, for example, the above (B1) to (B3)
The final image shift amount ZT is obtained by any one of the processes. In the above embodiments, a plurality of partial image shift amounts are calculated from a pair of image outputs, but a second embodiment for calculating a single image shift amount will be described next. FIG. 8A shows the data memory means 20 of FIG.
A pair of data strings A1 ... AN, B1 ... BN stored in No. 4
Shows one of. This data string may be the image output itself of the photoelectric element array as described above, or the image output obtained by filtering or sampling it. In FIG. 2, the image shift calculation unit 205 includes a pair of data strings A1 stored in the data memory unit 204.
... AN, B1 ... BN, and one data string A1 ... AN
While shifting the other data string B1 ... BN by a predetermined amount, the correlation amount C (L) for each shift amount L is obtained. That is, ## EQU1 ## The shift amount L that minimizes this function C (L)
m is obtained as the image shift amount. Since the image shift amount Lm thus obtained by the correlation calculation includes an error caused by insufficient adjustment of the optical system as described above, the image shift amount Lm must be corrected by the correction data S (x). I won't. However, this image shift amount is determined by the data strings A1 ... AN, B1 ... B.
Since the calculation is performed from all N areas, there is a problem in which area of the correction data S (x) is used as the correction amount. This problem is solved as follows. The data strings A1 ... AN, B1 ... BN do not all contribute equally to the above-mentioned correlation amount C (L), and FIG.
As shown in (a), the portion Y in which the data string changes drastically contributes greatly, and the portion in which the change changes gradually makes little contribution. That is, it depends on the magnitude of the contrast of each part. Therefore, if the degree of the above contribution (hereinafter referred to as contribution degree) for each location x of the data strings A1 ... AN, B1 ... BN is obtained, and the correction amount is obtained from the contribution degree correction data S (x) corresponding to this location. Good. The contribution Wm can be obtained, for example, from the difference between adjacent data in the data string. That is, Wm = | Am−Am + 1 | or | Bm−Bm + 1 |.
This value Wm is shown in FIG. Of course as Wm |
It is also possible to use Am-Am + 1 | + | Bm-Bm + 1 |. The correction amount ST is as follows: Here, Sm is s when x = m
(X). Therefore, the corrected image shift amount ZT is obtained from the following equation. ZT = Lm-ST It should be noted that the amount of positional deviation according to the location between the relative position of the first photoelectric element array and the optical image on it and the relative position of the second photoelectric element array and the optical image on it. When is extremely large, it may be difficult to correct the image shift amount with high accuracy using the correction data S (x). Therefore, the positional deviation amount is corrected to some extent in advance by changing the pitch of the photoelectric elements of the first and second photoelectric element arrays depending on the location, and the remaining positional deviation amount is stored as correction data. It is desirable to do. As is apparent from the above description, according to the present invention, the relative position between the first photoelectric element array and the optical image thereon due to insufficient adjustment of the optical system and the like, Since the correction data relating to the positional deviation caused according to the position of the relative position between the photoelectric element array and the optical image on the photoelectric element array is stored, and the image deviation amount is corrected by this correction data, the photoelectric deviation is corrected. The fine adjustment of the optical system of the dynamic image displacing device is not necessary, and the volume balance can be greatly improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is an optical diagram showing a relationship between a general focus detection optical system and a photoelectric element array. FIG. 3B is a front view showing an optical image position on the photoelectric element. FIG. 2 is a block diagram showing an embodiment of the present invention. FIG. 3 is a graph showing an example of a relative positional deviation amount. 4A and 4B are circuit diagrams showing a specific configuration example of a correction data storage unit. FIG. 5 is a graph showing another example of the relative positional deviation amount. FIG. 6A is a graph showing an example of image output. FIGS. 9B and 9C are diagrams showing how the image output is divided into a plurality of areas. FIG. 7 is a flowchart showing a specific operation of the first embodiment. FIG. 8A is a graph showing another example of image output. (B) is a graph showing the intensity of change in image output. [Explanation of Symbols of Main Parts] 105, 106 ... Photoelectric element array 205 ... Image shift calculating means 206 ... Correction calculating means 207 ... Correction data storing means

