JPH1068874A - Focus detection camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a focus detection camera adequately changing the reference value of moving body decision in accordance with contrast and the information of a photographing mode. SOLUTION: The amount of the moving speed of an object is compared with the reference value, so that which one is large is decided and decision that whether the object is the moving body or not is performed. At the time, a changing means 40 changes the reference value in accordance with the contrast and the information of the photographing mode. When the photographing mode is portrait and the contrast is low, the reference value is set high; so that it is hard to decide that the object is the moving body and when the photographing mode is sports, and the contrast is high, the reference value set low; so that it is easy to decide that the object is the moving body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a focus detection camera.

[0002]

2. Description of the Related Art For example, Japanese Patent Application No. 63-33 filed by the present applicant.
A focus detection device disclosed in No. 1748 is known.
This is because a so-called pupil division type focus detection optical system forms a pair of subject images on a photoelectric conversion element from a pair of light beams passing through an imaging optical system, and subjects the subject image to photoelectric conversion by the photoelectric conversion element. A signal is obtained, and a predetermined operation is performed on the subject image signal to calculate a defocus amount of the photographing optical system.

In such a pupil division type focus detection device, vignetting of a light beam used for focus detection may occur depending on a combination of a photographing optical system and a focus detection optical system.
If the vignetting is not uniform, there is a problem that the focus detection accuracy is adversely affected, and in the worst case the focus detection becomes impossible.

The principle of occurrence of vignetting will be described with reference to FIG.

The focus detection optical system shown in FIG. 10 is a so-called pupil division type optical system disclosed in Japanese Patent Application No. 63-331748 filed by the present applicant. This focus detection optical system
A field mask 300 having an opening 300A for regulating an area for focus detection in a field of view, which is arranged on a primary image forming plane of a photographing optical system; a field lens 301 arranged behind the field mask; Two pairs of re-imaging lenses 303A, 303B, 303C, 303D for re-imaging the subject image formed on the section 300A on the secondary imaging surface.
And four apertures 3 arranged in front of these re-imaging lenses for restricting a light beam incident on each of the re-imaging lenses.
And a stop mask 302 having 02A, 302B, 302C, and 302D. Each of the re-formed subject images is received by a light receiving unit (for example, a CCD image sensor) 304A, 3A on the photoelectric conversion element 304 arranged on the secondary imaging plane.
04B, 304C, and 304D, and a subject image signal corresponding to the light intensity distribution of the subject image is generated from each light receiving unit.

In the above configuration, the shape of the four openings 302A, 302B, 302C, and 302D is determined by the field lens 301 at a predetermined distance d from the primary imaging plane.
0 is projected onto a pupil plane 305 at 0 (hereinafter also referred to as a focus detection pupil), and the projected aperture shapes respectively form pupil areas 305A, 305B, 305C, and 305D (hereinafter also referred to as a focus detection pupil stop). doing. Therefore, the second
The subject image re-imaged on the next imaging plane is the pupil area 305A, 3
It is formed only by the light beam passing through 05B, 305C, and 305D.

FIG. 16 is a diagram in which the focus detection optical system shown in FIG. 10 is cut along a plane including the X and Z axes.

Light rays passing through the pupil areas 305A and 305B and condensing between the point A at the end point in the X-axis direction of the opening 300A of the field mask 300 and the other end point C are located inside the hatched area in the drawing. Assuming that the outer end points of the pupil regions 305A and 305B in the X-axis direction are point F and point H, a line connecting points A to F from the primary imaging plane to the pupil plane 305 at a distance d0 is C
-Inside the line connecting the point H, and beyond the pupil plane 305, CF
(The area inside the line connecting the points and the line connecting the points AH) without fail. Therefore, when the F-number of the photographing optical system is small and the outer diameter of the exit pupil 101 is in the shaded area, the light beam used for focus detection does not have vignetting, so there is no risk of adversely affecting the focus detection. When the F-number is large and the outer diameter of the exit pupil 101 enters an area inside the shaded area, vignetting occurs in the focus detection light beam, which adversely affects focus detection. The influence of focus detection due to vignetting depends on the size of the exit pupil 101 as well as the pupil position. For example, the openings 302A and 302 of the aperture mask 302
If B has a shape like a cat's eye, pupil areas 305A and 305B shown in FIG. Therefore, a light beam that passes through the openings 302A and 302B after being condensed on all points of the opening 300A of the field mask 300 is transmitted to the same pupil area 305 on the pupil plane 305.
A, 305B. Therefore, when the pupil position of the exit pupil 101 of the imaging optical system coincides with the pupil plane 305, even if vignetting occurs, the light flux passing through each point of the opening 300A and condensing on the photoelectric conversion element 304 is uniform. Therefore, the amount of light in each light receiving portion of the photoelectric conversion element 304 is uniformly reduced as a whole, and has no effect.

However, at a position other than the pupil plane 305, the light flux passing through each point of the opening 300A of the field mask 300 and condensing on the photoelectric conversion element 304 passes through a spatially different region. For example, as shown in FIG.
After condensing light at points B and C, the aperture 30 of the aperture mask 302
As shown in FIG. 18, the area where the light beam passing through 2B passes on a plane at a position d1 different from the pupil plane 305 is different for each light beam corresponding to each point.
306C. Accordingly, when the pupil position of the exit pupil 101 of the photographing optical system is other than the pupil plane, the amount of vignetting of the light beam passing through each point of the opening 300A and condensing on the photoelectric conversion element 304 when vignetting occurs is reduced , And the decrease in the amount of light varies depending on the location of the light receiving portion of the photoelectric conversion element 304, which adversely affects the focus detection.

FIGS. 19 (a), (b), (c) and (d) show the states of vignetting when vignetting as described above occurs.
Shown in In (b), (c) and (d), A ′,
B ', C', D ', E' and A ", B", C ", D",
E "indicates points A, B, and A of the opening 300A shown in FIG.
These are corresponding points when points C, D, and E are re-imaged by the re-imaging lenses 303A and 303B.

FIGS. 19B and 19C show an opening 30
0A indicates vignetting in the image re-formed by the re-imaging lenses 303A and 303B. There is no vignetting (100% light amount) inside the solid line (a portion including point A in the image formed by the re-imaging lens 303A and a portion including point C in the image formed by the re-imaging lens 300B) for a subject having uniform luminance. ). However, between the broken line and the solid line, vignetting occurs at a light amount of 90% to 100%, and outside the broken line, vignetting has a light amount of 90% or less. Re-imaging lens 303
When the images of A and 303B are superimposed on each other, a portion where no vignetting occurs is not common as shown in FIG. 19D. In this case, the two images to be compared at the time of focus detection do not coincide with each other. Detection becomes impossible.

Conventionally, the following countermeasures have been taken against such problems.

For example, the focus detection device disclosed in Japanese Patent Application Laid-Open No. 55-111927 has two types of focus detection systems having different focus detection F-numbers, and vignetting occurs in accordance with the F-number of the photographing optical system. The above problem is solved by a method of selecting a focus detection system that does not generate. Here, the F number for focus detection is, for example, the pupil area 305A, 305B, 305 in the pupil plane 305 shown in FIG.
It is determined by the size of the circumscribed circle including C and 305D and the position d0 of the pupil plane 305.

Alternatively, the applicant's Japanese Patent Application Laid-Open No. 60-865.
In the focus detection device disclosed in Japanese Patent Publication No. 17, the vignetting state of the focus detection light beam is detected from the output state of the focus detection photoelectric conversion element, and when the vignetting state occurs, the low frequency component is detected from the output of the photoelectric conversion element. The focus detection calculation is performed after reducing the influence of vignetting, thereby solving the above problem.

[0015] Japanese Patent Application Laid-Open No.
In the focus detection device disclosed in Japanese Patent Publication No. 213, a vignetting amount is calculated from the exit pupil F number of the photographing optical system and the exit pupil position information, and a focus detection calculation process for reducing the influence of vignetting according to the vignetting amount. To solve the above problem.

[0016]

However, in the above-mentioned conventional focus detecting device, since the light amount reduction due to vignetting does not take into account the reduction in the peripheral light amount of the photographing optical system and the focus detection optical system, the accurate light amount reduction is performed. Could not be calculated and the error was large. Therefore, when the focus detection calculation processing is switched based on the decrease in the amount of light, accurate switching cannot be performed. Further, it has been difficult to correct the decrease in the light amount of the photoelectric conversion output and use it for focus detection processing, or to use only a portion where there is no decrease in the light amount for focus detection. In particular, when the focus detection area is enlarged with respect to the photographing screen as recently, the decrease in the peripheral light amount of the photographing optical system and the focus detection optical system cannot be ignored, and this problem is further serious. Also, regarding the moving object determination reference value, for example, when the moving object determination reference value is set low during portrait shooting, it may be determined that the moving object is due to shaking of the photographer's body, etc. It is not fixed and it is troublesome. Conversely, if the moving object determination reference value is set high during sports shooting, for example, the focus adjustment position may not track the movement of the subject, and a photo opportunity is missed. Further, when the contrast is low, it is difficult to obtain a clear focus adjustment position, so that the focus detection position detected at the instant is likely to be unstable. In such a case, if the moving object determination reference value is set low, even if the subject Even if the object is a stationary object, the CPU sometimes determines that the object is a moving object, which causes instability of the focus adjustment operation. The purpose of the present invention is
Depending on the shooting mode setting and contrast information,
An object of the present invention is to provide a focus detection camera that changes the setting of a moving object determination threshold value and solves the above-described problem.

[0017]

[Means for Solving the Problems]

(1) An invention according to claim 1, wherein a photographing optical system for forming a subject image on a screen, contrast detection means for repeatedly detecting the contrast of the subject image at a predetermined position on the screen, and a predetermined position on the screen Focus detection means for repeatedly detecting the defocus amount of the subject image,
Calculating means for calculating an amount related to the moving speed of the object image plane from a plurality of defocus amounts detected by the focus detecting means; comparing the amount related to the moving speed with a reference value; and calculating an amount related to the moving speed detected from the reference value In the case where is large, the above object is achieved by providing a determination unit that determines that the subject is a moving subject and a change unit that changes a reference value according to contrast. (2) A second aspect of the present invention provides a photographing optical system for forming a subject image on a screen, a selection means for selecting an operation related to photographing of a camera by designating a genre of the subject, and a predetermined position on the screen. A focus detecting means for repeatedly detecting the defocus amount of the subject image, a calculating means for calculating an amount related to the moving speed of the subject image plane from the plurality of defocus amounts detected by the focus detecting means, and an amount related to the moving speed. If the amount related to the moving speed detected from the reference value is larger than the reference value, the reference value is determined in accordance with the genre of the subject designated by the determining means for determining that the subject is a moving subject and the genre of the subject designated by the selecting means. The above object is achieved by providing a changing means for changing.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The concept of a focus detecting device according to the present embodiment will be described with reference to FIG. 1. A focus detecting device according to the present invention comprises a photographing optical system 1 for forming a subject image on a reference plane.
And separating at least a pair of light beams passing through spatially different regions on a first predetermined surface separated by a first distance on the optical axis from the reference surface out of the light beams passing through the photographing optical system 1, and A focus detection optical system 2 for forming an image, a photoelectric conversion unit 3 comprising a plurality of light receiving elements and generating a subject image signal corresponding to the intensity distribution of the subject image, and an exit pupil F of the photographing optical system 1 when the aperture is opened. A photographing system information generating means 4 for generating information relating to a number, a second distance from the reference plane to the exit pupil, and a decrease in the amount of peripheral light of the photographing optical system 1, and a size of the area on the first predetermined plane; A focus detection system information generating means for generating information relating to the first distance and a decrease in the peripheral light amount of the focus detection optical system, and based on information from the imaging system information generating means and the focus detection system information generating means And shoot The decrease in the amount of light on the light receiving element surface of the photoelectric conversion means 3 caused by the decrease in the peripheral light amount when the optical system 1 and the focus detection optical system 3 are combined and the vignetting of the focus detection light beam are related to the position on the light receiving element surface. Light amount distribution detecting means 6 for obtaining the light amount distribution information as the light amount distribution information, and a focus detection calculating means for performing processing according to the light amount distribution information on the object image signal to detect the current defocus amount of the object image plane with respect to the reference plane. 7 is provided. FIG. 2 is a block diagram showing the overall configuration of a single-lens reflex camera provided with a focus detection device according to the present invention. Referring to FIG.
The interchangeable lens 10 can be detachably mounted. In a state where the lens 10 is mounted, the photographing light flux coming from the subject is
1 is partially reflected by a main mirror 21 provided on a camera body 20 and guided to a finder. You. The other part is transmitted through the main mirror 21 and reflected by the sub-mirror 22, and is guided to the focus detection optical system 30 as a light beam for focus detection.

The focus detection optical system 30 can be configured as shown in FIG. 10, for example, and re-images the subject image formed by the photographing lens 11 on the light receiving element of the photoelectric conversion circuit 32. The light receiving surface of the light receiving element is the focus detecting surface (film conjugate surface) of the focus detecting optical system 30. Therefore, the light receiving element of the photoelectric conversion circuit 32 photoelectrically converts the subject image re-formed by the focus detection optical system 30 to generate a subject image signal.

The subject image signal detected by the photoelectric conversion circuit 32 is input to the microcomputer 400 of the camera body, and is subjected to various calculations described later. When the components of the microcomputer 400 are functionally extracted, the microcomputer 400 includes a peripheral light amount calculation unit 400A of the focus detection optical system and various information storage units 40 of the focus detection optical system.
0B, the light amount distribution calculation unit 400C, and the focus detection calculation unit 4
00D. Details of each part will be described later. A well-known camera internal mechanism such as a shutter device 27 and a winding device (not shown) is also provided.

The AF motor 51 is rotationally driven based on the defocus amount calculated by the microcomputer 400, and takes a photographing lens through the body transmission system 52, the clutch 53, the couplings 54 and 18, and the lens transmission system 13. 11
Is moved in the optical axis direction. The encoder 55 detects the number of rotations of the AF motor 51 and inputs it to the microcomputer 400.

