JPS59208514A - Automatic focus detecting device of camera - Google Patents

Abstract

PURPOSE:To obtain the best imaged state on the surface of a film by taking a spherical aberration into consideration, by adding a focusing error caused by a spherical aberration of a photographic lens, as a focusing correcting value to focus detecting information from a focus detecting means, and controlling a focus member. CONSTITUTION:Data from a CCD1 is stored in a digital memory circuit 5 through a CCD driving circuit 3, its data is sent to an algorithm processor, and a defocus quantity DELTAL and a direction of defocus are derived. Both the data are sent to a subtracting circuit 9 and an adding circuit 11. Correcting data regarding a spherical aberration of an interchangeable lens EL is sent to the subtracting circuit 9 and the adding circuit 11 from a register 13, C is subtracted or added with respect to DELTAL, and its data and a direction signal are sent to an operating circuit 17 through a selecting circuit 15, and added to a data of a fixed data circuit 19. A coefficient of rotational conversion of a motor from a register 21 is multiplied to a defocus quantity of its output by a multiplying circuit 19, sent to a motor driving circuit 23, and a focusing optical system is controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic focus detection device for a camera, and more particularly to a technique for performing highly accurate focus detection of a photographic lens by taking into account the individual spherical aberration of the photographic lens during automatic focus detection.

2. Description of the Related Art There is no technology known in the art for performing focus adjustment in an automatic focus adjustment device in consideration of the spherical aberration of a photographic lens. Rather, in general, the best image plane position caused by spherical aberration is designed or adjusted so that it falls within the depth of focus for almost all lenses, including variations in various photographic lenses. There is. Therefore, there is a drawback that the film plane and the best image plane position do not match in a part of the variable focal length range of some of the interchangeable lenses and zoom lenses among the various interchangeable lens groups.

An object of the present invention is to provide an apparatus that can always obtain the best image formation state on the film surface, taking into account the fluctuation of the best position of the image plane of the photographing lens due to spherical aberration as described below. It is something.

``Summary'' - In order to achieve this, the gist of the present invention is to calculate the error between the best image plane position and the film plane based on the individual spherical aberration of the photographing lens in the focus detection information obtained by the focus detection means. is given as a focus correction value, and the focus adjustment member is controlled and the focus state is displayed so that the best focused image can be obtained on the film surface.

EXAMPLES Below, the present invention will be explained in detail based on the drawings, but before that, the present invention will be explained in detail.

Figure 1 is a characteristic diagram showing the spherical aberration characteristics of three typical interchangeable lenses: standard (S), telephoto (TI), and wide-angle (Ivl), as well as the best image plane position (IB) for each lens.
S) (IBT) (rBW) (hereinafter referred to as image surface best) is shown based on the same characteristics. As is well known, such spherical aberration characteristics occur, for example, at the d-line (λ-5880m).
It is shown under the standard and predetermined magnification conditions, and each image plane best is shown under the characteristics of various photosensitive materials (spectral sensitivity, emulsion thickness, eic
), various aberrations of the lens, various photographic magnifications, etc. are taken into consideration, and this position is determined in consideration of the lens aberrations, various photographic magnifications, etc., and the position where the best image quality can be obtained when the best image plane matches the actual film emulsion surface. The figure also shows aberration characteristics (5S') (S
T) (SW) and the best sensor position (SBS) for each lens using the light receiving sensor of the automatic focus detection device (S
BT) (SBW) is shown. These characteristics are the characteristics of the spectral sensitivity of the light-receiving sensor (for example, 5Q5nm is currently typical due to the constituent materials of the sensor), and each best sensor position (hereinafter referred to as sensor best) is the characteristic of the light-receiving sensor. It is located at a position determined by the aperture 1] height corresponding to the aperture value of the light beam received by the sensor.

