JPH09258093A - Camera provided with automatic focus detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To align the position and the range of a range-finding zone on a photographic image plane or a finder visual field with the position and the range of actual range-finding regardless of subject distance and focal distance by selecting a line sensor used for detection based on the variance of an optical device. SOLUTION: In the case of wide-angle photographing, range-finding is executed by utilizing a substance image projected in a light receiving range 53W, that is, range-finding calculation is executed by using signal charges accumulated in all the photodetectors of the line sensor 52A. In the case of standard photographing, range-finding calculation is executed by using the photodetector in a narrower light receiving range 53S and in the case of telephotographing, it is executed by using the photodetector in a much narrower light receiving range 53T. Thus, the width of the line sensor 52 is made larger than the conventional one, and the light receiving range of the line sensor 52 used for the range- finding is selected in accordance with the field magnification of a variable power finder. Therefore, the size of the range-finding zone in a finder visual field 56 becomes constant regardless of the field magnification and coincident with that of a range-finding frame.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera provided with an automatic focus detection device, and more particularly, to passive distance measurement in which the optical axes of the image pickup optical system or finder optical system and the focus detection optical system do not coincide. The present invention relates to an automatic focus detection device equipped with a device.

[0002]

2. Description of the Related Art One of the conventional automatic focus detection devices is a passive system that uses outside light.
This passive type automatic focus detection device (hereinafter referred to as "AF device") is mainly used in a lens shutter type camera, and a photographing optical system, a finder optical system, and a distance measuring optical system of the AF device are separately provided. Is configured. An outline of a lens shutter type camera equipped with this conventional AF device will be described with reference to FIGS.

A photographing lens 12, a viewfinder optical system (objective window) 14, and a light emitting window 16 of a built-in flash are provided on the front surface of the camera body 10, and a release button 18 is provided on the upper surface. Further, on the front surface of the camera body 10 and above the taking lens 12, a pair of A of the AF device 20 is provided.
F lenses 22 and 23 are provided.

A bottom view of the AF device 20 is shown in FIG. 22, and a front view thereof is shown in FIG. The subject light that has entered from the pair of AF lenses 22 and 23 is reflected inward at substantially right angles by the mirrors 24 and 25, respectively, passes through the condenser lenses 26 and 27, enters the mirror prism 28, and is reflected here. It is deflected backward by 90 ° and projected on the distance measuring sensor 30.

The distance measuring sensor 30, as shown in the front view of FIG. 24, is a CCD in which a large number of light receiving elements are arranged in a line.
It has a light-receiving unit provided with a line sensor 32. The line sensor 32 is composed of two parts 32A and 32B located in a line, and each line sensor 32A and 32B has
The subject light flux incident from the pair of AF lenses 22 and 23 is projected. Each light receiving element of the line sensor 32 photoelectrically converts this subject projection image and accumulates it as a signal charge. Reference numeral 34 is a monitor sensor for determining the optimum signal charge storage time of the line sensor 32.

The control device in the camera body reads out the signal charge accumulated in the light receiving element of the line sensor 32, calculates the distance to the object (object distance or shooting distance) by a predetermined predictor calculation, and the distance measurement value. The focus lens is driven to the in-focus position based on

"Problem due to change in focal length or field magnification" The relationship between the distance measuring zone and the viewfinder field in the above camera will be described with reference to FIG. In this camera, the field of view magnification of the finder optical system 14 changes in association with the zooming of the taking lens 12. When the range in the viewfinder field 36 of the subject projected on the line sensor 32 is defined as the distance measuring zone 37, the distance measuring zone 37T at the time of telephoto is as shown in FIG. A distance measuring frame 38 is provided in the viewfinder field 36 to visualize the distance measuring zone 37. From this state, the taking lens 12
When zooming in to the wide-angle side, the size of the field frame 38 does not change even if the field magnification of the finder optical system 14 decreases.

On the other hand, the magnification of the AF device 20 does not change regardless of zooming. Therefore, at the wide angle, as shown in FIG. 25, the distance measuring zone 37W in the viewfinder field 36 becomes small.

Finder field of view 3 at the above-mentioned telephoto and wide angle
26A and FIG. 26, taking the case of photographing the same person from the same position as an example of the relationship between 6 and the distance measuring zone 37.
This will be described with reference to FIG.

FIG. 26A shows a person image 39 and a distance measuring zone 37T in the viewfinder field 36 at the time of telephoto.
It is assumed that the size is shown in. Here, the taking lens 12
When the zoom lens is zoomed to the wide-angle side, the view field magnification of the finder optical system 14 is lowered, so that the human image 39 in the viewfinder field 36 becomes small, and the size becomes as shown in FIG.

On the other hand, since the magnification of the AF device 20 does not change as described above, the size of the distance measuring zone 37 for a person does not change. That is, the distance measuring zone 3 for the person image 39
The size of 7 is constant. Therefore, as shown in FIG.
W becomes small like the subject image 39.

As described above, in the conventional AF device 20 described above,
Focal length of taking lens 12, that is, finder optical system 1
The size of the distance measuring zone 37 in the finder visual field 36 was changed due to the change in the visual field magnification of No. 4. That is,
Since the size of the distance measuring zone 37 in the viewfinder field 36 varies depending on the focal length of the taking lens 12,
There is a problem that the distance is erroneously measured for a subject that the photographer does not intend.

"Problem Due to Parallax / Subject Distance" Further, in the conventional camera, the optical axis of the finder optical system and the optical axis of the AF device are apart from each other. For example, as shown in FIG. 27, a pair of AF lenses 41 and 42 of the focus detection device are provided substantially beside the finder optical system 40 when viewed from the front of the camera. In the finder field 46 of the finder optical system 40, as shown in FIGS. 28A and 28B, the distance measuring frame 4 for visualizing the distance measuring zone 47.
8 are provided.

However, as described above, the optical axes of the finder optical system 40 and the AF lenses 41 and 42 are apart from each other. Therefore, the distance measuring frame 48 and the actual distance measuring zone 47 are displaced depending on the distance of the subject. For example, the distance measuring zone 47 and the distance measuring frame 48 at a certain reference distance.
If the distances are matched, the distance measuring zone 47 will shift to the right of the distance measuring frame 48 for a subject at a shorter distance than this (see FIG. 28A), and for a subject at a long distance. The distance measuring zone 47 is displaced to the left with respect to the distance measuring frame 48 (see FIG. 28B).

Further, as shown in FIG. 29, when the AF lenses 41 and 42 are provided below the finder optical system 40, the distance measuring zone 47 is closer to the distance measuring frame 48 in the case of a subject at a short distance. Shift upwards (see FIG. 30 (A)), and a subject at a long distance shifts downwards (FIG. 3).
0 (B)).

That is, since the optical axis of the finder optical system and the optical axis of the AF optical system do not coincide, the finder field of view 4
The distance of the object deviated from the distance measurement frame 48 in 6 is measured. Therefore, there is a problem in that the subject that should have been shot with the distance measuring frames 48 exactly aligned is out of focus when developed and printed.

