JPS62189415A - Focus detecting device - Google Patents

Abstract

PURPOSE:To execute focusing in plural areas in a photographing picture by providing an automatic focus detecting element, an arithmetic means, and a correcting arithmetic means for collecting a focus detecting signal outputted from the arithmetic means, by a correcting data related to said aberration, and outputting a correcting signal for setting a photographic lens to the best image position. CONSTITUTION:A photographing screen is divided into plural areas, plural pieces of automatic focus detecting elements which are placed in the respective areas, and outputs of plural focus detecting elements are brought to an arithmetic processing in accordance with a prescribed algorithm, and a focus detecting signal is outputted. From plural correcting data related to an aberration of a photographic lens corresponding to each area of a photographing picture which is divided into plural areas contained in an interchangeable photographic lens, a correcting data related to an aberration corresponding to an area for executing a focus detection is selected and outputted. A correcting signal for correcting a focus detecting signal outputted from the arithmetic means, by a correcting data related to an averration, and setting a photographic lens to the best image surface position is outputted. When executing a focus detection to plural areas in a photographing picture the photographic lens is set to the best image surface position by correcting the focus detecting signal.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides a plurality of focus detection areas capable of correcting an error between a focus detection position and a best image plane position based on lens aberrations during focus detection. The present invention relates to a high-precision focus detection device.

[Conventional technology]

When taking photos that include multiple subjects, such as commemorative photos, if you want to take a photo in which both the main subject and the secondary subject in the background are in focus, a single A camera equipped with an automatic focus detection mechanism that focuses on a subject cannot produce satisfactory results.

For this reason, distance measurement is performed by dividing the shooting screen into multiple areas.
Based on this distance information, it is possible to focus on a position where all subjects are within the depth of focus of the photographing lens, or because the main subject is often a subject at a close distance, it is possible to measure the distance. A focus detection device has been proposed that focuses on a subject that is at the closest distance among objects that have been photographed.

[Problem that the invention seeks to solve]

However, as is well known, photographic lenses have various aberrations such as spherical aberration, astigmatism, and field curvature.
Also, due to the influence of the arrangement direction of the automatic focus detection element, etc.
When the focus of the photographic lens is adjusted based on the output signal of the focus detection element located at a position offset from the center position among the many focus detection elements arranged on the photographic screen,
A problem arises in that a deviation occurs between the focal position of the lens and the best image plane position of the lens.

Figure 1 shows this, where the horizontal axis X is along the optical axis, with the left side being the direction of the photographing lens and the right being the direction of the film surface.
The vertical axis Y indicates the distance from the optical axis.

In Figure 1, the position indicated as "on-axis" is the position where the imaging performance of the image formed by on-axis light (incident light parallel to the optical axis of the photographing lens) is best; It is called "Best Location". However, in a camera, if the film surface is located at this "best axial position", aberrations with respect to off-axis light (incident light tilted with respect to the optical axis) will worsen, which is not preferable. Therefore, conventionally, the film surface is positioned at a position slightly shifted from this "best axial position".In Figure 1, the aberration curve shown as "image" is , when using this "on-axis best position" as a reference, determine the amount of deviation caused by the actual light transmitted through the photographing lens, including on-axis light and off-axis light (when the open aperture is F = 2.0, for example). This shows the position with the best image contrast.

On the other hand, an automatic focus detection device detects focus by receiving only the light that passes through the part of the photographic lens close to the optical axis, that is, the light that passes through the part with a large aperture value (for example, F=5.6). Because of this, the aberration performance on the focus detection device is better than the aberration performance of the entire photographic lens, and when focusing by the automatic focus detection distance sensor (hereinafter referred to as AF sensor), the rAF sensor stop position is shown in Figure 1. As shown, the camera focuses on a position close to the ``best position on the axis.''

In this way, the lens stop position detected as the in-focus position by the AF sensor (rAF sensor stop position")
There is a deviation from the position with the best image contrast (the "image"), and this deviation increases as you move away from the optical axis.

