JP3406808B2 - Interchangeable camera back camera - 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 with a replaceable camera back, and more particularly to a camera that can be used with a camera back including an image pickup device such as a CCD.

[0002]

2. Description of the Related Art In recent years, still cameras have been proposed which are capable of taking an image using an image pickup device such as a CCD in addition to the conventional image pickup of a silver salt film. In order to enable electronic photography or digital photography using this image pickup device, for example, the portion supporting the film in the camera body can be attached to and detached from the camera body as a camera back, and this camera back can be attached to the image pickup device. It is conceivable that a system that enables digital photography by exchanging with a provided one. 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 image sensor is attached to the camera body, Something that has enabled shooting has already been proposed.

[0003]

In such a conventional camera back exchange type camera, the image pickup device is fixedly provided with respect to the camera back. Therefore, when the camera back including the image pickup device is attached to the camera body, a relative positional error may occur between the camera back and the camera body and between the camera back and the image pickup device due to a manufacturing error. However, it becomes difficult to take an image of the image pickup device in a focused state. Therefore, it is necessary to provide a mechanism for adjusting the position of the image pickup surface at the image pickup position on the camera back side, which causes a problem that the structure of the camera back becomes complicated and the cost becomes high. In addition, it is not practical that such a position adjustment is required every time the camera back is replaced with that of the image pickup device, because the time and effort required when actually using the camera increases.

An object of the present invention is to provide a camera capable of accurately and automatically aligning the image pickup surface of the image pickup device with the image formation surface of the camera body regardless of manufacturing errors in the camera back and the camera body. To provide.

[0005]

A camera of the present invention is a camera back interchangeable camera having a camera back which can be attached to and detached from a camera body provided with a lens for picking up an image of a subject. A reference plane rail is provided that extends on both sides of an aperture that defines a photographing area and defines a photographing surface of a silver salt film that is imaged by the lens. The camera back is in contact with the reference plane rail. A position in the optical axis direction with respect to the camera body and having an imaging surface at a position retracted from the reference surface rail in the optical axis direction, and the camera back at a position in front of the imaging surface of the imaging device. And is brought into contact with the reference surface rail to integrally form the subject image.
The image plane is set at a position equivalent to the image plane of the image pickup device.
It is characterized by being constituted by a cloth refraction type rod lens group .

The image pickup device and the protective glass are springs.
Is elastically supported in the direction of the optical axis by means of the spring hand.
The spring force of the step causes the protective glass to elastically move to the reference plane rail.
It is preferable that they are abutted. Also, the spring means is a camera bar.
It is composed of a leaf spring arranged between the camera and the imaging device.
It is preferable. Furthermore, the reference surface rail is a silver salt film.
It is preferable that the inner rail is in contact with the photographing surface of.

[0007]

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 showing a camera back with a camera body removed to show a schematic configuration of a main part of the camera. It is a figure. 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. The camera body 1 is provided with a lens mount 3 on which a lens 2 is attachable / detachable, and a prism 4 and a finder 5 are provided on an upper portion of the camera body 1. In addition, a quick return mirror 6 and a drive mechanism (not shown) for the quick return mirror 6 are provided inside, and an aperture 7 is opened behind the quick return mirror 6, which is not shown in the figure for opening and closing the aperture. A focal plane shutter and its drive mechanism are provided. A camera back 10 is detachably provided on the back surface of the camera body 1 via a camera back attaching / detaching mechanism 8.

The camera back attaching / detaching mechanism 8 is, for example,
On the back surface of the camera body, a hinge coupling concave portion 81 is provided on one side in the vertical position, and a lock groove 82 containing a lock piece 83 is provided on the other side. Further, a hinge coupling convex piece 84 to be engaged with the hinge coupling concave portion 81 is provided at a vertical position on one side portion of the front surface of the camera back 10 which faces the hook, and a hook 85 is provided on the other side. And the camera back 10
When the camera is mounted on 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 caused to enter the lock groove 82, 85 is locked by spring force 83
The camera back 10 can be fixedly supported by the camera body 1 by this engaging force. Also, by operating the lock release lever 86, the lock piece 8
The camera back 10 can be removed from the camera body 1 by releasing the engagement between the hook 3 and the hook 85.

Further, on the back side of the camera body 1, rails 9 are fixedly extended on both sides of the aperture 7. The rail 9 is composed of a pair of inner rails 91 arranged inside and a pair of outer rails 92 arranged outside thereof. Usually, these rails are used for guiding a film when using a camera back containing a silver salt film. For example, FIG. 3A shows an example of a camera back 20 for silver salt film, and a roll film 21 installed on the lower side is wound up on a spool 22 installed on the upper side. The pressure plate 24 located behind the film portion 23 extending between the roll film 21 and the spool 22 is
By contacting the outer rail 92 of the camera body 1 as shown in FIG. 3B by the spring force of the spring means (not shown), a tunnel is defined between them, and the film portion 23 is formed in this tunnel. The inner rail 91 is brought into contact with the inner rail 91, and the photographing is performed and the film is wound while the photosensitive surface is positioned.