To explain a specific example, for example, if the spherical aberration characteristic of a standard lens represented by the curve SL is taken as axis -1- is O,
Image surface best (TBS) approximately -0,0711) mlJ
ffi is chewing. The sensor that receives light at the spectral sensitivity peak of wavelength 5Q5nm has spherical aberration characteristics (SS).
Focus detection is performed at the sensor best position @ (SBS), so the image plane best (TBS) and sensor best (SBS)
A best difference of 528 minutes occurs between them. This difference varies depending on the individual lens type based on the spherical aberration unique to each lens, and is TΔS for a telephoto lens and WΔS for a wide-angle lens.
The same figure shows that S is obtained.

FIG. 2 schematically shows the state of the light flux generated by the focus detection light receiving sensor and the photographing lens disposed on the camera body side in relation to the present invention. In FIG. 2, (op) indicates a photographing lens, and (R8) indicates a focus detection light receiving sensor disposed within the camera body near the film plane (FP). Now, assume that the photographing lens (OP) 6- is a mulberry lens, and let (Ls) be the light ray that has passed through the area corresponding to its open aperture diameter. The light ray (LS) intersects the optical axis [Xi] at a point (R2) of the optical axis (X), and this point (R2) becomes the image plane best (IBS).

On the other hand, the light receiving sensor (R5) receives a light flux passing through a region closer to the optical axis (Xi) than the region through which the light ray (Ls) passes, and the outermost light ray is defined as (Ls').

As is clear from the fact that the sensor best (SBS) of the marker lens is shown behind the image plane best (IBS) in Fig.
It intersects the optical axis (Xi) at a point (PI) behind R2), and this point (Pl) becomes the sensor best (SBS). Therefore, the image plane best (TBS) and the sensor best (
SBS), an error of SΔS occurs. Furthermore, here,
The area that the light receiving sensor (R8) looks at is the photographing lens (OP)
The light receiving sensor (RS) is located inside the open aperture diameter of the camera because it is placed inside the body of the interchangeable lens camera and is used to detect the focus of various interchangeable lenses. ．． However, this is to enable focus detection.

In Figure 2, point (R3) is on the film plane (FP
), and it is conceivable that a gap may occur between the film plane (FP) and the sensor (SP) disposed on the sensor vest (SBS). and,
The most desirable focusing state is one in which the image plane best (SBS) is located at the film plane (FP) J-, so the difference Qs between the image plane best (TBS) and the film plane (FP) is Unless the lens (OP) is moved forward from the detected in-focus position, the most desirable in-focus state cannot be obtained.

That is, Gs=D-5ΔS. However, this applies when the photographic lens (OP) is a standard lens. Next, let us consider the case where the photographic lens (OP) is a wide-angle lens. Photography lens (OP)
) is a wide-angle lens, the light ray that passes through the vicinity of its open aperture diameter is shown as (Lw) in FIG. Wide-angle lenses have larger spherical aberration than the standard lenses mentioned above, so the rays (1
, W) intersect with the optical axis fXl at a point (R4) further forward than the image plane best (IBS) of the Shikuwa lens. This point (R
4) is the image plane best (IBW) position of the wide-angle lens, and on the other hand, the light ray (
Since Lw') follows the same optical path as (Ls'), it becomes the sensor best (SBW) point CPI)J- of the wide-angle lens. Therefore, for wide-angle lenses, Sensor Best (S
The difference between the best image plane (TT3W) and the best image plane (IBW) is WΔS, but since the best image plane (TT3W) is located in front of the film plane (pp), the best image plane (IBW) is compared to the film plane (FP). In order to match, the light receiving sensor (R3)
The lens (OP) must be retracted by Cw from the in-focus position detected in . Here, Cw = WΔS-D.

As shown below, the correction value C and the direction of correction to match the image plane best detected by the light receiving sensor (R5) with the film plane (pp) differ depending on the spherical aberration characteristics of each lens. Focusing on this fact, this embodiment transmits information regarding this correction value and correction direction from the attached photographic lens side to the focus adjustment device on the body side, and the device takes this correction into account to adjust the image plane to the best. The feature is that the focus is adjusted to match the film plane.