[Problem during Macro Shooting] The same shift as described above is a camera that deflects the optical axis of the finder optical system in the optical axis direction of the shooting lens in order to correct the shift between the viewfinder field and the shooting screen during macro shooting. Will be larger at. For example, as shown in FIG. 31, in a camera in which the finder optical system 40 and the taking lens 49 are laterally displaced, the optical axis of the finder optical system 40 is moved to the taking lens 49 side in macro mode. Therefore, in the viewfinder field 46, when the distance measuring frame 48 and the distance measuring zone 47 coincide with each other in the standard state (see FIG. 32A), the distance measuring zone 47 shifts to the left during macro shooting (FIG. 32A). 32
(B)).

Further, as shown in FIG. 33, when the finder optical system 40 is provided above the taking lens 49, the optical axis of the finder optical system 40 is directed to the optical axis of the taking lens 49 during macro photography. And shake downwards. Therefore, there is a problem that even if the distance measuring zone 47 and the distance measuring frame 48 coincide with each other in the standard mode, they are displaced during macro photography (see FIGS. 34A and 34B).

As described above, in the camera equipped with the conventional AF device, firstly, the optical axis of the photographing optical system and the optical axis of the AF optical system are deviated from each other. There was a problem that the distance measuring zone in the viewfinder field moved.

Secondly, in the case where the taking lens is a bifocal (including multifocal) lens or a variable focal length lens such as a zoom lens, when the focal length changes, the area occupied by the distance measuring zone in the taking screen or viewfinder field becomes large. There was a problem that it would change.

[0021]

SUMMARY OF THE INVENTION The present invention is a passive A of the above conventional camera.
This is made in view of various problems of the F-apparatus, and in a camera in which the optical axis of the photographic optical system or the optical axis of the finder optical system and the optical axis of the AF optical system do not match, regardless of the subject distance and focal length. It is an object of the present invention to provide a camera equipped with an automatic focus detection device that can match the position and range of a distance measuring zone on a shooting screen or a viewfinder with an actual distance measuring position and distance measuring range as much as possible.

[0022]

SUMMARY OF THE INVENTION In order to achieve the above object, the invention according to claim 1 divides a light flux of an object and projects images of the same object on at least two different light receiving areas of the line sensor, and the two different light receiving areas of the line sensor. An automatic focus detection device for detecting a focus based on outputs from two light receiving regions, wherein the line sensor is composed of two or more line sensors separated from each other, and the line sensor used for the detection is the automatic focus detection device. Is provided with a control means for selecting based on a variable condition of the optical device mounted with. According to this configuration, the line sensor can be selectively used according to the variable condition of the optical device, so that appropriate focus detection according to the condition can be performed.

According to a second aspect of the invention, there is provided a photographing optical system,
Focus detection that has a viewfinder optical system that has an optical axis different from that of the taking optical system and an optical axis that is different from the optical axes of the taking optical system and the viewfinder optical system, and projects a pair of subject images onto different areas of the line sensor. An optical system, the line sensor is composed of two or more line sensors separated from each other, and an automatic focus detection device having a control means for selecting a line sensor to be used according to the photographing conditions of the photographing optical system. It is characterized by being a camera. According to this configuration, since the line sensor to be used can be selected according to the shooting condition of the shooting optical system, it is possible to perform appropriate focus detection according to the condition.

According to the present invention, the above-mentioned taking optical system is a taking optical system whose focal length can be changed, and has an optical axis different from the optical axes of the taking optical system and the focus detecting optical system. A variable-magnification finder optical system that changes the field magnification in association with a variable distance operation is provided, and the control means operates a line sensor according to a focal length changing operation of the photographing optical system or a visual field magnification changing operation of the variable-magnification finder optical system. It is possible to adopt a configuration in which the use area range of the selected line sensor is selected and changed. According to this configuration, focus detection can be performed on a subject within a certain position and range in the shooting screen or the viewfinder field regardless of the focal length of the taking lens, the viewfinder magnification of the viewfinder, or the subject distance.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION An automatic focus detection device of the present invention which solves the above-mentioned problems will be described below with reference to illustrated embodiments. Since the present invention can be applied to the optical system of the conventional AF apparatus and can be mounted on the conventional camera, the configurations of the optical system and the camera will be described with reference to FIGS.
See 3.

[Description of Embodiments for Solving Problems Caused by Changing Focal Length or Field Magnification of Photographic Lens] FIG. 1 shows a front view of a distance measuring sensor 50 of a first embodiment according to the present invention. . This distance measuring sensor 50 has a pair of left and right line sensors 52A and 52B arranged in a row in the lateral direction similarly to the conventional distance measuring sensor 30, but each of the line sensors 52A and 52B is replaced with the conventional line sensor 32A. Three
It is formed to be longer than 2B in the lateral direction. A subject image that has passed through the corresponding AF lenses 22 and 23 is projected on each of these line sensors 52A and 52B. Therefore, the configurations and operations of the line sensor 52A and the monitor sensor 54 on which the subject image incident from the one AF lens 22 is projected will be described.

At wide angle, the subject light flux that has passed through the AF lens 22 is projected onto the entire range of the line sensor 52A. A range on the line sensor 52A projected in this way is defined as a light receiving range 53, and a range in the viewfinder field 56 of the variable power finder 14 of a subject projected on the wide range light receiving range 53W is defined as a distance measuring zone 57W. here,
When the taking lens 12 has a wide angle, the distance measuring frame 58 is formed so that the subject in the distance measuring frame 58 formed in the viewfinder field 56 of the variable magnification finder 14 matches the subject in the distance measuring zone 57W. Yes (Fig. 2 (C), Fig. 3
(See (A) and (B)). The taking lens 12 is a zoom lens capable of zooming from a wide angle to a telephoto range.
In this embodiment, for convenience of description, there are three types of wide angle, standard and telephoto.
A multi-focal length lens having a focal length will be described.

When the photographing lens 12 is zoomed to the standard, the subject in the distance measuring frame 58 is projected onto the light receiving range 53S indicated by the diagonal lines in FIG. 2B. Further, when the taking lens 12 is zoomed to the telephoto position, the subject in the distance measuring frame 58 is projected onto the light receiving range 53T indicated by the diagonal lines in FIG.

Therefore, in this embodiment, when the wide angle is used, distance measurement, that is, using the subject image projected on the light receiving range 53W, that is,
The distance measurement calculation is executed using the signal charges accumulated in all the light receiving elements of the line sensor 52A, and the light receiving elements within the narrower light receiving range 53S are used at the standard time, and within the narrower light receiving range 53T at the telephoto time. Distance measurement is executed using the light receiving element of. As a result, regardless of the focal length of the taking lens 12, the distance measuring zones 57W, 57S, 5
7T and the distance measuring frame 58 coincide with each other.

When the same person is photographed from the same distance by the camera to which the above embodiment is applied, when the wide angle is used, as shown in FIG.
As shown in (A), the distance measuring zone 57W and the distance measuring frame 58 match. When the photographic lens 12 is zoomed to the telephoto position at this camera position, the field of view magnification of the variable magnification finder 14 also increases in accordance with the change in the focal length of the photographic lens 12, so that the subject image 59 as shown in FIG. Looks big. However, the AF lens 22
Since the range of the subject image incident on the line sensor 52A through the line sensor 52A does not change, if all the line sensors 52A are used as in the conventional case, the subject range incident on the line sensor 52A is indicated by an imaginary line in FIG. It grows as shown.

