JPH07281080A - Camera - Google Patents

Abstract

PURPOSE:To enable a phase difference AF by forming an image of an aerial image of an object by a photographing optical system, and introducing it onto an image pickup element by using a monitoring optical system and a distance measuring optical system in order to realize a high speed and wide range AF by using the image pickup element for a finder. CONSTITUTION:A light flux incident through first and second group zoom lenses 1 and 2 and a diaphragm 3 is introduced to an image forming lens 9 for an image pickup element and distance measuring lenses 10a and 10b through a half mirror 4, a field lens 7 and a mirror 8, and is also introduced to an image pickup element 11 so that an image is formed. Output of this image pickup element 11 is supplied to a phase difference operation circuit 13, and is also supplied to a lens control circuit 15. In the first and the second group zoom lenses 1 and 2, the moving distance is controlled by the lens control circuit 15, a zoom encoder 16 and a zoom control circuit 17. The output of the image pickup element 11 is supplied to a signal processing circuit 23 through an FM modulating circuit 22 or the like, and the output of the image pickup element 11 is displayed on an LCD monitor 25.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement in high-speed, wide-range autofocus using an image pickup device in a camera having an electronic viewfinder.

[0002]

2. Description of the Related Art Conventionally, various techniques have been adopted for autofocus (AF) used in cameras. For example, Japanese Patent Application Laid-Open No. 63-11906 discloses a technique of performing AF by receiving a standard portion light flux and a reference portion light flux that pass through different areas of the exit pupil surface of a photographing lens by a photoelectric conversion element array. ing. Here, the photoelectric conversion element array realizes a phase-difference multi AF in which two photoelectric conversion element arrays are provided horizontally on one side of the optical axis and vertically on the other side without sandwiching the optical axis.

Further, a so-called hill-climbing method is used in which a point at which the sum of differences between brightness signals obtained from an image pickup device for image recording and adjacent pixels (so-called contrast signal) is obtained while scanning a lens. There is a technique to be done.

[0004]

However, in the AF using the phase difference method, the photoelectric conversion element array is dedicated to the AF. Therefore, the camera has a problem that the device becomes large in size.

On the other hand, in AF by the above-mentioned mountain climbing method, A
Although a special sensor for F is not required, it is impossible to determine in which direction the lens should be moved unless the lens is scanned. In addition, the amount of defocus and the quantitative value were unknown. Therefore, it has been difficult to realize AF in a wide range at high speed.

The present invention has been made in view of the above problems, and it is possible to easily realize high-speed and wide-range AF without increasing the size of the apparatus without requiring a photoelectric conversion element array exclusively for AF. The purpose is to provide a camera.

[0007]

That is, the present invention is directed to a photographing optical system for forming a subject image on a film surface, and an electronic view for monitoring the subject image using a part of a photographing light flux of the photographing optical system. In a camera having a finder device, a light-receiving element region for a monitor for monitoring the subject image and a light-receiving element region for distance measurement for measuring a subject distance are arranged in the electronic viewfinder device. Based on the image pickup means provided, a splitting optical system for splitting a part of the photographing light flux into light receiving element regions for monitor and distance measurement, and the output from the light receiving element region for distance measurement, the photographing optical system Drive means for driving the system to a predetermined position.

The present invention also includes a camera having a photographing optical system for forming a subject image on a film surface, and an electronic viewfinder device for monitoring the subject image by using a part of a photographing light flux of the photographing optical system. In the electronic viewfinder device, a light receiving element area for monitoring for monitoring the subject image and a plurality of distance measuring light receiving element areas for outputting a phase difference signal of the subject image are provided. Image pickup means, a monitor optical system for dividing a part of the photographing light flux into the monitor light receiving element region, and a part of the photographing light flux for dividing the plurality of distance measuring light receiving element regions. Distance measuring optical system for inputting light to the optical system, calculating means for calculating the defocus amount based on the phase difference signal from the light receiving element area for distance measuring, and the photographing optical system based on the output of the calculating means. Predetermined system Characterized by comprising a driving means for driving the location.