Here, in the embodiment, the 9-correction value C corresponding to the spherical aberration of the lens and its correction direction, that is, whether to extend or retract the focusing optical system, are given to the lens station movement control system using, for example, positive and negative signals. Enables highly accurate focusing. Even if the camera is equipped with a so-called focus aid that displays the focus status after manually adjusting the focus, the focus display will not display.
If the above-mentioned correction is taken into account, evenness of the best image surface due to spherical aberration can be corrected, and highly accurate focusing can be achieved.

Generally speaking, spherical aberration is axial as shown in Figure 1.
It is thought that the maximum distance is about 0.2 #1m (200μ) for the best, so the lens position should be adjusted in steps of about 20μ depending on the depth of focus, the condition of the film surface, and the mechanical control accuracy for lens focusing. Practical if corrected.
Since a sufficient match between the image plane best and the film plane can be obtained, sufficient correction can be made by providing 10 steps of correction value data and a dot/- signal for the direction of extension or retraction. $
Figure 3 shows the overall configuration of the camera body and interchangeable lens to which an embodiment of the present invention is applied, and the camera body (CB)
In this case, the light flux that has passed through the optical system (OP) of the interchangeable lens (EL) is first focused on the main mirror (MM), and part of the light flux is focused on the focus plate (PS). The light passes through a semi-transparent main mirror (MM) and reaches the sensor surface (SP) of a ranging element (ME) provided on the bottom surface of the camera at a sub-mirror (SM). Behind the main mirror (MM) is an imaging plane, that is, film 1 (FP). The film plane (FP) is configured to be observable through a pentaprism (r'p) and an eyepiece (OC) like the SEFT-1T Rex camera. Camera body (CB
) further contains the output data of the ranging lens (ME) and the lens information output circuit (L) provided on the interchangeable lens (EL).
A data processing unit (D
A transmission gear train (GT) that transmits the drive output of the motor (M) and the motor fMl, which are controlled by the output of the data processing unit (DP) and the data processing unit (DP).

A drive shaft (DA) is provided at the end of the gear train via a slip mechanism (SL), and a reflection plate (RP) rotatable in one direction with the drive shaft (DA) is provided.

The rotation of the reflector (RP) is controlled by a reflective photocoupler (r'
c) is fed back to the data processing unit (DP). Therefore, an encoder is constituted by the reflector (RP) and the photocoupler (PC).

The interchangeable lens (EL) is configured as a zoom lens, and as is well known, it has a first group (ap r ) and a second group (
It is shown as a two-component system consisting of (op n). The zoom ring (7R) is provided so as to be operable from the outside, and a brush (BR) rotatable in one direction with the zoom ring (ZR) is attached. Zoom ring (ZR) brush (B
Corresponding to R), a code plate (cn) is provided on the lens barrel fixing part (not shown), and a digital code signal can be generated according to each focal length according to the rotation of the zoom ring, that is, the setting of the focal length. It is composed of The code signal is connected to be input to a first lens information output circuit (L r D ) provided in the lens and including a ROM.

The lens information data of the lens information output circuit (LI[) is sent to the camera body (CB) through the connection terminal and data path (DL) between the camera body (CB) and the interchangeable lens (EL).
) can be input to the data processing unit (DP) in ).

Interchangeable lens (EL) focusing lens (ap r
) in the optical axis direction, a driven shaft (FD) that can be engaged with the drive axis (DA) of the camera body (CB) is provided.The rotation of 1-11 is the focusing lens. (apr).