However, in this embodiment, the range of the line sensor 52A to be used at the time of telephoto is limited to the light receiving range 53T as shown in FIG. Is approximately the same size as the distance measuring frame 58 as in the wide angle.

As described above, in this embodiment, the width of the line sensor 52 is made longer than that of the conventional one, and the light receiving range of the line sensor 52 used for distance measurement is set to the visual field magnification of the variable magnification finder 14 (focus of the photographing lens 12). Since the distance is selected according to the distance, the size of the distance measuring zone 57 in the viewfinder field 56 is constant regardless of the field magnification, and matches the distance measuring frame 58.

In other words, the light receiving elements (light receiving elements) used by the line sensors 52A and 52B are arranged so that the distance measuring zone 57 and the distance measuring frame 58 in the object viewfinder field 56 coincide with each other regardless of changes in the focal length and the field magnification. range)
Is selected.

In this embodiment, the taking lens 12 is set to 3
Although the focal length lens is used, this may be a zoom lens. In the case of a zoom lens, the light receiving range is divided more finely according to its focal length.

Next, the structure of the light receiving elements of the line sensors 52A and 52B and the manner of reading the signal charges accumulated by these light receiving elements will be described.

The line sensor 52 shown in FIGS. 2A, 2B and 2C is composed of light receiving elements of three kinds of widths a, 2a and 3a. These light receiving elements are arranged symmetrically with respect to the optical axis 0 with the width a as a reference.

In the present embodiment, the width of the light-receiving range 53 at each focal length is 2/3 in the standard-time light-receiving range 53S and 1 / in the telephoto-range 53T with reference to the wide-angle light-receiving range 53W. The size is set to 3.
In the light receiving range 53T at the telephoto end, there are 24 light receiving elements of width a.
The light receiving area 53S in the standard time includes a light receiving element of the width 2a outside the width a, and the light receiving elements of the width a and the width 2a are included in a total of the width 48a. In the line sensor 52W, a light receiving element having a width 3a is provided outside a light receiving element having a width a, 2a.
The light receiving element 3a is included in the total width 72a.

The reason why the light receiving width is changed at such a ratio is that the output of the line sensor 52 is processed as a 24-bit signal regardless of the light receiving range. That is,
At the time of telephoto, the bit of width a is processed as 1 bit, and at the standard time, the bit of width 2a is processed as 1 bit,
In the wide angle, the light receiving element for the width 3a is processed as 1 bit.

FIGS. 4A, 4B, and 4C show another embodiment of the line sensor 52. This example is
Although the number of the light receiving elements having the width a is 74, the light receiving range at each focal length is the same as that of the embodiment shown in FIG. Then, at each focal length, it is processed as 24-bit information as described above. In other words, at telephoto, 24
Each of the light receiving elements is processed as 1 bit, two adjacent light receiving elements are processed as 1 bit in the standard time, and 3 adjacent light receiving elements are processed as 1 bit in the wide angle. ing.

FIGS. 5A, 5B and 5C show still another embodiment of the line sensor 52. The structure of the light receiving element is the same as that shown in FIG. 4, and the light receiving range at each focal length is also the same as that of the above embodiment, but the bit processing is different. In this embodiment, each light receiving element is processed as 1 bit. In other words, it is processed as 24-bit information at the time of telephoto, as 48-bit information at the time of standard, and as 72-bit information at the time of wide angle.

The number of light receiving elements is not limited to that in the above embodiment, and the light receiving range may be changed in 1-bit units according to the focal length.

[Explanation of an Embodiment for Solving the Problem Due to Parallax] Next, there are various parallaxes caused by the fact that the optical axis of the AF device does not coincide with the optical axis of the taking lens or the optical axis of the finder optical system. An embodiment of the present invention for solving the problem will be described with reference to FIGS.

First, an embodiment applied to a camera in which AF lenses 61 and 62 of an automatic focus detection device are arranged beside the variable magnification finder 60 and a photographing lens 63 is arranged below the variable magnification finder 60 is shown. It will be described based on 6 to 9. In this arrangement, the subject image projected on the line sensor by the AF lenses 61 and 62 moves in the left-right direction depending on the subject distance. Therefore, the distance measuring zone for the distance measuring frame 68 in the subject field of view 66 is laterally displaced depending on the subject distance, as in the case shown in FIGS. 28 (A) and 28 (B).

Therefore, in this embodiment, the line sensor 64 is formed to be long in the lateral direction like the line sensor 52 shown in FIG. 1 so that the light receiving element of the line sensor 64 can receive the object image regardless of the object distance. Is configured. Then, as indicated by hatching in FIGS. 7A to 7C, 8A to 8C, and 9A to 9C, the light receiving range, that is, the light receiving range is used according to the subject distance. The range of the light receiving element is changed.

With the above configuration, the distance between the distance measuring zone 67 and the distance measuring frame 68 is reduced regardless of the object distance. Note that FIG. 7 illustrates a wide-angle mode, FIG. 8 illustrates a standard mode, and FIG. 9 illustrates a telephoto mode.

Further, in this camera, in order to reduce the parallax of the variable magnification finder 60 and the photographing lens 63 at the time of macro photography, the variable magnification finder 6 at the time of macro photography is used.
The optical axis of 0 is swung to the optical axis side (downward in the figure) of the taking lens 63. Therefore, during macro photography, the distance measuring zone 67 in the viewfinder field 66 moves upward (see FIG. 6D).

Therefore, in the present embodiment, line sensors 64C and 64D for macro photography are provided above the line sensors 64A and 64B for normal photography (see FIG. 6C), and the normal line below is used during normal photography. The sensors 64A and 64B are used, and during macro photography, the upper macro line sensors 64C and 64D are used for distance measurement. With this configuration,
The parallax is corrected, and the distance measuring frame 68 in the viewfinder field 66 and the actual distance measuring zone 67 match.

Further, in the above camera, since the object distance is unknown at the first distance measurement, the light receiving elements in the widest range are used for distance measurement at each focal length of the photographing lens. Therefore, when the subject is a three-dimensional subject, a plurality of output peaks of the light receiving element appear (see FIG. 3).
5), distance measurement cannot be performed, or even if distance measurement is possible, it is not known to which subject the distance measurement should be performed.

Therefore, in the present embodiment, the light receiving range is divided into three parts (see FIG. 7D, FIG. 8D and FIG. 9D) to obtain respective light receiving ranges 64α, 64β and 64γ. The distance is measured for each of the projected objects. The number of divisions of the light receiving range and the size of each divided portion are arbitrary, and the divided distance measurement may be performed in the same manner as described above even in the distance measurement at each focal length.

FIG. 10 shows another arrangement example of the optical system of the camera. In this embodiment, the zoom is the viewfinder 6.
0 and the AF lenses 61 and 62 of the AF optical system are arranged in the vertical direction, and these are arranged in the lateral direction of the taking lens 63.

