JP3718285B2 - Camera back exchangeable camera - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a camera in which the camera back can be replaced, and more particularly to a camera that can be replaced with a camera back that includes an imaging device such as a CCD.
[0002]
[Prior art]
As a still camera in recent years, a camera capable of imaging using an imaging device such as a CCD has been proposed in addition to the conventional photography for a silver salt film. In order to enable electronic photography using this imaging device, in other words, digital photography, for example, a part supporting the film in the camera body can be attached to and detached from the camera body as a camera back, and the camera back is imaged. A method that enables digital photography by replacing the device with a device is conceivable. As a camera of this type, in a certain 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 made it possible to shoot has already been proposed.
[0003]
In such a camera back exchange type camera, as in the case of a normal camera back using a film, when performing digital photography, so-called tilt photography, in particular, the imaging surface is horizontal or vertical with respect to the lens optical axis. In some cases, it is required to perform tilt shooting in a tilted direction. For this reason, conventionally, the portion connecting the camera back and the camera body is formed in an accordion shape, and the entire camera back is configured to be tiltable with respect to the optical axis of the camera body during tilt shooting. ing.
[0004]
[Problems to be solved by the invention]
However, when such a tilt mechanism is provided, there is a problem that the overall configuration of the camera is increased in size and weight. In particular, a camera back that enables digital photography is advantageous in terms of size 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 not utilized, and the mobility of the camera at the time of digital photographing is impaired. Also, when tilting the camera back as a whole, the weight of the driven part increases, making it difficult to drive the tilt mechanism. When this is used, the tilt mechanism is further enlarged. Problem arises.
[0005]
SUMMARY OF THE INVENTION An object of the present invention is to provide a camera that can reduce the size and weight of a tilt mechanism in a camera back for digital photography and can be electrically driven.
[0006]
[Means for Solving the Problems]
The camera of the present invention is a camera back exchangeable camera having a camera back that can be attached to and detached from the camera body, and the camera back includes an image pickup device having an image pickup surface having an aspect ratio of 1: 1. equipped with a device, in a state where the center of the imaging device coincides with the center of the imaging optical axis, a tilting mechanism comprising a tilting mechanism for tilting about an axis perpendicular to the imaging surface of the imaging element to the optical axis is furnished, the tilt The mechanism includes a rotation mechanism for rotating 90 degrees about the optical axis, and the rotation mechanism rotates the rotation table in a plane perpendicular to the optical axis and the rotation table at an angle of at least 90 degrees. The tilting mechanism is supported by the rotary table and is tiltable about an axis in one direction perpendicular to the optical axis, and supports the imaging device on the front surface thereof. A moving table and a tilting drive means for tilting the tilting table only about the axis in one vertical direction, and the rotation driving means is a motor that rotatably supports the rotating table at the rotation center position. And the tilt drive means is a spring means for biasing the tilt table in one direction of tilt, and a direction against the biasing force of the spring means at a position displaced with respect to the tilt center of the tilt table. A plunger is brought into contact with one side of the tilting table, and is composed of a linear actuator that forcibly tilts the tilting table in accordance with the protruding amount of the plunger .
[0007]
In the present invention, a video processing circuit for outputting a video signal from the imaging device as a TV signal, an output terminal for outputting the video signal from the video processing circuit, and a video signal from the video processing circuit A 90-degree rotation circuit for rotating the scanning direction by 90 degrees, a changeover switch for selectively outputting the video signal to either the output terminal or the 90-degree rotation circuit, and the rotation table from the normal position to 90 degrees And a control means for connecting a changeover switch to the 90-degree rotation circuit when rotated. In the present invention, the tilting mechanism is operated to perform tilt shooting, and the tilting mechanism and the rotation mechanism are operated to perform rotation shooting.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
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 and a camera back removed, and FIG. 2 is a concept of a state in which the camera back is detached from the camera body to show a schematic configuration of the 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. In addition, illustration is abbreviate | omitted about the release button and other parts with little relation to this invention. The camera body 1 is provided with a lens mount 3 to which the lens 2 can be attached and detached on the front surface, and a prism 4 and a viewfinder 5 on the upper part. In addition, a quick return mirror 6 and a driving mechanism (not shown) are disposed inside, and an aperture 7 is opened behind the quick return mirror 6. The aperture 7 is not shown in the drawing to open and close the aperture 7. A focal plane shutter and its drive mechanism are provided. A camera back 10 is detachably provided on the back of the camera body via a camera back attaching / detaching mechanism 8.