[Means for solving problems]

This invention aims to solve the above problems, and attempts to correct the position of the photographing lens by the difference between the in-focus position by the AF sensor and the position where the best image can be obtained. First, the principle of the correction will be explained.

Figure 2 shows an example of the arrangement of the AF sensor for so-called multi-division ranging, which divides the shooting screen into multiple areas and measures the distance in each area, and Figure 3 shows the shooting lens. 1 is a diagram showing the relationship between the direction of incident light incident on the AF sensor 1 and the position of the AF sensor 2. FIG.

Incident light on and near the optical axis enters the AF sensor located at the center of the photographic screen, and off-axis light enters the AF sensor located away from the center of the photographic screen.

Figure 4 also shows the amount of defocus on and off the optical axis of the photographic lens and the predetermined spatial frequency (for example, 50 IRM
), where IBO indicates the best image position on the optical axis at the position of maximum contrast on the optical axis, and SBo indicates the focus detection position when the AF sensor is on the optical axis. .

In the arrangement of the AF sensor shown in FIG. 2(a), the area e near the optical axis. When measuring distance with the sensor, the lens stop position (focus position) by AF is the position SBo in Figure 4, but since the best position of the image plane on the optical axis is IBo, the correction amount is applied to the photographing lens. The best image can be obtained by correcting the lens position by giving ΔS.

In addition, in the AF sensor arrangement shown in Fig. 2(a), when distance measurement is performed with the sensor in the area eo S off the optical axis, A
The stopping position of the lens due to F differs from the example shown earlier due to lens astigmatism, field curvature, etc., and is shown in Fig. 4SB,
, will be in position. In this case, the correction of the lens position is as follows: (a) In order to optimize the image quality near all s, which is the focus detection area, a correction amount of ΔSB,s is given (this is the sagittal image plane best position, the device IB, s and the meridional image plane best position I B, , ).

(b) In order to optimize the image quality near the optical axis, which is different from the focus detection area, a correction amount of Δ5Dos is given.

(C) A predetermined correction amount, for example m+
4 However, m and n are given positive constants as correction amounts.

(d) Changing the amount of correction depending on the focal length of the photographic lens.

For example, with a short focal length lens, because there are many landscapes, the weight should be set evenly so that the entire frame is evenly focused, and with a long focal length lens, because the subject is clear, such as a portrait. , weighting should be focused on the central part. (1) Distance sensor e on the optical axis. If you select long focus lens knee ΔSB.

Short focus lens knee ΔSBo % (Δ5B1s + Δ5B
os) (11) When off-axis distance measuring sensor elf S is selected Long focus lens: +Δ5Bo8 Short focus lens: +ΔSI3. -h(Δ5B1S+Δ5B
oS).

There are various correction methods depending on the purpose of photographing, and there are many correction amounts.

Therefore, the focus detection device of the present invention divides the photographing screen into a plurality of regions, and calculates the outputs of the plurality of focus detection elements according to a predetermined algorithm. A calculation means for processing and outputting a focus detection signal, and a plurality of correction data regarding aberrations of the photographing lens corresponding to each region of the photographing screen divided into the plurality of regions, which are built into the interchangeable photographing lens, are used to determine the focus. means for selecting and outputting correction data regarding aberrations corresponding to the area to be detected; and correcting the focus detection signal output from the calculation means using the correction data regarding the aberrations to position the photographing lens at the best image plane position. and a correction calculation means that outputs a correction signal for setting the image plane, and when performing focus detection for multiple areas within the shooting screen, the camera corrects the focus detection signal and sets the shooting lens at the best image plane position. be.

[For production]

Focus detection is performed based on the aberration correction data specific to the photographic lens, which differs for each area where focus detection is performed, based on the focus detection signal obtained by processing the outputs of multiple automatic focus detection elements arranged within the photographic screen. Since the focus detection signal is corrected by selecting the correction data for the area where the correction was performed, the shooting lens can be set at the best image plane position no matter which area of the shooting screen the focus detection is performed on the subject. becomes possible.