In this embodiment, the variable magnification finder 60 and A
Due to the deviation of the optical axes of the F optical systems 61 and 62, the distance measuring frame 68 and the distance measuring zone 67 in the viewfinder field 66 are similar to those in FIGS. It mainly shifts in the vertical direction. Further, during macro photography, the optical axis of the variable magnification finder 60 is swung in the optical axis direction of the taking lens 63, so the distance measuring zone 67 with respect to the distance measuring frame 68 shifts diagonally in the vertical direction.

Therefore, in this embodiment, three line sensors 64 are provided in the vertical direction (vertical direction). The bottom line sensors 64A and 64B are for short distance, the middle line sensors 64C and 64D are for intermediate distance, and the upper line sensor 64.
E and 64F are used for long distance and macro. Each line sensor 64 is laterally longer than the conventional one as in the embodiment shown in FIG.

In this embodiment, at the time of normal photographing, the object distance is first measured using the intermediate distance line sensors 64C and 64D. Then, the line sensor 64 to be used is selected based on the distance measurement value, the distance measurement is performed again using the selected line sensor 64, and the focusing lens is changed based on the distance measurement value. Drive to the in-focus position.

By the above operation, the parallax of the distance measuring zone 67 and the distance measuring frame 68 caused by the difference of the object distance is corrected, and the distance measuring zone 67 and the distance measuring frame 68 in the viewfinder field 66 are irrespective of the object distance.
Matches. Therefore, the subject intended by the photographer is accurately focused. It should be noted that, also in this embodiment, division distance measurement can be executed for a three-dimensional object.

Further, in this camera, since the optical axis of the variable magnification finder 60 is swung toward the optical axis of the taking lens 63 during macro photography, the distance measuring zone 67 is located above the distance measuring frame 68 in the finder field 66. Move to. Therefore, in this embodiment, the long-distance / macro line sensors 64E and 64F are selected during macro photography. As a result, the parallax due to the optical axis of the variable magnification finder 60 being shaken is corrected, and the distance measuring frame 68 and the distance measuring zone 67 in the finder field of view 66 coincide.

[Focal Length Information Reading Device and Focus Adjusting Device] Next, the line sensor 64 used according to the focal length.
An apparatus for reading the focal length information of the taking lens 12 for selecting will be described with reference to FIG.

The taking lens 12 is a variable focal length lens L.
Zooming is performed by the relative contact and separation movement of 1. A code plate 72 that codes the position of the zoom ring 71 is attached to the surface of the zoom ring 71 that moves the varifocal lens unit L1 closer to and away from it by a rectilinear motion. The code plate 72 is a 3-bit code, and each code is composed of a combination of a conductive portion and an insulating portion.

Each code of the code plate 72 has a brush 7 having a contact point 73a which is in sliding contact with each bit of each code.
CP after being read by 3 and decoded by the decoder 74
Sent to U80 (Fig. 13).

The CPU 80 stores focal length information corresponding to each code of the code plate 72 and use range information of the line sensor 52 corresponding to each focal length. And CP
U80 determines the use range of the line sensor 64 based on the information (focal length) output from the decoder 74.

Next, the focus adjusting device will be described with reference to FIG. Lens barrel 7 holding the focusing lens L2
The focus adjustment is performed by the movement of 5 in the optical axis direction. A pin 76 is implanted in the lens barrel 75, and the pin 76 is a screw 77 arranged parallel to the optical axis.
Fit in. This screw 77 is a focus motor 78
Is driven to rotate. Therefore, when the focus motor 78 rotates, the lens barrel 75 moves back and forth to adjust the focus. The rotation direction and rotation amount of the focus motor 78 are controlled by the CPU 80.

A conductive plate 7 is provided at the rear end of the lens barrel 75.
5a is attached, and a switch 79 having a contact 79a slidably contacting the conductive plate 75a is provided behind the switch 5a. Therefore, when the lens barrel 75 is in the fixed retreat range, the contact 79a comes into contact with the conductive plate 75a to be turned on, and when the lens barrel 75 advances beyond the fixed position, the contact 79a.
a is separated from the conductive plate 75a and turned off. The switch 79 is for detecting that the lens barrel 75 is at the reference position.

[Explanation of Control System of Camera] Next, the configuration of the control system of the camera to which the embodiment shown in FIG. 6 is applied will be described with reference to FIG. This camera is a lens shutter type camera equipped with an automatic focus detection device, a power zoom lens and a pop-up strobe.

The CPU 80 comprehensively controls the operations relating to photographing such as distance measurement, photometry and exposure of this camera. CPU8
0 executes the above control operations according to the program stored in the internal memory.

When the film is loaded, the CPU 80
The film speed information is read through the DX code reading means 81 and stored in the internal RAM as film ISO speed information.

Further, the CPU 80 causes the taking lens 82 (1
The focal length information of 2) and information on whether or not it is a macro are read and stored. This is executed via the focal length information reading device 83 and the decoder 84 which have the same configuration as that shown in FIG. Then, the CPU 80 selects the light receiving range of the line sensor 64 and the line sensor 64 to be used based on this focal length information and the like.

The photometric switch 85, the release switch 86, the macro switch 87, and the strobe pop-up switch 88 are input to the CPU 80 as switches. When the photometry switch 85 is turned on, photometry processing and AF processing are executed, and when the release switch 86 is turned on, exposure processing is executed. Macro switch 87
It is turned on when the taking lens 82 moves to the macro range. When the strobe pop-up switch 88 is turned on, the built-in strobe is popped up, enabling the strobe to emit light.

In the photometric processing, the photometric circuit 90 performs a predetermined process such as logarithmic compression on the signal output from the photometric light receiving element 89 that receives the subject light, and outputs the signal to the CPU 80. C
The PU 80 executes a photometric calculation based on the film ISO sensitivity information and the like already stored and the photometric signal to determine the aperture value and the shutter speed.

In the distance measuring process, first, the switching circuit 9
Switching to the line sensor 64 using 1 or 92, the line sensor to be used is selected. And the line sensor 6
4 to start accumulating signal charges.

After a lapse of a predetermined time, the charge accumulation of the line sensor 64 is stopped and the accumulated charges are read out as an electric signal. The timing of stopping the accumulation is determined by, for example, the monitor circuit shown in FIG.

The accumulated signals read from the line sensor 64 are input to the A / D converters 93 and 94 via the switching circuits 91 and 92, respectively, where they are converted into predetermined digital signals in predetermined light receiving element units. And output to the CPU 80. The CPU 80 does not A / D convert and read all the accumulated signals, but only A / D converts and reads only the accumulated signals accumulated by the light receiving elements in the light receiving range selected according to the focal length of the taking lens 82. To memory. Note that the clock generation circuit 9 performs the storage control, the reading, the A / D conversion, and the like.
5 is performed based on the pulse generated.

The CPU 80 executes the predictor calculation by using the signals read from the selected pair of line sensors 64 and stored in the memory as the reference signal and the reference signal, respectively, and obtains the subject distance. Then, the AF motor 96 (78) is activated based on this subject distance, and the focusing lens L2 is driven to the in-focus position via the lens driving unit 97. Reference numeral 98 is
This is a position detection switch for detecting the reference position of the lens driving unit 97.

