JPH09331475A - Camera back replacement camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a camera in which movement image pickup such as shift, rise and fall is attained and an optical axis between the image pickup device and a lens system is aligned automatically with high accuracy even when a relative position deviation takes place between a camera back and camera body. SOLUTION: A camera back 10 provided with an image pickup device 11 is provided with a mechanism to adjust the position of the image pickup device 11 vertically and horizontally. The position of the image pickup device 11 is adjusted vertically and horizontally with respect to the lens optical axis of the camera body 1 by using the position adjustment device 20 to move the image pickup device 11 vertically and horizontally so as to attain movement image pickup by rise, fall and shift. The movement mechanism is simplified and the small sized camera is realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera whose camera back is replaceable, and more particularly to a camera which is equipped with an image pickup device such as a CCD and can be replaced.

[0002]

2. Description of the Related Art In recent years, still cameras have been proposed which enable imaging using an imaging device such as a CCD in addition to the conventional imaging of a silver halide film. In order to enable electronic photography using this imaging device, in other words, digital photography, for example, the portion of the camera body that supports the film can be attached to and detached from the camera body as the camera back, and this camera back can be imaged. A method that enables digital photography by replacing the apparatus with a device is conceivable. As a camera of this type, in a certain type of single-lens reflex camera, the back cover can be attached to and detached from the camera body, and after removing the back cover, a camera back equipped with an imaging device is attached to the camera body, Something that has enabled shooting has already been proposed.

In such a camera back exchange type camera, as in the case of a normal camera back using film, so-called tilted shooting,
In particular, there are cases where it is required to perform tilting shooting with shift and rise / fall in which the imaging surface is moved in one direction or a direction orthogonal to the imaging surface. For this reason, conventionally, the portion connecting the camera back and the camera body is formed in a bellows shape, and the entire camera back is movable in a plane perpendicular to the optical axis of the camera body during tilted shooting. Is being done.

[0004]

However, if such a tilting mechanism is provided, there is a problem that the overall structure of the camera becomes large and heavy. In particular, a camera back that enables digital photography is advantageous in terms of downsizing and weight reduction because the internal structure can be simplified compared to a camera back that enables film photography. By providing the mechanism, the advantage is lost and the mobility of the camera during digital photography is impaired. Also, in tilt shooting with the entire camera back moved, it is difficult to electrify the tilt mechanism because the weight of the driven part increases, and if this is realized and used, the tilt mechanism will become even larger. The problem arises that

Further, in the camera of the camera back exchange type as described above, especially when the camera back having the image pickup device is mounted on the camera body, the center position on the image pickup surface of the image pickup device is mounted on the camera body. It is necessary to match the optical axis of the lens system. That is, in the image pickup apparatus, since the image signal is processed so that the center position of the image pickup apparatus becomes the center of the image pickup screen, if the center of the image pickup apparatus is displaced from the center position of the lens system, it is obtained. The image pickup screen will be distorted. Particularly, in the case where the tilting mechanism as described above is provided, the center position of the tilting mechanism is likely to vary. For this reason, in the past, various measures were taken in the coupling structure of the two in order to align the camera back with respect to the camera body. However, it is possible to perform highly accurate positioning due to manufacturing errors and assembly errors in these structures. It is not possible, and this structure is designed with high precision,
The problem with manufacturing is that the camera becomes expensive.

It is an object of the present invention to enable tilted photographing such as shift and rise / fall, and at the same time, even when a relative position shift occurs between the camera back and the camera body, the image pickup apparatus and the lens system are An object of the present invention is to provide a camera capable of highly accurately and automatically aligning the optical axis position of the.

[0007]

A camera of the present invention is provided with a position adjusting mechanism for moving a position of an image pickup device mounted on a camera back detachable from a camera body on an image pickup surface thereof. It is characterized by being With this position adjusting mechanism, the image pickup device can be moved on a plane perpendicular to the optical axis, and tilt-fall photography with rise / fall or shift can be performed. Further, in the present invention, a mechanism for moving the image pickup device in one direction on the surface of the photographing image forming surface, a mechanism for moving the image pickup device in the other direction on the surface of the photographing coupling surface in a direction orthogonal to the same, and a moving mechanism for them. Means for independently controlling the center position of the image sensor and the optical axis position of the camera body.