FIG. 4 is a block circuit diagram showing the data processing unit (DP) of this embodiment, in which an interchangeable lens (EL) is shown at the bottom left with a dashed line between them. The camera body (CB) is provided with a distance measuring photoreceptor (1) consisting of two rows of CCD lines, and is provided with a CCD drive circuit (3) that drives the COD and performs A, 'r) conversion. ing. There is a data path (
1a) exists. The A/D converted digital data is transferred to the digital memory circuit (5) via the data path (3a). The digital data stored in the digital memory circuit (5) is transferred via the data path (5a) to an algorithm processor (7) that calculates the amount of defocus according to a predetermined algorithm, where it is transferred to two The amount of defocus and the direction of defocus can be determined by the phase difference between the correlation signals of the CCDs. The defocus amount is indicated by ΔI4, and the defocus direction is indicated by a positive or negative sign ('':). The amount of defocus (ΔL) is transmitted through the data path (7a), and the direction of defocus is transmitted through the signal path (71)) through the subtraction circuit (9) and the addition circuit (
11) respectively. Among the lens information of the interchangeable lens (EL), correction data 'C' regarding spherical aberration is given from the register (13) to the subtraction circuit (9) and addition circuit (11), respectively, and both circuits perform defocusing. amount(
Correction data ``C'' is subtracted or added to ΔL), and the output data and direction signal (±) as a result of each addition and subtraction are data path (9a, 1.11) and signal path (91), nl).
) are all transmitted to the te select circuit (15). The selector circuit (15) is given a positive or negative signal from the register ``C'', and according to this signal, if it is a negative signal, it selects the output data and signal of the subtraction circuit (9),
If the signal is a positive signal, the output data and signal of the adder circuit (11) are selected and output. The 14- output of the selector circuit (15) is applied to the arithmetic circuit (17) via a data path (153) and a signal path (151). The arithmetic circuit f17)
Fixed data is applied to the fixed data circuit (19) via a data path (19a). The fixed data is data regarding a predetermined interval from a predetermined base position between the camera body (CB) and the interchangeable lens (EL), and the arithmetic circuit (1) selector circuit (1) according to the sign of this data. 15) to calculate the final lens movement amount, that is, the defocus amount ΔL' of the reference position reference and the direction.This calculated defocus data is sent to the multiplication circuit ( 19) and display comparison circuit (
2'7) via data path (1,71).

The multiplier circuit (19) is given a conversion coefficient 'K' for focus adjustment from the other register (21). This conversion coefficient '1K' is necessary to obtain the lens movement corresponding to the defocus amount ΔL'. It contains information on the focal length and mechanical configuration of the lens movement system (for example, information on the helicoid lead, etc.), and the required rotation speed N of the motor can be obtained by multiplying the defocus amount ΔL' by the conversion coefficient. . The data of this motor rotation speed N is the data path (1, 91
), and the direction of rotation of the motor is determined by an arithmetic circuit (17
) to the motor drive circuit (
23). The display comparison circuit (the display comparator contains the data of the defocus amount ΔL' described in −L) and the focusing width data circuit (2
The focusing width data from 5) is input via the data path (25a) e, and both of these data are compared to determine whether the focus is in focus or out of focus, and the data is sent to the display device (27a) via the data path (27a). DS). In addition, the arithmetic circuit (1
A defocus direction signal is supplied from 7) to the display device (DS) via a signal path (171), making it possible to display the out-of-focus direction at the time of out-of-focus. As mentioned above, the data on the motor rotation speed N and the signal on the rotation direction are input to the motor drive circuit f23), and the rotation of the motor (the same is rotated according to these information.The rotation of the motor is shown by the dotted line) A gear train (GT) and a slip mechanism (
St,) to the drive shaft (DA). An encoder consisting of a photocoupler (pc) is provided at a position after passing through the slip mechanism (S t, ).
The rotation of the drive shaft (DA) is controlled and the motor drive circuit (23)7'-old7 is fed back to rotate the motor a predetermined number of times, and the focus is adjusted, for example, to It is also configured to detect when the lens becomes immobile and to stop the rotation of the motor. For this termination detection, for example, a method can be applied in which if a count pulse is not generated within a predetermined time, it is determined that the termination has occurred.

