JP3288950B2 - Electro-developing camera and its focus detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera using a recording medium for electronically developing a subject image obtained by a photographing optical system, and more particularly to an apparatus for performing automatic focus detection in the camera.

[0002]

2. Description of the Related Art Hitherto, for example, Japanese Patent Application Laid-Open No. Hei 5-2280 has proposed a photographic material in which a recording medium itself is directly electronically developed and a developed visible image can be obtained immediately. In this specification, such a recording medium that is electronically developed is referred to as an electro-developing recording medium, and a camera using this recording medium is referred to as an electro-developing camera.

[0003]

In an electro-developing camera, it is necessary to focus a subject image obtained by a photographic optical system on a recording medium. For this purpose, if an optical sensor is specially provided, There is a problem that the configuration is complicated and large.

It is an object of the present invention to provide an electro-developing camera and a focus detecting device capable of performing automatic focus detection with a simple and compact structure.

[0005]

SUMMARY OF THE INVENTION A focus detection apparatus for an electro-developing camera according to the present invention includes an optical sensor for reading an image electronically developed by an electro-developing recording medium, and an auto-focus sensor for automatic focus detection. It is characterized in that it is used.

A focus detection device and means for positioning the optical sensor at different positions during the image reading operation and the automatic focus detection may be provided.

The optical sensor is, for example, a line sensor.
It is also preferable to provide a means for rotating the optical sensor around its longitudinal axis. Means for fixing the optical sensor at a predetermined rotation angle position during the image reading operation and the automatic focus detection may be provided.

An electro-developing type camera according to the present invention is used for an electro-developing recording medium for electronically developing an image, and for reading out an image and automatically detecting a focus of the photographing optical system on the electro-developing type recording medium. And an optical sensor capable of performing the following.

This electro-developing camera comprises means for positioning the optical sensor at different positions during an image reading operation and at the time of automatic focus detection, a focus detecting optical system, and a reading optical system. Is also good. This positioning means is arranged such that, at the time of focus detection, the expected focal plane optically equivalent to the light receiving surface of the electro-developing recording medium and the light receiving surface of the optical sensor are arranged at the conjugate point of the focus detection optical system. It is preferable to position the optical sensor and, during the reading operation, position the optical sensor such that the image forming surface on the electro-developing recording medium and the light receiving surface of the optical sensor are arranged at the conjugate point of the reading optical system. .

In this electronically developed camera, the optical sensor is, for example, a line sensor. Preferably, means are provided for rotating the optical sensor about its longitudinal axis. Means for fixing the optical sensor at a predetermined rotation angle position during the image reading operation and the automatic focus detection may be provided.

The electro-developing camera may include a light source for illuminating the electro-developing recording medium to read an image. The light source may be, for example, a side of the electro-developing recording medium opposite to a photographic optical system. It is arranged in.

An electro-developing recording medium is composed of an electrostatic information recording medium in which electric charges corresponding to an image are generated, and a charge holding medium capable of generating a visible image in accordance with the electric charges and holding the visible image. May be provided. The charge holding medium is, for example, a liquid crystal display device using a memory type liquid crystal.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an external view of an electro-developing camera to which an embodiment of the present invention is applied. Although the shape of the camera body 11 in FIG. 1 is different from FIGS. 3 and 5, FIG. 1 shows the arrangement relationship of each member provided on the outer surface of the camera body 11, and the shape of the camera body 11 is it's not correct.

When the camera body 11 is viewed from the front, a photographing optical system 12 having a photographing lens and the like is provided substantially at the center of the front surface, and a strobe 13 is provided at the upper right of the photographing optical system 12. A release button 14 is provided on the side opposite to the strobe 13. The finder 15 is provided at the center of the upper surface of the camera body 11 and extends from the front surface to the rear surface of the camera body 11. A scanning switch 16 is provided on a side of the finder 15 and on an upper surface of the camera body 11. An output terminal 17 is provided at a lower portion of a side surface of the camera body 11 to output an image signal obtained by the camera to an external recording device or the like.