The lens CPU 12 determines the amount of light around the photographing lens 11 and the F number (f0) of the exit pupil when the aperture is opened.
And information relating to the position of the exit pupil with respect to the film surface (d1 in FIG. 16) are generated and input to the microcomputer 400 via the couplings 59E and 19E. The lens CPU 12 focuses the photographing lens 11,
When the information changes due to zooming, the focusing and zooming positions are detected, and the information is changed according to the detected focusing and zooming positions.

For example, information on the amount of light around the photographing lens 11 as shown in FIG. 5 is given as a function F (d) using the distance d from the optical axis on the screen as a parameter. For example, as in equation (1), information on the amount of peripheral light can be generated by coefficients a0... An of an approximate expression obtained by expanding the function F (d) by a power term of d.

[0024] When the exit pupil shape of F (d) = a0 × d 0 + a1 × d 1 + a2 × d 2 + ··· + an × d n ... (1) taking lens 11 is a special, the lens CPU12 is , Information about the aperture shape and position is generated instead of the F-number. For example, in the case of a reflex lens, information about the circumscribed F-number and the inscribed F-number of the aperture shape and the respective pupil positions are generated.

The information storage section 400B of the focus detection optical system includes:
The peripheral light amount of the focus detection optical system 30, the focus detection pupil position (FIG. 16d0), and information on the shape and position of the focus detection pupil stop are stored in advance. For example, in the case of the focus detection pupil stop 305A shown in FIG. 17, the information on the shape and position of the focus detection pupil stop is the center position d2 of the outside diameter r0, the inside diameter r1, and the inside diameter of the pupil stop.

A peripheral light amount calculation unit 40 of the focus detection optical system 30
0A is calculated by converting the peripheral light amount information on the surface of the photoelectric conversion circuit 32 on which the light receiving element is installed, by converting the position of the photoelectric conversion surface into a position on the photographing screen, and in the same manner as the information on the peripheral light amount of the photographing lens 11. Just do it. However, focus detection optical system 3
Since 0 is an eccentric optical system, the information on the peripheral light quantity is not point-symmetric with respect to the center as in the equation (1). In such a case, the optical axis corresponding point (for example, point B,
Using two-dimensional axes X and Y centered on B "), the peripheral light amount information can be represented, for example, as equation (2). Ga (x, y) = Ha (x) .Ia (y) Ha ( ^{x) = b0 × x 0 +} b1 × x 1 + ··· + bn × x n Ia (y) = c0 × y 0 + c1 × y 1 + ··· + cn × y n ¬ ... (2)

When there are two pairs of focus detecting optical systems 30 as shown in FIG. 10, each separator lens 303A
, 303B, 303C, 303D, the peripheral light amount information Ga (x, y), Gb (x, y), Gc (x, y),
Gd (x, y) is required, but the separator lens 30
When 3A and 303B and 303C and 303D are symmetric with respect to the optical axis, Gb (x, y) = Ga (−x, y) and Gd (x, y) = Gc (x, −y), and thus the information amount. Can be compressed. Alternatively, the photoelectric conversion surface may be divided into fine cells (x, y), and peripheral light amount information may be expressed as light amounts corresponding to the respective cells. The peripheral light amount information of the focus detection optical system 30 is determined based on a light receiving element output in a state where a subject image having uniform luminance is formed on a focus detection surface (film conjugate surface) of the focus detection optical system, The determination may be made based on data at the time of designing the optical system.

The light quantity distribution detecting section 400C is a lens CPU.
12. The light amount distribution on the light receiving element for the uniformly illuminated subject is detected based on the information from the focus detection optical system peripheral light amount calculation unit 400A. This light quantity distribution is obtained for each image formed by the focus detection optical system 30. That is, in the case of the focus detection optical system as shown in FIG. 10, a light amount distribution is obtained for each of the four re-imaging lenses 303A, 303B, 303C, and 303D.

Here, the light amount distribution calculation will be described.

The exit pupil position of the photographing lens 11 is d1, the open F number is f0, and the function of the peripheral light amount information is F (x, y).
The focus detection optical system 30 has a configuration as shown in FIG.
The focus detection pupil position is d0, the focus detection pupil aperture shape on the focus detection pupil plane is a center position (xb, 0) as shown in FIG. 6, a circle of radius r2, and the peripheral light amount information is Gb (x, y). In this case, for example, the light amount distribution by the re-imaging lens 303B is obtained as follows.

The light flux passing through the coordinates (x0, y0) of the opening 300A and the re-imaging lens 303B is a circle having a radius r3 centered on the coordinates (x1, y1) as shown in FIG. It becomes P. On the other hand, since the shape of the exit pupil of the photographing lens 11 on the pupil plane is a circle Q having a radius r4 at the center (0, 0), the area A1 of the common part of the circle P and the circle Q is changed to the circle P
Is divided by the area A2 of coordinates (x0, y0) and the vignetting information Jb (x0, y) of the light beam passing through the re-imaging lens 303B.
0). Jb (x, y) = A1 / A2 x1 = x0 + (xb−x0) · d1 / d0 y1 = y0−y0 · d1 / d0 r3 = r2 · d1 / d0 r4 = d1 / (2f0) (3) Thus, the vignetting information Jb (x, y) at an arbitrary coordinate (x, y) can be obtained. Therefore, the final light quantity distribution information Kb (x, y) is expressed as in equation (4). Kb (x, y) = F (x, y) · Gb (x, y) · Jb (x, y) (4)

Similarly, the re-imaging lenses 303A, 303
C, vignetting information Ja (x, y) of a light beam passing through 303D,
Jc (x, y) and Jd (x, y) can be obtained,
Other peripheral light amount information of the focus detection optical system 30 is expressed as Ga (x,
y), Gc (x, y), Gd (x, y), the light amount distribution information Ka (x, y), Kc (x, y), Kd (x, y)
y) can be determined. FIG. 8 shows light amount distribution information Ka.
(X, y) is shown. The focus detection calculation unit 400D includes:
A well-known focus detection calculation is performed on the subject image signal output from the photoelectric conversion circuit 32 to detect a deviation (a defocus amount) between the current image plane of the photographing lens 11 and the film plane.

For example, the focus detection optical system 30 shown in FIG.
Of the subject image signals from the video signals 04B, 304C, and 304D.
Convert the converted data to ap, bp (p = 1 to n) and c
When q and dq (q = 1 to m), the defocus amount is obtained as follows.

For the sake of simplicity, in the following description of the correlation calculation, only the light-receiving element output data ap and bp will be described, but the same applies to the data cq and dq. First, a correlation amount C (L) is obtained from the light-receiving element output data ap and bp by the correlation operation shown in Expression (5). In the expression (5), L is an integer, and is a relative shift amount (shift amount) in units of the pitch of the light receiving elements of the pair of light receiving element output data. In addition, the range taken by the parameter i in the integration operation of the equation (5) is appropriately determined according to the shift amount L and the number n of data.

In the calculation result of the equation (5), the correlation amount C (L) is minimized when the shift amount L = kj where the data correlation is high. Next, the minimum value C (L) min = C (km) for the continuous correlation amount is obtained by using the three-point interpolation method of the equation (6). km = kj + D / SLOP C (km) = C (kj)-| D | D = {C (kj-1) -C (kj + 1)} / 2 SLOP = MAX (C (kj + 1) -C (kj), C (kj-1) -C (kj)) (6)

Further, the defocus amount DEF can be obtained by the following equation from the shift amount kj obtained by the equation (6). DEF = KX × PY × km (7)

In the equation (7), PY is the photoelectric conversion element 30
4, the pitch in the arrangement direction of the light receiving elements constituting each light receiving unit,
KX is a coefficient determined by the configuration of the focus detection optical system in FIG.

The parameter C (k
m), the reliability of the defocus amount DEF can be determined based on the value of SLOP, and whether or not focus detection is possible is determined based on this parameter.

Further, in the above description, the correlation calculation between one-dimensional data has been described. Can be extended to

The focus detection calculation unit 400D determines the range of data used for the correlation calculation of the equation (5) based on the light quantity distribution information and performs the correlation calculation. For example, as shown in FIG. 9, light amount distribution information Ka (x, 0) is obtained, and when the data a1 to an of the light receiving unit 304A are set on the screen, the data au. aw is used for the correlation operation. For other data bi, ci, di, the data range used for the correlation operation can be determined in the same manner. By doing so, it is possible to suppress imbalance between data due to a decrease in light amount in the correlation calculation, and to improve the accuracy of the focus detection calculation.

The focus detection calculation section 400D may further convert the data used for the correlation calculation of the equation (5) based on the light quantity distribution information. For example, when it is determined from the light amount distribution information that the light amount decrease is remarkable, data conversion may be performed by a low-frequency component removal filter operation as in Expression (8). a′i = −ai + 2 · a (i + 1) −a (i + 2) (8)

The data a'i, b'i, c'i, d'i converted as shown in the equation (8) are converted into raw data ai, bi, ci,
The correlation operation is performed by substituting into equation (5) instead of di. By doing so, it is possible to remove the low frequency component of the subject image signal caused by the decrease in the light amount, and to improve the accuracy of the focus detection calculation.

The focus detection calculation unit 400D also calculates the parameters C (km), SL in equation (6) based on the light amount distribution information.
The reference value for determining the reliability of the defocus amount DEF may be changed based on the value of OP. For example, when it is determined from the light amount distribution information that the light amount decrease is remarkable, the determination reference value can be reduced to save the reliability decrease due to the light amount decrease. In this way, it is possible to determine whether or not the same focus can be detected for the same subject regardless of whether or not the amount of light has decreased.

Further, based on the light amount distribution information, the object image signal may be corrected into a uniform state of the image signal without a decrease in light amount. For example, a photoelectric conversion element is a pair of 2
It is a dimensional sensor, and outputs the subject image signals Sa (x, y) and Sb (x, y), and outputs the light amount distribution information Ka.
Assuming that (x, y) and Kb (x, y), correction is performed as in equation (9). S′a (x, y) = Sa (x, y) / Ka (x, y) S′b (x, y) = Sb (x, y) / Kb (x, y) (9) By performing the appropriate correction, the amount of decrease in the amount of light included in the subject image signal is corrected, and an accurate correlation calculation can be performed in the focus detection calculation unit 400D, so that the accuracy of the focus detection calculation is also improved.

The above operations are performed by the microcomputer 40.
This is performed according to the program in 0.

FIG. 3A is a main flowchart. First, in step S100, the light amount distribution information ka to kd
Is calculated. Next, in step S200, processing is performed on the subject image signal based on the calculated light amount distribution information ka to kd. In step S300, focus detection calculation is performed using the processed subject image signal, and the defocus amount is calculated. Calculate. Then, the lens is driven in accordance with the defocus amount according to a processing procedure (not shown).

The light quantity distribution information ka to kd can be obtained by the flowchart shown in FIG.

In step S101, the peripheral light amount F (d) of the photographing lens 11 is obtained by the above equation (1). This is executed by reading the expression (1) stored in the lens CPU 12 in advance into the microcomputer 400 of the camera body. Then, the process proceeds to step S102, in which the peripheral light amounts Ga (x, y) to Gd (x, y) of the focus detection optical system are set.
Is determined from the above equation (2). Further, in step S103, the vignetting information Ja (x, y) to Jd (x, y) are obtained from the above equation (3). After that, in step S104, light quantity distribution information ka (x, y) to kd (x, y) are obtained from the above equation (4).

FIG. 3C shows the procedure of the pre-processing for the subject image signal.

In step S201, light amount distribution information ka
It is determined whether (x, y) to kd (x, y) are smaller than a reference value. If the light amount distribution information is larger than the reference value, step S201 is denied, and in step S202, the subject image signal is stored in the memory as Sa (x, y) to Sd (x, y). If the light amount distribution information is less than the reference value, step S201 is affirmed, and step S202 is jumped to step S203. In step S203, it is determined whether the comparison determination has been completed for all pixels,
When the determination is completed for all the pixels, the procedure of FIG. By the above procedure, the light amount distribution information ka (x,
Only the subject image signal in which y) to kd (x, y) are larger than the reference value is stored in the memory.

FIG. 3D is a flowchart of the focus detection calculation processing.

In step S301, a well-known correlation amount calculation is performed by the equation (5) using the preprocessed subject image signal to obtain a correlation amount C (L). Further, step S30
2, the shift amount k having a high correlation according to the above equation (6)
Calculate j. Further, in step S303, the defocus amount is obtained by the above equation (6).

In the preprocessing I shown in FIG. 3C, only the subject image signals whose light amount distribution information is larger than the reference value are stored in the memory. However, as shown in FIG. May be corrected based on the light amount distribution information ka to kd and stored in a memory.

In the pre-processing procedure of FIG. 4B, in step S221, the light amount distribution information ka to ka smaller than the reference value is set.
The presence or absence of kd is determined, and if affirmative, step S22
A low-frequency component removal filter operation is performed by Equation 8 in 2 and
Focus detection calculation is performed based on the subject image signal after the filter calculation.

Here, the configuration of the focus detection optical system 30 is shown in FIG.
0 or a configuration as shown in FIG. The focus detection optical system 30 shown in FIG. 11 includes a field mask 300 having a two-dimensional opening 300A, a field lens 301, an aperture mask 302 having a pair of openings 302A and 302B, and a pair of re-imaging lenses. 303
A and 303B, and a photoelectric conversion element 304 having light receiving sections 304A and 304B in which light receiving elements are arranged two-dimensionally. With this configuration, the focus detection area (AF area) on the screen can be arranged two-dimensionally, and the focus detection area can be arbitrarily changed based on the AF area selection result and the viewpoint detection result described later. Becomes possible.

The focus detection optical system 30 may be configured as shown in FIG. In the focus detection optical system 30, the aperture mask 302 is set to EC (electrochromic), LC
It is formed from a physical element such as (liquid crystal) which can electrically change light transmittance. Then, the shape of the opening portion is electrically selected from the outside, so that the shape of the opening portion 3 shown in FIG.
02A and 302B, and openings 302A 'and 302B' having a smaller circumcircle radius than the openings 302A and 302B. By doing so, the openings 302A,
When vignetting occurs with the use of the 302B, the openings 302A 'and 302 have small circumscribed circle radii.
By switching to B ', the focus detection aperture on the focus detection pupil plane can be reduced to prevent vignetting. In FIG. 12, the openings 302A 'and 302B'
Is made smaller so that the circumscribed circle is made smaller. However, for a lens having an exit pupil shape like a doughnut like a reflex lens, the openings 302A ′,
The inscribed circle of 302B 'may be increased so that the focus detection aperture does not vignet inside the donut-shaped exit pupil.