Next, the configuration of the interchangeable lens (EL) side will be explained. The interchangeable lens (E L
) is a brush (BR) that can rotate in one direction with the zoom ring (ZR), and a code plate (C) provided on the lens fixing part.
A digital code signal is given to a lens information output circuit (LTD) including a ROM according to the focal length set between D). The address of the ROM included in the circuit (r-■) is specified by a digital code signal, and the above-mentioned spherical aberration correction value 'C'' is set according to the start of reading from the reading circuit (RD) on the camera body (CB) side. and the motor rotational speed conversion coefficient "K" are read and transferred to the respective registers (13) f2]). Camera body (CB) and interchangeable lens (EL)
Five terminals are provided between them: a power supply terminal, a synchronous clock pulse terminal, a read signal terminal, a serial data terminal, and a ground terminal. To drive the focusing lens, the driven shaft (FD) is connected to the focusing ring (FR).
In Fig. 3, the first group (OPT
) is moved. The focusing ring (PR) may be of either a type that cannot be operated from outside the lens or a type that can be operated.

The operation of this embodiment will be explained below. interchangeable lens(
When the EL) is attached to the camera body (CB), the lens information output circuit (LID) and reading circuit (RD)
are connected through the terminal, and the ground terminal is similarly connected. Furthermore, mechanical engagement is required between the drive shaft (DA) and the driven shaft (FD) to move the focusing lens (OPI).
) is made by the unevenness between. When a focus start signal (not shown) is applied to the camera body (CB), a COD drive start signal is sent from the CCD drive circuit (3) to the CCD (
1) and the analog signal generated by the CCD is the CC
The signal is converted into a digital signal by an A/D conversion circuit provided in the D drive circuit (3). The digital signal is transferred via the data path (3a) to the digital memory circuit (5) and stored. Once the predetermined digital memory has been stored, the digital data is transferred via the data path (5a) to the algorithm processor (7) where it is calculated and processed according to a predetermined algorithm. The phase difference of the correlation signal of the CCD line is the defocus amount ΔI-
The defocus direction, that is, front focus or rear focus, is determined, and the defocus amount ΔI- is sent to the data path (7a), and the defocus direction signal +Or- is sent to the signal path (7+).
) through the subtractor circuit (9) and the adder circuit (11)
will be forwarded to.

On the other hand, at a predetermined timing, first power is supplied from the reading circuit (RD) to the lens information output circuit (LID) via the power supply terminal, and further, according to the read signal from the synchronization clock pulse terminal and the read signal terminal, the lens information output circuit (LI
The contents of the ROM are read from registers (D) and
3) and taken into the register (21).

The contents of the ROM that can be read ηZ are shown using the zoom link (Z
It is determined by the address specified by the digital code of the code plate (CD) determined by the position of the brush (B l?) that moves according to the setting of R). Therefore, for example, in a zoom lens, the spherical aberration changes as the focal length changes,
Even if the image plane best position changes accordingly, the correction value
Since C" is included in the contents of the ROM accordingly, the optimal complementary +E value 'C" is stored in the register (13) via the lens information output circuit (LID) and reading circuit (RD) according to the zooming. It is captured. Correction value data ``C'' is supplied from the register (13) to the subtraction circuit (9) and addition circuit (11) described above through the data path (13a), and the correction value data ``C'' is applied to the defocus data ΔI. C is subtracted in (9) or added in (11). In the register (13), in addition to the correction value data mentioned above, a correction direction signal or- is given to the selector circuit (15) via the signal path (13+), and according to the signal, for example, if it is a - signal, , the data and signals from the subtraction circuit 9) are taken into the selector circuit (15) via the data path (9a) and the signal path (91), and if it is a 10 signal, the data from the addition circuit (11). and signals are taken into the selector circuit (15) via (lla) and (llb). Selector circuit (15
) are selected by the data path (is
), is given to the arithmetic circuit (1) via the signal path (15b). Fixed data is given to the arithmetic circuit (17) from the fixed data generation circuit (19) via the data path (19a). Then, addition is performed with the output data of the selector circuit (15). This addition of fixed data is a constant addition with respect to the reference point of the correction value 1C" for correcting spherical aberration.