FIG. 2 is a block diagram of the electro-developing camera. The system control circuit 20 is a microcomputer, and controls the entire electro-developing camera.

The photographing optical system 12 includes a plurality of lens groups 12b.
In addition, an aperture 12a is provided. An electro-developing recording medium 30 is provided behind the photographing optical system 12.
A quick return mirror 21 is provided between the imaging optical system 12 and the electro-developing recording medium 30, and a shutter 22 is provided between the quick return mirror 21 and the electro-developing recording medium 30. Above the quick return mirror 21, a focus plate 23a of the finder optical system 23 is provided.

The position of the lens group 12b is adjusted in the optical axis direction by a lens driving circuit 19, and an automatic focus adjustment or a zooming operation is performed. At the time of automatic focus adjustment, the lens drive circuit 19 is controlled based on a control signal output from the system control circuit 20, and a command signal corresponding to the amount of movement is output to the lens group 12b.

Aperture 12a, quick return mirror 21
And the shutter 22 are provided in the iris drive circuit 2 respectively.
4. Driven by a mirror drive circuit 25 and a shutter drive circuit 26, and these circuits 24, 25 and 26 are controlled by an exposure control circuit 27. The exposure control circuit 27 operates according to a command signal output from the system control circuit 20. That is, at the time of exposure control, the photometric sensor 2
The aperture of the aperture 12a is adjusted by the iris drive circuit 24 under the control of the exposure control circuit 27 based on the output signal from the iris 8. The quick return mirror 21 is normally set at a down position (in an inclined state shown by a solid line), which is a position for observing a subject, and guides light passing through the imaging optical system 12 to the finder optical system 23. During operation, under the control of the exposure control circuit 27, the mirror is rotated upward by the mirror drive circuit 25 and is set to the up position (horizontal state indicated by a broken line). The shutter 22 is normally closed, but is released for a predetermined time by the shutter drive circuit 26 under the control of the exposure control circuit 27 during the photographing operation, so that the light passing through the photographing optical system 12 The light is irradiated on the light receiving surface.

A voltage (ie, a recording medium activation signal) is applied to the electro-developing recording medium 30 under the control of the recording medium drive circuit 41, and the electro-developing recording medium 30 is exposed during this voltage application. Has a photographing optical system 12
Is developed as a visible image. The recording medium drive circuit 41 operates according to a command signal output from the system control circuit 20.

A support frame 50 is provided in the vicinity of the electro-developing recording medium 30. The support frame 50 includes a light source 42, a scanner optical system (reading optical system) 43, a line sensor (optical sensor) 44, and a mirror 51. Each is supported. As the line sensor 44, for example, a CCD one-dimensional sensor having 2000 pixels can be used. The light source 42 is, for example, LE
D (light emitting element), which is disposed on the side opposite to the imaging optical system 12 of the electro-developing recording medium 30. The light source 42 illuminates the electro-developing recording medium 30 when reading an image recorded on the electro-developing recording medium 30.
A collimator lens 55 is provided in front of 2 as shown in FIGS. That is, the light output from the light source 42 is applied to the electro-developing recording medium 30 as parallel light having a width covering at least the dimension in the length direction of the line sensor 44. The scanner optical system 43, the line sensor 44, and the mirror 51
0 is disposed on the side of the photographing optical system 12, and the mirror 51 is
2. The scanner optical system 43 is provided between the mirror 51 and the line sensor 44.

The electro-developing recording medium 30 can be moved in a direction perpendicular to the optical axis of the photographing optical system 12 by a recording medium moving mechanism 52, and can pass between the light source 42 and the mirror 51. In this moving operation, the electro-developing recording medium 3
The image recorded on 0 is illuminated by a light source 42,
An image is formed on the light receiving surface of the line sensor 44 by the action of the mirror 51 and the scanner optical system 43. The on / off control of the light source 42 is performed by an illumination light source driving circuit 45, and the control such as the reading operation of the image signal generated in the line sensor 44 is performed by a line sensor driving circuit 47. Illumination light source drive circuit 45, line sensor drive circuit 47, and recording medium moving mechanism 5
2 is controlled by the system control circuit 20.