〔Example〕

Next, embodiments of the invention will be described.

FIG. 5 is a block diagram showing the circuit configuration of an embodiment of the focus detection device according to the present invention.

First, the configuration of the camera body side will be explained.

100a, 100b, 100c, -, 100rL
is a focus detection light-receiving element placed within the photographing screen, and is denoted by e in FIG. 2(a). Corresponds to those shown as etc. As this element, for example, a one-dimensional line sensor such as a CCD is used. 101a, 101b, 101c,
.=101rL is a light-receiving element driving circuit such as a COD, which drives the light-receiving element and converts an output analog signal into a digital signal and outputs the digital signal. 102a, 102
b, 102c, -102a are digital memory circuits that temporarily store detection signals of the light receiving elements.

103a, 103b, 103c, -103n
is a gate circuit, and the digital memory circuit 102a...1
The output of the decoder 118 is controlled by a signal (transmitted through lines m, n, o, . . . When the output is 5I-I'', a circuit is formed, and the digital memory circuits 102a, . . . 1
One of the outputs of 02rL is selected and input to the control calculation circuit 104 via line d.

104 is a control calculation circuit that controls the focus detection system, processes the focus detection signal detected by the CCD and stored in the digital memory according to a predetermined calculation algorithm, and calculates the defocus amount ΔL of the photographing lens; Outputs the defocus direction (positive/negative).

105 is a subtraction circuit, and 106 is an addition circuit, both of which store the defocus amount ΔL1 defocus direction calculated by the arithmetic control circuit 104 and a random access memory (hereinafter referred to as RAM).
5) Photographic lens stored in 116.

The correction data C regarding the lens aberrations (spherical aberration, astigmatism, field curvature, etc.) is input, the correction data C is subtracted and added to the defocus amount ΔL, and the result is output together with the defocus direction signal (positive/negative). do.

107 is a selector, which includes a subtraction circuit 105 and an addition circuit 106.
The output from the RAM and the positive/negative signals stored in the RAM are input, and if the signal from the RAM is negative, the signal from the subtraction circuit 105 is selected, and if the signal from the RAM is positive, the signal from the addition circuit 106 is selected and output.

108 is an arithmetic circuit, which outputs the output of the selector 107;
The output of a fixed data storage circuit 109 that holds data regarding a predetermined interval from a predetermined reference position between the camera body and the interchangeable lens is input, and is added to the output data of the selector 107 according to the sign of the fixed data. , or subtraction is performed to calculate the final movement amount of the photographing lens, that is, the focusing optical system defocus amount ΔL' from the reference position and its direction.

Reference numeral 113 denotes a multiplier circuit which contains the focusing optical system defocus amount ΔL' which is the output of the arithmetic circuit 108 and information regarding the helicoid in a register.

Reference numeral 115 denotes a motor drive circuit, which controls the rotation direction and rotation speed of the motor M based on the output of the multiplication circuit 113.

The rotation of the motor M is transmitted to the lens drive shaft DA via the gear train GT and the slip mechanism SL. The rotation angle of the lens drive axis DA is monitored by an encoder consisting of 7 Otocoupler PCs, and feedback is sent back to the motor drive circuit 115 to rotate the motor at a predetermined number of rotations, and the lens is adjusted to an infinite distance or a close distance to adjust the focus. When the motor becomes inactive, the motor is configured to detect this and stop the motor. To detect the end of this lens movement,
For example, it is possible to apply a method of determining the end when no pulse is generated from the encoder within a predetermined time.

A display comparison circuit 110 compares the defocus amount ΔL/ with a signal from a circuit 111 that stores in-focus data indicating an allowable range of the in-focus position, and outputs an in-focus/out-of-focus signal.