[0009]

According to the present invention, there are provided a photographing optical system for forming a subject image on the film surface, and an electronic viewfinder device for monitoring the subject image by using a part of the photographing light flux of the photographing optical system. In a camera having the image pickup means arranged in the electronic viewfinder device, a light receiving element region for monitoring for monitoring the subject image and a light receiving element region for distance measurement for measuring a distance of the subject are provided. Has been. A part of the photographing luminous flux is divided into light receiving element regions for monitoring and distance measurement by the division optical system. Further, based on the output from the light receiving element area for distance measurement, the photographing optical system is driven to a predetermined position by the driving means.

Further, according to the present invention, there is provided a photographing optical system for forming a subject image on a film surface, and an electronic viewfinder device for monitoring the subject image by using a part of a photographing light flux of the photographing optical system. In the camera, the image pickup means is arranged in the electronic viewfinder device. The image pickup means is provided with a monitor light-receiving element region for monitoring the subject image and a plurality of distance-measuring light-receiving element regions for outputting a phase difference signal of the subject image. A part of the photographing light flux is split and enters the monitor light receiving element region by the monitor optical system,
Light is incident on the plurality of distance measuring light-receiving element regions by the distance measuring optical system. The calculation means calculates the defocus amount based on the phase difference signal from the light receiving element area for distance measurement. Then, based on the output of the calculation means, the driving means drives the photographing optical system to a predetermined position.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of the first embodiment according to the camera of the present invention. In the figure, the first group zoom lens 1 and the second group zoom lens 2 are arranged with a diaphragm 3 interposed therebetween. This camera is composed of a positive (convex) negative (concave) group consisting of the first and second group zoom lenses 1 and 2, and constitutes a two-group zoom lens. By moving the first and second group zoom lenses 1 and 2, the focal length changes, and the first group zoom lens 1 is extended to adjust the focus.

A half mirror 4 and a focal plane type shutter 5 are arranged on the side of the second group zoom lens 2 opposite to the diaphragm 3, and a film 6 is arranged behind the shutter 5 with respect to the incident direction of the light beam. It The half mirror 4 is arranged between the second group zoom lens 2 and the shutter 5 at an angle of 45 ° with respect to the optical axis, and reflects approximately half of the incident light beam upward.

Above the half mirror 4, there is a field lens 7 and a reflectance of about 100% and 45 with respect to the optical axis.
A mirror 8 having an angle of ° is arranged. The field lens 7 is arranged at a position conjugate with the film surface.

In the direction in which the incident light flux is reflected by the mirror 8, a large number of image pickup lenses 9 for image pickup devices and distance measuring lenses 10a and 10b arranged on both sides of the image pickup lens 9 are provided. An image sensor 11 including a light receiving element is provided. The image pickup device 11 is for displaying a subject image on a monitor 25, which will be described later, and for performing a distance measuring operation.

The preamplifier 12 is for amplifying a signal output from the distance measuring light receiving element array of the image pickup element 11, and supplies the output to the phase difference calculation circuit 13. In the phase difference calculation circuit 13, the phase difference is calculated from the outputs sent from the two light receiving element arrays for distance measurement, and the defocus amount is detected. An AF area designating circuit 14 which selects which area of the subject image is to be distance-measured and which designates a light-receiving element array required to measure the selected area is supplied to the phase difference calculation circuit 13. Output is also provided.

The first group zoom lens 1 is driven by the lens control circuit 15 based on the defocus amount.
Then, the lens position encoder generates a pulse in accordance with the driving of the first group zoom lens 1, and feeds back to the lens control circuit 15 how much the first group zoom lens 1 has moved. The lens control circuit 15 includes a zoom control circuit 17 for changing the focal length of the taking lens (first and second group zoom lenses 1 and 2) and a zoom encoder 18 for recognizing the current focal length. The output of is supplied. Even with the same defocus amount, the lens extension amount differs depending on the focal length.