The image signal read from the line sensor 44 is amplified by an amplifier 61 and converted into a digital signal by an A / D converter 62. The digital image signal is subjected to processing such as shading correction and gamma correction in the image processing circuit 63 under the control of the system control circuit 20, and then temporarily stored in the memory 64. The memory 64 is a memory having a storage capacity for one frame. The memory 64 is an E ² PROM
The E ² PROM stores correction values such as shading correction.

The image signal read from the memory 64 is
The image data is input from the image processing circuit 63 to the interface circuit 65, subjected to predetermined processing such as format conversion, and can be output to an external computer (not shown) via the output terminal 17. The image signal output from the image processing circuit 63 can be recorded in a recording medium such as an IC memory card in the image recording device 67. The interface circuit 65 and the image recording device 67 operate according to a command signal from the system control circuit 20.

An operation unit 70 including a release button 14, a scanning switch 16, and the like is connected to the system control circuit 20. In accordance with the operation of the release button 14 and the scanning switch 16, a photographing operation (recording operation), an image signal reading operation, and the like are performed. The system control circuit 20 includes
A display element 68 for displaying various setting states and the like of the electro-developing camera and a strobe drive circuit 69 for controlling light emission of the strobe 13 are connected.

In this embodiment, the line sensor 44 can be used for automatic focusing. For automatic focus adjustment by the line sensor 44, AF optical systems 53a and 53b and a mirror 54 are provided near the support frame 50,
On the back of the quick return mirror 21, there is a sub mirror 2
1a is provided, and the AF optical systems 53a and 53b and the mirror 54 are located below the sub-mirror 21a. The line sensor 44 is rotatable around its longitudinal axis. Quick return mirror 21 for automatic focus adjustment
Is in the down position, and the light receiving surface of the line sensor 44 is directed to the mirror 54 side. Therefore, the light that has passed through the imaging optical system 12 is reflected by the sub-mirror 21a, collected by the AF optical systems 53a and 53b, and guided to the light receiving surface of the line sensor 44 via the mirror 54.

FIGS. 3 and 4 show the state of each member during the photographing operation, and FIGS. 5 and 6 show the reading operation. 3 and 5, the photographing optical system 1
2 (see FIGS. 1 and 2) is omitted.

The electro-developing recording medium 30 is mounted on a mounting frame 71, and the mounting frame 71 is supported by a pair of support shafts 72 so as to be able to move up and down. An engaging member 73 is fixed to a side surface of the mounting frame 71, and the engaging member 73 is engaged with a screw of a screw shaft 74 extending parallel to the support shaft 72.
A drive gear 75 is provided at the lower end of the screw shaft 74, and a recording medium drive motor 76 is provided near the lower end of the screw shaft 74. The drive gear 75 is a recording medium drive motor 76
Is connected via a reduction gear 78 to an output gear 77 fixed to the output shaft.

Therefore, when the recording medium driving motor 76 rotates, the screw shaft 74 rotates via the output gear 77, the reduction gear 78, and the driving gear 75, and the engaging member 73, ie, the mounting frame 71 and the electro-developing recording medium 30 Goes up and down.
That is, the recording medium moving mechanism 52 is configured by the recording medium driving motor 76, the output gear 77, the reduction gear 78, the driving gear 75, and the screw shaft 74.

FIG. 7 is a diagram showing a configuration for rotating the line sensor 44 about a longitudinal axis. As shown in this figure, the line sensor 44 is attached to the mounting surface 81 of the support member 81.
The support member 81 is rotatably supported around a longitudinal axis A passing through the light receiving surface of the line sensor 44.
Note that the support member 81 is positioned such that the longitudinal axis A of the line sensor 44 is a position optically equivalent to the light receiving surface of the electro-developing recording medium 30 and a conjugate point of the scanner optical system 43. , Is located. A gear 82 is fixed to the back surface of the flange 81b of the support member 81, and the gear 82 is screwed to a gear 84 provided on an output shaft of a sensor drive motor 83. The sensor drive motor 83 is a stepping motor, which is controlled by the system control circuit 20, whereby the line sensor 44 rotates around its longitudinal axis.

