JPH10133264A - Camera back interchangeable camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a camera capable of high-accurately and automatically positioning the image pickup surface of an image pickup device on the image formation surface of a camera body regardless of manufacturing error in a camera back and the camera body. SOLUTION: A reference surface rail 91 is extended and set on the camera body 1, and a CCD image pickup device 11 innerly mounted in the camera back 10 attached to the rail 91 is supported in a state where it is pressed in a front surface direction by a leaf spring 12. When the back 10 is attached to the camera body 1, the image pickup surface of the image pickup device abuts on the rail 91 by the spring force of the spring 12, the image surface of the object image to be image-formed on the photosensitive surface of a silver halide film is retreated in an optical axis direction by the refracting operation of a protection glass provided on the image pickup device, and the object image is high-accurately and automatically set on the image formation position on the optical axis of the image pickup surface of the device 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera having a replaceable camera back, and more particularly to a camera having an image pickup device such as a CCD and capable of using the camera back.

[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 or digital photography using this imaging device, for example, a portion supporting a film in a camera body can be detachably attached to a camera body as a camera back, and this camera back can be used as an imaging device. A system that enables digital photographing by replacing it with a provided one is conceivable. As a camera of this type, in a certain type of single-lens reflex camera, the back cover is detachable from the camera body, and after removing the back cover, a camera back having an image sensor is attached to the camera body, and a digital camera is mounted. One that has enabled shooting has already been proposed.

[0003]

In such a camera of the conventional camera back exchange type, the image pickup device is provided fixedly to the camera back. For this reason, when a camera back provided with an imaging device is attached to a camera body, a relative positional error occurs between the camera back and the camera body and between the camera back and the imaging device due to a manufacturing error. This makes it difficult to image the imaging device in a focused state. For this reason, it is necessary to provide a mechanism for adjusting the position of the imaging surface at the imaging position on the camera back side. Therefore, there is a problem that the structure of the camera back is complicated and the price is high. Further, the necessity of such position adjustment every time the camera back is replaced with that of the image pickup apparatus is not practical because the time and effort when actually using the camera increases.

An object of the present invention is to provide a camera capable of automatically and accurately aligning an imaging surface of an imaging device with an imaging surface of a camera body regardless of a manufacturing error in the camera back or the camera body. To provide.

[0005]

In a camera according to the present invention, a reference plane rail is extended from a camera body, and an image pickup device internally supported by a camera back detachably attached thereto is brought into contact with the reference plane rail. In this case, the position of the image plane is set. The reference plane rail is provided on both sides of an aperture that defines a photographing area on the camera body side, abuts against a silver halide film surface of a camera back using a silver halide film, and defines an imaging plane of a lens system. The inner rail is used. Further, the imaging device housed inside the camera back is elastically supported in the optical axis direction by a spring means, and is elastically contacted with the reference plane rail by the spring force of the spring means.

Here, in the present invention, the image pickup apparatus is provided with a protective glass in front of an image pickup device provided therein, and this protective glass is used for imaging a subject image formed on a film surface when a silver halide film is used. The amount of retreat of the image plane is set so that an image is formed on the imaging plane. In this case, the retreat amount of the image plane is set by the refractive index of the protective glass. Further, the spring means is constituted by a leaf spring disposed between the camera back and the imaging device.

[0007]

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 such as 6 × 6 or 6 × 7. The camera body 1 has a lens mount 3 on the front surface of which a lens 2 can be attached and detached, and a prism 4 and a finder 5 on the top. Further, a quick return mirror 6 and a driving mechanism (not shown) are provided therein, and an aperture 7 is opened behind the quick return mirror 6, and is not shown in the figure to open and close the aperture. A focal plane shutter and its driving mechanism are provided. A camera back 10 is detachably provided on the back of the camera body 1 via a camera back attaching / detaching mechanism 8.

The camera back attaching / detaching mechanism 8 includes, for example,
On the back side of the camera body, a hinge coupling concave portion 81 is provided at an upper and lower position on one side, and a lock groove 82 containing a lock piece 83 is provided on the other side. In addition, a hinge coupling convex piece 84 engaged with the hinge coupling concave portion 81 is provided at a vertical position on one side of the front surface of the camera back 10 opposed thereto, and a hook 85 is provided on the other side. And camera back 10
When the camera body 1 is mounted on the camera body 1, the hinge coupling concave portion 81 and the hinge coupling convex piece 84 on one side are connected to each other, and the hook 85 on the other side is inserted into the lock groove 82. 85 is locked by a spring force.
The camera back 10 can be fixedly supported on the camera body 1 by this engaging force. By operating the lock release lever 86, the lock piece 8 can be moved.
The engagement between the hook 3 and the hook 85 is released, and the camera back 10 can be removed from the camera body 1.