On the other hand, in the camera back according to the present invention,
As shown in FIG. 2, a CCD image pickup device 11 is incorporated in the camera back 10. This CCD image pickup device 11 is provided with a leaf spring 12 on its back surface.
Due to this, the front side is biased. As shown in the perspective view of the back side of the CCD image pickup device 11 in FIG. 4, the leaf spring is formed by bending a laterally H-shaped leaf spring 12 in the thickness direction thereof, and a central portion 121 thereof. Is fixed to the camera back 10 by screws or caulking. The four ends 122 of the leaf spring 12 are CC
It is connected to the back surface of the D imaging device 11. This connection structure is
Pins 123 are provided upright on the back surface of the CCD image pickup device 11 so as to correspond to the respective end portions 122.
3 has slits 124 provided at each end 122 of the leaf spring 12.
The leaf spring 12 and the CCD imaging device 11 by inserting the
The structure is such that and are connected so that they can move relative to each other.

The CCD image pickup device 11 is shown in FIG.
As shown in the sectional structure of the reference example , a CCD image pickup device 112 is mounted inside a package 111, and this is sealed with a protective glass 113. The protective glass 113 has a horizontal length slightly shorter than that of the aperture 7, while the package 111 has a horizontal length shorter than that between the outer rails 92 but longer than the aperture 7. As a result, both sides of the front surface of the package 111 are configured to come into contact with the rail surfaces of the inner rails 91 arranged on both sides of the aperture 7. Further, the protective glass 113 has its refractive index and glass thickness appropriately set, and as a result, the image forming light transmitted through the protective glass 113 is retreated by the protective glass 113 and the silver halide film CCD image sensor 1 retracted from the film surface
An image is formed on 12 imaging planes. The CCD image pickup device 11 is configured to be able to output a video signal picked up by the CCD image pickup element 112 by a lead (not shown) provided in the package 111.

In the camera having such a structure, the camera back 20 shown in FIG. 3 is detached from the camera body, and instead the camera back 10 shown in FIG. By mounting it on the No. 1 unit, digital photographing using a CCD image pickup device becomes possible. The operation of mounting the camera back 10 on the camera body 1 is as described above, and the mounted state is held by the hook 85 and the lock groove 82. When the camera back 10 is attached to the camera body 1, as shown in FIG.
As shown in, the CCD image pickup device 11 is pressed toward the camera body by the spring force of the leaf spring 12, and the package 1
The front of both sides of 11 are the inner rails 9 on both sides of the aperture 7.
1 is abutted. Further, the protective glass 113 is located inside the aperture 7.

At this time, the leaf spring 12 is deformed in the thickness direction, and its four ends 122 are slid relative to the back surface of the CCD image pickup device 11, but both are slits 124.
Because of the connection between the pin 123 and the pin 123, the leaf spring 12 can be elastically deformed. Further, the relative movement due to this deformation occurs equally at the four end portions 122, so that the image pickup surface of the CCD image pickup device 11 is kept in a state perpendicular to the optical axis.

As described above, since the CCD image pickup device 11 appropriately sets the refractive index and the thickness of the protective glass 113, the amount of image plane receding caused by the protective glass 113 is reduced by the silver salt film. From the film surface position of C
It is designed to be equal to the distance to the image pickup surface of the CD image pickup element 112. Therefore, the object image to be formed on the rail surface position of the inner rail 91 at the position of the aperture 7 by the lens 2 is the image surface of the protective glass 113. The retreating action substantially forms an image on the image pickup surface of the CCD image pickup device 112.

As described above, in this camera, the relative positional relationship between the camera back 1 and the camera body 10 and the relative positional relationship between the camera back 10 and the CCD image pickup device 11 need not be designed and manufactured with high accuracy, and When the camera back 10 is attached to the camera body 1, the image pickup surface of the CCD image pickup device 11 is automatically set to the image formation position of the subject image even if the camera back is not attached at the desired position. Therefore, the structure of the camera can be simplified and the price of the camera can be reduced.

FIG. 6A is a diagram showing an embodiment of the present invention and is a diagram corresponding to FIG. 5 of the reference example . In this embodiment, the protective glass 113 is composed of a rod lens array, and the protective glass 113 is made shorter than both outer rails 92 and longer than the aperture 7, so that the front surfaces of both side portions are rails of the inner rail 91. Contact the surface and CCD
The position of the imaging device 11 is set. Here, as shown in FIG. 6B, the rod lens array has a plate shape in which short rod lenses 113a made of a light-transmissive resin are closely arranged in a plane direction perpendicular to the optical axis. It is composed. A rod lens 113a that constitutes this rod lens array has a distributed refractive index type rod-shaped lens having a parabolic refractive index distribution from the center of the optical axis to the periphery as shown in FIG. 7A. Is configured as. As such a rod lens, for example, “SELFOC® manufactured by Nippon Sheet Glass Co., Ltd.
There is a lens array. According to the distributed index type rod lens 113a, as shown in FIG. 7B, the light incident from one end of the rod lens 113a is caused to travel in the rod lens while meandering along the optical axis direction. Can be emitted from the other end side, and as a result, the optical image IM1 positioned on the front end face of the rod lens can be formed as an upright optical image IM2 at the rear position of the rod lens 113a. Thereby, the rod lens 11
By appropriately setting the length of 3a, the rod lens 11
The optical image on the front side of 3a is retreated to the rear side by the length L1 by the rod lens 113a, and the CCD image pickup device 1
12 has a function of forming an erect image of the same size.