In other words, this is the value when performing the overall correction by adding the correction value '''cN on the lens side and a constant value on the body side.If you do this, even if the conditions on the body side change, for example, the difference between the film surface and the light receiving sensor will be corrected. Even if changes in the sensor vest occur in the future due to changes in the distance between the light receiving surface and the spectral sensitivity of the light receiving sensor, countermeasures can be taken by changing this fixed data.This calculation circuit (17) uses the fixed data. In some cases, subtraction may be performed.The calculated output data ΔL' becomes the defocus amount of the focusing optical system, and this data is sent to the multiplier circuit (19) and the display comparison circuit (supplied to the display comparator circuit) via the data path (17a). In the multiplier circuit (19), the rotation speed data is multiplied by the motor rotation speed conversion coefficient ``K'' from the register (21), and the rotation speed data is applied to the motor drive circuit (23) via the data path (19a). Display comparison circuit (2
In 7), the defocus amount data ΔL' is compared with the data of the focusing width data circuit (25), and if Δ(j is within the predetermined focusing width, the display device (DS) displays the focus. The element (DSI) is turned on.'' Two arithmetic circuits (1
7), the signal in the defocus direction further passes through the signal path (1, 7).
1)) through the motor drive circuit (display device (DS)
), the rotation direction of the motor (Ml) and a defocus display element (D
Turn on either the left or right side of SO).

The motor (Ml) rotates according to the motor rotation speed data N and the rotation direction signal input to the motor drive circuit (23).The rotation of the motor is transmitted to the drive shaft (r) via a gear train (GT) and a slip mechanism (SL). A), ＼ are transmitted to the focusing ring (PR) via the driven shaft (FD) of the interchangeable lens (EL, ), and the amount of defocus is transmitted to the focusing optical system (OP) in the optical axis direction. The rotation of the drive axis (DA) is monitored by an encoder (PC) consisting of a photocoupler and is accurately controlled by feeding back to the motor drive circuit (focusing optics). When the system (OP) becomes stationary due to ① or a stopper at a close distance, the drive shaft (DA) as well as the driven shaft (FD) also become stationary, and the rotation of the motor 4 slips and is no longer transmitted by the slip mechanism (sr). Therefore, since the encoder (PC) no longer generates pulse signals, the motor drive circuit (23) stops the rotation of the motor if no pulses are generated within a predetermined period of time.

As described above, according to this embodiment, even if there is an error between the best image plane detected by the focus detection device and the film plane due to the spherical aberration of the photographic lens, this is corrected and the best result is obtained. You can get a focused state. Furthermore, as in this embodiment, even if the photographic lens is a zoom lens, the best focusing state can be obtained by configuring the information for correction to be changed according to zooming. I can do it.

FIG. 5 shows another embodiment of the present invention. In this embodiment, not only focal length data obtained by zooming with a zoom lens, but also aperture value data used and subject distance data (photographing magnification data) are output as lens information. Circuit (■, in)
The information is manually input to the data processing unit (Dp) via the . This is because, as is well known, spherical aberration does not change depending only on the focal length as mentioned above, but also on the aperture value,
Varies depending on the shooting magnification. Therefore, for example, if you specify the address of the ROM in the lens data output circuit (LTD) using 2 bits for the aperture value, 3 bits each for the focal length and photographic magnification, you can obtain 256 combinations, which is sufficient. Spherical aberration can be corrected.

In this case, the correction value 'C'' can be determined by using the 10 stages of the 20 μs block and the direction indication as described above.

The configuration is as shown in Figure 4, where the digital signal emitted from the code plate (CO) is the aperture ring (AR).

Zoom ring (ZR) and focus ring (FR)
The configuration may be such that it is set depending on the position of .

Further, the correction of spherical aberration according to the present invention is effective not only with the zoom lens shown in the embodiment but also with a lens with a fixed focal length.
Alternatively, it is also possible to make the correction value variable in conjunction with the aperture value.