[0009]
The camera back attaching / detaching mechanism 8 includes, for example, a plurality of hinge coupling recesses 81 on one side and a lock groove 82 containing a lock piece 83 on the other side on the back of the camera body. In addition, a plurality of hinge coupling convex pieces 84 engaged with the hinge coupling concave portions 81 are provided on one side of the front surface of the camera back 10 facing this, and a hook 85 spring-biased on the other side is provided. . When attaching the camera back 10 to the camera body 1, the hinge coupling concave portion 81 and the hinge coupling convex piece 84 provided on each one side are coupled, and the hook 85 on the other side portion is locked into the lock groove. 82, the hook 85 is engaged with the lock piece 83 by a spring force, and the camera back 10 can be fixedly supported on the camera body 1 by this engagement force. Further, by operating the lock release lever 86, the engagement between the lock piece 83 and the hook 85 can be released, and the camera back 10 can be detached from the camera body 1. Further, a contact 9 for electrical connection with the camera back 10 is provided on a part of the back surface of the camera body 1.
[0010]
The camera body 1 is usually attached with a camera back with a silver salt film, but instead, a camera back 10 with a CCD image pickup device 11 as shown in FIG. 2 is attached. It is possible. In the camera back 10, as shown in FIGS. 3 and 4, a perspective view of the internal main structure and a cross-sectional view taken along the line AA, respectively, the CCD image pickup device 11 is at least 90 around the optical axis of the image pickup surface. A tilt mechanism 12 is provided for performing a rotation operation for rotating the imaging surface and a tilting operation for rotating the imaging surface optical axis in the vertical direction or the horizontal direction within a required angle range.
[0011]
In the tilt mechanism 12, for example, a step motor 121 having a rotating shaft 121a disposed on the optical axis of the lens is fixedly supported in the camera back. A rotating table 122 is provided on the rotating shaft 121a of the step motor 121. It is fixed. In addition, a pair of bearings 123 are erected on the rotary table 122, and tilting shafts 124 are rotatably supported by the bearings 123 at both ends thereof. A tilting table 125 that is tilted is integrally supported on the tilting shaft 124, and the CCD imaging device 11 is supported on the front surface of the tilting table 125. Further, a tension spring 126 is stretched between one side of the tilting table 125 and the rotary table 122, and this one side of the tilting table 125 is biased toward the rotary table 122. Further, a plunger 127a of a linear motion actuator 127 supported by the rotary table 122 is in contact with the other side surface of the tilting table 125 on the opposite side.
[0012]
The linear actuator 127 is already known. To briefly explain the mechanism, a motor is formed in the main body 127b, and a screw groove is formed at the rotational center position of the rotating body of the motor. Is formed, and a plunger 127a having a screw structure is screwed thereto. Accordingly, when the motor is driven to rotate the rotating body, the plunger 127a screwed to the rotating body is screwed in the axial direction with respect to the rotating body, and the protruding amount of the plunger 127a from the main body 127b is changed. Will be. As can be seen from FIG. 4, the tip of the plunger 127a is in contact with the other side surface of the tilting table 125 at a position displaced by δ with respect to the tilting shaft 124. In accordance with the change in the protruding amount, the tilting table 125 is applied with a displacement force on the other side surface, and is rotated , that is , tilted, about the tilting shaft 124.