Reference numeral 112 is a display element, which inputs the output of the display comparison circuit 110 and the defocus amount and its direction (positive or negative) output from the arithmetic circuit 108 to indicate in-focus, out-of-focus, and out-of-focus. The time is displayed along with the direction.

A trigger circuit 116 generates a focus detection operation start signal in response to ON/OFF of a shutter button or a separately provided switch, and inputs an output to the control calculation circuit 104.

Next, the configuration of the interchangeable lens will be explained. The part partitioned off by the dashed line in the lower left of FIG. 5 is the configuration on the interchangeable lens side, and shows an embodiment of the zoom lens.

ZR is a manually operated zoom ring, and an integrally rotatable brush BR is attached to the zoom ring ZR.

CD is a code plate, which corresponds to the brush BR, and is provided on the lens barrel, and depending on the rotation of the zoom ring ZR, that is, the setting of the focal length, the digital code plate corresponds to the set focal length. It generates a code signal.

LID is a lens information output circuit, which outputs correction data C regarding aberrations of the photographing lens and rotational speed conversion coefficient I of the motor M.
It has a built-in read-only memory (ROM) that stores the correction data C and the conversion coefficient I (I), and reads out the correction data C and the conversion coefficient I ( , RAM via the reading circuit ILD on the camera body side.
116 and the register 114.

The correction data C regarding the aberration of the photographing lens described above is ΔsB0. Δ5BIS+ΔSB,,,Δ5Bost
ΔSBo, etc., and when the correction amount requires calculation as illustrated in (c), the RAM 11 shown in FIG.
6 and subtraction circuit 105. This can be dealt with by providing an arithmetic circuit (not shown) between the adder circuit 106 and the adder circuit 106.

Furthermore, the R included in the lens information output circuit LID is
The OM has correction data regarding aberrations of the photographic lens corresponding to the focus detection light receiving elements 100a to 100r&.
This correction data is transferred to RAM 116.

Of course, the correction data C regarding the aberrations of the photographic lens is read out one after another from the ROM and updated in accordance with the zooming operation of the photographic lens.

FR is a focusing ring which is configured to mesh with a driven shaft FD coupled to a lens drive shaft DA on the camera body side to drive the focusing lens.

Next, the control calculation circuit 104 will be explained.

FIG. 6 is a detailed diagram thereof. 200 is a control circuit that outputs a control signal to control the system;
The operation is started by a signal outputted from the trigger circuit 117 (see Fig. 5) via the signal line a, and first, the write signal W/R is outputted from the signal line e, and then outputted from the lens information input circuit LID on the lens side. The aberration correction data C of the photographic lens read by the reading circuit RD is stored in the RAM 116, and the rotational speed conversion coefficient K of the motor M is inputted to the register 114.

Next, the CCD drive circuit 1 which is a CCD drive signal from the signal ab
01a to 101rL, and the CCD starts operating. When the focus detection signals output from the CCDs 100a to 100L are input to the digital memory circuits 102a to 102rL, a pulse is output from the signal line C to the decoder 118, and the decoder 118 responds to the input signal to the gate circuit 1.
03a to 1037L are sequentially made conductive, and the contents of the memory circuit are sequentially output to the arithmetic control circuit 104 via the signal line d.

A ring counter 201 has the same number of counter stages as the focus detection light receiving elements 100a to 100, and counts and outputs pulses output from the control circuit via the signal line k. This count value indicates which focus detection light receiving element outputs the closest signal.

Reference numeral 202 denotes a gate circuit, which is normally open and closes every time a pulse signal from the comparator circuit 213 is input. to communicate.

The now address encoder 203 and the COL 0MN address encoder 204 convert the count signal of the ring counter 201 into an address code that specifies the address of the RAM 116, and the output of the FLOW address encoder 203 is sent to the select gate 208 and the signal line f. The output of the COLUMN address encoder 204 is connected to the COLUMN address decoder of the RAM 116 via the select gate 209 and the signal line g.
Connected to the LUMN address decoder.