A light-shielding plate 85 is provided on the outer peripheral surface of the flange 81b of the support member 81, and a photo interrupter 86 is provided on a portion facing the outer peripheral surface of the flange 81b. The light blocking plate 85 is located in a gap formed in the photo interrupter 86 according to the rotation angle position of the support member 81. When the light receiving surface of the line sensor 44 faces the mirror 51,
When facing the two sides (during the reading operation), the light shielding plate 85 is arranged so as to be located inside the photo interrupter 86. When the light shielding plate 85 is set at this position, a signal indicating that the line sensor 44 faces the light source 42 is output from the photo interrupter 86 and input to the system control circuit 20. When the motor is driven from this position by a predetermined step drive amount set in advance, the line sensor 44 rotates 90 degrees to face the mirror 54, and a position optically equivalent to the light receiving surface of the electro-developing recording medium. And a focus detection operation is enabled.

As shown in FIGS. 3 and 4, during the photographing operation, the electro-developing recording medium 30 is fixed at the raised position. The quick return mirror 21 is in the down position,
The line sensor 44 is fixed at a position where its light receiving surface faces the mirror 54. This line sensor 44
Is fixed based on the state in which the light shielding plate 85 is located inside the photo interrupter 86.
The number is determined by counting the number of pulses output from 3. In a state where the line sensor 44 faces the mirror 54, the light that has passed through the imaging optical system 12 is reflected by the sub-mirror 21 a, collected by the AF optical systems 53 a and 53 b, and
Are guided to the light receiving surface. As a result, a part of the subject image is formed on the line sensor 44, and automatic focusing is performed as described below.

FIG. 8 shows the structure of the focus detection unit 90. The focus detection unit 90 has an infrared cut filter 91, a mirror 54, a condenser lens 53a, and a separator lens unit 53b, and the separator lens unit 53b is provided adjacent to the line sensor 44 in the longitudinal direction. It comprises two separator lenses 53c and an aperture mask 53d that supports these lenses.

The light beam reflected by the sub-mirror 21a is projected to a focal plane immediately before entering the focus detection unit 90 (a position optically equivalent to the light receiving surface of the electro-developing recording medium).
After forming an image once, the infrared cut filter 91,
The light is incident on the condenser lens 53a, the mirror 54, and the separator lens unit 53b.
Is re-imaged on two areas on the line sensor 44. That is, the luminous flux that has passed through each of the two divided regions on the plane including the optical axis of the imaging optical system 12 is re-imaged on the two regions on the line sensor 44 by the separator lens unit 53b, and is used for focus detection. Is formed. The focus detection line sensor 44 includes a sensor drive motor 83, a light shielding plate 85, and a photo interrupter 86.
By the operation of the positioning means having the above-mentioned arrangement, the predetermined focal plane and the light receiving surface of the line sensor 44 are positioned so as to be arranged at the conjugate point of the optical system provided in the focus detection unit 90.

Since the line sensor 44 rotates and moves, it is necessary to secure a certain distance between the separator lens unit 53b and the line sensor 44. Therefore, compared with a focus detection unit used in a known autofocus camera, The separator lens unit 90 is designed to have a longer focal length and a slightly larger image magnification.

When performing the automatic focus adjustment, the system control circuit 20 correlates two subject images on the line sensor 44 based on the video signal read from the line sensor 44 to determine the focus by the photographing optical system 12 and the schedule. The shift amount (defocus amount) from the focal plane (corresponding to the light receiving surface of the electro-developing recording medium) and its direction are calculated. In the lens driving circuit 19, the lens driving amount and the driving direction are obtained based on the defocus amount and the defocus direction, the focusing lens of the photographing optical system 12 is driven, and the focusing operation is performed.