Therefore, in this configuration, the aperture 7
The imaging light of the subject image from the lens system that has passed through reaches the CCD image pickup device 11 through the protective glass 113, and the CCD image pickup device 112 can electronically pick up the subject image. In this case, the subject image is located on the film surface of the silver salt film by the lens system, that is, the rail surface position of the inner rail 91, in other words, the protective glass 113.
The image is formed on the front surface of the rod, but the above-mentioned distributed index type rod lens array 113a constituting the protective glass 113 is formed.
Due to the image plane receding action by the image pickup device, the subject image is made to recede to the image plane of the CCD image pickup device 112, and the image pickup in the in-focus state by the CCD image pickup device 112 becomes possible.

In the above embodiment, the inner rail provided on the camera body is used as the reference surface of the image pickup device, but other rails or other portions may be used as the reference surface. In this case, when the reference plane is different from the image plane of the lens system in the optical axis direction, the optical axis position is corrected on the image pickup plane of the CCD image pickup device by the different size on the camera back side. do it. It should be noted that the spring means for urging the image pickup device to the front side can use a coil spring or an elastic member such as rubber.

Although not described in this embodiment, if an LCD monitor is attached to the camera back or camera body, an image pickup screen is displayed on the monitor by a video signal obtained by picking up an image with a CCD image pickup element. Digital image pickup is possible while checking this screen. It is also possible to provide an external terminal for a video signal and check the image on an external monitor. Further, in the above embodiment,
An example in which the present invention is applied to a so-called medium-sized camera is shown.
Needless to say, the present invention can be applied to a small camera using a 35 mm roll film.

[0020]

As described above, according to the present invention, the reference plane rail is extended to the camera body, and the image pickup device internally supported by the camera back which is attached to and detached from the reference plane rail is brought into contact with the reference plane rail so that the optical system can be used. The axial position is set and the distributed refraction rod-shaped lens is integrally provided on the front side of the imaging device.
Since the subject image formed on the reference surface rail is retracted in the optical axis direction by the protective glass composed of a group, if the camera back is attached to the camera body, the image pickup surface of the image pickup device will be automatically changed. It is set at a predetermined position of the body, that is, the image forming position of the lens system. As a result, it is not necessary to design and manufacture the attachment / detachment mechanism of the camera back and the camera body or the support mechanism of the image pickup device with high accuracy, the camera structure can be simplified, and the cost of the camera can be reduced. is there.

[Brief description of drawings]

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

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

FIG. 3 is a perspective view of a film camera back and a horizontal cross-sectional view when the film is mounted.

FIG. 4 is a rear perspective view of the imaging device and the leaf spring.

FIG. 5 is a horizontal cross-sectional view of the image pickup apparatus with the camera back of the reference example attached.

6A and 6B are a cross-sectional view in the horizontal direction in the image pickup apparatus with the camera back mounted according to the embodiment of the present invention, and a diagram for explaining the configuration of the protective glass.

FIG. 7 is a diagram for explaining the configuration of a rod lens and its function.

[Explanation of symbols]

1 camera body 2 lens 7 aperture 9 rails 91 Inner rail 92 Outer rail 10 camera back 11 CCD imaging device 112 CCD image sensor 113 protective glass 113a rod lens 12 leaf spring

Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G03B 17/14 G03B 17/02

Claims (4)

(57) [Claims] 1. A camera back interchangeable camera having a camera back that can be attached to and detached from a camera body having a lens for capturing an image of a subject, wherein the camera body has both sides of an aperture defining a photographing area. The camera back includes a reference surface rail that defines a photographing surface of the silver salt film that is imaged by the lens, and the camera back is in contact with the reference surface rail and is positioned in the optical axis direction with respect to the camera body. And an imaging device having an imaging surface at a position retracted in the optical axis direction from the reference surface rail, and the reference surface rail provided integrally with the camera back at a position on the front side of the imaging surface of the imaging device. A protective glass configured by a distributed refraction type rod-shaped lens group that is brought into contact with the image pickup device and sets the image formation surface of the subject image at a position equivalent to the image pickup surface of the image pickup apparatus. An interchangeable camera back camera, which is equipped with. Wherein said image pickup device and the protective glass, claims toward the optical axis direction is elastically supported by a spring means, the protective glass by a spring force of said spring means is resiliently abuts against the reference surface rail An interchangeable camera back camera according to item 1 . 3. The camera back interchangeable camera according to claim 2 , wherein the spring means is constituted by a leaf spring arranged between the camera back and the imaging device. 4. The reference surface rail is an inner rail with which a photographing surface of a silver salt film is brought into contact.
The interchangeable camera back camera according to any one of 1 to 3 .