Alternatively, a focus detection optical system 30 as shown in FIG. 13 can be used. This focus detection optical system 3
0 is different from the configuration of FIG. 12 in the structure of the aperture mask 302 and the configuration of the re-imaging lens.
2 can be selected from the openings 302A and 302B shown in FIG. Further, the re-imaging lens 3 is provided behind the openings 302C and 302D.
03C and 303D are provided. With such a configuration, it is possible to select the openings in the arrangement direction in which focus detection can be easily performed according to the pattern (length and width) of the subject, and it is possible to improve focus detection accuracy. Further, since the light receiving portion 304E of the photoelectric conversion element 304 has a two-dimensional shape, when the openings 302A and 302B and the re-imaging lenses 303A and 303B are used,
When the C and 302D and the re-imaging lenses 303C and 303D are used, the photoelectric conversion region can be shared. That is, since the images formed by the re-imaging lenses 303A and 303B and the images formed by the re-imaging lenses 303C and 303D are not formed at the same time, the problem of overlapping between the images is eliminated.

In FIG. 13, the direction in which the openings 302C and 302D are arranged is perpendicular to the direction in which the openings 302A and 302B are arranged.

In the configurations shown in FIGS. 12 and 13, a physical element is used to switch the shape of the opening, but a plurality of openings may be mechanically switched.

Next, a specific application example when the present invention is applied to a single-lens reflex camera will be described with reference to FIGS. <Operation of AF detection system control CPU> AF detection system control CPU
Reference numeral 33 denotes the selection of the AF aperture, which is described later in an AF calculation CP.
While under the direction of U40 or under its own judgment,
It has a function of controlling operations such as charge accumulation control and charge transfer of the photoelectric conversion element 32 using a well-known control signal and a transfer clock signal, and AD-converting the transferred subject image signal and storing it in the memory 34.

AF detection system control C using FIGS.
The operation of the PU 33 will be described in detail.

FIG. 21 is an example of an operation flowchart of the AF detection system control CPU 33. In step S000, the photoelectric conversion element 3 is charged for the charge accumulation time determined before that.
2 is charged. When the storage is completed, step S00
In step 5, the header indicating the memory storage area of the data obtained by AD-converting the output of the photoelectric conversion element 32 is updated. Step S01
At 0, the transfer of the output of the photoelectric conversion element 32, AD conversion, data correction, and storage in the memory are performed for each data. The data correction includes performing the calculation of equation (9) for peripheral light amount correction. In this case, the AF detection system control CPU 33 incorporates information of the focus detection optical
The information of the photographing optical system is received from 2 and the above-described correction operation is performed. When all output transfers are completed, the header of the latest data storage area is updated to the header of the current data storage area in step S015, and the next accumulation time is set in step S020 so that the obtained peak value of the subject image data becomes a predetermined value. And returns to step S000 to repeat the above series of operations. FIG. 22 is a conceptual diagram showing how the data storage area of the memory 34 changes when the above-described operation is performed. The latest data storage area of this time and the data storage area in which data is being stored are as shown in the figure. Then, next time, the current data storage area becomes the next latest data storage area.
Since the latest data storage area and the header of the data storage area are stored in the memory 34, the AF calculation CPU 40 reads out the header of the latest data storage area from the memory 34 and performs focus detection calculation using the data in the area. With this, the latest data can always be used and the photoelectric conversion element 3
Since the control operation 2 and the focus detection calculation operation are separated, the control operation of the photoelectric conversion element 32 and the focus detection calculation operation can be performed in parallel, and the time efficiency, that is, the focus detection responsiveness is improved.

FIG. 23A is a time chart in the case where the above-described operation is performed. When the charge storage operation of the photoelectric conversion element 32 is completed, the transfer operation of the output is started immediately. When the transfer operation is completed, the next charge storage operation is started immediately. In FIG. 23A, the accumulation operation and the transfer operation are temporally separated, but these operations can be overlapped temporally as shown in FIGS. 23B and 23C. The charge accumulation time is compared with the transfer time of the output. If the accumulation time is longer than the transfer time, the current transfer operation is started immediately after the end of the accumulation operation as shown in FIG. Start the accumulation operation. When the accumulation time is shorter than the transfer time, as shown in FIG. 23C, the current transfer operation is started immediately after the end of the accumulation operation, and the end of the next accumulation operation is immediately after the end of the current transfer operation. Next, the next accumulation operation is started. By temporally overlapping the accumulation operation and the transfer operation in this manner, the temporal efficiency, that is, the response of the focus detection can be improved, and the number of data when a two-dimensional photoelectric conversion element is used is increased. Can also absorb a decrease in responsiveness due to

As another measure for absorbing a decrease in responsiveness due to an increase in the number of data when a two-dimensional photoelectric conversion element is used, there is a square two-dimensional light receiving portion as shown in FIG. In such a case, the light receiving section is elongated YB1 to Y parallel to the X axis.
Bn may be divided into n blocks, and each block may be temporally separated and stored and transferred. 24A, the synchronization of data in the X-axis direction is maintained, so that matching is performed when the apertures 302A and 302B of the aperture mask shown in FIG. 15 are arranged in the X-axis direction. Good. On the other hand, the openings 302C and 302D of the aperture mask shown in FIG.
Is used, as shown in FIG. 24B, the light receiving unit is divided into n long and narrow blocks YB1 to YBn parallel to the X axis, and each block is temporally separated. Performing the accumulation and transfer operations is convenient because the data synchronization in the Y-axis direction is maintained.

In the case where the fluctuation of the light source (flicker) causes a problem at high luminance (the output differs even at the same accumulation time depending on when the accumulation operation is performed in the light source fluctuation cycle), FIG. As described above, the accumulation operation is divided into a plurality of times, and the accumulation operation is performed a plurality of times during the fluctuation (flicker) period of the light source, so that the influence of the light source fluctuation can be reduced.

When the amount of peripheral light has fallen as shown in FIGS. 8B and 9, the normal transfer operation is performed only for the portion of the subject image used for the focus detection calculation, and the normal transfer operation is performed for the portion not used. It is also possible to increase the transfer time by performing faster transfer. For example, in the aperture mask shown in FIG. 15, the openings 302A, 302B or Y arranged in the X-axis direction.
When the data that can be used for the focus detection calculation when the openings 302C and 302D arranged in the axial direction are used are inside the broken line on the light receiving unit shown in FIGS. Only the corresponding output performs the normal transfer operation, and the outputs corresponding to the other portions perform the high-speed transfer operation and do not perform AD conversion and memory storage. Information on the correspondence between the data stored in the memory by performing the normal transfer operation and the area on the light receiving unit is also stored in the memory, and is used when the AF calculation CPU 40 performs the focus detection calculation.

When a two-dimensional image sensor is used as the photoelectric conversion element 32, the signal amount becomes enormous, and a considerable amount of time is consumed only by signal transfer and AD conversion. If the accumulation time becomes long, the accumulation operation and the read operation of the image sensor do not fall within a predetermined time, and the responsiveness is reduced. In order to avoid such a situation, only one portion of the entire output of the image sensor is used for focus detection at the time of low luminance, and only the transfer of the image sensor output of the used portion and the AD conversion are performed in a normal operation. The transfer operation is performed at a high speed, and the output of other unused parts is transferred at a high transfer rate so that the A / D conversion is not performed, or the output of only the used parts of the image sensor can be taken out, and the accumulation operation and readout are performed. The sum of the operations is set to fall within a predetermined time. It is desirable that the portion used for the low-luminance focus detection be the center portion of the screen.

In the above description, the charge accumulation time of the photoelectric conversion element 32 is determined so that the peak value of the subject image signal data becomes a predetermined value. When a subject is illuminated by a light source whose intensity varies periodically, such as a fluorescent lamp, oscillation may occur. It is also possible to provide a monitor element near the light receiving section of the photoelectric conversion element and monitor the average value of the image intensity of the object in real time, and terminate the charge accumulation in the light receiving section when the monitor signal reaches a predetermined value. In some cases, such as a white line, the peak value may exceed the range of AD conversion.

FIGS. 26 and 27 show an accumulation time control method which solves such a problem.

In FIG. 26, the monitor signal is reset to VR simultaneously with the start of accumulation, and the monitor signal increases according to the average value of the luminance of the subject image, and reaches the predetermined value Vs at time Tm after the reset. AF detection system control CPU 33
Is the peak value PE of the previous subject image data shown in FIG.
AK, average value AV, monitor time Tml, previous accumulation time Til, target peak value, and current monitor time Tm
And the predetermined value K1, the current storage time Ti
Is determined, and the accumulation is ended after the time Ti from the start of the accumulation.

When the AF detection system control CPU 33 determines that the amount of peripheral light has decreased based on the information on the focus detection optical system and the information on the photographing optical system from the lens CPU 12, or there has been a request from the AF calculation CPU 40. In the case (for example, to expand the range of the defocus amount that can be detected when the focus cannot be detected), the aperture mask openings 302A and 302B shown in FIG.
2A 'and 302B' can also be switched. Further, a request from the AF calculation CPU 40 (for example, when the focus cannot be detected in the horizontal direction because there is no vertical pattern) or a vertical / horizontal selection by the AF area selecting means 66 described later (the horizontal light receiving units 304A and 304B shown in FIG. Part 304
C or 304D is selected for focus detection) or the aperture mask openings 302A, 302A,
The opening 302B can be switched to the openings 302C and 302D. The information when the aperture mask is switched is A
The data is sent to the F calculation CPU 40, and the corresponding processing is performed. <Operation of AF Calculation CPU> In FIG.
The PU 40 has a function of performing a well-known focus detection calculation based on subject image data stored in the memory 34 and calculating a defocus amount of the photographing optical system. For example, when a focus detection optical system as shown in FIG. 10 is employed, as disclosed in Japanese Patent Application No. 63-331748 filed by the present applicant, the focus detection area is divided into a plurality of blocks and each of the focus detection areas is focused. A detection calculation is performed, and an optimum defocus amount is selected from the calculated plurality of defocus amounts according to various policies. The operation of the focus detection calculation performed by the AF calculation CPU 40 is as shown in the operation flowchart of FIG.
This is roughly divided into data correction / conversion in step S030, focus detection area selection in step 035, block division in step S040, defocus amount calculation for each block in step S045, and final defocus amount selection in S050. The above operation is repeated by the arithmetic CPU 40. Hereinafter, the operation in each step will be described in detail.

The data correction / conversion step includes calculating the expression (9) for correcting the peripheral light amount. In this case, the AF calculation CPU 40 receives the information of the focus detection optical system from the built-in or AF focus detection system control CPU 33, receives the information of the photographing optical system from the lens CPU 12, obtains the light amount distribution information, and obtains the correction calculation (9). I do.

If it is determined from the obtained light amount distribution information that the light amount is significantly reduced, data conversion is performed by a low-frequency component removal filter operation as shown in equation (8).
The data conversion by the low-frequency component removal filter operation as in the equation (8) may be performed only for a subject containing a large amount of high-frequency components by detecting the subject contrast.
For example, when an image signal as shown in FIGS. 31A and 31B is obtained, the image signal is divided into a plurality of blocks, and a contrast (= CON) detection operation as shown in Expression (11) is performed in each block. Is performed, and if a predetermined value of contrast cannot be obtained in all blocks, it is determined that the object is a low-frequency object, and (8)
When the contrast of a predetermined value or more is obtained in one or more blocks without performing the data conversion of the equation, the data conversion of the equation (8) is performed. CON = Σ | ai−a (i + 1) | (11)

As described above, if the data conversion by the filter is determined according to the contrast of the subject image, the focus detection operation can be performed without filtering the low frequency for the subject including many low frequency components. The focus detection accuracy is improved.

In the step of selecting the focus detection area, for example, as shown in FIG. 29A, when the center spot area (narrow) and the wide area (wide) of the screen are set as the areas for focus detection in the screen, Switch the area in some way. FIG. 29 shows the focus detection area.
As shown in (b), an area (a plurality of areas) at an arbitrary position on the screen may be set manually (the AF area selecting means 66) or the viewpoint detecting means 68.

FIGS. 30A and 30B show the viewpoint detecting means 68.
An example of the configuration will be described. The infrared light surface emitting element 683 is projected to a finder observer's eye 685 via a half mirror 681, a lens 680, and an infrared light reflecting dichroic mirror 682 installed in the eyepiece 25. In such an optical system, the shape and position of the optical member are set such that the light emitting surface of the infrared light emitting element 683 overlaps the shape and position with the viewfinder screen. The infrared light projected on the eyes 685 of the observer is reflected by the retina 686 and is again reflected on the eyepiece 2.
5 and follows a path reverse to that when the light is emitted, is reflected by the infrared light reflecting dichroic mirror 682 and is
0, the light passes through the half mirror 681 and is received by the surface light receiving element 684. In the above configuration, since the reflection efficiency in the gazing point direction is higher than in other directions, the amount of light received in the area on the surface light receiving element 684 corresponding to the area (gazing point) on which the observer is gazing on the finder screen is different. Area. In order to remove the influence of infrared light from the finder, the difference (shown in FIG. 30B) between the light receiving amount distribution of the surface light receiving element 684 when the surface light emitting element 683 emits light and when it does not emit light is calculated. The gazing point is detected based on the area position indicating the maximum amount of received light.

According to the result of the viewpoint detection, the focus detection area may be selected as described above, or the area for spot photometry may be selected. In the above configuration, a two-dimensional CCD sensor may be used as the surface light receiving element 684, or a position sensor that detects the position of the center of gravity of the amount of received light may be used. Surface emitting element 68
Instead of 3, beam scanning may be performed in two dimensions.
In addition, when detecting the above-mentioned point of gaze, there is a possibility of erroneous detection due to blinking of the observer. Do not use it for viewpoint detection, and do not follow unstable factors such as blinking or momentary changes in the gazing point.
Stability is improved by lowering the temporal response of gaze point detection by using statistical processing or the like.