As shown in FIGS. 5 and 6, at the start of the reading operation, the electro-developing recording medium 30 is set at the lowered position. The quick return mirror 21 is at the down position, and the line sensor 44 is positioned such that its light receiving surface faces the mirror 51, that is, toward the light source 42, and the image on the electro-developing recording medium 30 is transmitted through the scanner optical system 43. The light shielding plate 85 is located in the photo interrupter 86. The illumination light output from the light source 42 passes through the electro-developing recording medium 30 via the collimating lens 55, and is guided to the line sensor 44.
Therefore, while the electro-developing recording medium 30 is gradually rising, the image recorded on the electro-developing recording medium 30 is read by the line sensor 44. During the reading operation, the line sensor 44 moves between the image forming surface on the electro-developing recording medium 30 and the light receiving surface of the line sensor 44 by the action of positioning means including a sensor drive motor 83, a light shielding plate 85, a photo interrupter 86, and the like. It is positioned so as to be arranged at the conjugate point of the scanner optical system 43.

FIG. 9 is a diagram showing the structure of the electro-developing recording medium 30, which is basically the same as that disclosed in Japanese Patent Application Laid-Open No. 5-2280. That is, the electro-developing recording medium 30 includes the electrostatic information recording medium 31 and the charge holding medium 32
And the electrostatic information recording medium 31 and the charge holding medium 3
2 is supplied with a voltage by a power supply 33. The electrostatic information recording medium 31 includes a substrate 34, an electrode layer 35, and an inorganic oxide layer 36.
And a photoconductive layer 37. The photoconductive layer 37 is formed by polymerizing the charge generation layer 37a and the charge transport layer 37b. The charge holding medium 32 is configured by sealing a liquid crystal 40 between a liquid crystal support 38 and a liquid crystal electrode layer 39. The charge transport layer 37b of the electrostatic information recording medium 31 and the liquid crystal support 38 of the charge holding medium 32 face each other with a small gap.

The power supply 33 is controlled on and off by the recording medium drive circuit 41. When the power supply 33 is in the on state, the electrode layer 3 is turned on.
5 and the liquid crystal electrode layer 39, that is, the electrostatic information recording medium 3
1 and a voltage are applied to the charge holding medium 32. When the electrostatic information recording medium 31 is exposed in this voltage applied state, charges corresponding to an image are generated on the electrostatic information recording medium 31. Since the intensity of the electric field acting on the liquid crystal 40 changes according to the charge, the image is displayed on the liquid crystal 40 as a visible image, and the subject image is developed. The charge holding medium 32 is, for example, a liquid crystal display element using a memory type liquid crystal in which smectic liquid crystal is sealed, and the developed visible image is held even when the electric field is removed. This liquid crystal display element can erase a developed visible image by heating it to a predetermined temperature using a laser beam. In that case, the same recording medium can be repeatedly used.

FIG. 10 is a timing chart showing an operation of recording an image on the electro-developing recording medium 30 and an operation of reading the image by the line sensor 44.

In the initial state, the electro-developing recording medium 3
0 is in the ascending position and on the optical axis of the photographing optical system 12,
The quick return mirror 21 is at the down position. Further, the light receiving surface of the line sensor 44 faces the position facing the mirror 54, that is, the imaging optical system 12 side. here,
When the photometry switch is turned on by half-pressing the release button 14 (reference S11), the drive power supply of the line sensor 44 is turned on (reference S12), and charge accumulation is performed in the line sensor 44 (reference S1).
3). When the predetermined accumulation time has elapsed, a signal corresponding to the accumulated charge is output from the line sensor 44 (reference S13),
The lens position of the photographing optical system 12 is adjusted according to this output signal, and an AF operation (automatic focus adjustment operation) is performed (reference S15).