According to the present invention, the image pickup apparatus is provided with a means for detecting a movement position in one direction and a means for detecting a movement position in the other direction orthogonal to the one direction. The means for controlling these movement mechanisms are It is preferable that each moving mechanism is feedback-controlled based on the detection output of each detecting means. Further, the means for detecting the moving position is provided in the camera body, and is arranged at a position facing the optical axis of the camera body in one direction and a position facing the other direction orthogonal to the optical axis of the camera body. It is preferable that the position detecting body provided on the side is configured to detect when the position detecting body faces each position detecting means. Further, it is preferable that the image pickup surface of the CCD image pickup device is smaller than the size of the aperture for defining the image pickup area provided in the camera body.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an external view of a camera according to an embodiment of the present invention with a lens removed, and FIG. 2 is a conceptual perspective view of the camera with a camera back detached from a camera body to show a schematic configuration of a main part of the camera. FIG. In this embodiment, the present invention is applied to a so-called medium-sized single-lens reflex camera having a photographic film size of 6 × 6 or 6 × 7. It should be noted that the release button and other parts having little relation to the present invention are omitted from the drawing. Further, the up-down direction and the left-right direction hereinafter mean the X direction and the Y direction in FIG. 1, and therefore the optical axis is the Z axis direction. Camera body 1
The lens mount portion 3 to which the lens 2 is attachable / detachable is provided on the front surface thereof, and the prism 4 and the finder 5 are provided on the upper portion. Also, there is a quick return mirror 6 inside.
And its drive mechanism (not shown) are arranged, and an aperture 7 is opened behind this quick return mirror 6.
A focal plane shutter and a drive mechanism for the focal plane shutter, which are not shown, are provided to open and close the aperture 7. A camera back 10 is removably provided on the back surface of the camera body via a camera back attaching / detaching mechanism 8.

The camera back attaching / detaching mechanism 8 is, for example,
On the back side of the camera body, there are a plurality of hinge coupling recesses 81 on one side and a lock groove 8 having a lock piece 83 built in on the other side.
Two are provided. In addition, the camera back 1 facing this
A plurality of hinge-coupling protrusions 84 engaged with the hinge-coupling recess 81 are provided on one side of the front surface of 0, and a hook 85 to which a spring (not shown) is hooked is provided on the other side. When the camera back 10 is attached to the camera body 1, the hinge coupling concave portion 81 and the hinge coupling convex piece 84 on one side are coupled to each other, and then the hook 85 on the other side is locked in the lock groove 82. Then, the hook 85 is engaged with the lock piece 83 by a spring force, and the camera back 10 can be fixedly supported by the camera body 1 by this engaging force. Further, by operating the lock release lever 86, the engagement between the lock piece 83 and the hook 85 is released, and the camera back 10 can be removed from the camera body 1.

Further, in the camera body 1, rails 9 are fixedly extended on both sides of the aperture 7 on the back surface of the camera body 1. These rails 9 are made of a film used for film photographing using a silver salt film. It becomes a guide rail. Further, when viewed from the rear surface of the camera body 1, reflective photosensors 12 and 13 are provided at the center positions of the upper side and the left side of the aperture 7, respectively.
It serves as a sensor for detecting the horizontal position and the vertical position of the D imaging device 11 with respect to the aperture 7. Further, a contact 14 for electrically connecting to the camera back 10 is provided on a part of the back surface of the camera body 1.

The camera body 1 is usually provided with a camera back containing a silver salt film, but instead of this, as shown in FIG.
The camera back 10 in which the imaging device 11 is installed can be attached. A position adjusting mechanism 20 for adjusting the position of the CCD image pickup device 11 in the vertical and horizontal directions is provided in the camera back 10. As the position adjusting mechanism 20, a rise / fall guide 21 having a dovetail groove section is vertically provided in the camera back 10 in the vertical direction, and the rise / fall guide 21 is provided along the rise / fall guide 21.
The fall table 22 is supported so as to be vertically movable. Further, a shift guide 23 having a dovetail section is fixedly supported in the rise / fall table 22 in the horizontal direction, and the shift table 23 is mounted on the shift guide 23.
4 is movably supported in the horizontal direction. A CCD image pickup device 11 having an image pickup screen size slightly smaller than the vertical and horizontal sizes of the aperture 7 is fixedly supported on the front surface of the shift table 24.

