JP2004212751A - Video camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To actualize a mechanism of adjusting the stop position of an imaging device when a power source is turned on, for a video camera in which the imaging device is retreated into a container formed of radiation shield material when a power source is not on, and the imaging device is shifted to a prescribed position on the optical axis of the camera only when the power source is turned on. <P>SOLUTION: The video camera is provided with: an imaging device shifting mechanism equipped with a driving device for retreating the imaging device loaded in an imaging device holder into the container formed of the radiation shield material when the power source is not on, and shifting the imaging device to a prescribed position on the optical axis of the lens only when the power source is turned on; an adjusting screw which is arranged in parallel to the imaging device shifting mechanism in a linear shifting direction and adjusts a flange back by bringing the end face of the screw into contact with the imaging device holder; and a spring which is arranged between the imaging device holder and the driving device and absorbs the positional fluctuation due to the adjustment of the flange back. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a flange back adjustment mechanism for adjusting a distance between a lens and a CCD in an optical axis direction in a video camera using a CCD (Charged Coupled Device).
[0002]
[Prior art]
In the conventional flange back adjustment mechanism, for example, the cam of the adjustment ring and the cam follower of the image pickup device holder are both divided into three in the circumferential direction, and these cam followers are divided into three cams by pressing means in the optical axis direction. , And the cam follower of the image sensor holder can always be brought into contact with the cam of the adjustment ring at three points, so that the balance of the image sensor holder can always be stably maintained (for example, see Patent Document 1). ).
[0003]
[Patent Document 1]
JP-A-11-308518
[Problems to be solved by the invention]
A video camera used in a radiation environment may have a structure in which the imaging device is retracted to the shadow of a radiation shielding material when the video camera is not used in order to protect the image sensor from radiation.
Since the conventional flange back adjustment mechanism is configured as described above, the adjustment ring that determines the position of the image sensor is located behind the image sensor holder, and presses the image sensor holder from behind. Therefore, there is a problem that the image pickup device cannot be moved backward by the image pickup device moving mechanism.
[0005]
Further, in the conventional flange back adjustment mechanism, since the position of the image sensor holder is determined by the slope of the cam of the adjustment ring, when the cam and the image sensor holder are separated by the image sensor moving mechanism and come into contact again, the play of the cam is caused by the play of the mechanism. There is a problem that the point at which the image sensor holder and the image sensor holder contact each other changes, and as a result, the position of the image sensor holder in the optical axis direction changes.
[0006]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and is intended to stably perform an operation of moving an image sensor by an image sensor moving mechanism and positioning the image sensor again at a predetermined position on a lens optical axis. The objective is to obtain a flange-back adjustment mechanism.
[0007]
[Means for Solving the Problems]
In the video camera according to the present invention, when the power is not turned on, the image pickup device mounted on the image pickup device holder is retracted into a container of the radiation shielding material, and the image pickup device is placed on the optical axis of the lens only when the power is turned on. An image sensor moving mechanism having a driving device for moving the image sensor to a predetermined position, and an adjusting screw that is provided in parallel in the linear movement direction of the image sensor moving mechanism and adjusts the flange back by applying the image sensor holder to the end face. A spring provided between the imaging element holder and the driving device to absorb a change in position when the flange back is adjusted.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Embodiment 1 FIG.
1 to 6 show the first embodiment. FIG. 1 is an external perspective view of a CCD camera as viewed obliquely from the front, FIG. 2 is an external perspective view of the CCD camera as viewed obliquely from behind, and FIG. FIG. 4 is a sectional view showing a CCD camera, FIG. 5 is a perspective view showing an image pickup device moving mechanism of the CCD camera, and FIG. 6 is a sectional view showing an image pickup device moving mechanism of the CCD camera.
As shown in FIGS. 1 and 2, the CCD camera 1 includes a camera case 2, a front panel 3, and a camera unit 4. The front panel 3 and the camera unit 4 are fixed to the camera case 2 by a latch 5. . As shown in FIG. 3, the front panel 3 and the camera 4 have a structure that can be easily removed by releasing the latch 5. A lens 6 is fixed to the camera unit 4. A power supply / control connector 7 and a video connector 8 are attached to the camera unit 4, and a cable is connected thereto to supply power to the camera, control the camera, and take out a video signal.
[0009]
As shown in FIG. 4, an image sensor 9 and a camera substrate 10 are attached to the camera unit 4. The imaging element 9 has a property of being deteriorated by irradiation with neutron rays and γ rays. In addition, some electronic components mounted on the camera substrate 10 have characteristics that deteriorate when irradiated with γ-rays. For this reason, in the CCD camera 1 of the present invention, which is intended to be used in a radiation environment, it is necessary to protect the imaging device 9 from neutron rays and γ rays and protect the camera substrate 10 from γ rays.
[0010]
For this reason, neutron moderators 11, 12, 13, and 14 are attached inside the camera case 2. A neutron moderator 16 is also attached to the camera unit 4 behind the image sensor 9. The front panel 3 is also made of a neutron moderator, and when the camera unit 4 and the front panel 3 are attached to the camera case 2, the image sensor 9 has a structure in which the entire periphery is covered with the neutron moderator. Further, γ-ray shielding members 17 and 19 are attached around the image sensor 9. Therefore, the image sensor 9 is protected from external neutrons and gamma rays.