In the exposure processing, based on the previously determined aperture value and shutter speed, the aperture is narrowed down to the set aperture value via the shutter / diaphragm drive circuit 99, and the shutter is opened and closed at the set shutter speed to open the film. To expose.

After the exposure is completed, although not shown, the film is wound up by one frame by an auto winder and the shutter is charged. The film may be wound manually.

Further, in this embodiment, the pop-up strobe 100 is incorporated. Pop-up flash 100
Includes a light emitting circuit 101 and a light emitting unit 102 that can be popped up from the camera body.

In the photometric processing, when it is determined that the brightness of the subject is lower than a certain value, a warning prompting the use of a strobe is given by blinking the in-viewfinder display 103 provided in the field of view of the finder. The in-viewfinder display 103 can also display the in-focus state.

When the strobe pop-up switch 88 is turned on, the light emitting portion 102 projects and the light emitting state becomes possible. When the release switch 86 is turned on in this state,
The light emitting unit 102 emits light at a predetermined timing.

Reference numeral 104 in the drawing denotes a battery for supplying electric power to the CPU 80, the pop-up flash 100, etc.
Reference numeral 105 denotes an X contact switch forcibly causing the light emitting unit 102 to emit light, which is turned ON / OFF in conjunction with the operation of the shutter / diaphragm drive circuit 99.

Next, the operation of reading the signal charge from the line sensor 64 will be described with reference to FIG.
The line sensors 64A to 64D are provided on one integrated substrate, and the pair of line sensors 64A and 64B and the other pair of line sensors 64C and 64D are arranged in a row in the lateral direction and each pair of line sensors 64. Are arranged in parallel in the vertical direction. The subject light fluxes that have passed through the AF lenses 61 and 62 are respectively projected onto different areas of the line sensor 64, that is, on the left side line sensors 64A and 64C and on the right side line sensors 64B and 64D, and the signal charges are received by the respective light receiving elements. Is converted to. The signal charge accumulated in each light receiving element of each line sensor 64 is simultaneously transferred to the horizontal transfer unit on the substrate.

This horizontal transfer section is provided for each line sensor 64, and a pair of read transfer sections is provided outside the horizontal transfer section. The signal charges transferred to the read transfer unit are transferred to the left read transfer unit in stages, and the signal charges of the left line sensors 64A and 64C are read alternately one by one from the read end of this read transfer unit. To be done. Similarly, the signal charges accumulated by the right line sensors 64B and 64D are alternately read one by one from the read terminal of the right read transfer unit. Since the operation of each line sensor is the same, the operation of one of the line sensors 64B and 64D will be described.

The clock generation circuit 95 controlled by the CPU 80 stores a signal charge accumulated in each light receiving element of the line sensor 64 to the horizontal transfer section all at once, and a storage control signal ΦT for stopping the accumulation of the signal charge, and a horizontal control signal ΦT. A read pulse for sequentially reading the signal charges transferred to the transfer unit is output. The pulse output from the clock generation circuit 95 is
Not only the line sensor 64 but also the counter 106 and A
It is also sent to the / D conversion circuit 92.

The CPU 80 sets the count value in the count setter 107 according to the range of use of the line sensor 64 that takes in the signal charges. Count setter 107 outputs the set value to count comparison circuit 108. On the other hand, the counter 106 counts the number of read pulses generated by the clock generation circuit 95 and outputs the count value to the count comparator 108. Count comparator 108
Compares the set value with the count value and outputs a match signal to the CPU 80 when they match.

The CPU 80 having received the coincidence signal converts the signal output from the line sensor 64 via the switching circuit 92 into a digital signal by operating the A / D converter 94. The switching circuit 92 includes line sensors 64B and 6B.
The 4D read terminal is selectively connected to the A / D converter 94, and its switching is controlled by the CPU 80.

The above operation will be described from the end of charge accumulation in the line sensor 64. When the storage control signal is output from the clock generation circuit 95, the charges of the light receiving elements of the line sensor 64 are transferred to the horizontal transfer section all at once, and the charge storage ends, the CPU 80 causes the clock generation circuit 95 to output a read pulse. , The light receiving range of the line sensor 64 is selected based on the focal length information of the photographing lens 82 output from the decoder 84 and the information from the macro switch 87, the value of the count setter 107 is set, and the changeover switch is selected. Select 91 and 92. Here, in normal shooting,
It is assumed that the line sensor 64B and the telephoto receiving range 64T are selected.

Since the clock generation circuit 95 outputs a read pulse at a constant cycle, the signal charge accumulated by each light receiving element of the line sensor 64B is output to the switching circuit 92 as an electric signal at a constant cycle. However, the light receiving range 64T
Until the signal charge of
Since no match signal is output from the CPU 80, the CPU 80 does not take in those signals. The comparison circuit 108 compares the set value output by the count setter 107 with the read pulse number output by the counter 106, and outputs a match signal when they match.

When the CPU 80 detects that the coincidence signal has been output, it activates the A / D converter 94 to capture the signal output from the line sensor 64 and stores it in the RAM. The above process is performed for each light receiving element (bit). In addition, when the signals of two or three light receiving elements are added and processed by 1 bit at standard or telephoto,
The signals output by the three or three light receiving elements are A / D converted by the A / D conversion circuit 94, and the C
Addition is performed by PU80.

In this embodiment, the signals output from the pair of left and right line sensors 64 are fetched into the CPU 80 via the common read pulse and data bus. Therefore, as shown in FIG. 15, by changing the timing of the transfer signal, one signal data 1 and the other signal data 2 are alternately loaded on the data bus.

When the first reading of the signals accumulated by the line sensors 64A and 64B and the end of the memory are completed, the CPU 80 executes a predetermined distance measurement calculation (predictor calculation) based on the stored information to obtain the subject distance.
Then, the light receiving range is selected according to the subject distance, the count value is set again in the count setter 107, and the reading of the signals accumulated by the line sensors 64A and 64B is started.

When the reading of the signals and the memory work are completed, the CPU 80 executes a predetermined distance measurement calculation based on the memory information to obtain the subject distance, and based on this value, activates the focus motor 96 (78), The focusing lens L2 is driven to the in-focus position.

The above-described processes are performed by the CPU 8 according to the program stored in the ROM of the CPU 80 in advance.
0 runs.

Next, the circuit configuration for controlling the signal charge storage time of the line sensor 64 will be described with reference to FIG.

A monitor sensor 110 is provided near the line sensor 64A. This monitor sensor 110
Is for measuring the amount of light incident on the line sensor 64 and optimally controlling the charge storage time of the line sensor 64.