205 is a pulse output circuit, which includes a ROW address counter 206 and a COLUMN address counter 20, which will be described later.
Provides 7 hectare clock pulses.

Note that the frequency of the clock pulse output from the pulse output circuit 205 is determined by the ring counter 2 from the control circuit 200.
The frequency is set much higher than the frequency of the clock pulse outputted from 01.

The ROW address counter 206 and the COLUMN address counter 207 are connected to the ROW address encoder 203, C
OLUMN R separately from the address encoder 204.
It has the function of specifying the address of the RAM 116, and the output of the ROW address counter 206 is sent to the R of the RAM 116 via the select gate 208 and the signal line f.
connected to an OW address decoder (not shown) and COL
The output of the UMN address counter 207 is sent to the COLUM of flAM 116 via the select gate 209 and signal line g.
N address decoder (not shown).

The select gates 208 and 209 are controlled by a control signal transmitted from the control circuit 200 via the signal line i, and are set to the W side in the write mode. And ROW address counter 206 and COLUMN address counter 2
The output signal from 07 is sent to rtAM116 via the signal line f1g.
The correction data C regarding the aberration of the photographing lens read by the reading circuit RD is stored in the designated address. In the read mode, it is set to the R side, and output signals from the ROW address encoder 203 and COLUMN address encoder 204 are sent to the RAM1 via the signal line frg.
16, and the correction data C regarding the aberration of the photographing lens corresponding to the position of the light receiving element outputting the signal having the value at the position where the focus detection distance is the shortest distance is read out.

210 is an algorithm processor, and the focus detection element 10
0a to 100, and memory circuits 102a to 102 are detected.
2? The focus detection signal stored in L is sent to the gate circuit 1033.
-103n in time series, and outputs the defocus amount ΔL and defocus direction (positive/negative) of the photographic lens at predetermined timing.

213 is a comparison circuit that compares the output of the algorithm processor 210 and the output of the memory circuit 212;
When the output of No. 10 is a signal of a shorter distance than the distance data stored in the memory circuit 212, an "H" signal is output.

211 is a gate circuit, which is controlled by an OR gate 214 which inputs the output of the comparison circuit 213 and the output of the control circuit 200, and stores the output of the algorithm processor 210 in the memory circuit 212 when the output of the OR gate 214 is H". do.

The control signal input from the control circuit 200 to the OR gate 214 via the signal line j is instantaneously determined by the timing of the defocus amount ΔL and its direction (positive or negative), which is first output from the algorithm processor 210 after the start of the focus detection operation.
The output defocus amount ΔL and its direction (positive or negative) are stored in the memory circuit 212.

Further, the signal supplied from the comparison circuit 213 to the gate circuit 211 via the OR gate 214 is transmitted to the memory circuit 212.
Data stored in and algorithm processor 21
As a result of comparing the output data of 0, when the output of the algorithm processor 210 is a signal from a shorter distance, it becomes "H", so the memory circuit 212 stores the defocus amount from a shorter distance and its direction (positive or negative). will be done.

The output signal from the comparator circuit 213 is also supplied to the gate circuit 202, and as explained earlier, the circuit is closed every time the "I" signal is output from the comparator circuit, and the ring counter 20
1 count signal ROW address encoder 203, CO
Output to LUMN address encoder 204.

Next, the operation of the above circuit will be explained.

When the interchangeable lens is attached to the camera body, the lens information output circuit LID and reading circuit RD are connected via the terminal.
A drive shaft DA and a driven shaft FD for driving the focusing lens are also mechanically coupled.

When camera operation is started and the shirt button is pressed, lens information is read from the ROM in the lens information output circuit LID and sequentially stored in the specified address of the RAM specified by the ROW address counter 206 and COLUMN address counter 207. Also, the rotation speed conversion coefficient I(
is also stored in register 114. Reading and storing of this data is repeated at a predetermined timing, and the data is updated every moment. For example, in the case of a zoom lens, even if the aberration of the lens changes as the focal length changes due to the zooming operation, the corresponding correction value will be
The data is read from M and the data is updated.