When the release switch is turned on by fully pressing the release button 14 (reference S1).
6), an output signal from the photometric sensor 28, that is, a photometric value is detected, an exposure calculation is started based on the photometric value (reference S17), a recording medium activation signal is output (reference S18), and electronic development is performed. A voltage is applied to the mold recording medium 30. When the exposure calculation is completed, the opening of the aperture 12a changes from the fully opened state to a predetermined opening (reference S19), the quick return mirror 21 changes from the down state to the up state (reference S20), and the shutter 22 is opened. (Reference S21).

When the exposure period obtained by the exposure calculation elapses and the completion of the exposure is detected, the shutter 22 is closed (reference S22). With the completion of the closing operation of the shutter 22, the mirror 21 changes to the down state (reference S23), and the aperture 12a is opened to the fully open state (reference S24). The output of the recording medium activation signal is stopped (reference S25).

That is, the recording medium activation signal is output while the shutter 22 is open, and during this time, a predetermined voltage is applied to the electro-developing recording medium 30. By exposing in this state, the subject image is developed on the electro-developing recording medium 30 as a visible image. This visible image is retained even when the output of the recording medium activation signal is stopped.

Next, when the scanning switch 16 is pressed, scanning by the recording medium moving mechanism 50 starts, and the reading operation described below is executed.

When the scanning switch 16 is pressed and a scanner driving command signal is output (reference S
31), the shutter 22 is opened (reference S32), and the line sensor 44 is rotationally driven and directed toward the light source 42 (reference S33). Further, the light source 42 is turned on (reference S3).
4), the electro-developing recording medium 30 is illuminated. Then
The scanner system drive signal is output (reference S35), the recording medium drive motor 76 rotates forward, and the electro-developing recording medium 30
Starts decreasing (reference S36). Further, the line sensor driving power supply is turned on (reference S37).

When it is confirmed that the line sensor 44 has been set at the reading start position, the output of the scanner drive signal is stopped (reference S38), and the recording medium drive motor 76
Is stopped (reference S39). This stop operation is controlled by, for example, counting pulse signals for driving the recording medium drive motor 76 to rotate.

Exposure to the line sensor 44 is started, and charge accumulation is performed (reference S40). For example, when it is confirmed that the exposure of the line sensor 44 is completed by detecting that a predetermined time has elapsed, the reading of the line sensor 44 is started, and the output of the image signal for one horizontal scanning line is started. (Reference S41). Then, a scanner drive signal for rotating the recording medium drive motor 76 forward is output (reference S42), and the electro-developing recording medium 30 starts to lower further (reference S43). When it is confirmed that the line sensor 44 is set at the position of the next horizontal scanning line,
The output of the scanner drive signal is stopped (reference S44),
The recording medium drive motor 76 is stopped (reference S45).
Then, in the same manner as described above, an image signal for the next one horizontal scanning line is output.

When the read operation for all the horizontal scanning lines is completed in this way (reference S50), the line sensor 4
4 is switched to the off state (reference S51), and the light source 42 is set to the off state (reference S).
52). Further, the shutter 22 is closed (reference S5).
3) A scanner drive signal for reversing the recording medium scan drive motor 76 is output (reference S54), and the electro-developing recording medium 30 starts to rise (reference S55). Further, the line sensor 44 is rotated so that the light receiving surface faces the mirror 54, that is, the imaging optical system 12 side.

During the raising operation of the electro-developing recording medium 30,
When it is confirmed that the electro-developing recording medium 30 has returned to the initial position, the output of the scanner drive signal is stopped (reference S56), and the recording medium drive motor 76 is stopped (reference S57). The operation of detecting the initial position of the electro-developing recording medium 30 is performed, for example, based on a signal output when a part of the mounting frame 71 of the electro-developing recording medium 30 crosses a photo interrupter (not shown).

As described above, in the present embodiment, the line focus sensor 44 for reading out the image recorded on the electro-developing recording medium 30 is used to perform automatic focus adjustment of the photographing optical system 12. Therefore, it is not necessary to provide an optical sensor for automatic focus adjustment, and the configuration of the electro-developing camera can be simplified and reduced in size.