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[Procedure Amendment] [Date of Submission] July 3, 1991 [Procedure Amendment 1] [Document Name for Amendment] Specification [Item Name for Amendment] Claims [Amendment Method] Change [Amendment Content] [Patent] Claims: (1) In a focus detection apparatus, which forms two images having parallax for a plurality of different regions of a subject, and calculates a plurality of image shift amounts for the plurality of regions from photoelectric outputs of the two images, And a determination unit that determines the depth of the subject, wherein the depth determination unit determines the presence or absence of the depth of the subject based on the amounts related to the plurality of image shift amounts regarding the plurality of different regions in the subject, A focus detection apparatus, wherein one focus detection output is created from the plurality of image shift amount-based amounts based on the depth determination result. (2) The depth determining means determines the presence or absence of depth by comparing whether a difference in magnitude between the plurality of image shift amounts is larger or smaller than a predetermined value. The focus detection device according to item (1). (3) The depth determination means, when there is no depth, a first processing unit that creates one focus detection output from the amounts related to the plurality of image shift amounts; and when there is depth, the plurality of image shift amounts. The focus detecting apparatus according to claim 1, further comprising a second processing unit that creates one focus detection output by a different process from the amount related to the first processing unit. [Procedure correction 2] [Name of document to be corrected] Specification [Name of item to be corrected] 0003 [Correction method] Change [Details of correction] Focus detection is performed from the relative positional relationship of the detected secondary image. [Procedure Amendment 3] [Name of Document to be Amended] Specification [Name of Item to Amend] [Correction Method] Change [Content of Amendment] [Problem to be Solved by the Invention] In the case of performing focus detection in this way , When the light image formed on the first and second photoelectric element arrays is a subject having a depth,
The calculation of the relative positional relationship becomes impossible or leads to an erroneous result, which causes a problem that focus detection becomes impossible or malfunctions. [Procedure Amendment 4] [Document name to be amended] Specification [Correction target item name] 0005 [Correction method] Deleted [Procedure Amendment 5] [Correction target document name] Specification [Correction target item name] 0006 [Correction method] Change [Details of correction] The above problem is not limited to the pupil division type focus detection device of FIG. 1, but in a device for photoelectrically detecting a pair of optical images of the same object and performing distance measurement or focus detection from their relative positions. This is common when performing photoelectric image displacement detection.
An object of the present invention is to provide a focus detection device (distance measuring device) capable of reliable focus adjustment even for a subject having a depth. In order to achieve this object, in the present invention, a region for calculating a relative positional relationship with respect to a light image on a photoelectric element array is divided into a plurality of regions, and the above-mentioned relative images are respectively obtained with respect to the light images of the respective regions thus divided. Calculation is performed to obtain a physical positional relationship, and an amount relating to a plurality of image displacement amounts (partial image displacement amount) is calculated. The depth of the subject is detected from the amount relating to the plurality of image displacement amounts to determine whether or not there is a depth. One focus detection output is created based on the result of the depth determination. This depth determination can be performed at the stage of calculating the image shift amount, but the depth determination may be performed after converting each of the plurality of partial image shift amounts into a plurality of defocus amounts. [Procedure correction 6] [Name of document to be corrected] Specification [Name of item to be corrected] [Correction method] Change [Details of correction] Returning to FIG. 2 again, the correction calculation unit 206 is the image shift calculation unit 205. The output Z (x) is corrected by the correction data S (x) of the correction data storage unit 207, and specifically, the calculation Z (x) -S (x) is performed to calculate the corrected image shift amount ZT. To do. The corrected image shift amount ZT is converted into a defocus amount (a shift amount between the subject image and a predetermined image plane of the photographing lens) by the correction calculation unit 206 and sent to the display drive unit 208. This means 208 displays the focus adjustment state based on the defocus amount and drives the taking lens to the in-focus position. [Procedure Amendment 7] [Name of Document to be Amended] Specification [Name of Item to Amend] 0024 [Correction Method] Change [Content of Amendment] In the step, for example, (A1)-