In the block division step of step S040 in FIG. 28, the inside of the focus detection area selected in the previous step is divided into a plurality of blocks according to the subject pattern. For example, when image signals as shown in FIGS. 31A and 31B are obtained, the image signal is divided into a plurality of blocks, and a contrast (= CO
N) Perform a detection operation, and if a predetermined value of contrast cannot be obtained in all blocks, the block is determined to be a low-frequency subject,
As shown in FIG. 31 (c), the focus detection area is divided into a small number of blocks (broken lines in FIG. 31 indicate block boundaries). If a contrast equal to or more than a predetermined value is obtained in one or more blocks, FIG. Divided into many blocks.

In the step of calculating the defocus amount for each block in step S045, a known focus detection operation may be applied to each of the blocks divided in the previous step. In this way, the defocus amount can be obtained for each of a plurality of blocks.

In the step of correcting the defocus amount in step S050, the correction based on the optical aberration of the photographing optical system is added to the defocus amount according to the block position. For example, when the information of the field curvature aberration is a function S (d) of the distance d from the center on the screen, the coefficients M2, M4,.
.. When the lens CPU 12 is sent in such a manner, the correction amount for the defocus amount of the block can be obtained by substituting the distance dc of the center position of the block from the screen center into the equation (12). S (d) = M2 × d ² + M4 × d ⁴ +... (12)

The other aberrations can be corrected in the same manner.

In the step of selecting the final defocus amount in step S055, one defocus amount is calculated according to a predetermined reference (algorithm) from the plurality of defocus amounts obtained as described above. For example, when the selection algorithm is center-priority, the defocus amount of the block that is closest to the center of the screen and that is not detectable is selected. In the case of closest priority, the calculated defocus amount indicates the shortest distance, in the case of long distance priority, the calculated defocus amount indicates the longest distance, and in the case of average priority, the calculated defocus amount is calculated. Among the defocus amounts, an average or a weighted average using the reliability as a weight is selected, and in the current priority, the calculated defocus amount having the smallest absolute value is selected.

After the operation of each of the above steps,
One defocus amount is calculated. Next, variations of area selection and algorithm selection in the step of determining the focus detection area and selecting the final defocus amount will be described in detail.

First, when the area is selected manually,
An AF area selecting means 66 is provided on the camera body, and by operating the AF area selecting means 66, an AF area can be selected as shown in FIG.

In FIG. 50, the viewpoint is detected based on the result of the viewpoint detecting means 68, the center spot is the spot area at the center of the screen of FIG. 29 (a), and the selected spot is arbitrary in the screen of FIG. 29 (b). The wide area is the wide area shown in FIG. 29A, and the horizontal and vertical areas are the areas corresponding to the screen horizontal direction light receiving units 304A and 304B when the focus detection optical system shown in FIG. This indicates that an area corresponding to the direction light receiving units 304C and 304D is selected. The center spot → wide mode is a mode in which the focus is once at the center spot and the AF area is a wide area after focusing. By allowing the AF area to be manually selected in this manner, the photographer can himself select the optimum area for the subject.

The algorithm may be switched as shown in the right column of FIG. 50 in conjunction with the selection of the AF area. When the AF area is selected in the viewpoint detection mode or the selected spot mode, A
Since a plurality of F areas may be set, by setting the algorithm to the average priority mode, it is possible to roughly focus on any of the plurality of subjects. Also,
When the AF area is selected in the center spot mode, the AF area is set at the center. By setting the algorithm to the center priority mode, the subject at the center of the screen can be focused. Furthermore, AF area selection is center spot →
Since the AF area is wide in the wide mode, wide mode, and horizontal mode, the algorithm is set to the closest priority → the current priority mode to focus on the closest subject with the closest priority until focusing, and the current priority is closest after focusing. The stability can be increased so that an object that is not in the way enters the lens and drives the lens. Furthermore, when the AF area is selected in the vertical mode, the AF area is relatively narrow, and there is little possibility that a disturbing subject enters. Therefore, by setting the algorithm to the closest priority mode, it is possible to always focus on the closest subject.

When the algorithm is selected manually, an AF object selecting means 67 is provided in the camera body, and by operating this, the algorithm can be selected as shown in FIG.

In FIG. 51, the center priority → the current status priority is the center priority before focusing, the current status priority after focusing, and the closest priority →
The current priority indicates that prior to focusing, the closest priority is given, and after focusing, the current priority is given. In this way, by allowing the algorithm to be manually selected, the photographer can himself select the most appropriate algorithm for the subject.

Further, in conjunction with the selection of the algorithm, FIG.
The AF area may be switched as in the center column of No. 1. When the algorithm selection is in the center priority mode or the close priority mode, it is better to make the AF area smaller so that A
Make area F a central spot. Algorithm selection is average priority mode, long distance priority mode or close priority →
In the current priority, it is better to make the AF area larger, so the AF area is made wider. When the algorithm selection is center priority → current priority, it is better to make the AF area smaller at the center spot before focusing and widen it after focusing to improve stability. I do.

Next, an example will be described in which AF area selection and algorithm selection are not selected by dedicated selection means but are selected in conjunction with the operation of the selection means used to select and switch other operations of the camera.

As shown in the left column of FIG. 52, the photometric mode is selected from the central spot (a photometric mode based on a relatively narrow area at the center of the screen) and the selected spot (a photometric mode based on a relatively narrow area at an arbitrary area on the screen). ), Part (metering mode with area wider than spot in center of screen), center-weighted (metering mode with emphasis on center in entire screen area), and multi (metering mode that divides entire screen into multiple areas) In this case, the AF area is selected in the center column and the algorithm is selected in the right column in conjunction with the selection.
When the metering mode is the center spot, the center of the screen is emphasized. Therefore, the AF area is set to the center spot, and the algorithm is set to the center priority. When the photometry mode is the selected spot, a plurality of locations on the screen are selected. Therefore, the AF area is also set to the selected spot in accordance with the photometry, and the algorithm is given the closest priority. If the metering mode is partial or center-weighted, a relatively large area is selected, so the AF area is also a center spot.
Widen and the algorithm is given priority from the center → current priority.
When the metering mode is multi, the entire screen is metered, so the AF area is also wide and the algorithm has the closest priority. →
Give priority to the current situation. In this way, the correspondence between the AF area and the photometry area can be obtained, and the stability of AF and the selectivity of the subject can be improved.

When the AE mode is selected by the AE mode selection means 70 as aperture priority, shutter speed priority, or program as shown in the left column of FIG.
Select the F area as shown in the center column and the algorithm as shown in the right column. When the AE mode is aperture-priority, a stationary subject at the center of the screen is often photographed. Therefore, the AF area is also changed from the center spot to the wide area, and the algorithm is also changed from the center-priority to the current state to improve the object selectivity. When the AE mode is prioritizing the shutter speed, the moving subject is often photographed. Therefore, the AF area is widened, and the algorithm is prioritized to the closest, thereby improving the capturing performance of the subject. When the AE mode is a program, beginners often take pictures or take snapshots. Therefore, the AF area is widened, and the algorithm is given priority from the closest to the current state to improve the capturing performance and stability of the subject. In this way, the optimum A / A mode for the subject type can be obtained simply by selecting the AE mode corresponding to the subject type.
F area and algorithm can be selected.

When the winding mode is selected by the winding mode selection means 65 as single (single-sheet taking), continuous high speed, continuous low speed, or self (self-timer) as shown in the left column of FIG. Select the area as the center column and the algorithm as the right column. When the winding mode is single, a still subject in the center of the screen is often photographed. Therefore, the AF area is set to the center spot, and the algorithm is given priority to the center to improve the selectivity of the subject. When the winding mode is continuous high speed, a moving subject is often photographed. Therefore, the AF area is widened, and the algorithm is given priority from the closest to the current state, so that the subject capturing performance and the AF stability are improved. When the winding mode is continuous low speed, the AF area is intermediate between single and continuous high speed. Therefore, the AF area is set to the center spot → wide, and the algorithm is set to the closest priority → the current priority, thereby harmonizing the capturing property and the selectivity of the subject. When the winding mode is the self mode, it is not known where the main subject enters the screen, so that the AF area is widened and the algorithm is given the closest priority to improve the capturing performance of the subject. With this configuration, the optimum AF mode for the shooting situation can be obtained simply by selecting the winding mode according to the shooting situation.
Area and algorithm can be selected.

When the photographing mode is selected by the photographing mode selecting means 64 into the sports, portrait, snap, landscape, close-up mode as shown in the left column of FIG. Select as shown in the right column. By selecting a shooting mode, a photometric mode, an AE mode, a winding mode, and a focus mode that are optimal for each mode are automatically selected.
When the shooting mode is sports, a moving subject is often photographed. Therefore, the AF area is widened, and the algorithm is given priority from the closest to the current state, thereby improving the capturing performance of the subject. When the photographing mode is portrait, a still subject is often photographed. Therefore, the AF area is also set to the center spot, and the algorithm is prioritized to the nearest, thereby improving the selectivity of the subject. When the shooting mode is snap, the subject does not always come to the center. Therefore, the AF area is widened, and the algorithm is given priority from the closest to the current status, thereby improving the subject capturing performance and the AF stability. If the shooting mode is landscape, there is often room for the main subject to be centered before locking the focus and changing the framing.
The AF area is set to the center spot, and the algorithm is set to the center priority to improve the selectivity of the subject. When the shooting mode is the close-up mode, the focus area of the subject is often narrow, so that the AF area is set to the center spot and the algorithm is given priority to the center to improve the selectivity of the subject. By doing so, it is possible to select an AF area and an algorithm that are optimal for the target by simply selecting a shooting mode according to the target.

As shown in the left column of FIG. 56, the focus mode is set to single (focus lock after focusing), continuous, tracking (correcting the lens drive amount for a moving subject), power focus, If you select manual, A
Select the F area as shown in the center column and the algorithm as shown in the right column. When the focus mode is single, a still subject is often photographed. Therefore, the AF area is set to the center spot, and the algorithm is given priority to the center to improve the selectivity of the subject. When the focus mode is continuous, a moving subject is often photographed.
The object capturing performance and AF stability are improved. When the focus mode is tracking, an object moving in a close direction is often photographed. Therefore, the AF area is also changed from the center spot to the wide area, and the algorithm is prioritized to the close area, thereby improving the selectivity and the capturing property of the object. When the focus mode is the power focus, there is often no room to change the framing, so that the AF area is widened and the algorithm is given priority from the closest to the current state to improve the subject capturing performance. When the focus mode is manual, you often want to focus on just one part of the subject accurately,
The AF area is set to the center spot, and the algorithm is set to the center priority to improve the selectivity of the subject. With this configuration, it is possible to select an optimum AF area and algorithm for the target by simply selecting the focus mode according to the target.

As described above, when the mode for various photographing is manually switched, the AF area and the algorithm are switched in conjunction with the switching, but the various photographing modes are automatically switched. In this case, the same effect can be obtained by switching the AF area and the algorithm in conjunction with the switching.

As shown in FIG. 57, the switching between the AF area and the algorithm may be performed by comparing the elapsed time T from the half-press ON of the release button 61 with a predetermined time T1.
If the elapsed time T is shorter than the predetermined time T1, the selectivity of the subject is emphasized, the AF area is set to the center spot, and the algorithm is given the closest priority.
Focusing on the stability of the AF area, the AF area is made wide, and the algorithm is given the current priority.

Next, an example will be described in which AF area selection and algorithm selection are not performed in conjunction with the selection of other camera operation selection means, but are selected in accordance with the results of various detection means of the camera itself.

When the information on the subject distance is obtained, the AF area and the algorithm are selected as shown in the center column and the right column of FIG. 58 according to the information. As is well known, the subject distance information can be obtained, for example, from the defocus amount information of the focus detection result and the absolute position information of the photographing lens. When the subject distance is short, the subject is up, and the focus position is considerably different depending on the screen position. Therefore, in order to enhance the subject selectivity, the AF area is set to the center spot and the algorithm is set to the center priority. If the subject distance is long, the subject becomes small and it becomes difficult to capture it. Therefore, the AF area is widened and the algorithm is given priority from the closest to the present. When the subject distance is intermediate, the AF area is set to the middle spot from the center spot to wide, and the algorithm is set to the closest priority to the current priority. This makes it possible to select an optimal AF area and algorithm according to the subject distance.

If information on the photographing magnification can be obtained, an AF area and an algorithm are selected according to the information as shown in the center column and the right column in FIG. As is well known, the magnification information can be obtained from, for example, defocus amount information of the focus detection result, absolute position information of the photographing lens, and focal length information of the photographing lens. When the magnification is large, the object is up and the focus position is considerably different depending on the screen position. Therefore, in order to enhance the object selectivity, the AF area is set to the center spot and the algorithm is set to the center priority. If the magnification is small, the subject becomes small and it becomes difficult to capture it.
Give priority to the current situation. When the magnification is in the middle, the AF area is set to the center spot → wide, and the algorithm is given the closest priority →
The middle of the above selection is set as the current priority. In this way, an optimal AF area and algorithm can be selected according to the shooting magnification.

If information on the focal length can be obtained, the AF area and algorithm are selected as shown in the center column and right column of FIG. 60 according to the information. As is well known, the focal length information can be obtained from the lens information sent from the lens CPU 12, for example. In the macro state, the subject is up and the focus position is considerably different depending on the screen position. Therefore, in order to enhance the selectivity of the subject, the AF area is set to the center spot, and the algorithm is set to the center priority. If the focal length is short, the subject becomes small and it becomes difficult to capture it. Therefore, the AF area is widened, and the algorithm is given priority from the closest to the current. If the focal length is long, the AF area is considered to be halfway between the macro and short focal lengths, and the AF area is
Wide and algorithm are given priority from the closest to the current priority, which is in the middle of the above selection. This makes it possible to select an optimal AF area and algorithm according to the focal length information.

When an AF area is selected and an algorithm is selected based on the information on the subject distance, the magnification, and the focal length, if the subject is enlarged on the screen, the AF
When the area and algorithm are spotted to enhance the subject selectivity and the subject is reduced on the screen, the AF area is widened to improve the subject capture, but the subject is enlarged on the screen. If the subject is large, the AF area will be widened to improve the subject capture and AF stability, and if the subject is reduced on the screen, the AF area will not be mixed with other subjects. And the algorithm may be spotted to enhance the object selectivity.