The line sensor 44 is not limited to a configuration for detecting an image signal for one horizontal scanning line.
It may have a configuration capable of detecting a horizontal scanning line.

[0052]

As described above, according to the present invention, automatic focusing can be performed with a simple and compact structure.

[Brief description of the drawings]

FIG. 1 is an external view of an electro-developing camera to which an embodiment of the present invention is applied.

FIG. 2 is a block diagram showing a circuit configuration of the electro-developing camera of FIG.

FIG. 3 is a cross-sectional view illustrating a state of each member in a camera body during a photographing operation.

FIG. 4 is a partial cross-sectional view showing an electro-developing recording medium and a recording medium moving mechanism during a photographing operation.

FIG. 5 is a cross-sectional view illustrating a state of each member in the camera body during a reading operation.

FIG. 6 is a partial cross-sectional view showing an electro-developing recording medium and a recording medium moving mechanism during a reading operation.

FIG. 7 is a perspective view showing a configuration for rotating a line sensor around a longitudinal axis.

FIG. 8 is a perspective view illustrating a configuration of a focus detection unit.

FIG. 9 is a diagram illustrating a configuration of an electro-developing recording medium.

FIG. 10 is a timing chart showing a photographing operation and an image reading operation.

[Explanation of symbols]

 Reference Signs List 30 electro-developing recording medium 42 light source 44 optical sensor

Claims (12)

(57) [Claims] 1. An electro-developing camera configured to read out an image electronically developed by an electro-developing recording medium by an optical sensor, wherein the optical sensor is used for automatic focus detection. A focus detection device for an electronic development camera. 2. A focus detection apparatus according to claim 1, further comprising means for positioning said optical sensor at different positions during an image reading operation and an automatic focus detection. apparatus. 3. The focus detection device for an electro-developing camera according to claim 1, wherein the optical sensor is a line sensor. 4. The focus detection device for an electro-developing camera according to claim 3, further comprising means for rotating the optical sensor around its longitudinal axis. 5. A reading optical system for reading the image, wherein a longitudinal axis of the optical sensor is at a position optically equivalent to a light receiving surface of the electro-developing recording medium, and The focus detection device for an electro-developing camera according to claim 4, wherein the focus detection device is set at a position that is a conjugate point. 6. The apparatus according to claim 4, wherein the positioning unit positions the optical sensor at different predetermined rotation angle positions during the image reading operation and the automatic focus detection. Focus detection device for electronically developed cameras. 7. An electro-developing recording medium for electronically developing an image, and an optical sensor that reads the image and that can be used for automatic focus detection of the photographing optical system on the electro-developing recording medium. An electro-developing camera, comprising: 8. An image pickup device comprising: means for positioning the optical sensors at different positions during an image reading operation and automatic focus detection; a focus detection optical system; and a reading optical system, wherein the positioning means comprises: At the time of focus detection, the optical system is configured such that a predetermined focal plane optically equivalent to a light receiving surface of the electro-developing recording medium and a light receiving surface of the optical sensor are arranged at a conjugate point of the focus detection optical system. A sensor is positioned, and in a reading operation, the optical sensor is positioned such that an image forming surface on the electro-developing recording medium and a light receiving surface of the optical sensor are arranged at a conjugate point of the reading optical system. The electro-developing camera according to claim 7, wherein: 9. An electro-developing camera according to claim 7, wherein said optical sensor is a line sensor. 10. An electro-developing camera according to claim 8, further comprising means for rotating said optical sensor around its longitudinal axis. 11. The apparatus according to claim 1, further comprising: means for fixing the optical sensor at a predetermined rotation angle position during the image reading operation and during the automatic focus detection.
0. The electro-developing camera according to 0. 12. A light source for illuminating the electro-developing recording medium for reading the image, wherein the light source is disposed on the opposite side of the electro-developing recording medium from the photographing optical system. The electro-developing camera according to claim 7, wherein