When reading of the above data is completed, a CCD drive signal is output from the control circuit 200, and the output signal of the focus detection light receiving element is stored in the digital memory circuits 102a to 102rL. Then, the control circuit 200 also sends a pulse signal to the decoder 118.

Upon receiving the pulse signal, the decoder 118 first sends an "H" signal to the gate circuit 103a via the signal line m. The gate circuit 103a outputs the data stored in the digital memory circuit 102a to the algorithm processor 2i0 via the signal line d. algorithm processor 210
Then, the input data is processed according to a predetermined algorithm, and the defocus amount ΔL and its direction (positive or negative) at that point in time are output from the phase difference of the correlation signals of the CCD lines.

When the calculation is completed, the control circuit 200 outputs the 'H# signal to the OR gate 214 via the signal line j, stores the calculation result in the memory circuit 212, waits for the completion, and outputs the signal from the control circuit 200. Bind 'L#, OR gate 21
4 is in an open state.

Next, the decoder 118 connects the gate circuit 1 to the gate circuit 1 via the signal line n.
03b Send the K″′H” signal, and as before, the algorithm processor 210 calculates the defocus amount ΔL and its direction (
Calculate and output (positive/negative).

This output signal is input to the comparison circuit 213 and compared with the previously stored contents of the memory circuit 212. As explained above, when the output signal of the algorithm processor 210 is a shorter distance signal, the comparator circuit 213 outputs a signal of 'H#, which is stored in the output memory circuit of the algorithm processor 210.

On the other hand, the output of the ring counter 201 is configured to count in synchronization with the output of the decoder 118, and since it has the same number of counting stages as the focus detection light receiving elements 100a to 100, the output of the ring counter 201 is It corresponds to the address of the element. The output of the comparison circuit 213 is also input to the gate circuit 202, and the output of the comparison circuit 213 is also input to the gate circuit 202.
When the output of 3 is H'', the gate circuit 202 closes the circuit,
The output of the ring counter 201 is transmitted to the ROW address encoder 203 and the COLUMN7 address encoder 204.

Therefore, ROW address encoder 203, COL
The UMN-y address encoder 204 outputs the address of the focus detection light-receiving element that outputs the signal at a closer distance.

The above signal processing operation applies to all focus detection light receiving elements 10.
Since it is performed sequentially for 0a to 100rL, at the time of completion, the address of the focus detection light receiving element outputting the signal at the closest distance, the defocus amount ΔL, and its direction (
(positive and negative) will be output.

Note that during the above signal processing operation, the control circuit 200 outputs the @H" signal to the select gates 208 and 209 via the signal line i to set the gates to the R side.
The outputs of the address encoder 203 and COLUMN address encoder 204 are sent to the RAM 11 via the signal line r2g.
6 ROW address decoder and C'OLUMN admit decoder.

When the above signal processing for the focus detection light receiving elements 100a to 100 is completed, a reading signal is sent from the control circuit 200 to the RAM 116 via the signal line e, and the light receiving element outputting the signal at the closest distance is Correction data related to lens aberrations stored at the address of , correction direction - (
The signals (positive and negative) are read out, and the correction data is sent to the subtraction circuit lO5.
, the addition circuit 106 and the correction direction signal are input to the selector 107.

Further, the defocus amount ΔL and its direction (positive/negative) of the light receiving element outputting the closest signal are stored in the memory circuit 212.
is output from the subtracter circuit 105 via the signal line 11.
, are input to the addition circuit 106 and are operated on the previously input correction data.

According to the correction direction signal input to the selector 107, for example, if the signal is negative, the output of the subtraction circuit 105 is sent to the selector 107, and if the signal is positive, the output of the addition circuit 106 is sent to the selector 107.
is selected and input to the arithmetic circuit 108.