[0013]
As shown in FIG. 4, the CCD image pickup device 11 has a CCD image pickup device 112 mounted inside a package 111 and is sealed with a protective glass 113. A lead (not shown) is connected to the CCD image pickup device 112, and a video signal picked up by the CCD image pickup device 112 is output to the outside. Here, the CCD image pickup device 112 is set to have an aspect ratio of its image pickup surface of 1: 1, and a vertical and horizontal dimension slightly smaller than the area of the image on the silver salt film. The mounting position of the CCD image pickup device 11 with respect to the tilt shaft 124 is set so that the center position of the image pickup surface of the CCD image pickup device 112 becomes the rotation center of the tilt table 125. A contact 13 (see FIG. 2) that is electrically connected to the step motor 121 and the linear actuator 127 is disposed on a part of the front surface of the camera back 10, and the camera back 10 is attached to the camera body 1. Sometimes, the contact 13 contacts the contact 9 of the camera body 1 and is electrically connected to each other.
[0014]
FIG. 5 is a block circuit diagram of the main part of an electric circuit including the CCD image pickup device 11, the step motor 121, and the linear actuator 127. A video image processing circuit 14 is connected to the CCD image pickup device 11 disposed on the optical axis of the lens L together with the color filter CF, and a video signal obtained from the CCD image pickup device 11 is output as a color video signal from the output terminal OUT here. . Since the video processing circuit 14 is a known circuit, a detailed description thereof is omitted, but a delay circuit 15 that delays horizontal scanning by 1H, a color separation circuit 16 that separates RGB color signals, and RGB Low-pass filters 17R, 17G, and 17B, process amplifier circuits 18R, 18G, and 18B, a high-frequency separation circuit 19, and a color encoder 20 that forms the video signal as a TV signal therefrom. It consists of. In addition, a 90-degree rotation circuit 21 for rotating the image by 90 degrees by converting the scanning direction of the image signal between the horizontal direction and the vertical direction is provided at the output end OUT of the image signal in parallel. The video signal can be output to the output terminal OUT through the 90-degree rotation circuit 21 by selecting the changeover switch SW. The step motor 121 and the linear actuator 127 are provided with drivers 22 and 23 for driving the step motor 121 and the linear actuator 127, respectively, and these drivers 22 and 23 are controlled by a system control circuit 24. As shown in FIG. 1, the system control circuit 24 includes a linear motion actuator drive switch 25a provided on the camera back 10 for driving the linear motion actuator 127, and a step for driving the step motor 121. A drive switch 25 is integrally connected to the motor drive switch 25b. A switch signal is input from the drive switch 25, and the drivers 22 and 23 are driven based on the switch signal. The system control circuit 24 is also configured to control the switching operation of the selector switch SW.
[0015]
In the camera having such a configuration, the camera back (not shown) for film that is normally mounted is removed from the camera body 1 and the camera back 10 shown in FIG. Digital photography is possible by attaching to. The operation when the camera back 10 is mounted on the camera body 1 is as described above, and the mounting state is maintained by the engagement between the hook 85 and the lock groove 82. When the camera back 10 is attached to the camera body 1, the CCD image pickup device 11 is set at the image plane position on the optical axis of the lens unit, and the photographed subject image is formed on the image plane. The digital imaging by the CCD imaging device 11 becomes possible. The video signal from the CCD imaging device 11 or the video processing circuit 14 is output from the output terminal OUT. At this time, when the vertical direction of the CCD image pickup device 11 is directed to the original vertical direction, the changeover switch SW is connected to the output terminal OUT side, and the video signal is output as it is from the output terminal OUT.
[0016]
Then, when performing tilt shooting, by operating an operation button (not shown), when swing information and tilt information are input to the system control circuit 24, the system control circuit 24 sends the drivers 22 and 23 to each driver. A control signal is output, and the step motor 121 and the linear actuator 127 are driven by each driver. When tilting imaging is performed in which the imaging surface is tilted in the vertical direction, that is, in tilt imaging, the rotary table 122 has the normal rotation position shown in FIG. 3, that is, the vertical direction of the CCD imaging device 11 is the original vertical direction. The linear motion actuator 127 is driven while being fixed in a direction directed. As a result, the projection amount of the plunger 127a is changed in the linear actuator 127, and when the linear actuator 127 is projected, the other side surface of the tilting table 125 is pressed in a state of being displaced with respect to the tilting shaft 124. Be inclined. When the plunger 127a is retracted, the imaging surface is inclined downward by the spring force of the tension spring 126. As a result, the image pickup surface of the CCD image pickup device 112 changes the tilt angle in the vertical direction around the image pickup optical axis, and tilt shooting in this direction becomes possible.