When the information on the aperture value can be obtained, the AF area and the algorithm are selected as shown in the center column and the right column of FIG. 61 according to the information. As is well known, the aperture value information can be obtained from the main CPU 60 that controls the aperture control unit 83. When the aperture value is small, focusing accuracy is required, so that the AF area is set to the center spot and the algorithm is given priority to the center in order to enhance the subject selectivity accordingly. When the aperture value is large, the depth of field is large and the focus accuracy is not so required, so that the AF area is widened and the algorithm is given the average priority. This makes it possible to select an optimal AF area and algorithm according to the aperture value information.

When information on the shutter speed can be obtained,
According to the information, the AF area and the algorithm are selected as shown in the center column and the right column of FIG. As is well known, the shutter speed information can be obtained from the main CPU 60 that controls the shutter speed control means 82. When the shutter speed is high, the moving subject is often photographed. Therefore, in order to enhance the subject capturing performance, the AF area is widened and the algorithm is prioritized from the closest to the present. When the shutter speed is low, a still object is often photographed. Therefore, in order to enhance the object selectivity, the AF area is set to the center spot, and the algorithm is given priority from the center to the current state. This makes it possible to select an optimal AF area and algorithm according to the shutter speed information.

When the information on the subject luminance can be obtained, the AF area and the algorithm are selected according to the information as shown in the center column and the right column of FIG. As is well known, the luminance information is output from the photometric sensor 86, for example, and the main CPU 60 receives the luminance information.
Can be obtained by detecting the luminance. In the case of high brightness, the subject can be clearly identified in many cases. Therefore, focusing on the subject selectivity, the AF area is set to the center spot, and the algorithm is set to the center priority. In the case of low brightness, the subject cannot be clearly identified in many cases. Therefore, the focus on the subject is emphasized, the AF area is widened, and the algorithm is given the closest priority. This makes it possible to select an optimal AF area and algorithm according to the subject luminance information.

When information on strobe light emission can be obtained,
According to the information, the AF area and the algorithm are selected as shown in the center column and the right column of FIG. As is well known, the flash information is, for example, a main C for controlling a built-in flash (not shown).
Control CP (not shown) built in PU60 or strobe
It can be obtained by communicating with U. When the strobe is not fired, the subject can often be clearly identified with high brightness. Therefore, the AF area is set to the center spot and the algorithm is set to the center priority with emphasis on the object selectivity. When a flash is used, it is often difficult to clearly identify the subject at low brightness.
Make the area wide and give the algorithm the closest priority. In this way, an optimal AF area and algorithm can be selected according to the flash information.

When the information on the aberration of the photographing optical system can be obtained, the AF is performed according to the information as shown in the center column and the right column of FIG.
Select area and algorithm. As is well known, the aberration information can be obtained from the lens information sent from the lens CPU 12, for example. If the on-axis and peripheral aberrations are large (for example, the curvature of field is large), it is better to perform focus detection near the axis, so that the AF area is set to the central spot and the algorithm is given priority to the center. When on-axis and peripheral aberrations are small, accuracy can be obtained even when focus detection is performed at the periphery, so the AF area is widened and the algorithm is given priority to the closest point. →
Give priority to the current situation. This makes it possible to select an optimum AF area and algorithm according to the aberration information.

If the camera body posture information can be obtained, AF information can be obtained as shown in the center column and right column of FIG.
Select area and algorithm. As is well known, the body posture information can be obtained by providing a position detecting means 69 such as a mercury switch in the body, for example.
When the body is in the vertical position, the focus detection in the horizontal direction is more likely to detect the subject, so the AF area is set to the light receiving section in the vertical direction in FIG. 10 and the algorithm is given the closest priority. When the body is in the horizontal position, the focus detection in the horizontal direction is more likely to detect the subject.
The area is set in the row direction in FIG. This makes it possible to select an optimal AF area and algorithm according to the body posture information.

Next, an example in which AF area selection and algorithm selection are selected according to the result of focus detection or subject image data will be described.

If the information on the subject pattern can be obtained, the AF is performed according to the information as shown in the center column and the right column of FIG.
Select area and algorithm. The subject pattern information can be obtained by the AF calculation CPU 40 itself by applying the calculation of the formula (11) to the subject image data for focus detection, for example. When the subject pattern has a high contrast, the subject can be clearly identified in many cases. Therefore, the focus is placed on the subject selectivity, and the AF area is set to the center spot, and the algorithm is set to the center priority. In the case of low contrast, the subject cannot be clearly identified in many cases. Therefore, emphasis is placed on the subject capturing property, the AF area is widened, and the algorithm is given priority from the closest to the present. In this way, an optimal AF area and algorithm can be selected according to the subject pattern information.

When defocus information can be obtained, an AF area and an algorithm are selected according to the information as shown in the center column and the right column of FIG. The defocus information can be obtained, for example, by the AF calculation CPU 40 that performs the focus detection calculation. When the defocus is small, the subject can often be clearly identified, and the amount of mutual shift of the subject image data may be small even in the correlation calculation for focus detection. And make the algorithm a central priority.
When the defocus is large, the subject cannot be clearly identified in many cases, and the mutual shift amount of the subject image data also becomes large in the correlation calculation for the focus detection. And give the algorithm the closest priority. This makes it possible to select an optimal AF area and algorithm according to the defocus information.

In the above, the selection of the AF area and the algorithm in conjunction with various conditions has been described. However, various determination conditions in the AF calculation may be switched according to the above conditions. For example, the defocus amount DEF is determined by the value of the parameter C (km) and SLOP obtained by the equation (6).
Can be determined, and it is possible to determine whether or not the focus can be detected based on this parameter as shown in Expression (13). C (km)> Cs or SLOP <Ss --- not detectable C (km) ≤Cs and SLOP≥Ss --- detectable ... (13)

Therefore, the predetermined values Cs, S in the equation (13)
If s is changed in conjunction with the various conditions described above, it is possible to determine whether or not focus detection is optimal for various conditions. Basically, a state where accurate focus detection can be performed or needs to be performed (the AF area is small, the algorithm is centered or close priority, the metering mode is spot, the AE mode is aperture priority, the winding mode is single, and the shooting mode is port (Single rate, focus mode, close subject distance, high magnification, long focal length, small aperture value, fast shutter speed, high brightness, small aberration, high contrast, small defocus amount) A predetermined value is set strictly (Cs is small and Ss is large), and a state in which accurate focus detection cannot be performed or a state in which accurate focus detection is not required (AF
Area is large, algorithm is current priority, metering mode is multi, AE mode is programmed, winding mode is continuous, shooting mode is sports, focus mode is continuous, subject distance is long, magnification is small, focal length is short, When the aperture value is large, the shutter speed is low, the brightness is low, the aberration is large, the contrast is low, and the defocus amount is large, the predetermined value is set loosely (Cs is increased,
Ss).

The reference values Ns and Ws (> Ns) for the focus determination as shown in the equation (14) may be made variable according to the above conditions. Out of focus | DEF |> Ns, in focus | DEF |> Ws-out of focus Out of focus | DEF | ≦ Ns, in focus | DEF | ≦ Ws—in focus… (14)

Basically, a state in which accurate focus detection can be performed, or a state in which accurate focus detection is required, and a state in which accuracy is more important than responsiveness (A
F area is small, algorithm is center or close priority, metering mode is spot, AE mode is aperture priority, winding mode is single, shooting mode is portrait,
Single focus mode, short subject distance, high magnification, long focal length, small aperture value, fast shutter speed, high brightness, small aberration, high contrast, small defocus value) Strictly setting (Ns, Ws small), a state where accurate focus detection cannot be performed or a state where responsiveness is more important than accuracy (AF area is large, algorithm has priority over current, photometry mode is multi, AE mode is program, Winding mode is continuous, shooting mode is sports, focus mode is continuous, subject distance is long, magnification is small, focal length is short, aperture value is large, shutter speed is slow, low brightness, aberration is large, and contrast is high. The predetermined value is set loosely (Ns, Ws is increased) for (low, large defocus amount).

Also, Japanese Patent Application No. 63-247 filed by the present applicant.
No. 829, which describes a reference value for a moving subject in the predictive driving technique (detecting the movement of the subject in the optical axis direction and correcting the AF lens drive amount with the movement of the subject). Steps 490, 510, 51
The five parameters α, δ, r, and k) may be changed according to the above conditions. Basically, a state in which a still object is photographed or a state in which stability is more important than responsiveness (A
F area is small, algorithm is center or close priority, metering mode is spot, AE mode is aperture priority, winding mode is single, shooting mode is portrait,
Predictive driving when the focus mode is single, the subject distance is short, the magnification is long, the focal length is long, the aperture value is small, the shutter speed is slow, the brightness is low, the aberration is large, the contrast is low, and the defocus amount is small. Hard to enter (δ and k are large, α and r are small), and a state in which a moving subject is photographed or a state in which responsiveness is more important than stability (the AF area is large, the algorithm currently has priority, the metering mode is multi, AE mode is program, winding mode is continuous, shooting mode is sports, focus mode is continuous, subject distance is long, magnification is small, focal length is short, aperture value is large, shutter speed is fast, high brightness, aberration Is small, the contrast is high, and the defocus amount is large).
Is smaller, and α and r are larger). As described above,
When the tracking mode is selected by the focus mode selection means 63, the AF calculation CPU 40 determines the moving subject, and when the tracking mode is determined, adds the correction amount due to the movement of the subject to the defocus amount.

The above is the operation of the AF calculation CPU. <Operation of Lens Drive Control CPU> When the AF calculation CPU 40 performs the processing as shown in FIG. 28 and finally calculates one defocus amount and makes a focus determination, the defocus amount and the focus adjustment state ( Fig. 2
0 is sent to the lens drive control CPU 50. In the lens drive control CPU 50, the AF mode (single, continuous, tracking) is set by the focus mode selection unit 63.
Is selected, the lens driving amount up to the focal point is calculated based on the defocus amount, and the AF motor 51 is rotated in a direction in which the photographing lens 11 approaches the focal point. A
The rotational motion of the F motor passes through a body transmission system 52 composed of gears and the like built in the body 20 and a clutch B53, and is fitted to a body-side coupling 54 provided on the mount portion of the body 20 and the lens 10. The coupling is transmitted to the coupling 18 on the lens side, and further passes through a lens transmission system 13 composed of gears and the like built in the lens 10,
Finally, the photographing lens 11 is moved in the focusing direction. AF
The drive amount of the motor 51 is converted into a pulse train signal by an encoder 55 including a photo interrupter and the like, and the feedback amount is fed back to the lens drive control CPU 50. The lens drive control CPU 50 detects the drive amount and drive speed of the AF motor 50 by measuring the number of pulses and the pulse interval, and controls the drive stop and drive speed of the AF motor 51 so that the lens stops accurately at the focal point. I do.

When the power focus mode is selected by the focus mode selection means 63, the lens drive control CPU 50 determines the operation direction, the operation amount, and the operation speed of the lens distance ring 15 built in the lens The signal is received by the encoder 16 composed of an interrupter or the like via a contact 19B on the lens side provided on the mount portion of the body 20 and the lens 10 and a corresponding contact 59B on the body side. The operation direction can be identified, for example, by generating two signals obtained by monitoring the movement of the lens distance ring by shifting the phase by 90 ° and detecting the phase relationship between the monitor signals. The lens drive amount, the drive speed, and the drive direction are determined based on the operation amount, the operation direction, and the operation speed detected in this manner, and the AF operation is performed in the same manner as the AF mode control operation.
The drive control of the motor 51 is performed, and the photographing lens 11 is moved in accordance with the operation of the lens distance ring.

In the AF mode and the power focus mode, the power source for driving the lens is the AF motor 5.
Therefore, the lens drive control CPU 50 sets the clutch B53 to the coupled state by the clutch control means 56 so that the rotational force of the AF motor 51 is transmitted to the lens side, and the lens provided on the mount portion of the body 20 and the lens 10. The clutch L14 built in the lens side is disconnected via the contact 19A on the lens side and the contact 59A on the body side corresponding thereto, and the operating force of the lens distance ring 15 is applied to the lens transmission system 1.
Do not transmit to 3. In addition, the movement of the body transmission system 52 is monitored by the encoder 55 in order to monitor the lens drive amount and the drive speed. However, in this case, since the path for transmitting the drive force from the body to the lens is long, the gear Error due to rush increases. Therefore, in order to solve this problem, an encoder 17 that monitors the movement of the lens transmission system 13 on the lens side so as to directly monitor the movement of the photographing lens 11 that is the final drive control target.
And the monitor signal of the drive amount is transmitted to the body 20 and the lens 1.
A drive control for feeding back to the lens drive control CPU 50 via a contact 19C on the lens side provided on the mount portion of No. 0 and a corresponding contact 59C on the body side is performed.
The lens driving amount and the driving speed may be controlled more accurately.

When the manual mode is selected by the focus mode selection means 63, the lens drive control CPU 50 determines that the power source for driving the lens is the operation of the lens distance ring 15, so that the clutch control means 56 controls the clutch B53. In order to prevent the rotational force of the AF motor 51 from being transmitted to the lens side, a lens-side contact 19A provided on the mount portion of the body 20 and the lens 10 and a corresponding body-side contact 59A.
The clutch L14 built in the lens side is brought into the connected state via the
3

In the above description, the power focus mode and the manual focus mode have been selected by the focus mode selection means 63 provided on the body side. As shown in FIG. A contact sensor means 41 is provided for detecting that the photographer has touched or operated the ring 15. When the contact sensor means 41 detects that the photographer has touched or operated the lens distance ring 15. The mode is switched between the power focus mode and the manual focus mode, and when it is detected that the photographer is not touching or operating the lens distance ring 15, the mode is switched to another AF mode selected by the focus mode selection unit 63. You may do so. In this way, when the photographer wants to perform the focus adjustment in the power focus mode or the manual focus mode, it is not necessary to select the focus mode selection unit 63 each time, and the distance ring is operated as in the conventional manual focus adjustment operation. It is easy to use because only it is necessary.