Of the light receiving element array of the image pickup element 11, the output of the image pickup (monitor) light receiving element is supplied to the preamplifier 19. Then, the output of the preamplifier 19 is separated, processed by the luminance signal processing circuit 20 and the color signal processing circuit 21, and combined by the FM modulation circuit 22. The output of the FM modulation circuit 22 is combined with the signal of the superimposing information by the signal combination circuit 23 and transmitted to the monitor drive circuit 24, and is displayed on the LCD monitor 25. The output of the FM modulation circuit 22 is also A / D conversion circuit 2
It is supplied to and stored in the solid-state memory 27 via 6. The contents of the solid-state memory 17 are stored in the D / A conversion circuit 2
The signal is sent to the signal synthesis circuit 23 via 8.

The brightness signal output from the brightness signal processing circuit 20 is also supplied to the brightness calculation circuit 29, where the brightness of the subject is calculated. In the brightness calculation circuit 29,
An output is supplied from a photometric area designating circuit 30 which selects a photometric area and designates a light receiving element necessary for photometrically measuring the selected area. Then, the subject brightness obtained by the brightness calculation circuit 29 and the output from the film sensitivity reading circuit 32 are supplied to the AE calculation circuit 31, and the diaphragm and shutter speed values are determined.

The output of the AE arithmetic circuit 31 is supplied to the diaphragm control circuit 33 and the shutter control circuit 34, and the operations of the diaphragm 3 and the shutter 5 are controlled respectively. Also,
The film feeding circuit 36 winds up the film 6, and the magnetic recording circuit 37 records necessary information on the magnetic recording layer (not shown) provided outside the screen of the film 6 during the film winding. .

The control circuit 38 controls the entire system. The control circuit 38 includes a release input section 39 including a first release switch (1RSW; half-pressed state) and a second release switch (2RSW; pressed-off state), a telephoto side switch (TSW), and a wide-angle side switch (WSW). A zoom input section 40, an AF area input section 41 for selecting an area for distance measurement while looking at the LCD monitor 25, and a photometric area input section 4 for similarly selecting a photometric area.
Two outputs are supplied respectively.

FIG. 2 shows the principle of phase difference AF. As is known, two distance measuring lenses 10a and 10b are arranged behind a position conjugate with the film surface,
Further, the light receiving element 11 is arranged behind it. When the distance from the distance measuring lenses 10a and 10b to the light receiving element 11 is f, the parallel optical axis interval (baseline length) between the two lenses 10a and 10b is S, and the distance between the two object images on the light receiving element 11 is x, The distance L to the imaging point is calculated by L = Sf / (x−S) (1). Compared to the best focus state shown in FIG. 2A, x becomes smaller in the front focus state shown in FIG. 2B. On the other hand, in the rear focus state shown in FIG. 7C, x becomes larger than in the best focus state.

Assuming that the distance from the distance measuring lenses 10a and 10b to the conjugate plane is L ₀ , L−L ₀ = (Sf / (x−S)) − L ₀ (2) is obtained and the obtained value is obtained. Focusing is achieved by controlling the lens by the code.

Next, the photographing optical system of the distance measuring device of FIG. 1 will be described. FIG. 3 is a diagram showing a mechanical layout of the photographing optical system, and FIG. 4 is a ray diagram at the time of focusing. In order to simplify the description, the half mirror 4 and the mirror 8 in FIG. 3 are omitted in FIG. 4, and the photographing lens is also represented by only one convex lens (first group zoom lens) 1. .

The aerial image formed on the light beam emitted from the subject at a position conjugate with the film is imaged again.
In the case of forming an image by (1), the light ray is eclipsed unless the diameter of the re-imaging lens is made very large, so that the field lens 7 is usually arranged near the image forming point. As a result, the light beam is almost not eclipsed and is incident on the imaging element imaging lens 9 and is focused on the imaging light receiving element array 11 ₁ of the imaging element 11.

The incident light fluxes of the distance measuring lenses 10a and 10b, which have passed through the periphery of the photographing lens 1, are incident and imaged in the vicinity of the distance measuring light receiving element rows 11a and 11b on the image pickup device 11.