The monitor sensor 110 corresponds to the light receiving ranges 64T, 64S, 64W of the line sensor 64 used, and the central portion 110A and the intermediate portions 110 on both outer sides thereof.
B, 110B and the outer parts 110 on both outer sides thereof
It is divided into C and 110C. Only the central portion 110A in the telephoto state, and the central portion 110A in the standard state.
And when the intermediate portions 110B, 110B are wide-angle, all portions 110A, 110B, 110C are used. The output of each monitor sensor 110 is connected to the inverting input terminals of comparators 111, 112, and 113, respectively. The reference voltages Vr1, Vr2, and Vr3 are input to the inverting input terminals of the comparators 111, 112, and 113, respectively. Therefore, when the output level of the line sensor 64 falls below a certain value, the output of the comparator becomes "H" (high level).

The outputs of the comparators 111, 112 and 113 are AND gates 114, 115 and 116, respectively.
Is connected to one input. AND gate 114,
The output switching circuit 11 is connected to the other inputs of 115 and 116.
7 output terminals A, B and C are connected. Therefore, the AND gates 114, 115 and 116 are provided for the line sensor 6 when the output of the output switching circuit 117 is at "H" level.
If the output of 4 changes to "H", the AND gate 11
The outputs of 4, 115 and 116 change from "L" (low level) to "H".

The output of each AND gate 114, 115, 116 is connected to the input of an OR gate 118, respectively. Therefore, the AND gates 114, 115, 11
If even one output of 6 changes to "H", OR gate 11
The output of 8 changes from "L" to "H".

The output of the OR gate 118 is input to the φT generation circuit 119 (clock generation circuit 95). Φ
In the T generation circuit 119, the output of the OR gate 118 is "H".
Then, the storage control signal ΦT that stops the charge storage of the line sensor 64 is output. When the storage control signal ΦT is output, the line sensor 64 simultaneously transfers the signal charges accumulated by the light receiving elements to the horizontal transfer unit, and ends the accumulation of the signal charges.

The operation of the charge storage control circuit having the above structure will be described with reference to FIG. When the subject image is projected on the monitor sensor 110, the monitor sensor 1
The output potential of 10 starts to drop. The descent speed is proportional to the brightness of the projected subject. In other words, the brighter the subject, the more rapidly it drops, and the darker the subject, the more gently it drops. When the potential becomes the same as the potential (Vr) of the non-inverting input terminal, the comparators 111 and 11
The output of 2,113 changes to "H".

On the other hand, the comparators 111, 112, 11
A constant reference voltage Vr is applied to each of the three non-inverting input terminals. Therefore, the divided portions 110A, 11
When the outputs of 0B and 110C become equal to the reference voltage, the comparators 111, 112 and 1 to which the outputs are input.
The output of 13 changes to "H".

Output terminals A, B of the output switching circuit 117,
Any or all of Cs are set to "H" by the CPU 80 according to the focal length of the taking lens. In this embodiment, the output terminals A, B and C are set to "H" when the angle is wide, only the output terminals A and B are set to standard when the angle is wide, and only "A" is set when the lens is telephoto. Therefore, one of the comparators 111, 11
If the outputs of the corresponding output terminals A, B, and C are "H" when the outputs of 2, 113 become "H", the outputs of the AND gates 114, 115, and 116 become "H",
The output of the OR gate 118 also becomes "H" and the storage control signal ΦT is output from the ΦT generation circuit 119, and the charge storage of the line sensor 64 ends. The monitor sensor 110
Is preferably configured to correspond to the light receiving range to be used, but may not be divided and may be configured to use one corresponding to the light receiving range to be used.

By the above operation, the optimum charge accumulation time according to the subject brightness can be obtained. The reference voltage Vr is determined based on various conditions such as the line sensor, the monitor sensor standard, and the monitor sensor division area. It should be noted that, even if the output potential of the monitor sensor does not drop to the reference voltage, the signal for issuing the storage control signal ΦT is C
It is output from the PU 80.

Next, the operation sequence of the camera having the above circuit configuration will be described with reference to the flow charts shown in FIGS. This operation is all C
The PU 80 executes according to the program stored in the internal memory.

When the power is turned on, the main routine shown in FIG. 17 is entered. In the main routine, it is first checked whether or not the photometric switch 85 is on, and if not, this process is repeated until it is turned on (S1).
1).

When the photometry switch 85 is turned on, the photometry circuit 90 is activated to start photometry (S13), and the switch states of the macro switch 87 and the strobe / pop-up switch 88 are checked (S15). A photometric calculation is executed based on the photometric signal (S17).

Then, the focal length information of the taking lens 82 is input, and the line sensor 64 is input based on the focal length information.
Select the light receiving range of and the line sensor 64 to be used,
Based on these, the signal charge is accumulated in the line sensor 64, the signal is A / D converted and read, distance measurement is executed, and the focus lens L2 is moved through the AF motor 96 based on the distance calculation value. AF processing for driving to the in-focus position is executed (S19).

When the AF processing is completed, display processing such as displaying the in-focus state display or causing the in-finder display 103 to display a flash usage recommendation display if the subject brightness is the flash usage recommendation value is performed. (S
21).

Then, it is checked whether or not the release switch 86 is on, and if not, S11
If the release switch 86 is turned on, the shutter / diaphragm drive circuit 99 is driven to perform the exposure process, and then the process returns to S11 (S23, S2).
5).

The above is the basic operation of the camera.
Next, the AF process when shooting a three-dimensional subject will be described. In this embodiment, when it is determined that the object is a three-dimensional object as a result of the divided distance measurement, the closest object is focused. Further, when the strobe is used, the closest subject is focused within the proper strobe range.

The above operation will be described with reference to FIG. 18 showing the AF processing subroutine (S19) of FIG. When this subroutine is entered, first, information on the taking lens 82 (focal length information and information on the macro switch 87) is input, and it is determined whether or not it is a macro (S31, S33).

If not macro, line sensors 64A, 6
4B is selected, and the use range (see FIG.
(A), FIG. 8 (A), and FIG. 9 (A)) are selected (S3
5). Then, the signal of the line sensor 64 accumulated in the use range is read and the distance measurement calculation is executed (S37,
S39).

Based on the result of the distance measurement calculation, it is determined whether or not the object is a three-dimensional object, and if it is not a three-dimensional object, the light receiving ranges on the line sensors 64A and 64B are set to 64S, 64T and 64W based on the distance calculation value. 8 (S41, S43, FIGS. 7A to 7C, and FIG. 8).
(A) to (C) and FIG. 9 (A) to (C)). And
Line sensors 64A, 64 that meet the selected conditions
The signal accumulated by the light receiving element of B is read and stored in the memory, and after the memory is stored, the distance measurement calculation is executed (S43, S
45).

Next, whether the flash is used or not
It is determined by turning ON / OFF the pop-up switch 88, and if it is not used, the AF motor 96 is driven based on the calculated distance measurement value, the focusing lens L2 is driven to the in-focus position, and then the process returns to the main routine (S47, S49).

If the taking lens 82 is a macro, the process proceeds from the determination step S33 of whether it is a macro to S51, and the line sensors 64C and 64D for macro are selected. Then, the signals accumulated by the line sensors 64C and 64D are read and distance measurement calculation is executed (S53, S5).
5). Further, in this distance measurement calculation, the AF motor 96 is driven based on the subject distance (shooting distance), and the focus lens L
After moving 2 to the in-focus position, the process returns to the main routine (S49).