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

On the other hand, in the camera back according to the present invention,
As shown in FIG. 2, a CCD imaging device 11 is provided inside a camera back 10. The CCD image pickup device 11 is provided with a leaf spring 12 on the back thereof.
Gives a biasing force to the front side. As shown in a perspective view of the rear side of the CCD image pickup device 11 in FIG. 4, the leaf spring 12 is formed by bending a horizontal H-shaped leaf spring 12 in the thickness direction. 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 of the D imaging device 11. This connection structure
On the back surface of the CCD image pickup device 11, pins 123 are respectively provided upright corresponding to the respective ends 122, and these pins 12
3 is provided at each end 122 of the leaf spring 12 with a slit 124
Through the leaf spring 12 and the CCD image pickup device 11.
And are connected so that they can move relative to each other.

As shown in FIG. 5, the CCD image pickup device 11 has a CC
A D imaging element 112 is mounted, and this is sealed with a protective glass 113. The horizontal length of the protective glass 113 is slightly shorter than that of the aperture 7, while the horizontal length of the package 111 is
Although it is shorter than the gap, it is longer than the aperture 7. As a result, both sides of the front surface of the package 111 are configured to contact the rail surfaces of the inner rails 91 provided on both sides of the aperture 7. You. The refractive index and the glass thickness of the protective glass 113 are appropriately set. As a result, the image forming light transmitted through the protective glass 113 is retreated by the protective glass 113 to form an image. An image is formed on the image pickup surface of the CCD image pickup device 112 which is retracted from the film surface. The CCD imaging device 11 is configured to output a video signal captured by the CCD imaging device 112 through a lead (not shown) provided on the package 111.

In the camera having such a configuration, the camera back 20 made of a silver halide film as shown in FIG. 3 is detached from the camera body, and the camera back 10 shown in FIG. By mounting the camera on the digital camera 1, digital photographing using a CCD image pickup device becomes possible. The operation of attaching the camera back 10 to the camera body 1 is as described above, and the attached state is held by the hook 85 and the lock groove 82. When the camera back 10 is mounted on the camera body 1, FIG.
As shown in (1), the CCD imaging device 11 is pressed toward the camera body by the spring force of the leaf spring 12, and
11 are inner rails 9 on both sides of the aperture 7
Contact 1 In addition, the protective glass 113 enters 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 rear surface of the CCD image pickup device 11, but both are slits 124.
And the pin 123, the elastic deformation of the leaf spring 12 becomes possible. Further, since the relative movement due to this deformation occurs equally at the four ends 122, the state of the imaging surface of the CCD imaging device 11 perpendicular to the optical axis is maintained.

As described above, the CCD image pickup device 11 can reduce the amount of image retreat caused by the protective glass 113 by setting the refractive index and the thickness of the protective glass 113 appropriately. From the film surface position of C
The object image which is designed to be equal to the distance to the image pickup surface of the CD image pickup element 112 and is 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. By the retreating operation, an image is substantially formed on the imaging surface of the CCD imaging 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 Also, when the camera back 10 is mounted on the camera body 1, the imaging surface of the CCD imaging device 11 is automatically set to the imaging position of the subject image even when the camera back is not mounted at the expected 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 another embodiment of the present invention, and corresponds to FIG. 5 of the above embodiment. In this embodiment, the protection glass 113 is formed of a rod lens array, and the protection glass 113 is shorter than the space between the outer rails 92 and longer than the aperture 7.
The position of the CCD imaging device 11 is set by bringing the front surfaces of both sides into contact with the rail surface of the inner rail 91. here,
As shown in FIG. 6B, the rod lens array is formed of a short rod lens 113a made of a light-transmitting resin.
Are arranged closely in a plane direction perpendicular to the optical axis to form a plate. As shown in FIG. 7A, the rod lens 113a constituting the rod lens array is a distributed refractive index type rod-shaped lens having a parabolic refractive index distribution from the center of the optical axis to the periphery. It is configured as As such a rod lens, for example, there is a “Selfoc lens array” manufactured by Nippon Sheet Glass Co., Ltd. According to the distributed refractive index type rod lens 113a, as shown in FIG. 7B, light incident from one end side of the rod lens 113a is made to travel in the rod lens while meandering along the optical axis direction. As a result, the optical image IM1 located on the front end surface of the rod lens can be formed as an erect optical image IM2 at the rear position of the rod lens 113a. Thus, by appropriately setting the length of the rod lens 113a, the optical image on the front side of the rod lens 113a is retreated by the length L1 to the rear side by the rod lens 113a, and the CCD image pickup element 112 is magnified. It has a function of forming an image as an erect image.