Next, referring to the flowchart of FIG.
The operation of this distance measuring device will be described. When the power is turned on, the output of the monitor light receiving element array 11 ₁ on the image pickup element 11 as shown in FIG. 6 is amplified by the preamplifier 19 (step S1), and the luminance signal processing circuit 20 and the color signal processing circuit 21 are processed. Are combined in the FM modulation circuit 22 via After that, in order to superimpose the AF area / photometric area on the monitor 25, a signal obtained by combining the output of the FM modulation circuit and the superimposing information in the signal processing circuit 23 is supplied to the monitor driving circuit 24, and the monitor 25 When it is desired to change the AF area / photometric area (step S3), it is displayed above (step S2).
Change using the photometric area input unit 42 (step S
4). By doing so, the superimpose on the LCD monitor 25 also changes in conjunction (step S5).

7 to 9 show the relationship between the superimposing display on the LCD monitor 25 and the range-finding light receiving element array used when the AF frame display is changed. ) Is a diagram showing the image pickup device 11,
(B) is a diagram showing the LCD monitor 25. Further, FIG. 7 shows an example in which the AF area is a spot AF, FIG. 8 shows an example in which the AF area is a horizontally long AF, and FIG. 9 shows the AF area as an area A.
It is the figure which showed the example set to F.

When the AF area / photometric area is displayed, it is then determined whether or not a release button (not shown) is half-pressed (1RSW ON) (step S6). When the release button is pressed halfway, the AF phase difference calculation is performed and the defocus amount (L-L _{0 in} FIG. 2) is detected (step S7). This is because the outputs of the range-finding light-receiving element rows 11a and 11b on the image sensor 11 are amplified by the preamplifier 12,
It is executed by the phase difference calculation circuit 13. At this time, the AF area designating circuit 14 instructs which part of the light receiving element array is to be used.

How much the lens control circuit 15 drives the lens is determined according to the obtained defocus amount and the output of the zoom encoder 18 (steps S8, S).
9). As a result, the taking lens is driven to a predetermined position while observing the output of the lens position encoder 18 (step S10). Then, after the lens is driven, the defocus amount is detected again, and when the defocus amount becomes equal to or less than the predetermined amount, the focus display is performed (step S11).

Next, exposure calculation is performed (step S1).
2). The average value of the output from each element is calculated by the brightness calculation circuit 29 only for the signal of the area designated by the photometric area designation circuit 30 among the luminance signal outputs of the monitor light-receiving element array. With respect to this output, the AE calculation circuit 31 determines the aperture value (Av) and the shutter speed (Tv) based on the program diagram (step S13).

Here, the release button is pressed (2R
SW is turned on) (step S14), the aperture control circuit 33 performs aperture control based on the determined Av value (step S15), and the shutter control circuit 35 releases the shutter 5
Are driven (step S16). In synchronization with this shutter drive signal, the image signal is digitized by the A / D conversion circuit 26, and the same image as the subject image exposed on the film is recorded in the memory 27 (step S17).

When the photographing is completed, the film 6 is wound up one frame (step S18), and necessary information is recorded on the magnetic recording layer (step S19). FIG. 10 is a diagram showing the principle of calculation regarding the phase difference AF.

The light flux from the subject image shown in FIG. 2 is incident on the range-finding light receiving element rows 11a and 11b on the image pickup element shown in FIG. In order to obtain the distance between the object images on the light receiving element array, the output of the element array 11a is shifted by one pixel of the light receiving element, and the expression for obtaining the sum of absolute values of the differences between the pixels at that time is expressed as follows:

[0034]

[Equation 1] And the output of the light-receiving element array 11a is shifted by j when ΔV _j has the smallest value.
It can be seen that it matches b (j = j ₀ ).