[0017]
On the other hand, in the case of tilt shooting in which the imaging surface is inclined in the horizontal direction, that is, in the case of swing shooting, first, the step motor 121 is driven, and the rotary table 122 is rotated 90 degrees from the normal rotation position shown in FIG. Set the rotation to. As a result, the CCD image pickup device 11 is in a state where the vertical direction and the horizontal direction of the image pickup surface are reversed. Then, the linear motion actuator 127 is driven, and the tilting table 125 is tilted by the change in the protruding amount of the plunger 127a as described above. That is, when the plunger 127a is protruded, the other side surface of the tilting table 125 is pressed while being displaced with respect to the tilting shaft 124, so that the imaging surface is tilted in the horizontal right direction. When the plunger 127a is retracted, the imaging surface is inclined in the horizontal left direction by the spring force of the tension spring 126. As a result, the image pickup surface of the CCD image pickup device 112 is changed in the inclination angle in the horizontal direction around the image pickup optical axis, and tilt shooting in this direction becomes possible.
[0018]
Further, at the time of this swing shooting, since the image pickup surface of the CCD image pickup device 11 is rotated 90 degrees in the vertical direction around the optical axis, the video signal obtained by scanning the video signal in the CCD image pickup device 112 becomes a horizontal image. End up. Therefore, the system control circuit 24 switches the change-over switch SW provided at the video output end to the 90-degree rotation circuit side 21 simultaneously with the rotation control of the step motor 121 described above. As a result, the video signal output from the video processing circuit 14 is output from the output terminal OUT as a video signal whose scanning has been rotated by 90 degrees, and an upright image regardless of the 90-degree rotation of the CCD image sensor. A signal can be output.
[0019]
In this embodiment, the image pickup surface of the CCD image pickup device 11 has a vertical and horizontal dimension of 1: 1. Therefore, even if the image pickup surface is rotated 90 degrees, there is no problem in scanning as a video signal. Further, since the image pickup surface of the CCD image pickup device 11 is made smaller than the vertical and horizontal dimensions of the aperture 7, the entire image pickup surface can be positioned within the image formation plane even by tilting operation, and the image is distorted. There is no.
[0020]
As a result, even if the camera back is fixedly attached to the camera body, the internal CCD image pickup device is operated independently, and photography can be performed. Therefore, there is no need to add a tilt mechanism to the connecting portion between the camera back and the camera body, and the camera can be reduced in size and weight. In this embodiment, since the CCD image pickup device is rotated and tilted by a step motor or a linear actuator, the tilt adjustment can be motorized, and the tilt adjustment can be easily performed.
[0021]
Here, in the present invention, an LCD monitor is attached to the camera back or camera body, and the monitor screen is confirmed by displaying the image screen obtained by imaging with the CCD imaging device on the monitor. However, it is preferable to perform tilt adjustment. Alternatively, the image can be confirmed on an external monitor. Needless to say, these monitors can be used to set the angle of view and adjust the focus (manual focus). In the embodiment, the linear motion actuator is used to perform the tilting operation, but a step motor or other rotational drive mechanism can also be used. Similarly, a solenoid can be used instead of the stepping motor. Furthermore, in the above-described embodiment, an example in which the present invention is applied to a so-called medium-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.