The arithmetic circuit 108 uses the above input value and the fixed data circuit 109.
is added (or subtracted in some cases) to a constant from , and the focusing optical system defocus amount ΔL/ is output.

The obtained focusing optical system defocus amount ΔL/ is multiplied by the rotation speed conversion coefficient of the motor M stored in the register 114 in the multiplication circuit 113, and the obtained rotation speed data is sent to the drive circuit 115 of the motor M. Supplied. The focusing optical system defocus amount ΔL' is also given to the display comparison circuit 110, where it is compared with the data in the in-focus data circuit 111, and when the defocus amount is within a predetermined in-focus range, the in-focus Turn on the display element.

Further, a defocus direction signal is given from the arithmetic circuit 108 to the motor drive circuit 115 and the display circuit 112, and either the left or right element that displays the rotational direction of the motor M and the defocus state is turned on.

The motor M is controlled by the modulus data and rotation direction signal input to the motor drive circuit 115, and drives the focusing ring FR via the gear train GT, slip mechanism SL, drive shaft DA, and furthermore, the interchangeable lens side driven shaft FD. Then, a focusing optical system (not shown) is moved in the optical axis direction by a focusing optical system defocus amount ΔL'.

The rotation of the drive shaft DA is monitored by an encoder made of a photocoupler, and fed back to the motor drive circuit for accurate control.

One embodiment of the present invention has been described above. In the above embodiment, the focus detection signal of the closest object is output from the control calculation circuit 104, and this is used as the defocus amount ΔL. The focus detection signal for areas with high contrast is output from the control calculation circuit,
This may be set as the defocus amount ΔL.

〔Effect of the invention〕

As explained above, according to the present invention, in a focus detection device that divides a photographic screen into multiple parts and performs focus detection for each region, no matter which region's focus detection signal is adopted, the aberration of the photographic lens in that region By correcting the error between the best image plane position and the focus position based on Since the correction is performed, it is possible to provide a highly accurate focus detection device suitable for an interchangeable lens camera or the like.

[Brief explanation of drawings]

Figure 1 is a diagram showing the relationship between the in-focus position by the AP sensor and the best image plane position based on the aberration of the photographing lens, Figure 2 is a diagram showing an example of the arrangement of the AF sensor within the photographing screen, and Figure 3 is a diagram showing the relationship between the focusing position by the AP sensor and the best image plane position based on the aberration of the photographing lens. A diagram showing the relationship between incident light near the axis and incident light from off the optical axis and the arrangement of the AP sensor that detects it. Figure 4 shows the amount of defocus and contrast on and off the optical axis of the photographic lens. FIG. 5 is a block diagram showing the circuit configuration of an embodiment of the focus detection device of the present invention, and FIG. 6 is a block diagram of the control calculation circuit. 100a to 100rL: focus detection element, 104: control calculation circuit, 107: selector, 108: calculation circuit, 200
: control circuit, 201: ring counter, 210: algorithm processor, IJD: lens information output circuit. 11, 5 Resis'' order 11-To--7-Ru b2 A pasted tJLt11 (d) (e) Fig. 2 Fig. 4

Claims (1)

[Claims] A photographing screen is divided into a plurality of regions, and a plurality of automatic focus detection elements are placed in each region, and the outputs of the plurality of focus detection elements are processed according to a predetermined algorithm to output a focus detection signal. a calculation means and a plurality of correction data regarding aberrations of the photographing lens corresponding to each region of the photographing screen divided into the plurality of regions, which is built into the interchangeable photographing lens, and concerning the aberration corresponding to the region in which focus detection is performed. means for selecting and outputting correction data; and correction calculation means for correcting the focus detection signal output from the calculation means using the correction data regarding the aberrations and outputting a correction signal for setting the photographing lens at the best image plane position. What is claimed is: 1. A focus detection device characterized in that the device is equipped with: and is capable of adjusting focus on multiple areas within a photographic screen.