Therefore, assuming that the pitch of each pixel in the light receiving element array is P, x-S = Pxj ₀ (4) L = Sf / (x-S) = Sxf / (Pxj ₀ ) By obtaining (5), the distance from the principal points of the distance measuring lenses 10a and 10b to the image forming point can be obtained. L>
If L _0, it is in the front pin state, and if L <L ₀ , it is in the rear pin state.

FIG. 11 is a flow chart for explaining the operation for obtaining and focusing L according to the first principle. First, the AF area designating circuit 14 designates the light receiving element array to be used (step S21) (FIG. 10).
(1) to (n) in (a)). Next, the outputs of these light receiving elements (see FIG. 10B) are output by serial transfer (step S22), A / D converted (step S23), and then stored (step S24).

When the transfer is completed (step S25), the operation of the equation (3) is performed. That is, the address of the light receiving element and the extension amount of the photographing lens are initialized (steps S26 to S28). Then, based on the above (3), calculation is performed up to the n-th in the i direction of the light receiving element (steps S29 to S31), and the value is set to ΔV _j (step S32). Similarly, the nth calculation is performed in the j direction (steps S33 and S34).

Then, the most ΔV _j among the calculated values is obtained.
The shift amount j ₀ when becomes smaller (steps S35 to S40). Thus, when j ₀ as shown in FIG. 10C is obtained, L is obtained according to the above equation (5), and L ₀ is further subtracted to divide the obtained value by β ² (step S41).

[0039]

[Equation 2] Here, β ² represents the vertical magnification determined by the focal length at that time.

That is, when the first group zoom lens 1 which is the force adjusting group is moved by 1 mm, the image on the surface of the film 6 moves by β ² mm in the optical axis direction. Here, when Y is smaller than the predetermined value Δ (step S42), the first lens unit zoom lens 1 is not moved because the surface of the film 6 is substantially in focus.

If the expression (6) has a positive sign (step S43), it means that the motor is not shown, and the motor (not shown) is rotated in the reverse direction to move the first group zoom lens 1 by Y (step S43). Step S44). On the other hand, if the expression (6) has a negative sign, it means that the motor is in the rear pin state, so that the motor is rotated in the normal direction and only Y is fed (step S45).

As shown in FIG. 7, in the case of spot AF, only one AF operation is required, but as shown in FIG. 8 and FIG. The operation is repeated for the number of distance measuring points, the average of the plurality of distance measuring results is averaged, or the data in the state of the rearmost focus (the object distance is closest) is adopted.

FIG. 12 shows a known interline transfer system showing the manner of transfer of the monitor light-receiving element array 11 ₁ and the distance-measuring light-receiving element array 11 a and 11 b on the image pickup device 11.

In FIG. 12, a vertical transfer shift register 44 is arranged beside each light receiving element 43, and a horizontal analog shift register 45 is arranged at the bottom thereof. The output of each light receiving element 43 is simultaneously transferred to the vertical transfer shift register 44 after a predetermined integration time has passed, and vertical transfer and horizontal transfer are combined by a transfer pulse and output from the output end 46. This output terminal 46 is
Monitor light-receiving element array 11 ₁ and distance-measuring light-receiving element array 11 a,
11b are provided separately.

FIG. 13 shows a second embodiment of the present invention, L
FIG. 7 is a diagram showing a relationship between a state of superimpose display on the CD monitor 25 and a distance measuring light-receiving element array to be used. In the above-described first embodiment, since the distance measuring lenses 10a and 10b are arranged in the horizontal direction, even when performing multi-distance measurement, as shown in FIGS. 8 and 9, scanning of the light receiving element array is performed. The direction was always horizontal. Therefore, for example, a vertically striped subject can measure distances, but a horizontally striped subject is not good.

In the second embodiment, the distance measuring lens 10 is used.
c and 10d and the light receiving element rows 11c and 11d also in the vertical direction.
By individually arranging and scanning also in the vertical direction, even when the distance cannot be measured successfully in the horizontal light receiving element array, the vertical light receiving element array is used to cover the distance.

The detailed description of the operation of the second embodiment is the same as that of the first embodiment described above, and will not be repeated here. FIG. 14 shows a third embodiment of the present invention, and is a ray diagram when the photographic optical system is in focus.