Further, the rise / fall table 2
2, a nut 25 is integrally provided on one side portion thereof, and the nut 25 is screwed onto an upper and lower lead screw 26 extending vertically along one side portion of the rise / fall table 22. . The upper and lower lead screws 26 are
This step motor 2 is connected to the rotary shaft of a step motor 27 fixedly supported by the camera back 10.
When 7 is driven, it is possible to screw the nut 25 that is axially rotated and screwed into this, and to move the rise / fall table 22 integrated with the nut 25 in the vertical direction. Further, a nut 28 is integrally provided on the lower side portion of the shift table 24, and the nut 28 is screwed to a left and right lead screw 29 extending horizontally along the lower side portion of the shift table 24. Are combined. The left and right lead screws 29 are connected to a rotary shaft of a step motor 30 fixedly supported by the rise / fall table 22, and are axially rotated when the step motor 30 is driven and screwed to the step motor 30. It is possible to screw the nut 28 and move the shift table 24 integrated with the nut 28 in the left-right direction.

The rise / fall table 2
In a part of the shift guide 23, which is integrated with the vertical direction in this example, a vertical position detection groove 31, which is a concave groove, is provided at a position corresponding to the vertical center position of the CCD imaging device 11. It is formed. The vertical position detection groove 31 is positioned to face the vertical position photo sensor 13 provided on the left side of the aperture 7 when the camera back 10 is mounted on the camera body 1. Similarly, a part of the shift table 24 is formed with a lateral position detection groove 32, which is a concave groove, at a position corresponding to the center position of the CCD imaging device 11 in the lateral direction. The left / right position detection groove 32 is positioned to face the left / right position photo sensor 12 provided on the upper side of the aperture 7 when the camera back 10 is mounted on the camera body 1. The camera back 1
Each of the step motors 27, 30 is provided on a part of the front surface of 0.
33 is arranged to be electrically connected to the camera body 10. When the camera back 10 is mounted on the camera body 1, the contact 33 makes contact with the contact 14 of the camera body 1 to electrically connect to each other. The connection is made.

FIG. 4A shows the above-mentioned two position sensors 12 and 13 on the camera body side, two position detection grooves 31 and 32 on the camera back side, and step motors 27 and 3.
It is a figure which shows the circuit structure of 0 typically. The position sensors 12 and 13 and the step motors 27 and 30 are connected via contacts 14 and 33 to a system control circuit 40 composed of a CPU installed inside the camera body 1, respectively. The step motor 27 for moving is feedback-controlled so that the output of the vertical position sensor 13 is minimum, and the step motor 30 for moving the shift table 24 is the output of the horizontal position sensor 12 is minimum. It is configured to be feedback-controlled so that The system control circuit 40 is
Although detailed description is omitted, the components provided for controlling the shooting operation on the camera body side, that is, the operations such as photometry, distance measurement, and shutter opening / closing can be used almost as they are.

In a camera having such a structure, a camera back (not shown) for a film, which is normally mounted, is removed from the camera body 1, and instead, the camera back 10 shown in FIG. Camera body 1
By attaching to, it becomes possible to digitally shoot. The operation of mounting the camera back on the camera body is as described above, and the mounted state is maintained by the engagement of the hook 85 and the lock groove 82.

Then, subsequently, the optical axes of the CCD image pickup device 11 and the lens 2 are automatically adjusted by the system control circuit 40 shown in FIG. That is, the system control circuit 40 detects that the camera back is mounted by, for example, the conduction of the contacts 14 and 33, and first, in order to match the vertical optical axes of the CCD image pickup device 11, the step motor 27 causes the vertical lead screw to move. 26 is axially driven to move the rise / fall table 22 up and down within a required range. Then, the output of the vertical position photo sensor 13 at that time is detected. As can be seen from FIG. 4, the vertical position photosensor 13 detects the amount of light reflected from the vertical position detection groove 31 that is located opposite to it. The amount of light is reduced and the detection output is reduced. Therefore, the system control circuit 40 performs feedback control of the step motor 27 so that the detection output of the vertical position photosensor 13 is minimized, so that the rise / fall table 22 and the shift table 24 integrated in the vertical direction are provided. CCD
The vertical optical axis position of the imaging device 11 can be matched with the center position of the aperture 7, that is, the optical axis position of the lens 2.