[0022]
【The invention's effect】
As described above, according to the present invention, tilting is performed by tilting an image sensor with a vertical / horizontal dimension ratio of 1: 1 on the imaging surface only about an axis in one direction perpendicular to the optical axis , on the camera back of the camera back exchangeable camera. A tilt mechanism including a mechanism is built in, and the tilt mechanism includes a rotation mechanism for rotating the imaging device 90 degrees within the plane of the imaging surface. The rotation mechanism is composed of a rotary table and a rotation driving means, and is tilted. The mechanism is composed of a tilting table and tilting driving means, the rotational driving means is composed of a motor, and the tilting driving means is composed of a spring means and a linear actuator, so that one rotating mechanism and one tilting mechanism are provided. Thus, a tilting mechanism for tilting the image sensor in the vertical and horizontal directions with respect to the optical axis can be obtained. Accordingly, even if the camera back is fixedly attached to the camera body, tilt shooting can be performed by the imaging apparatus, and it is not necessary to provide a tilt mechanism at the connection portion between the camera back and the camera body. As a result, the entire camera can be reduced in size and weight, and the entire camera back does not need to be operated in a tilting manner. The tilting mechanism can be motorized, and the tilt adjustment can be easily performed. is there. Further, since the image sensor has a vertical / horizontal dimension ratio of 1: 1 on the imaging surface, there is no problem in scanning even when the image sensor is rotated by 90 degrees by the rotation mechanism or when the scanning direction of the video signal is changed.
[Brief description of the drawings]
FIG. 1 is an external view of a camera according to an embodiment of the present invention with a lens unit removed.
2 is a perspective view showing a state where a camera back of the camera shown in FIG. 1 is detached. FIG.
FIG. 3 is a perspective view showing an internal configuration of a camera back.
4 is a cross-sectional view taken along line AA in FIG.
FIG. 5 is a block circuit diagram showing a circuit configuration of a main part.
6 is a perspective view corresponding to FIG. 3 for explaining a tilting operation. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Camera body 2 Lens 7 Aperture 8 Camera back attachment / detachment mechanism 9 Contact 10 Camera back 11 CCD imaging device 111 Package 112 CCD imaging device 12 tilt mechanism 121 Step motor 122 Rotary table 124 Tilt axis 125 Tilt table 126 Tensile spring 127 Direct acting actuator 13 Contact 14 Video processing circuit 21 90-degree rotation circuit 22, 23 Driver 24 System control circuit 25 Drive switch

Claims (3)

A camera back exchangeable camera having a camera back that can be attached to and detached from a camera body, the camera back having an image pickup device having an image pickup element having an image pickup surface with a vertical to horizontal dimension ratio of 1: 1, and the image pickup A tilting mechanism including a tilting mechanism that tilts the imaging surface of the imaging element about an axis orthogonal to the optical axis in a state where the center of the element coincides with the center of the imaging optical axis is provided, and the tilting mechanism is centered on the optical axis. A rotation mechanism for rotating the rotation table at an angle of at least 90 degrees, and a rotation table capable of rotating in a plane perpendicular to the optical axis. The tilting mechanism is supported by the rotary table, is tiltable about an axis in one direction perpendicular to the optical axis, and has a tilting table that supports the imaging device in front of the tilting table. Tilting drive means for tilting the tilting table only about the axis in one vertical direction, and the rotation driving means is a motor that rotatably supports the rotary table at its rotation center position. The drive means includes a spring means for urging the tilt table in one direction of tilting, and one of the tilt tables from a direction against the biasing force of the spring means at a position displaced with respect to the tilt center of the tilt table. A camera back exchangeable camera comprising: a plunger abutting on the side and a linear motion actuator that forcibly tilts the tilting table in accordance with a protruding amount of the plunger . A video processing circuit for outputting a video signal from the imaging device as a TV signal, an output terminal for outputting the video signal from the video processing circuit, and a scanning direction of the video signal from the video processing circuit are set to 90. A 90 degree rotation circuit for rotating the image, a changeover switch for selectively outputting the video signal to either the output terminal or the 90 degree rotation circuit, and the rotation table rotated 90 degrees from the normal position. The camera back exchangeable camera according to claim 1, further comprising a control unit that connects a changeover switch to the 90-degree rotation circuit. The camera back exchangeable camera according to claim 1 or 2, wherein the tilting mechanism is operated to perform tilt shooting, and the tilt mechanism and the rotation mechanism are operated to perform rotation shooting.

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