In the above-described first embodiment, the distance measuring light receiving element rows 11a and 11b are arranged on both sides of the monitor light receiving element row 11 _1. However, in the third embodiment, the distance measuring light receiving elements are arranged. Both rows 11a and 11b are the light receiving element row 1 for monitoring
By arranging in this way on one side of 1 ₁ , the field lens 7 is arranged near the image forming point in the first embodiment, and the image forming lens 9 is arranged once again on the image sensor 11. Although the optical path length to the image pickup device 11 after re-imaging is required to be long, it can be shortened in the third embodiment.

That is, the light flux passing through the taking lens 1 is reflected by the half mirror 4 in a substantially upward direction. After that, by inserting the reduction optical system 47, the principal point moves further toward the image pickup device 11 side with respect to the position of the principal point with respect to the film surface. Therefore, the monitor light-receiving element array 1 of the image sensor 11
Yet the film plane is conjugate to 1 ₁ position, the screen size is smaller than the film surface size.

Behind the reduction optical system 47, another half mirror 48 and a mirror 49 are arranged. Due to these mirrors, a part of the light flux is received by the light receiving element arrays 11a, 1a for distance measurement.
Similar to the above-described first embodiment guided to 1b, the distance can be measured by obtaining the inter-image distance x of the light receiving element arrays 11a and 11b.

However, in the first embodiment, the distance measuring lens 1 is used.
When the distance L from 0a and 10b to the image forming surface is obtained, the driving amount of the taking lens 1 is (L−L ₀ ) / β ² , whereas in the third embodiment, the reduction optical system 47 is used. Since the image is reduced, if the magnification is β '(<1), the driving amount of the taking lens 1 is (L-L ₀ ) / (β ² ×
β ').

FIGS. 15 (a), 15 (b) and 15 (c) show the best focus state in the third embodiment, respectively.
It shows a state of the front pinned state and the rear pinned state. However, in the figure, the half mirror 4 and the reduction optical system 47 are omitted for simplification.

According to the above embodiment of the present invention, the following constitution can be obtained. (1) In a camera having a photographing optical system for forming a subject image on a film surface and an electronic viewfinder device for monitoring the subject image using a part of a photographing light flux of the photographing optical system, An image pickup means disposed in the electronic viewfinder device, which is provided with a light receiving element region for monitoring for monitoring the subject image and a plurality of distance measuring light receiving device regions for outputting a phase difference signal of the subject image, An optical system for monitoring that splits a part of the photographing light flux into the monitor light-receiving element region, and a measuring optical system that splits a part of the shooting light flux into the plurality of distance-measuring light-receiving element regions. An optical system for distance, a driving means for driving the photographing optical system to a predetermined position, and the object image can be monitored based on the output from the light receiving element region for monitoring, and the light receiving element for distance measurement is also provided. From the area Based on the phase difference signal camera, characterized by a control means for controlling said drive means.

(2) The plurality of distance measuring light receiving element regions are
It is provided on both sides of the light receiving element area for the monitor,
The camera according to (1) above, wherein the distance measuring optical system is provided so as to divide a part of the photographing light flux into distance measuring light receiving element regions provided on both sides thereof.

(3) The plurality of distance measuring light receiving element regions are
The distance measuring optical system is arranged around the monitor light receiving element region at approximately 90 ° intervals, and the distance measuring optical system places a part of the photographing light flux in the distance measuring light receiving element regions. The camera according to (1) above, which is divided.