Although the distance measuring method in the above embodiment uses a so-called phase difference method based on the phase difference of correlation signals using a two-row CCD array, the realization of the gist of the present invention is not limited to this method. A so-called contrast method may be used. In this case, when a goldfish signal is obtained, focus adjustment or display may be performed by shifting the focus position by a correction value. Alternatively, the device may project light toward the subject and detect the focus by receiving the reflected light. Furthermore, although the lens information generating device (LID) has been described as being provided within the lens barrel, it may be provided within the camera body and only the code plate (CD) may be left inside the lens barrel.

However, it may be a rangefinder-linked automatic focus detection camera that uses various types of interchangeable lenses, and the photographic lens is not limited to an interchangeable lens type. In other words, a camera with a fixed zoom lens is fine.

25- Effects As described above, the automatic focus detection device for a camera according to the present invention detects the focus adjustment state of the photographic lens at the best image position by receiving the light transmitted through the photographic lens, and generates focus detection information corresponding to the state of focus adjustment at the best image position of the photographic lens. a focus detection means for generating information about a focus correction value for compensating for an error between the best image position and the film position within the camera body; a calculation means for calculating focus adjustment information regarding the amount and direction of focus adjustment for focusing the photographing lens on the film surface based on the information and the recorded combined correction value information; and based on the focus adjustment information. and an instruction means for instructing the focus adjustment of the photographic lens, and with this configuration, the error between the best image position and the film plane based on the spherical aberration characteristics unique to the lens can be reduced. By compensating for this, the best imaging condition can always be obtained on the film surface, making it suitable for cameras with interchangeable lenses in which various lenses can be replaced and cameras using zoom lenses.

26-1

[Brief explanation of the drawing]

Figure 1 shows the spherical aberration characteristics and best image plane position of general wide-angle, standard, and telephoto lenses, as well as the characteristics of the light receiving sensor for focus detection. Figure 2 shows the best image due to changes in the spherical aberration characteristics. FIG. 3 is a diagram showing a camera according to an embodiment of the invention, FIG. 4 is a diagram showing the configuration of its data processing section, and FIG. It is a figure which shows the photographic lens of Example. (1) C3) +51 C71; Focus detection means,
(BR) (CD) (LIID) (RD) (13)
i Focus correction value generation means, (91fil) (151
i calculation means, +19) :21) C23)δ)(JUN(DS); instruction means. Applicant Minolta Camera Co., Ltd. 27- Fig. 1 Fs.

Claims (1)

[Claims] 1. Detecting the focus adjustment state of the photographing lens at a predetermined reference position by measuring the light transmitted through the photographing lens;
a focus detection means for outputting focus detection information corresponding to the focus detection information; a focusing correction value generating means for outputting focusing correction value information related to the above-mentioned reference position; calculation means for calculating focus adjustment information regarding the amount and direction of focus adjustment necessary to match the film in a predetermined relationship; 1. An automatic focus detection device for a camera, comprising: indicating means. 2. The camera further comprises a position correction value generating means for generating position correction value information indicating a position correction value corresponding to the error between the reference position and the film surface, and the calculation means is configured to generate two focus detection information and focus correction values. 2. An automatic focus detection device for a camera according to claim 1, characterized in that the focus adjustment information is calculated based on the position correction value information in addition to the value information. 3. The camera described in "2" is an interchangeable lens camera, and the focusing correction value generating means is provided on the lens side and is a lens information generating means that generates lens information according to the spherical aberration characteristics unique to the lens system of the photographing lens. and a focus correction value calculation means provided on the camera body for reading lens information of a photographic lens attached to the camera body and calculating the focus correction value. automatic focus detection device for cameras. 4. The lens information is configured to be read by the focusing correction value calculation means through the camera-side and lens-side connection terminals that are electrically connected to each other when the photographic lens is attached to the camera body. An automatic focus detection device for a camera according to claim 3, characterized in that: 5. The photographing lens is a zoom lens system whose spherical aberration characteristics change as the focal length changes, and the focusing correction value is set according to the focal length selected by zooming with the zoom lens system. An automatic focus detection device for a camera according to any one of claims 1 to 4, characterized in that the camera is configured as follows.