The final displacement amount ZT is obtained by any of the processes in (A5). In the step, for example, the above (B1) to (B3)
The final image shift amount ZT is obtained by any one of the processes. This final image shift amount is converted into a defocus amount, and display and lens driving are performed. Since the image shift amount and the defocus amount are in a proportional relationship, a plurality of image shift amounts may be converted into a plurality of defocus amounts and then the processing after the depth determination may be performed. Next, a correction method in the case where the correction amount S (x) greatly changes in one detection area will be described. [Procedure Amendment 8] [Name of Documents to Amend] Specification [Name of Items to Amend] 0027 [Correction Method] Change [Contents of Amendment] [0027] [Equation 1] [Procedure Amendment 9] [Name of document to be amended] Specification [Name of item to be amended] [Correction method] Change [Content of amendment] [Shift amount L that minimizes this function C (L)]
Obtain _m as the image shift amount. Since the image shift amount L _m thus obtained by the correlation calculation includes an error caused by insufficient adjustment of the optical system as described above, the image shift amount L _m is corrected by the correction data S (x). There must be. However, this image shift amount is determined by the data strings A1 ... AN, B1 ... B.
Since the calculation is performed from all N areas, there is a problem in which area of the correction data S (x) is used as the correction amount. [Procedure Amendment 10] [Name of Document to Amend] Specification [Name of Item to Amend] 0029 [Method of Amendment] Change [Content of Amendment] [0029] This problem is solved as follows. The data strings A1 ... AN, B1 ... BN do not all contribute equally to the above-mentioned correlation amount C (L), and FIG.
As shown in (a), the portion Y in which the data string changes drastically contributes greatly, and the portion in which the change changes gradually makes little contribution. That is, it depends on the magnitude of the contrast of each part. Therefore, if the degree of the above contribution (hereinafter referred to as contribution degree) for each location x of the data strings A1 ... AN, B1 ... BN is obtained, and the correction amount is obtained from the contribution degree correction data S (x) corresponding to this location. Good. The contribution W _m can be obtained, for example, from the difference between adjacent data in the data string. [Procedure Amendment 11] [Name of Document to Amend] Specification [Name of Item to Amend] 0030 [Correction Method] Change [Details of Correction] That is, W _m = | A _m −A _{m + 1} | or | B _m -B _{m + 1} |. This value W _m is shown in FIG. Of course as W _m |
It is also possible to use A _m −A _{m + 1} | + | B _m −B _{m + 1} |. The correction amount ST is [procedure correction 12] [correction target document name] specification [correction target item name] 0031 [correction method] change [correction content] [0031] [Equation 2] [Procedure amendment 13] [Document name for amendment] Specification [Item name for amendment] [Correction method] Change [Content of amendment] Here, S _m is s when x = m
(X). Therefore, the corrected image shift amount ZT is obtained from the following equation. ZT = L _m −ST In addition, a positional deviation corresponding to a position between the relative position of the first photoelectric element array and the optical image on it and the relative position of the second photoelectric element array and the optical image on it. When the amount is extremely large, it may be difficult to correct the image shift amount with high accuracy using the correction data S (x). Therefore, the positional deviation amount is corrected in advance to some extent by changing the pitch of the photoelectric elements of the first and second photoelectric element arrays according to the location, and the remaining positional deviation amount is stored as correction data. It is desirable to do. [Procedure Amendment 14] [Name of Document to Amend] Specification [Name of Item to Amend] [Correction Method] Change [Details of Amendment] [Effect of the Invention] As described above, according to the present invention, there is a depth. The subject is divided into multiple areas, and the amount of image shift (partial image shift) is calculated for each optical image in each region. The depth of the subject is detected from the amount of multiple image shifts to determine the depth. Since it is designed to determine the presence or absence of the image and create one focus detection output based on the result of the depth determination, proper focus detection can be performed even for a subject having a depth. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is an optical diagram showing a relationship between a general focus detection optical system and a photoelectric element array. FIG. 3B is a front view showing an optical image position on the photoelectric element. FIG. 2 is a block diagram showing an embodiment of the present invention. FIG. 3 is a graph showing an example of a relative positional deviation amount. 4A and 4B are circuit diagrams showing a specific configuration example of a correction data storage unit. FIG. 5 is a graph showing another example of the relative positional deviation amount. FIG. 6A is a graph showing an example of image output. FIGS. 9B and 9C are diagrams showing how the image output is divided into a plurality of areas. FIG. 7 is a flowchart showing a specific operation of the first embodiment. FIG. 8A is a graph showing another example of image output. (B) is a graph showing the intensity of change in image output. [Explanation of Signs of Main Parts] 105, 106 ... Photoelectric element array 205 ... Image shift calculating means 206 ... Correction calculating means 207 ... Correction data storing means ─────────────────── ───────────────────────────────────
[Procedure amendment] [Date of submission] July 20, 1992 [Procedure amendment 14] [Document name for amendment] Specification [Item name for amendment] 0033 [Correction method] Change [Correction content] [0033] [Invention As described above, according to the present invention, a subject having a depth is divided into a plurality of regions, and an amount relating to an image shift amount (a partial image shift amount) is calculated for each of the optical images in each region. Since the depth of a subject is detected from the amounts relating to a plurality of image shift amounts to determine the presence or absence of the depth, and one focus detection output is created based on the result of the depth determination, it is possible to detect a subject with depth. Also enables proper focus detection. [Procedure Amendment 15] [Document Name for Amendment] Description [Item Name for Amendment] Brief Description of Drawing [Correction Method] Change [Details of Amendment] [Simple Description of Drawing] [Fig. 1] (a) is General FIG. 6 is an optical diagram showing the relationship between a focus detection optical system and a photoelectric element array. FIG. 3B is a front view showing an optical image position on the photoelectric element. FIG. 2 is a block diagram showing an embodiment of the present invention. FIG. 3 is a graph showing an example of a relative positional deviation amount. 4A and 4B are circuit diagrams showing a specific configuration example of a correction data storage unit. FIG. 5 is a graph showing another example of the relative positional deviation amount. FIG. 6A is a graph showing an example of image output. FIGS. 9B and 9C are diagrams showing how the image output is divided into a plurality of areas. FIG. 7 is a flowchart showing a specific operation of the first embodiment. FIG. 8A is a graph showing another example of image output. (B) is a graph showing the intensity of change in image output. [Explanation of Symbols of Main Parts] 105, 106 ... Photoelectric element array 205 ... Image shift calculating means 206 ... Correction calculating means 207 ... Correction data storing means

Claims (1)

Claims: (1) A focus detection device that forms two images having parallax for a plurality of different regions of a subject and calculates a plurality of image shift amounts for the plurality of regions from photoelectric outputs of the two images. In, including a determination means for determining the depth of the subject, the depth determination means determines the presence or absence of the depth of the subject based on the plurality of image shift amounts of the plurality of different regions in the subject, A focus detection device, wherein one focus detection output is created from the plurality of image shift amounts based on the depth determination result. (2) The depth determining means determines presence / absence of depth by comparing whether a difference in magnitude of the plurality of image shift amounts is larger or smaller than a predetermined value. The focus detection device described. (3) the depth determining means, when there is no depth, a first processing unit that creates one focus detection output from the plurality of image shift amounts, and when there is depth, statistics from the plurality of image shift amounts. A second processing unit that performs a dynamic process to generate one focus detection output is included.
The focus detection device according to the item.