(4) A camera having a photographing optical system for forming a subject image on a film surface and an electronic viewfinder device for monitoring the subject image by using a part of the photographing light flux of the photographing optical system. A monitor light receiving element area for monitoring the subject image and a phase difference signal of the subject image provided on both sides of the monitor light receiving element area, which is arranged in the electronic viewfinder device. An image pickup device provided with a distance light receiving element region, a field lens provided at a position conjugate with a position where the above-mentioned photographing light beam forms an image on a film, and a part of the light beam condensed by this field lens is divided. Then, the monitor optical system for entering the light into the monitor light-receiving element region and a part of the light beam condensed by the field lens are divided, and the two distance-measuring light-receiving element regions are divided. The distance measuring optical system for making the light incident on the optical system, the driving means for driving the photographing optical system to a predetermined position, and the subject image being monitorable based on the output from the monitor light receiving element area, and A control means for controlling the drive means on the basis of a phase difference signal from a light receiving element region for distance, the camera.

(5) A camera having a photographing optical system for forming a subject image on a film surface and an electronic viewfinder device for monitoring the subject image by using a part of a photographing light flux of the photographing optical system. And an image pickup means disposed in the electronic viewfinder device, which is provided with a light-receiving element region for monitoring for monitoring the subject image and a plurality of light-receiving element regions for distance measurement for measuring the distance to the subject. , A splitting optical system for splitting a part of the photographing luminous flux into light receiving element areas for monitor and distance measurement, distance measurement area selection means for selecting a distance measurement area of a subject image displayed on the monitor screen, and this measurement Drive amount calculating means for calculating the drive amount of the photographing optical system based on the output of the distance measuring light receiving element of the distance measuring light receiving element corresponding to the area selected by the distance area selecting means, and the drive amount calculating means Out of Based on the camera, it characterized by comprising driving means for driving the photographing optical system to a predetermined position.

(6) In a camera having a photographing optical system for forming a subject image on a film surface, and an electronic viewfinder device for monitoring the subject image by using a part of the photographing light flux of the photographing optical system. An image pickup means is provided in the electronic viewfinder device, and is provided with a monitor light-receiving element region for monitoring the subject image and a plurality of distance-measuring light-receiving element regions for measuring a distance to the subject, A monitor optical system for forming an image of a part of the photographing light beam on the monitor light receiving element region and a part of the light beam of the monitor optical system are divided, and the divided light is divided into the plurality of distance measuring light receiving element regions. Based on the output of the distance measuring optical system for forming an image and the distance measuring light receiving element area, the driving amount calculating means for calculating the driving amount of the photographing optical system, and the output of the driving amount calculating means. , The above shooting optical system Camera, characterized by comprising driving means for driving the position.

(7) The photographing optical system includes a semi-transmissive mirror which divides the light-receiving element area for monitoring and a light-receiving element area for distance measurement, and a light beam split by the semi-transmissive mirror on the light-receiving element for monitoring. A split mirror arranged at a position where an image is formed on the optical path side of the distance measuring light receiving element region side rather than a position conjugate with the subject image, and the divided light flux is formed on the plurality of distance measuring light receiving elements. The camera according to (6) above, comprising:

[0060]

As described above, according to the present invention, in a camera having an electronic viewfinder device, phase difference AF can be realized by improving the image pickup device for the finder, and a photoelectric conversion element array dedicated for AF can be provided. It is possible to easily realize high-speed and wide-range AF without needing to increase the size of the apparatus without needing it.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of a camera according to the present invention.

FIG. 2 is a diagram showing the principle of phase difference AF.

FIG. 3 is a diagram showing a mechanical layout of a photographing optical system.

FIG. 4 is a ray diagram when the photographing optical system is in focus.

5 is a flowchart illustrating an operation of the distance measuring device in FIG.

FIG. 6 is a diagram showing details of the image sensor of FIG.

FIG. 7 shows the relationship between the superimposing display on the LCD monitor 25 and the range-finding light-receiving element array when the AF frame display is changed. An example in which the AF area is spot AF is shown. It is the figure shown.

FIG. 8 shows the relationship between the superimposing display on the LCD monitor 25 and the range-finding light-receiving element array used when the AF frame display is changed. It is the figure shown.

FIG. 9 shows the relationship between the superimposing display on the LCD monitor 25 and the range-finding light-receiving element array when the AF frame display is changed. An example in which the AF area is an area AF is shown. It is the figure shown.

FIG. 10 is a diagram showing a principle of calculation regarding phase difference AF.