Next, the system control circuit 40
Uses the step motor 30 to align the left and right optical axes of the CCD image pickup device 11 with each other.
9 is axially driven to move the shift table 24 left and right within a required range. Then, the output of the left / right position photo sensor 12 at that time is detected. When the right and left position detection groove 32 of the left and right position photo sensor faces the right and left position detection groove 32, the amount of reflected light is reduced by the left and right position detection groove 32, and the detection output is reduced. Therefore, the system control circuit 40 feedback-controls the step motor 30 so that the detection output of the left-right position photosensor 12 is minimized, and the left and right of the shift table 24 and the CCD image pickup device 11 integrated in the left-right direction. Direction optical axis position is the center position of the aperture 7,
That is, it is possible to match the optical axis position of the lens 2. The state of position setting at this time is shown in FIG.

As a result, the center of the CCD image pickup device 11 is automatically and quickly aligned with the optical axis position of the lens 2. Therefore, even if there is a manufacturing error in the camera back attaching / detaching mechanism 8 and the mounting position of the camera back 10 with respect to the camera body 1 is displaced,
By controlling the system control circuit 40, the center position of the CCD image pickup device 11 can always be set to the optical axis position of the lens 2, and operations such as highly accurate alignment of the mounting position of the camera back are completely unnecessary. This allows CC
The image pickup screen obtained by the D image pickup device 11 is a distortion-free image with no swaying effect, and an image pickup screen with high image pickup quality or a video signal can be obtained. Also,
Even when the CCD image pickup device 11 is moved up and down, left and right in this way to align the optical axes, the image pickup surface size of the CCD image pickup device 11 is smaller than the image pickup size of the aperture 7, and therefore, the CCD image pickup device 11 The image pickup surface does not fall outside the image pickup area of the aperture 7, and so-called scratching does not occur.

When performing tilt shooting, a tilt switch 50 having a seesaw structure is provided in a part of the camera back 10 as shown in FIG. 1, and the tilt switch 50 is operated to operate the system control circuit 40. To selectively drive the front stepping motors 27 and 30 to drive the rise / fall table 22 and the shift table 24 to change the position of the CCD image pickup device 11 vertically and horizontally, thereby performing rise / fall and shift tilting photographing. It becomes possible to do.

Therefore, even if the camera back is fixedly attached to the camera body, it is possible to perform tilt / fall and shift tilting photography, whereby the camera back and the camera body are connected to each other. The camera can be made smaller and lighter without the need for a tilt mechanism. Further, in this embodiment, since the position of the CCD image pickup device is adjusted by the step motor, the tilt adjustment can be electrically driven, and the tilt adjustment can be easily performed.

Here, the position adjusting mechanism 20 for vertically moving the rise / fall table and horizontally moving the shift table is not limited to the mechanism using the screw and the nut described above, but may be, for example, a structure using a rack and a pinion.
Various mechanisms can be adopted. Further, the position detection groove used when detecting the vertical and horizontal positions may be, for example, black paint as long as it has a light reflectance different from that of the other portions.

Although not described in this embodiment, if an LCD monitor is attached to the camera back or the camera body, the image pickup screen is displayed on the monitor by the video signal obtained by the CCD image pickup device. Digital image pickup is possible while checking this screen. It is also possible to provide an external terminal for the video signal and check the image on an external monitor. It goes without saying that the angle of view and focus adjustment (manual focus) can be performed by using these monitors. Furthermore, in the above-described embodiment, an example in which the present invention is applied to a so-called middle-sized camera is shown, but it goes without saying that the present invention can also be applied to a small camera using a 35 mm roll film.