If the object is not a macroscopic object but a three-dimensional object, the process proceeds from S41 to S57, and the divided light-receiving ranges 64α, 64β, 64γ for the three-dimensional object according to the focal length (FIG. 7 (D), FIG. 8). (D), refer to FIG. 9 (D)).
Then, the distance measurement calculation, that is, the divided distance measurement calculation is executed based on the signals of the respective light receiving ranges, the closest calculation value is selected from the respective calculation values (distance measurement subject distance), and S4
Proceed to 7 (S59).

Also, the strobe pop-up switch 8
When 8 is turned on, the process proceeds from S47 to S61 to input the strobe usable distance range information, and it is checked whether the distance measurement value calculated in S45 or S59 is within the strobe usable distance range. (S63). If the distance is not within this range, a warning is displayed by the in-viewfinder display 103 and then the lens driving process is executed (S65, S).
49), if the distance is within the above range, the lens driving process is immediately executed (S63, S49).

By the above processing, the distance measuring zone 67 and the distance measuring frame 68 match regardless of the focal length, macro or not, and the subject distance, and the distance measuring and automatic focus adjusting operations are performed in this matched state. Furthermore, even a three-dimensional object can be focused on an object at the closest distance.

If it is determined in S63 that the closest distance measurement value selected in S59 is not within the strobe usable distance range, the strobe use distance is selected from the plurality of distance measurement values calculated in S59. It is also possible to search for a range finding value within the range, select an applicable range finding value, and perform a focusing operation based on this. If such a process is performed, for example, when a plurality of persons are photographed using a strobe, at least the person located in the distance measuring zone 67 can be photographed with an appropriate focus and an appropriate exposure value.

"Auxiliary Projector" The passive automatic focus detection device uses a dark subject (a subject whose brightness is lower than a certain value),
Alternatively, the accuracy of distance measurement deteriorates for a subject having a low surface contrast such as a white wall. Therefore, in this embodiment, an auxiliary light projecting element is installed near the finder. The situation is shown in FIGS. 19 (A) and 19 (B).

This viewfinder optical system is a variable power viewfinder in which the field magnification fluctuates in association with zooming of the zoom lens. The objective side lens is relatively movable 2
It is composed of one variable power lens (objective lens system) 121 and 122, and the eyepiece side lens is composed of one fixed lens (eyepiece lens system) 123. Variable magnification lens 122 and fixed lens 1
A prism 124 for forming a subject image formed by the objective lenses 121 and 122, and a half mirror 125 are installed between the two. The photographer observes the subject image, which is formed by the variable power lenses 121 and 122 and is erected by the prism 124, through the fixed lens 123. Further, the half mirror 12 is placed outside the optical path of the finder optical system.
Towards 5, the light emitting element with an output wavelength of 700 nm or more (for example,
IRED) 126 is provided. A pattern plate 127 for forming a stripe pattern (contrast pattern) is arranged on the front surface of the light emitting element 126. If the half mirror 125 is configured to reflect light having a wavelength of 700 nm or more at an incident angle of 45 ° and transmit visible light, the efficiency of auxiliary light projection is improved and the viewfinder field becomes bright.

The variable power lenses 121 and 122 are interlocked with the zooming of the zoom lens via an interlocking mechanism (not shown) and relatively moved toward and away from each other to change the view magnification of the finder according to the focal length of the zoom lens. Have changed. In other words, regardless of zooming, the viewfinder field is configured to be substantially the same as or slightly smaller than the shooting screen.
The interlocking mechanism includes, for example, a cam plate provided with a cam groove and slid by a zoom motor, and a variable power lens 12
There is a configuration in which the zoom lenses 121 and 122 are relatively moved toward and away from each other by the sliding of the cam plate by the cam follower pins fitted to the cam grooves attached to the Nos. 1 and 122.

Next, the optical path of this embodiment will be described with reference to the drawings. The prism 124 is composed of three triangular prisms. Light rays that have entered from the surface 124 a of the prism 124 through the variable power lenses 121 and 122 are reflected by the inclined surface 124 a.
b is reflected downward by 90 °, inclined surface 124c is reflected in the backside direction with respect to the paper surface, inclined surface 124d is reflected upward, and inclined surface 124e is reflected by 90 ° rightward.
Eject from f. Then, the light enters the eyes of the photographer through the half mirror 125 and the fixed lens 123.

On the other hand, the auxiliary light emitted from the light emitting element 126 is reflected by the half mirror 125 toward the prism 124, and enters the prism 124 from the surface 124f,
The light is emitted from the surface 124a through the optical path opposite to the above. Then, the light is emitted from the camera through the variable power lenses 122 and 121 to illuminate the subject. Therefore, the auxiliary light projected from the light emitting element 126 is condensed by the variable power lenses 122 and 121 and is applied to the subject.

Here, the degree of light condensing by the variable power lenses 122 and 121 is low at wide angle and high at telephoto. That is,
It illuminates a wide range at wide-angle and a narrow range at telephoto. Therefore, it becomes possible to illuminate the subject according to the light receiving range selected according to the focal length,
Since the irradiation area is narrowed in the telephoto mode, it is possible to illuminate a distant subject.

[0122]

As is apparent from the above description, according to the first aspect of the invention, the light flux of the subject is divided and the images of the same subject are projected onto at least two different light receiving areas of the line sensor. An automatic focus detection device for performing focus detection based on outputs from two different light receiving areas, the line sensor having two or more rows and based on variable conditions of an optical device equipped with a line sensor used for detection. Since the line sensor according to the variable condition of the optical device can be selectively used because the control means for selecting the focus is provided, an appropriate focus detection according to the condition becomes possible. Further, according to the present invention, in an automatic focus detection device having an optical axis different from the optical axis of the photographing optical system, two or more line sensors are provided in parallel, and the line sensor to be used and its use range are set to the focal length of the photographing optical system. Alternatively, since it is changed according to the viewfinder field magnification, the distance measurement position and the distance measurement range in the photographing screen or the viewfinder field can be made constant regardless of the change of the focal length of the photographing lens or the change of the viewfinder field magnification.

[Brief description of drawings]

FIG. 1 is a front view showing a main structure of an embodiment of a distance measuring sensor (line sensor) applied to an automatic focus detection device according to the present invention.

FIG. 2 is a front view showing a light receiving range of the distance measuring sensor.

FIG. 3 is a diagram showing a finder field of view at a wide angle and at a telephoto in a camera equipped with an embodiment of the present automatic focus detection device.

FIG. 4 is a diagram showing a structure of another embodiment of the distance measuring sensor and a light receiving range according to a focal length, respectively.

FIG. 5 is a diagram showing a structure of another embodiment of the distance measuring sensor and a light receiving range according to a focal length, respectively.

FIG. 6 is a diagram showing an embodiment for solving a problem caused by a difference in subject distance due to parallax.

7 (A), (B) and (C) are diagrams showing a light receiving range of a line sensor according to a subject distance at a wide angle, and (D) is a division mode of the line sensor at a time of division distance measurement. FIG.