FIG. 11 is a flowchart illustrating an operation for obtaining L and focusing in accordance with the principle of calculation related to the phase difference AF.

FIG. 12: Monitor light-receiving element array 11 ₁ on the image sensor 11
FIG. 6 is a diagram showing a known interline transfer method showing a state of transfer of a light receiving element array for distance measurement 11a, 11b.

FIG. 13 shows an LCD monitor 2 according to a second embodiment of the present invention.
6 is a diagram showing the relationship between the state of superimpose display on FIG. 5 and the range-finding light-receiving element array to be used. FIG.

FIG. 14 shows a third embodiment of the present invention and is a ray diagram at the time of focusing in the photographing optical system.

15 (a), (b) and (c) are respectively the third
FIG. 6 is a diagram showing a state of a best focus state, a front focus state, and a rear focus state in the embodiment of FIG.

[Explanation of symbols]

1 ... 1st group zoom lens (photographing lens), 2 ... 2nd group zoom lens, 3 ... diaphragm, 4 ... half mirror, 5 ... shutter, 6 ... film, 7 ... field lens, 8 ... mirror, 9 ... image sensor Imaging lens, 10a, 10b ... Distance measuring lens, 11 ... Imaging element (light receiving element), 12, 19 ...
Preamplifier, 13 ... Phase difference calculation circuit, 14 ... AF area designation circuit, 15 ... Lens control circuit, 17 ... Zoom control circuit, 18 ... Zoom encoder, 20 ... Luminance signal processing circuit, 21 ... Color signal processing circuit, 22 ... FM Modulation circuit, 23
... signal synthesis circuit, 24 ... monitor drive circuit, 25 ... LCD
Monitor, 26 ... A / D conversion circuit, 27 ... Solid-state memory, 2
8 ... D / A conversion circuit, 29 ... Luminance calculation circuit, 30 ... Photometric area designation circuit, 31 ... AE calculation circuit, 32 ... Film sensitivity reading circuit, 33 ... Aperture control circuit, 35 ... Shutter control circuit, 36 ... Film supply Sending circuit, 37 ... Magnetic recording circuit,
38 ... Control circuit, 39 ... Release input section, 40 ... Zoom input section, 41 ... AF area input section, 42 ... Photometric area input section.

Claims (3)

[Claims] 1. A camera having a photographing optical system for forming a subject image on a film surface and an electronic viewfinder device for monitoring the subject image by using a part of a photographing light flux of the photographing optical system. An image pickup means disposed in the electronic viewfinder device, the image pickup means having a light-receiving element area for monitoring for monitoring the subject image and a light-receiving element area for distance measurement for measuring a distance of the subject; A division optical system that divides a part of the light flux into light-receiving element areas for monitoring and distance measurement, and a drive that drives the photographing optical system to a predetermined position based on the output from the light-receiving element area for distance measurement. And a camera. 2. A light-receiving element area for distance measurement is provided at least two around the light-receiving element area for monitoring, and the split optical system forms a subject image in the light-receiving element area for monitoring. 2. The camera according to claim 1, comprising a monitor optical system for forming an image and a distance measuring optical system provided corresponding to each of the at least two distance measuring light receiving element regions. 3. A camera having a photographing optical system for forming a subject image on a film surface and an electronic viewfinder device for monitoring the subject image by using a part of a photographing light flux of the photographing optical system. An image pickup means disposed in the electronic viewfinder device, which is provided with a light receiving element region for monitoring for monitoring the subject image and a plurality of distance measuring light receiving device regions for outputting a phase difference signal of the subject image. An optical system for monitoring which splits a part of the photographing light flux into the monitor light receiving element area, and a portion of the photographing light flux splits into the plurality of distance measuring light receiving element areas. Based on the optical system for distance measurement and the phase difference signal from the light receiving element area for distance measurement,
A camera comprising: a calculating unit that calculates a defocus amount; and a driving unit that drives the photographing optical system to a predetermined position based on the output of the calculating unit.