In the above-described AF mode, it is necessary to accurately control the lens driving amount. However, in order to accurately control the lens position, it is necessary to reduce the driving speed near the focal point. Generally, the drive speed control of the lens is performed by turning ON / OFF the drive stop of the AF motor 51 in a pulse manner and changing the duty of the pulse. The above speed control is performed, for example, in Japanese Patent Application Laid-Open No.
As disclosed in Japanese Patent Application Laid-Open No. 16, the deviation from the focal point to the current lens position is divided into several zones, and speed control is performed so that the same driving speed is obtained in the same zone. However, in the control method in which the speed is gradually decreased by dividing into zones based on the deviation from the focal point as described above, the speed is gradually reduced, so that useless speed control occurs and until the focal point is finally reached. Time has become longer.

In general, the stop characteristics of the motor are expressed by equation (15). That is, the rotation speed of the motor is attenuated by an EXPONENTIAL function. N (t) = N0.times.exp (-t / T0) WT = T0.times.N0 (15)

In equation (15), N (t) is the motor rotation speed, N0 is the rotation speed at the start of braking, t is time, T0
Is the time constant, and WT is the rotation amount from the start to the stop of the brake. Therefore, if the brake is applied when the remaining rotation amount (drive amount) becomes WT with respect to the target rotation amount (drive amount),
Ideally, the vehicle can be stopped at the target stop position with the brake applied. Generally, there is a difference in driving torque between lenses, and a deviation from equation (15) occurs.
If the rotational speed Nr at the time of deceleration is controlled so as to be proportional to the remaining rotation amount (drive amount) Wr as in Wr / T0, the vehicle can be stopped at the target stop position in the shortest time. In the case of AF drive control, the number of pulses generated by the encoder 16 or 55 from the start of braking is subtracted from the driving amount (number of pulses) from the brake start lens position to the focal point for the remaining drive amount until the focal point. The driving speed can be measured by the pulse interval. For example, FIG. 32 shows the state of the monitor signal when the brake is applied at the point of the residual pulse m short of the focal point and theoretically stops at the focal point, based on the rotation speed at the time of full-speed rotation of the AF motor and the time constant of the drive system. Show.
In this case, if the pulse interval tn when the number of remaining pulses is n is determined so as to be inversely proportional to the number of remaining pulses as shown in the equation (16), the stop characteristics may be slightly reduced due to a change in driving load and the like. Even if it changes, it can reach the focal point in a short time. tn = t0 / n (16) In the equation (16), the time constant t0 is a value theoretically determined according to the lens driving system. Therefore, the remaining pulse number n
FIG. 34 shows the relationship between and the pulse interval tn. When the pulse interval tn ′ measured at the remaining pulse number n is shorter than the theoretical pulse interval tn in FIG. 34, the driving speed is decreased because the driving speed is too high, and when it is longer, the driving speed is increased because it is too slow. The drive speed is increased / decreased by changing the ON / OFF duty of the drive signal of the AF motor. For example, in the drive signal shown in FIG. 33, the drive speed can be changed by increasing or decreasing the time td when the drive is ON with respect to the fixed cycle tx.

Next, the operation of the lens drive control CPU 50 will be described with reference to FIGS. In FIG. 35, first, when the power is turned on, it is determined whether or not lens position information is necessary in step S060. If necessary, in step S065, the lens is retracted to the ∞ end, and the position is set as the lens reset position. Is increased or decreased according to the driving direction to measure the amount of extension from the ∞ end of the lens. If not necessary, step S065 is omitted.
In step S070, the focus mode selection unit 63
The operation according to the focus mode set in the above is repeated. However, when the focus mode is changed, the process returns to step S060. Conventionally, even when lens position information is unnecessary, the lens is uniformly retracted, so even if you do not need lens position information and want to shoot immediately with the power on, you have to wait until the lens retraction is completed. In this case, the lens moves in only when lens position information is required (for example, the operation mode or parameter of the AE or AF is changed according to the lens moving-out position), so that the conventional inconvenience can be eliminated.

FIG. 36 is an operation flowchart in the AF driving mode (single mode, continuous mode, tracking mode). First, in step S080, clutch control is performed, the driving force of the AF motor is transmitted to the photographing lens, and the distance ring is controlled. The 15 operation forces are not transmitted to the taking lens. In step S085, it is determined whether the focus detection result of the AF calculation CPU 40 is in focus. If the focus is not in focus, the defocus amount is converted into a lens drive amount in step S090, and the lens is moved by the AF motor 51 by the drive amount in step S095. Drive, and when the drive is completed, step S is performed again.
Return to 085. If the focus is achieved in step S085, it is determined in step S100 whether the mode is the single mode. If the mode is not the single mode, the process returns to step S085 without driving and waits for the next focus detection result. In the case of the single mode, the focus is locked in step S105, the subsequent lens driving is prohibited, and a release permission is issued to the main CPU 60. From step S105, the process returns to step S085 by half-pressing the release button 61 or by shutter operation.

FIG. 37 is a flowchart of the operation in the power focus mode. In step S110, clutch control is performed so that the driving force of the AF motor 51 is transmitted to the photographing lens and the operating force of the distance ring 15 is not transmitted to the photographing lens. . In step S115, the operation amount and operation direction of the lens distance ring are measured. In step S120, the operation amount is converted into a lens drive amount. In step S125, the lens is driven by the AF motor 51 by the drive amount. It returns to step S115 again.

FIG. 38 is an operation flowchart in the manual mode. In step S130, clutch control is performed.
The operating force of the distance ring 15 is transmitted to the photographing lens, and the driving force of the AF motor 51 is not transmitted to the photographing lens.

In the description of the operation of the lens drive control CPU 50, the focus mode is the focus mode selection means 63.
Next, an example will be described in which the focus mode is selected in conjunction with the operation of the selection unit used for selecting / switching other operations of the camera, instead of selecting the focus mode using the dedicated selection unit. .

The AF area is selected by the AF area selecting means 6
When the user selects viewpoint detection, center spot, selected spot, wide, center spot → wide as shown in the left column of FIG. 69 according to 6, the focus mode is selected as shown in the right column in conjunction with the selection. When the AF area is a center spot or a selected spot, a still subject at a specific point on the screen is often photographed. When the AF area is the viewpoint detection and wide, the subject often changes one after another. Therefore, the focus mode is also made continuous with emphasis on responsiveness. When the AF area is from the center spot to the wide area, the moving subject is often photographed. In this way, the correspondence between the AF area and the focus mode can be obtained, and the stability and responsiveness of the AF can be improved.

The algorithm selection is performed by the AF subject selecting means 66 as shown in the left column of FIG.
When average priority, long-distance priority, close-priority priority → current priority, central priority → current priority is selected, the focus mode is selected as shown in the right column in conjunction with the selection. In the case where the algorithm is centered priority or long distance priority, a still subject at a specific point on the screen is often photographed. When the algorithm is average priority, closest priority → current priority, central priority → current priority, the subject often changes one after another, so that the focus mode is also continuous with emphasis on responsiveness. Since the moving object is often photographed when the algorithm has the closest priority, the focus mode is also set to the tracking with emphasis on followability. In this way, the correspondence between the algorithm and the focus mode can be obtained, and the stability and responsiveness of the AF can be improved.

When the photometry mode is selected by the photometry mode selection means 71 as shown in the left column of FIG. 71, center spot, selected spot, portion, center-weighted, and multi-point, the focus mode is linked to that as shown in the right column. select.
When the metering mode is the center spot or the selected spot, a still subject at a specific point on the screen is often photographed. Therefore, the focus mode is also made single with emphasis on stability. When the photometry mode is partial or center-weighted, the subject often changes one after another. Therefore, the focus mode is also made continuous with emphasis on responsiveness. When the metering mode is multi, the moving subject is often photographed. By doing so, it is possible to select a focus mode that is optimal for the type of subject simply by selecting the photometric mode in accordance with the type of subject.

When the AE mode is selected by the AE mode selection means 70 as aperture priority, shutter speed priority, or program as shown in the left column of FIG. 72, the focus mode is selected in conjunction with the selection as shown in the right column. When the AE mode is aperture-priority, a still object at a specific point on the screen is often photographed. Therefore, the focus mode is set to single with emphasis on stability. When the AE mode is a program, the subject often changes one after another. Therefore, the focus mode is also made continuous with emphasis on responsiveness. AE
When the mode is the shutter speed priority, a moving subject is often photographed. Therefore, the focus mode is also set to the tracking with emphasis on the followability. By doing so, it is possible to select the optimum focus mode for the subject type simply by selecting the AE mode corresponding to the subject type.

When the winding mode is selected by the winding mode selecting means 65 as single (single image taking), continuous high speed, continuous low speed, and self (self-timer) as shown in the left column of FIG. Select the mode as shown in the right column. When the winding mode is the single mode, a still subject at a specific point on the screen is often photographed. When the winding mode is the self mode, the subject may be added later, so the focus mode is also made continuous with an emphasis on responsiveness. When the winding mode is continuous high-speed or continuous low-speed, a moving object is often photographed. By doing so, it is possible to select a focus mode that is optimal for the type of subject simply by selecting the winding mode corresponding to the type of subject.

When the photographing mode is selected by the photographing mode selecting means 64 into the sports, portrait, snap, landscape, and close-up mode as shown in the left column of FIG. 74, the focus mode is selected in conjunction with the mode as shown in the right column. I do. When the shooting mode is portrait or landscape, a still subject at a specific point on the screen is often shot, so the focus mode is also made single with emphasis on stability. When the shooting mode is snap or close-up, the subject often changes one after another. Therefore, the focus mode is also made continuous with emphasis on responsiveness. When the shooting mode is sports, a moving subject is often shot, so that the focus mode is also set to track with emphasis on followability. By doing so, it is possible to select a focus mode that is optimal for the type of subject simply by selecting a shooting mode corresponding to the type of subject.

As described above, when the mode for various shootings is manually switched, the focus mode is switched in conjunction with the switching. However, when the switching between the various shooting modes is performed automatically. However, a similar effect can be obtained by switching the focus mode in conjunction with the switching.

The switching of the focus mode may be performed by comparing the elapsed time T from the half-press ON of the release button 61 with a predetermined time T1, as shown in FIG. When the elapsed time T is shorter than the predetermined time T1, importance is placed on responsiveness to the moving subject, and the focus mode is set to continuous or tracking. When the elapsed time T is longer, the stability of AF is emphasized, and the focus mode is set to single. .

Next, an example will be described in which focus mode selection is not performed in conjunction with the selection of other camera operation selection means, but is selected in accordance with the results of various detection means of the camera itself.

When the information on the subject distance is obtained, the focus mode is selected as shown in the right column of FIG. 76 according to the information. As is well known, the subject distance information can be obtained, for example, from the defocus amount information of the focus detection result and the absolute position information of the photographing lens. When the subject distance is short, a still subject at a specific point on the screen is often photographed. Therefore, the focus mode is also made single with emphasis on stability. When the subject distance is intermediate, the subject often changes one after another, so that the focus mode is also continuous with emphasis on responsiveness. When the subject distance is long, a moving subject is often photographed. Therefore, the focus mode is also set to the tracking with emphasis on followability. In this way, the focus mode can be selected according to the subject distance.

When the information of the photographing magnification can be obtained, the focus mode is selected as shown in the right column of FIG. 77 according to the information. When the magnification is large, a still object at a specific point on the screen is often photographed, so that the focus mode is made single with emphasis on stability. When the magnification is intermediate, the subject often changes one after another. Therefore, the focus mode is also made continuous with emphasis on responsiveness. When the magnification is small, the moving subject is often photographed, so that the focus mode is also set to the tracking with emphasis on the followability.
In this way, the focus mode can be selected according to the photographing magnification.

If the focal length information can be obtained, the focus mode is selected as shown in the right column of FIG. 78 according to the information. When the focal length is short, a still subject such as a landscape is often photographed. Therefore, the focus mode is set to a single focusing on stability. When the focal length is long, a moving subject is often photographed, so that the focus mode is continuous or tracking with emphasis on responsiveness.
In the case of a macro, the portion to be focused often changes depending on the intention of the photographer, so that the focus mode is set to manual or power focus with emphasis on the subject selectivity. This makes it possible to select an optimal focus mode according to the focal length.

If the information on the aperture value can be obtained, the focus mode is selected as shown in the right column of FIG. 79 according to the information. When the aperture value is small, a still object such as a person or a landscape is often photographed. When the aperture value is large, a moving subject is often photographed. Therefore, the focus mode is set to continuous or tracking with emphasis on responsiveness. This makes it possible to select an optimum focus mode according to the aperture value information.

When information on the shutter speed can be obtained,
According to the information, the focus mode is selected as shown in the right column of FIG. When the shutter speed is low, a still object such as a person or a landscape is often photographed. Therefore, the focus mode is set to a single focusing on stability. When the shutter speed is high, a moving subject is often photographed. Therefore, the focus mode is set to continuous or tracking with emphasis on responsiveness. This makes it possible to select an optimal focus mode according to the shutter speed information.

When information on the subject luminance can be obtained, the focus mode is selected as shown in the right column of FIG. 81 according to the information. In the case of low brightness, a still object such as a person or a landscape is often photographed, so that the focus mode is made single with emphasis on stability. In the case of high brightness, a moving subject is often photographed, so that the focus mode is set to continuous or tracking with emphasis on responsiveness. This makes it possible to select an optimal focus mode according to the luminance information.

When information on strobe light emission can be obtained,
The focus mode is selected as shown in the right column of FIG. 82 according to the information. In the case of stroboscopic light emission, a still object such as a person is often photographed. Therefore, the focus mode is set to single with emphasis on stability. In the case of no flash emission, a moving subject is often photographed, so that the focus mode is set to continuous or tracking with emphasis on responsiveness. This makes it possible to select an optimal focus mode according to the flash information.

If the information on the aberration of the photographing optical system can be obtained, the focus mode is selected as shown in the right column of FIG. 83 according to the information. AF when the on-axis and peripheral aberrations are large
Since it is not suitable for shooting in the mode, the focus mode is also set to manual or power focus. If the on-axis and peripheral aberrations are small, it is suitable for shooting in the AF mode. Therefore, the focus mode is also set to the single, continuous, or tracking AF mode. This makes it possible to select an optimal focus mode according to the aberration information.

Next, an example in which the focus mode is selected according to the result of focus detection or subject image data will be described.

When focus information can be obtained, the focus mode is selected as shown in the right column of FIG. 84 according to the information. Before focusing, the focus mode is also set to single in order to shoot in the AF mode. After focusing, the focus mode is manually or power-focused in order to finely adjust the focus according to the photographer's will. This makes it possible to select an optimum focus mode according to the focusing information.