8A, 8B, and 8C are diagrams showing a light receiving range of a line sensor according to a subject distance in standard time, and FIG. 8D is a division mode of the line sensor in divided distance measurement. FIG.

9A, 9B and 9C are diagrams showing a light receiving range of a line sensor according to a subject distance in a telephoto state, and FIG. 9D is a division mode of the line sensor in a divided distance measurement mode. FIG.

FIG. 10 is a diagram showing another embodiment for solving the problem caused by the different subject distances when a parallax is provided.

FIG. 11 is a perspective view showing an outline of a photographing distance information reading device.

FIG. 12 is a perspective view showing an outline of a focus adjustment device.

FIG. 13 is a block diagram showing an embodiment of a control circuit of a camera to which the automatic focus detection device of the present invention is applied.

FIG. 14 is a circuit diagram more specifically showing the vicinity of a line sensor in the control circuit.

FIG. 15 is a diagram showing a timing chart showing the timing of each part of the circuit.

16A is a circuit diagram for controlling the accumulation control time of the line sensor, and FIG. 16B is a timing chart thereof.

FIG. 17 is a diagram showing a part of an embodiment of an operation flowchart of the present invention.

FIG. 18 is a diagram showing a part of an embodiment of an operation flowchart of the present invention.

FIG. 19 is a diagram showing an optical path of an embodiment of the auxiliary light projecting device of the present invention.

FIG. 20 is a perspective view of a prism of the auxiliary light projecting device.

FIG. 21 is a front view of a camera including a passive AF device.

FIG. 22 is a bottom view of the optical system of the passive AF device.

FIG. 23 is a front view of an optical system of the passive AF device.

FIG. 24 is a front view showing the structure of a conventional line sensor.

FIG. 25 is a diagram showing a relationship between a finder field of view and a distance measuring sensor area of a conventional camera.

[Fig. 26] Fig. 26 is a diagram for explaining a problem in a viewfinder field of a conventional camera at wide angle and at telephoto.

FIG. 27 is a diagram showing an example of a positional relationship between a viewfinder of a conventional camera and an active distance measuring sensor.

FIG. 28 is a diagram illustrating a problem caused by a short-distance subject and a long-distance subject in the conventional camera.

FIG. 29 is a diagram showing another example of the positional relationship between the finder of the conventional camera and the active distance measuring sensor.

FIG. 30 is a diagram illustrating a problem caused by a short-distance subject and a long-distance subject in the conventional camera.

FIG. 31 is a diagram showing an example of a positional relationship between a viewfinder of a conventional camera and a passive automatic focus detection device.

FIG. 32 is a diagram for explaining a problem at the time of macro photography of the conventional camera.

FIG. 33 is a diagram showing another example of the positional relationship between the viewfinder of the conventional camera and the passive automatic focus detection device.

FIG. 34 is a diagram illustrating a problem at the time of macro photography of the conventional camera.

FIG. 35 is a diagram for explaining a problem caused by a three-dimensional subject such as a three-dimensional subject with depth.

[Explanation of symbols]

12 shooting lens 14 variable magnification finder 22 AF lens 23 AF lens 52 distance measuring sensor (AF sensor) 52A 52B line sensor 53 53S 53T 53W light receiving range 54 monitor sensor 56 finder field of view 57 57T 57W distance measuring zone 58 distance measuring frame 64A 64B 64C 64D 64E 64F Line sensor 64S 64T 64W Light receiving area 64α 64β 64γ Divided light receiving area 66 Finder field of view 67T 67W Distance measuring zone 68 Distance measuring frame 80 CPU 121 122 Variable magnification finder variable magnification lens 124 Prism 125 Half mirror

Claims (12)

[Claims] 1. An autofocus system which divides a light flux of an object, projects an image of the same object on at least two different light receiving areas of a line sensor, and detects a focus based on outputs from the two different light receiving areas of the line sensor. A detection device, wherein the line sensor is provided in two or more rows, and a line sensor used for the detection is provided with control means for selecting the line sensor based on a variable condition of an optical device in which the automatic focus detection device is mounted. An automatic focus detection device. 2. A line sensor comprising: a photographing optical system; and a focus detection optical system having an optical axis different from the optical axis of the photographing optical system and projecting a pair of subject images on different areas of the line sensor. A camera equipped with an automatic focus detection device, characterized by comprising two or more rows of, and control means for selecting a line sensor to be used according to the shooting conditions of the shooting optical system. 3. The camera according to claim 2, wherein the plurality of line sensors are arranged apart from each other in a direction orthogonal to the extending direction of each line sensor. . 4. The object according to claim 1, wherein the condition is a distance to a subject, and the focus detection device is based on outputs from two light receiving areas of the selected line sensor. A camera equipped with an automatic focus detection device, which is characterized by detecting the distance of. 5. The automatic focus detection device according to claim 2, further comprising a finder optical system having an optical axis different from those of the photographing optical system and the focus detection optical system. camera. 6. The objective system of the finder optical system and the focus detection optical system according to claim 5, wherein the objective systems of the finder optical system and the focus detection optical system are provided on the front surface of the camera body so as to be separated from each other in the vertical direction, and the line sensors of the plurality of rows are separated from each other in the vertical direction. A camera equipped with an automatic focus detection device. 7. The automatic focus detection device according to claim 1, further comprising a calculation unit that calculates a subject distance based on an output of the line sensor selected by the control unit. A camera equipped with a featured automatic focus detection device. 8. The photographing optical system according to claim 3, wherein the photographing optical system is a photographing optical system capable of changing a focal length, and the viewfinder optical system is interlocked with a focal length changing operation of the photographing optical system. A variable magnification finder optical system for changing a field magnification, wherein the control means selects a line sensor according to a focal length changing operation of the photographing optical system or a visual field magnification changing operation of the variable magnification finder optical system. A camera equipped with an automatic focus detection device. 9. The photographing optical system according to claim 2, wherein the photographing optical system has a switchable normal photographing and macro photographing mechanism, and the control means is a line used according to the normal photographing and macro photographing. A camera equipped with an automatic focus detection device, characterized in that a range of a light receiving area used for detection is selected. 10. The variable focal length photographing optical system according to claim 8, wherein the variable focal length variable photographing optical system is a macro photographing mechanism, and the variable magnification finder optical system has a variable focal length photographing optical system. The optical axis is swung in the direction of the optical axis of the variable focal length optical system, and the control means controls an object image within a certain range in the finder field regardless of whether the variable-magnification finder optical system is in normal shooting or macro shooting. A camera equipped with an automatic focus detection device characterized by selectively using a projected line sensor and a light receiving area thereof. 11. The line sensor according to claim 1, wherein the line sensor is capable of receiving a subject within a certain range on a photographing screen of the photographing optical system regardless of a subject distance or a focal length. A camera provided with an automatic focus detection device, characterized in that the control means is used for detection of a light receiving area of a line sensor onto which a subject image in a certain range on the photographing screen is projected. 12. The control means according to claim 3 or 8, when the distance to the subject is not detected,
A camera provided with an automatic focus detection device, characterized in that a predetermined line sensor is selected, and then the line sensor is selected according to the distance to the subject detected by the predetermined line sensor.