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 imaging device 11 through the protective glass 113, and the CCD imaging device 112 can electronically capture the subject image. In this case, the subject image is positioned on the rail surface of the inner rail 91 at the film surface position of the silver halide film by the lens system, in other words, the protective glass 113.
An image is formed at the front position of the above, but the above-mentioned distributed index type rod lens array 113a constituting the protective glass 113
As a result, the subject image retreats to the image forming plane of the CCD image sensor 112 by the image surface retreating operation, and the image can be captured in the focused state by the CCD image sensor 112.

Here, in the above-described embodiment, the inner rail provided on the camera body is used as a reference plane of the imaging device, but another rail or another part may be used as the reference plane. In this case, if the reference plane differs in the optical axis direction with respect to the imaging plane of the lens system, the camera back side corrects the optical axis position with respect to the imaging plane of the CCD imaging device by the different dimension. do it. Note that a spring means for urging the imaging device to the front side may use an elastic member such as a coil spring or rubber.

Although an explanation is omitted in this embodiment, if an LCD monitor is attached to the camera back or the camera body, an image screen is displayed on the monitor by a video signal obtained by imaging with the CCD image sensor. Digital imaging 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. Further, in the above embodiment,
Although an example in which the present invention is applied to a so-called medium-sized camera is shown,
It goes without saying that 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 from the camera body, and the image pickup device internally supported by the camera back which is attached to and detached from the camera body is brought into contact with the reference plane rail and the Since the axial position is set, when the camera back is mounted on the camera body, the imaging surface of the imaging device is automatically set to a predetermined position of the camera body, that is, an imaging position of the lens system. . As a result, there is no need to design and manufacture the mechanism for attaching and detaching the camera back and the camera body, or the support mechanism for the imaging device with high accuracy, so that the camera structure can be simplified and the cost of the camera can be reduced. is there.

[Brief description of the 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 camera back for film and a horizontal sectional view when the camera back 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 imaging device with the camera back of the present invention attached.

FIG. 6 is a cross-sectional view in a horizontal direction of an image pickup apparatus with a camera back mounted according to another embodiment of the present invention, and a view for explaining a configuration of a protective glass.

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Camera body 2 Lens 7 Aperture 9 Rail 91 Inner rail 92 Outer rail 10 Camera back 11 CCD imaging device 112 CCD imaging device 113 Protective glass 113a Rod lens 12 Leaf spring

Claims (6)

[Claims] 1. A camera back exchangeable camera having a camera back detachable from a camera body, wherein a reference surface rail is extended from the camera body, and an image pickup device internally supported by the camera back is provided. A camera-back replaceable camera, wherein an imaging plane position is set by contacting the reference plane rail. 2. Inner rails are provided on both sides of an aperture defining a photographing area of the camera body to abut on a silver halide film surface of a camera back using a silver halide film to define an image forming surface. The camera-back replaceable camera according to claim 1, wherein the inner rail is configured as the reference plane rail. 3. The camera according to claim 1, wherein the imaging device is elastically supported in a direction of an optical axis by a spring means, and is elastically contacted with a reference plane rail by a spring force of the spring means. Back exchangeable camera. 4. The camera-back interchangeable camera according to claim 3, wherein said spring means is constituted by a leaf spring disposed between a camera back and an imaging device. 5. An image pickup apparatus, wherein a protective glass is provided in front of a built-in image pickup element, and this protective glass forms a subject image formed on a film surface when a silver halide film is used on an image pickup surface of the image pickup apparatus. The camera-back interchangeable camera according to claim 4, wherein the amount of retreat of the image plane is set so as to form an image. 6. The camera-back interchangeable camera according to claim 5, wherein an amount of retreat of an image plane is set by a refractive index of the protective glass.