When the detection possibility information can be obtained, the focus mode is selected as shown in the right column of FIG. 85 according to the information. If the focus can be detected, the focus mode is also set to single or continuous for shooting in the AF mode. If the focus cannot be detected, the focus mode is set to manual or power focus in order to adjust the focus by the photographer. This makes it possible to select an optimum focus mode according to the detection possibility information.

If the information on the subject pattern can be obtained, the focus mode is selected as shown in the right column of FIG. 86 according to the information. If the subject contrast is low, it is not suitable for photographing a moving subject, so the focus mode is made single with emphasis on stability. When the contrast is high, it is suitable for photographing a moving subject. Therefore, the focus mode is set to continuous or tracking with emphasis on responsiveness. This makes it possible to select an optimal focus mode according to the shutter speed information.

When the defocus information can be obtained, the focus mode is selected as shown in the right column of FIG. 87 according to the information. When the defocus is large, responsiveness is emphasized and the focus mode is set to continuous. When the defocus decreases, focus on stability,
Set focus mode to single. This makes it possible to select an optimum focus mode according to the defocus information.

The operation of the lens drive control CPU 50 has been described above.

<Operation of Main CPU> Referring to FIG.
Inside the body 20, there is also a main CPU 60 for mainly controlling the camera sequence and the exposure operation. Main C
The PU 60 obtains the subject brightness from the photometric sensor 86, obtains information on exposure settings such as the film sensitivity, the aperture value, and the shutter speed from setting means (not shown), and determines the aperture value and the shutter speed based on the information. At the same time, such information is displayed on the display means 85. In the photographing operation, the mirror control unit 81 controls the up / down operation of the main mirror 21, the aperture control unit 83 controls the operation of the aperture mechanism, and the shutter control unit 82 controls the operation of the shutter mechanism. After the photographing operation is completed, the operation of the winding charge mechanism is controlled by the winding charge control means 84 in preparation for the next photographing operation. The main CPU 60 includes operation means 80 of various cameras, a lens CPU 12, a lens drive control CPU 5,
0, an AF calculation CPU 40, an AF detection system control CPU 33, etc., to obtain information necessary for controlling the camera sequence and the exposure operation from another CPU or the like.
It sends necessary camera sequence information to the PU.
For example, when the focus mode is set to single, the release operation is controlled by the release permission information sent from the lens drive control CPU 50.

The main CPU 60 controls the AF detection system control C
It is connected to the PU 33 and the memory 34, and the subject luminance information is not obtained from only the dedicated photometric sensor 86,
It can also be obtained based on the subject image data used for focus detection and the charge accumulation time of the photoelectric conversion means. For example, the average value of the data of the subject image area used for photometry is B
If v and the accumulation time are Tv, the subject brightness can be determined based on Bv / Tv.

The following is used as a method of selecting a subject image area used for photometry. For example, FIG.
The area shown in (b) can be used as a photometry area according to the operation of the AF area selection unit 66 or the operation of the viewpoint detection unit 68. By doing so, the AF area and the photometry area always match, so that focus and exposure can be optimized for the same subject. Also, AF detection system control CP
If the decrease in the peripheral light amount is determined by the U33 or the AF calculation CPU 40, and the data area of the subject image used in the focus detection calculation is limited, the data area of the subject image used in the photometry calculation is limited accordingly. Is also good.

The above is the operation of the main CPU 60.

<Operation of Image Display Control CPU> In FIG. 20, inside the body 20, there is also an image display CPU 90 for controlling information display relating to focus detection. The image display control CPU 90 obtains focus detection information (focus detection area, selection point, focus / non-focus, focus direction, etc.) from the AF calculation CPU 40 and displays the information on the display means 92. Further, the display selection means 91 is configured so that display ON / OFF can be manually selected.

Alternatively, ON / OFF of the display means 92 may be selected in conjunction with the operation of another operation means. For example, when the manual mode is selected by the focus mode selection unit 63, the display unit 92 is not automatically displayed. In this way, when the display is troublesome, the display can be erased by the photographer's will. The display means 92 is composed of a photoelectric property element such as an electrochromic element or an electroluminescence element and a transparent electrode on a surface conjugate to the film surface on the screen 23. For example, the spot and the wide in the selected state of the focus detection area are shown in FIG.
0 (a) and (b) are displayed in the screen. As described above, the focus detection area is selected in conjunction with the detection result of the light amount distribution detection means, the operation of the AF area selection means 66, and the operation of other operation means. When a plurality of focus detection areas are set in the screen by the AF area selection unit 66 or the viewpoint detection unit 68, the area finally selected by the AF calculation CPU 40 is determined as shown in FIG.
It is displayed as shown in (c).

The display of the focus detection state (in-focus, out-of-focus) is displayed as shown in FIG. In FIG. 41A, only the frame portion (distance measurement frame) of the distance measurement area is displayed at the time of out-of-focus, and at the time of focus, the inside of the distance measurement frame is made translucent to display focus.
As a modification of the display mode of (a), the coloring in the ranging frame may be switched between in-focus and out-of-focus, or the coloring may be switched depending on the defocus direction when out of focus. In FIG. 41B, the focusing frame is displayed thin when out of focus, and the focusing frame is displayed thick by focusing when focusing. As a variation of (b), the coloring of the distance measurement frame is switched between in-focus and out-of-focus, and
Coloring may be switched depending on the defocus direction when out of focus. In FIG. 41 (c), when out of focus, the distance measurement frame is displayed by a broken line, and when in focus, the distance measurement frame is displayed in focus by a normal line. In FIG. 41D, the focusing frame is displayed in brackets when out of focus, and the focusing frame is displayed as a rectangle when focused. In FIG. 41 (e), the focusing frame is displayed only when the subject is out of focus, and the focusing frame is not displayed when the subject is in focus. In this way, the focus detection area is displayed only when it is necessary to select a subject, and after focusing, the area display disappears and the screen becomes easy to see, so that the usability is improved. In FIG. 41 (f), when out of focus, a part of the rectangular ranging frame is cut out, and the defocus direction and the amount are displayed by the position of the notch,
At the time of focusing, the focusing frame is displayed by displaying the distance measurement frame without a notch. By displaying the focus detection information on the screen as described above, it is not necessary to look away from the subject compared to the display outside the screen, and the focus detection information is confirmed while following the subject even for the moving subject can do.

As shown in FIG. 20, there is a display means 92 on the screen 23 and a photometric sensor 86 in the finder. When the photometric sensor 86 measures light passing through the screen 23, the operation of the display means 92 is performed. The photometric value may fluctuate depending on the state. Therefore, the operation of the display means 92 and the photometric operation of the photometric sensor are periodically performed in a time-division manner.
The cycle is ON / OF of display in consideration of human visual characteristics.
A period (100 ms or less) is set so that F is inconspicuous.

The display means 92 may be configured as shown in FIG. 42 so as not to affect the display of the photometric sensor. In FIG. 42, the display element 93 illuminated by the illumination means 94 is projected to the eye 97 of the finder observer via the lens 95 and the half mirror 96 installed in the eyepiece 25. In such an optical system, the shape and position of the optical member are set such that the display surface of the display element 93 overlaps the shape and position with the viewfinder screen. In the configuration of FIG. 42, the display surface is set to be substantially conjugate with the screen surface in order to display the focus detection area. However, if only the focused display is required, the conjugate relationship is broken to simplify the optical system. Alternatively, the light of a light emitting element such as an LED may be simply projected toward the eyes. In this way, the space in the camera can be reduced.

In FIG. 20, an optical object image is observed by the finder. However, as shown in FIG. 43, if the image display means 98 observes the object image once converted into an electric signal, the object can be observed. The display synthesis of the image and the AF information can be performed relatively easily.

In FIG. 43, when the lens 10 is mounted on the camera body 20, a photographing light beam coming from the subject passes through the photographing lens 11, passes through a reduction optical system 99 that can enter and exit the optical path in the camera body 20, and The light is reflected by the mirror 100 and guided to the focus detection optical system 30 as a light beam for focus detection and observation. Reduction optical system 9
9 is a screen size after passing the focus detection optical system 30
This is an optical unit for adjusting the size of the light receiving unit of the two-dimensional photoelectric conversion unit 32 for F. When the film is exposed, it is evacuated to the outside of the optical path together with the mirror 100 under the control of the AF detection system control CPU 33. You. The plural pairs of subject image data photoelectrically converted by the photoelectric conversion unit 32 are stored in the memory 34 and read out by the image display control CPU 90, and the subject image data and the AF display information are stored in the image display control C.
The images are synthesized by the PU 90 and displayed on the image display means 98, and the display screen is observed through the eyepiece 25.
For example, in the focus detection optical system shown in FIG.
Although one-dimensional subject image data is obtained, only one subject image data may be used as subject image data to be displayed, both may be combined, or two methods may be switched. If only one of them is used, the blur of the subject is small even at the time of defocusing, so that the visibility of the subject is improved. In addition, when combined, the blur becomes closer to the time of shooting, which is advantageous for confirming the state of blur. Further, by moving a part of the reduction optical system 99 under the control of the AF detection system control CPU 33 to change the reduction magnification, the image display means 9 is controlled.
The magnification by 8 can be changed, which is convenient when it is desired to detect and observe a focus by enlarging only a part of the subject without changing the photographing optical system 11.

In the above description, the image display means 98 is the body 20
Next, an example in which an image is displayed outside the body will be described with reference to FIG.

In FIG. 44, the image data composed of the subject image data and the AF display information synthesized by the image display control CPU 90 is supplied to a liquid crystal television or the like outside the body via a connecting means B202 for connecting the body 20 to an external device. Is displayed on the external image display means 200. Coupling means B202
May be wired or wireless. In this way, the subject image and the AF state can be observed without holding the camera body 20 at hand, and therefore, when combined with a remote control photographing device (not shown) or the like, it is possible to expand the photographable state. Further, the subject image data taken in by the image display control CPU 90 is connected to a connecting means A203 for connecting the body 20 and an external device.
Via an external image storage means 201 such as a memory card outside the body.

In the above configuration, the object image data for observation or storage is shared with the data for pupil division type focus detection obtained by the photoelectric conversion means for AF. This is also advantageous in terms of cost.

In the configuration of the focus detection device shown in FIG. 20, the AF detection system control CPU 33, the AF calculation CPU 40,
Since the lens drive control CPU 50 and the image display control CPU 90 are provided separately and independently, the control of the photoelectric conversion means, the focus detection calculation, the lens drive control, and the display control operation can be temporally overlapped, and the focus detection operation can be performed. Responsiveness can be improved.

The focus detection apparatus shown in FIG. 20 has been described. Next, another embodiment of the focus detection device in which the focus detection optical system is changed will be described.

FIG. 45 shows a photographing optical system 1 as a pupil division type focus detection optical system, instead of the re-imaging optical system shown in FIG.
An optical system of a type that mechanically splits the pupil before the primary image plane without re-imaging is installed by installing a physical stop 450 using a photoelectric physical element such as an electrochromic element in the optical path of 1. FIG. 2 is a block diagram of a focus detection device according to the first embodiment.
Parts that are the same as 0 are omitted.

FIG. 46 is a perspective view when only the focus detection optical system portion is taken out. The focus stop pupils 305A and 305B are formed by the physical stop 450, and the light beam passing through the pupil is transmitted to the reduction optical system 99. A subject image is formed on the photoelectric conversion unit 32 having the two-dimensional light receiving unit 304D placed at a position equivalent to the film surface. In such an optical system, the focus stop pupils 305A and 30
5B is switched in a time-division manner, and at the same time, the focus detection pupil 305
A, the photoelectric conversion means 32
The defocus amount of the photographing lens 11 can be obtained by processing the pair of subject image signals obtained from the above in the same manner as the focus detection calculation processing described above.

In FIG. 45, when the lens 10 is mounted on the camera body 20, the luminous flux coming from the subject is
It passes through a physical property stop 450 installed in the taking lens 11,
The light passes through a reduction optical system 99 that can be put into and taken out of the optical path in the camera body 20, is reflected by the mirror 100, and is guided as a focus detection light beam to the photoelectric conversion unit 32 provided on a surface conjugate with the film surface. The physical property stop 450 is a means for controlling the focus detection pupil for AF in a time-division manner, and includes a body 20, a contact 19F on the lens side provided on the mount portion of the lens 10, and a corresponding body side contact 19F. Contact 59
Under the control of the AF detection system control CPU 33 via F, the aperture shape is switched in a time-division manner as shown in FIGS. 47A and 47B, and when the film is exposed, the aperture shape shown in FIG. The shape is controlled so as to have the determined aperture value, and functions as a normal shooting aperture. Further, the focus detection pupils 305A, 305A, 3
Information on the shape and position of 05B is transmitted from the lens CPU 12 to the body side, and the information is used for vignetting detection and focus detection calculation. The reduction optical system 99 is an optical unit for adjusting the screen size to the size of the light receiving unit of the two-dimensional photoelectric conversion unit 32 for AF, and detects AF along with the mirror 100 outside the optical path when the film is exposed. System control CPU
It is saved by the control of 33. Note that the reduction optical system 99 is not an essential component.

The light receiving portion 304D of the photoelectric conversion means 32 has, for example, a configuration as shown in FIG.

In FIG. 49, charges generated in the photoelectric conversion element array 500 such as a photodiode are
After being temporarily stored in the charge storage element arrays 503 and 504 by 1 and 502, C
The charge is transferred to the charge transfer unit 507 such as a CD, and
Is output and transferred to the outside of the photoelectric conversion means 32.

The operation of the focus detection device shown in FIG. 45 when the photoelectric conversion means 32 having the structure shown in FIG. 49A is used will be described with reference to the timing chart of FIG.
This will be described with reference to the conceptual diagrams of the light receiving portion potential of the photoelectric conversion means 32 shown in FIG. 49 (a) shown in (c), (d) and (e).