[0024]

As described above, according to the present invention, there is provided a mechanism for adjusting the position of the image pickup device incorporated in the camera back which can be attached to and detached from the camera body on the image pickup surface, and the image pickup device is provided. Since it can be moved in one direction on the surface of the image-forming focusing surface and also in the other direction orthogonal to this on the surface of the image-capturing coupling surface, shift, rise, and
You can take each tilting shot of the fall. In addition, by controlling the movement of the image pickup device, the center position of the image pickup device can be matched with the optical axis position on the camera body side, and if the camera back is attached to the camera body, the center of the image pickup device will be the center of the camera body. The position of the optical axis of the lens system is automatically and quickly matched. Therefore,
Even if there is a manufacturing error in the camera back attachment / detachment mechanism that causes the camera back mounting position to shift relative to the camera body, the center position of the imaging device can always be set to the optical axis position of the lens system. , Operations such as highly precise alignment of the camera back mounting position are completely unnecessary, and there is no distortion, high quality image pickup screen without distortion, or digital image capture that can obtain video signals is realized. There is an effect that can be done.

[Brief description of drawings]

FIG. 1 is an external view of a camera according to an embodiment of the present invention with a lens unit removed.

FIG. 2 is a perspective view of the camera of FIG. 1 with a camera back removed.

FIG. 3 is a perspective view showing an internal configuration of a camera back.

FIG. 4 is a configuration diagram of a control circuit including a step motor.

FIG. 5 is a partially cutaway plan view showing a state in which the imaging device is moved in the left-right direction.

[Explanation of symbols]

 1 camera body 2 lens 7 aperture 8 camera back attachment / detachment mechanism 9 reference plane rail 10 camera back 11 CCD imaging device 12, 13 position detection sensor 20 position adjustment mechanism 22 rise / fall table 24 shift table 27, 30 pulse motor 31, 32 position Detection groove 40 System control circuit 50 Agitating switch

Claims (7)

[Claims] 1. A camera back interchangeable camera having a camera back which can be attached to and detached from a camera body, wherein an imaging device is incorporated in the camera back, and the position of the imaging device is changed on its imaging surface. A camera back interchangeable camera characterized by being provided with a position adjusting mechanism. 2. The camera back interchangeable camera according to claim 1, wherein the position adjusting mechanism is configured to be capable of shifting and rising / falling tilt tilt shooting with respect to the optical axis of the camera lens. 3. A mechanism for moving the image pickup device in one direction on the surface of the image forming and imaging surface, a mechanism for moving the image pickup apparatus in the other direction on the surface of the image taking coupling surface in a direction orthogonal to this, and a moving mechanism for these respectively. The camera back interchangeable camera according to claim 1, further comprising means for independently controlling the center position of the imaging device to coincide with the optical axis position on the camera body side. 4. An image pickup device comprising means for detecting a moving position in one direction and means for detecting a moving position in the other direction orthogonal to the one, wherein the means for controlling each moving mechanism is each detecting means. The interchangeable camera back camera according to claim 3, wherein each moving mechanism is feedback-controlled based on the detection output of the camera. 5. A guide supported by the camera back in one direction, a rise / fall table guided by the guide and movable in one direction, and a screw for reciprocating the rise / fall table in one direction. A nut mechanism, a shift guide supported by the rise / fall table in the other direction orthogonal to the one direction, a shift table guided by the shift guide and movable in the other direction, and the shift table A screw nut mechanism that reciprocates in the other direction, a CCD image pickup device supported by the shift table, a one-way position detection body formed on an object that is moved in the one direction, and a move in the other direction. Other direction position detecting body formed on the object, means for detecting the position of the one direction position detecting body, and position of the other direction position detecting body And a control circuit for controlling the screw and nut mechanisms in the one direction and the other direction based on the outputs of the detection devices in the one direction and the other direction, respectively. Camera back interchangeable camera in any of 4. 6. A means for detecting the position of the position detecting body is provided on the camera body, and each of them is opposed to the optical axis of the camera body in one direction and in another direction orthogonal thereto. 6. The camera back interchangeable camera according to claim 5, wherein the camera back interchangeable camera is arranged at a position which detects when each position detecting member faces each position detecting means. 7. The camera back exchange according to claim 1, wherein a size of an image pickup surface of the CCD image pickup device is smaller than a size of an aperture for defining a photographing area provided in the camera body. Expression camera.