When processing a pair of subject image signals obtained from the photoelectric conversion means 32 in synchronization with the focus detection pupils 305A and 305B which are switched in a time-division manner by the physical property stop 450, a pair of subject images captured only once in synchronization Since the image signal has low synchronism, an error occurs when focus detection is performed using the signal on a temporally changing subject such as a moving subject. Therefore, by inserting the phases P1 and P2 shown in FIGS. 48A and 48B alternately a plurality of times during the accumulation time ON of the photoelectric conversion means 32 shown in FIG. Enhance the nature. FIG.
In FIG. 47A, during the ON period of the phase P1, FIG.
(A) As shown in FIG.
A is set, and as shown in FIG. 49B, the potential of the gate 501 is lowered to store the charges generated in the photoelectric conversion element array 500 in the charge storage array 503. At this time, the potentials of the gates 502, 505, and 506 are set high. In FIG. 48 (b),
In the ON period of the phase P2, the focus detection pupil 305B is set by the physical property stop 450 as shown in FIG. 47B, and the potential of the gate 502 is lowered as shown in FIG. Are stored in the charge storage array 504. At this time, the potentials of the gates 503, 505 and 506 are set high.

As described above, during the accumulation time, the phase P1,
After P2 is repeated a plurality of times, the accumulation is terminated, and the process proceeds to the charge reading phases P3 and P4. In phase P3, as shown in FIG. 49 (d), the potential of the gate 505 is lowered, the charge stored in the charge storage element array 503 is transferred to the charge transfer unit 507 in parallel, and then moved to the charge transfer unit 507. The charge is transferred to the outside by the operation of the charge transfer unit 507. When all charges stored in the charge storage element array 503 are transferred to the outside by the operation of the charge transfer unit 507 and the phase P3 ends, the phase P4 starts. In phase P4, as shown in FIG. 49 (e), the potential of the gate 506 is lowered, the charge stored in the charge storage element array 504 is transferred to the charge transfer unit 507 in parallel, and then the charge moved to the charge transfer unit 507. Are transferred to the outside by the operation of the charge transfer unit 507. When all the charges stored in the charge storage element array 504 are transferred to the outside by the operation of the charge transfer unit 507, the phase P4 ends, and a series of storage reading operations ends.

As described above, when switching the focus detection pupils 305A and 305B by the physical property stop 450 and switching the gates of the photoelectric conversion means 32 at high speed during the accumulation time, the subject image signal is inevitably accompanied by the transition at the time of switching. Crosstalk (light flux or charge leakage) occurs between them.
Assuming that a pair of subject image signals in an ideal state without crosstalk are f (x, y) and g (x, y), a pair of subject image signals F (x, y) when crosstalk occurs. , G
(X, y) is expressed as in equation (17). F (x, y) = a × f (x, y) + b × g (x, y) G (x, y) = b × f (x, y) + a × g (x, y) (17) In the equation (17), a and b are constants, and a and b are known values if measured in advance. Accordingly, f (x, y) and g (x, y) can be obtained from a pair of subject image signals without crosstalk as in equation (18) by modifying equation (17). f (x, y) = {b × F (x, y) −a × G (x, y)} / (ba) g (x, y) = {a × F (x, y) −b × G (x, y)｝ / (ab) (18) The focus detection calculation processing can be performed in the same manner as in the related art by using a pair of subject image signals without crosstalk obtained by Expression (18).

As described above, in the focus detection device shown in FIG. 45, a pupil division optical system of a type that does not re-image is used as the focus detection optical system. The space inside the camera is not required, the camera body can be made compact, and the cost is also advantageous. In addition, since the physical diaphragm can be used for both the AF diaphragm and the photographing diaphragm, the space in the lens can be saved.

[0179]

As described above in detail, according to the first aspect of the present invention, the setting of the moving object determination reference value is changed according to the information of the contrast. By making the determination difficult, the instability of the focus adjustment operation can be prevented. According to the second aspect of the present invention, the setting of the moving object determination reference value is changed in accordance with the selection of the shooting mode. It can be performed, and when shooting sports, it is easy to judge that the subject is a moving object, so that a shutter chance is not missed.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a configuration of a focus detection device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a focus detection device according to the embodiment of the present invention.

FIG. 3 is a flowchart showing a processing procedure of a focus detection calculation.

FIGS. 4A and 4B are flowcharts showing a modification example of the preprocessing routine shown in FIG. 3C, in which FIG. 4A shows a flow for correcting a decrease in the amount of light included in a subject signal, and FIG. The flow which performs a removal filter operation is shown, respectively.

FIG. 5 is a diagram showing a peripheral light amount ratio of a photographing lens.

FIG. 6 is a diagram showing a focus detection pupil aperture shape on a focus detection pupil plane.

FIG. 7 shows an opening 300 in the exit pupil plane of the taking lens.
FIG. 6 is a diagram showing coordinates (X0, Y0) of A and a light beam passing through a re-imaging lens.

FIG. 8 is a diagram showing a state of light amount distribution information Ka.

FIG. 9 is a diagram showing an example of light amount distribution information Ka.

FIG. 10 is a diagram showing an example of a configuration of a focus detection optical system according to an embodiment of the present invention.

FIG. 11 is a diagram showing another example of the configuration of the focus detection optical system according to the embodiment of the present invention.

FIG. 12 is a diagram showing still another example of the configuration of the focus detection optical system according to the embodiment of the present invention.

FIG. 13 is a diagram showing another example of the configuration of the focus detection optical system according to the embodiment of the present invention.

FIG. 14 is a diagram showing an example having two split pupils.

FIG. 15 is a diagram showing an example having four split pupils.

FIG. 16 shows the focus detection optical system shown in FIG.
The figure cut | disconnected by the plane containing an axis | shaft.

FIG. 17 is a diagram showing how pupil regions 305A and 305B are formed by vignetting.

FIG. 18 is a diagram showing a state in which the vignetting amount of a light beam condensed on a photoelectric conversion element is not uniform.

19A and 19B are diagrams illustrating vignetting of a light beam condensed on a photoelectric conversion element. FIG. 19A illustrates each point A on an opening 300A.
(B) shows an image formed by the re-imaging lens 303B, (c) shows an image formed by the re-imaging lens 303A, and (d) shows (b) and (b). 3C shows a state in which the images shown in FIG.

FIG. 20 is a block diagram showing a more specific embodiment of the focus detection device.

FIG. 21 is a flowchart illustrating the operation of an AF detection system control CPU.

FIG. 22 illustrates a data storage area of a memory.

23A and 23B are diagrams showing operation timings of a charge accumulation operation and a transfer operation of the photoelectric conversion element, wherein FIG. 23A is a diagram in which the accumulation operation and the transfer operation are temporally separated, and FIGS. Are overlapped in time, (d)
Indicate that the transfer operation is performed after the storage operation is performed in a plurality of times.

FIG. 24 is a diagram illustrating a state in which a two-dimensional photoelectric conversion element is divided to perform accumulation and transfer operations.

FIG. 25 is a diagram illustrating an area of data that can be used on a two-dimensional photoelectric conversion element.

FIG. 26 is a diagram illustrating a state in which the accumulation time of a photoelectric conversion element is controlled.

FIG. 27 is a diagram showing an example of a subject image intensity distribution on a photoelectric conversion element.

FIG. 28 is a flowchart illustrating an operation of a focus detection calculation performed by the AF calculation CPU.

FIG. 29 is a diagram showing a setting example of a focus detection area.

FIG. 30 is a diagram illustrating a configuration example of a viewpoint detection unit, wherein (a)
7B is a diagram schematically illustrating the configuration, and FIG. 7B is a diagram illustrating the distribution of the amount of light received by the surface light receiving element 684.

FIG. 31 is a view showing an example of division of an image signal obtained on a photoelectric conversion element and a contrast detection block.

FIG. 32 is a view for explaining monitor signals of an AF drive system.

FIG. 33 is a diagram showing ON / OFF duty of a drive signal of an AF motor.

FIG. 34 is a view showing the relationship between the number of remaining pulses of the monitor signal and the pulse interval with respect to the target stop position of the AF drive system.

FIG. 35 is a flowchart illustrating the operation of a lens driving CPU.

FIG. 36 is a flowchart when the lens drive CPU performs lens drive control according to the AF drive mode.

FIG. 37 is an operation flowchart of a lens drive CPU in a power focus mode.

FIG. 38 is an operation flowchart of a lens driving CPU in a manual mode.

FIG. 39 is a view schematically showing a taking lens.

FIG. 40 is a view showing an example in which a focus detection area selection state is displayed in the viewfinder.

FIG. 41 is a diagram showing an example in which a focus detection state is displayed in a viewfinder.

FIG. 42 illustrates an example of a structure of a display device.

FIG. 43 is a view showing an example in which a finder is constituted by an image display device 98 in the focus detection device according to the present invention.

FIG. 44 is a diagram showing an example in which the focus detection device according to the present invention is configured to display the subject image and the AF state on an external display device outside the body of the camera.

FIG. 45 is a diagram showing a modification of the focus detection device according to the present invention.

FIG. 46 is a diagram showing an example in which the focus detection pupil of the focus detection device according to the present invention is configured by a physical diaphragm.

FIG. 47 is a view for explaining the operation of the physical property stop of the focus detection device shown in FIG. 46;

48 is a diagram showing a photoelectric conversion operation timing of the focus detection device shown in FIG. 46.

FIGS. 49A and 49B are diagrams illustrating a photoelectric conversion device used in the focus detection device illustrated in FIG. 46. FIG.
(B)-(e) show the concept of the potential of the light receiving section.

FIG. 50 is a diagram showing a correspondence between an AF area and an algorithm when an arbitrary AF area is selected.

FIG. 51 is a diagram showing a correspondence between an AF area and an algorithm when an arbitrary AF subject is selected.

FIG. 52 is a diagram showing a correspondence between an AF area and an algorithm corresponding to an arbitrary photometric mode when the mode is selected.

FIG. 53 is a view showing a correspondence between an AF area and an algorithm corresponding to an arbitrary AE mode selection.

FIG. 54 is a diagram showing a correspondence between an AF area and an algorithm corresponding to an arbitrary winding mode when the winding mode is selected;

FIG. 55 is a view showing a correspondence between an AF area and an algorithm corresponding to an arbitrary shooting mode when the mode is selected;

FIG. 56 is a view showing a correspondence between an AF area and an algorithm corresponding to an arbitrary focus mode when the focus mode is selected.

FIG. 57 is a diagram showing the correspondence between the AF area and the algorithm corresponding to the elapsed time from the half-press ON of the release button.

FIG. 58 is a diagram showing a correspondence between an AF area corresponding to subject distance information and an algorithm;

FIG. 59 is a diagram showing a correspondence between an AF area corresponding to magnification information and an algorithm;

FIG. 60 is a diagram showing a correspondence between an AF area corresponding to focal length information and an algorithm;

FIG. 61 is a diagram showing a correspondence between an AF area corresponding to aperture value information and an algorithm;

FIG. 62 is a view showing a correspondence between an AF area corresponding to shutter speed information and an algorithm;

FIG. 63 is a view showing a correspondence between an AF area corresponding to luminance information and an algorithm;

FIG. 64 is a diagram showing a correspondence between an AF area corresponding to strobe information and an algorithm.

FIG. 65 is a view showing a correspondence between an AF area corresponding to aberration information and an algorithm.

FIG. 66 is a view showing a correspondence between an AF area and an algorithm corresponding to body posture information.

FIG. 67 is a view showing a correspondence between an AF area corresponding to subject pattern information and an algorithm;

FIG. 68 is a diagram showing a correspondence between an AF area corresponding to defocus information and an algorithm;

FIG. 69 is a view showing a focus mode associated with selection of an arbitrary AF area.

FIG. 70 is a view illustrating a focus mode associated with selection of an arbitrary AF subject.

FIG. 71 is a view showing a focus mode corresponding to an arbitrary photometric mode selection.

FIG. 72 is a view showing a focus mode corresponding to an arbitrary AE mode selection.

FIG. 73 is a view showing a focus mode corresponding to an arbitrary winding mode selection.

FIG. 74 is a view showing a focus mode corresponding to an arbitrary photographing mode selection.

FIG. 75 is a diagram illustrating a focus mode corresponding to the elapsed time from the half-press ON of the release button.

FIG. 76 is a view showing a focus mode corresponding to subject distance information.

FIG. 77 is a view illustrating a focus mode corresponding to magnification information.

FIG. 78 is a view illustrating a focus mode corresponding to focal length information.

FIG. 79 is a view illustrating a focus mode corresponding to aperture value information.

FIG. 80 is a view showing a focus mode corresponding to shutter speed information.

FIG. 81 is a view showing a focus mode corresponding to luminance information.

FIG. 82 is a view showing a focus mode corresponding to strobe information.

FIG. 83 is a view illustrating a focus mode corresponding to aberration information.

FIG. 84 is a view showing a focus mode corresponding to focus information.

FIG. 85 is a view showing a focus mode corresponding to detection possibility information;

FIG. 86 is a view showing a focus mode corresponding to subject pattern information.

FIG. 87 is a view illustrating a focus mode corresponding to defocus information.

[Explanation of symbols]

 Reference Signs List 10 lens 30 focus detection optical system 31 AF stop 32 photoelectric conversion means 33 AF detection system control CPU 34 memory 40 AF calculation CPU 64 shooting mode selection means

Claims (2)

[Claims] An imaging optical system for forming a subject image on a screen; contrast detection means for repeatedly detecting a contrast of the subject image at a predetermined position on the screen; Focus detecting means for repeatedly detecting the defocus amount of the image; calculating means for calculating an amount related to the moving speed of the subject image plane from a plurality of defocus amounts detected by the focus detecting means; Comparing with the reference value, when the amount related to the moving speed detected from the reference value is large, determining means for determining that the subject is a moving subject; and changing means for changing the reference value according to the contrast. A focus detection camera, comprising: 2. A photographing optical system for forming a subject image on a screen, a selection unit for selecting an operation related to photographing of a camera by designating a genre of the subject, and the subject image at a predetermined position on the screen. Focus detecting means for repeatedly detecting the amount of defocusing; calculating means for calculating an amount related to the moving speed of the subject image plane from a plurality of defocus amounts detected by the focus detecting means; and a reference value for the amount related to the moving speed. Comparing with the reference value, when the amount related to the moving speed detected from the reference value is large, determining means for determining that the subject is a moving subject; and the reference value according to the genre of the subject designated by the selecting means. A focus detecting camera, comprising: changing means for changing the distance.