A gamma ray shielding member 18 is attached around the camera substrate 10 to protect the camera substrate 10 from gamma rays.
As described above, the radiation shielding material includes the neutron moderator and the γ-ray shielding material.
[0011]
By the way, since the γ-ray shielding member 19 cannot be made transparent, the γ-ray shielding member cannot be arranged in the front direction of the image sensor 9 or in the direction in which light from the lens 6 is incident. For this reason, in the CCD camera 1 of the present invention, only when power is supplied, the imaging element 9 is moved to a regular position (the position in FIG. 5) on the optical axis of the lens 6 to perform photographing. Adopts an image pickup device moving mechanism 20 that retracts behind the γ-ray shielding member 19.
[0012]
5 and 6 show the image pickup device moving mechanism 20. When the power is not turned on, the CCD substrate 32 is retracted behind the γ-ray shielding member 19. When the power is turned on in this state, the solenoid 21 and the motor 22 are energized, and the gear plate 23 is rotated by the rotation of the motor 22 shaft. When the projection 23a of the gear plate 23 and the latch 24 mesh with each other, the gear plate 23 stops rotating at that position, and the rotation of the motor 22 is transmitted to the gears A25, B26, and C27 to linearly move the rack 28. Then, since the driving pin 29 fixed to the rack 28 and the cylindrical cam 30 are engaged with each other, the cylindrical cam 30 guided by the guide rod 31 rotates, and the imaging element 9 fixed to the cylindrical cam 30 is mounted. The CCD substrate 32 is rotated from behind the γ-ray shielding member to a position on the optical axis.
As described above, the cylindrical cam 30 functions as an image sensor holder.
Further, the motor 22, the gear plate 23, the gear A25, the gear B26, the gear C27, the rack 28, and the drive pin 29 constitute a drive device.
[0013]
Next, the drive pin 29 pushes the cylindrical cam 30 toward the lens 6 via the sleeve 34 and the spring 35, and the cylindrical cam 30 is guided by the guide rod 31 and linearly moves. Before the rack 28 stops, the cylindrical cam 30 hits the flange back adjustment screw 36 and stops. The rack 28 continues to move further, and the spring 35 is compressed via the sleeve 34 by the drive pin 29. When the rack 28 advances to the home position, the current of the motor 22 is cut off by the limit switch 37, and the rack 28 stops. In this state, the imaging element 9 is on the optical axis of the lens 6, and the distance in the optical axis direction is also determined.
[0014]
When the flange back adjustment screw 36 is rotated in this state, the cylindrical cam 30 is pressed against the flange back adjustment screw 36 by the spring 35, and is positioned and moved by the flange back adjustment screw 36. Since the CCD substrate 32 is fixed to the cylindrical cam 30, it moves in the optical axis direction of the lens 6. The cylindrical cam 30 is guided by the guide rod 31, and the fitting length between the cylindrical cam 30 and the guide rod 31 can be made sufficiently long. Therefore, since the image pickup device 9 moves smoothly in the optical axis direction without tilting, the flange back which appropriately adjusts the distance between the image pickup device 9 and the lens 6 while monitoring the image while the power of the camera unit 4 is turned on. Adjustment can be performed stably.
[0015]
Next, when the power supply of the camera unit 4 is turned off, the current of the solenoid 21 is cut off, so that the latch 24 is disengaged from the projection 23a of the gear plate 23, and the gear plate 23 can freely rotate. Then, the gear B26 and the gear C27 are disengaged from each other, and the rack 28 is pushed back by the return spring 38. Then, the cylindrical cam 30 is linearly moved in the direction opposite to the lens 6 by the drive pin 29, and then is rotated and retracted behind the γ-ray shielding member 19.
[0016]
As described above, in the flange back adjustment mechanism according to the present invention, the cylindrical cam 30 is positioned from the front, and the cylindrical cam 30 and the flange back adjustment screw 36 can be separated. It is possible to move. In addition, positioning when the image pickup device 9 is moved to the photographing position is performed by bringing the surface of the cylindrical cam 30 perpendicular to the guide rod 31 into contact with the end surface of the flange-back adjusting screw 36. Even if the location that comes into contact with the flange back adjustment screw 36 varies due to, for example, the position of the image sensor 9 in the optical axis direction does not vary, and stable positioning is possible.
[0017]
Embodiment 2 FIG.
7 and 8 are views showing Embodiment 2, FIG. 7 is an exploded perspective view showing an image pickup device moving mechanism of the CCD camera, and FIG. 8 is a perspective view showing an image pickup device moving mechanism of the CCD camera.
As shown in the figure, the flange back adjustment screw 36 is screwed into the frame 33, and the oval hole 39 a of the flange back adjustment knob 39 is fitted with the oval projection 36 a of the flange back adjustment screw 36. For this reason, the flange back adjustment screw 36 and the flange back adjustment knob 39 transmit only the force in the rotational direction, and move freely in the axial direction. With the flange back adjustment screw 36 and the flange back adjustment knob 39 fitted, the groove 39b on the side surface of the flange back adjustment knob 39 and the claw 40a of the knob holding bracket 40 are fitted, and the flange back adjustment knob 39 is axially moved. It does not fall off.
[0018]
With this structure, even if a force is applied in the axial direction when rotating the flange back adjustment knob 39 with a finger, the force is not transmitted to the flange back adjustment screw 36, and the flange back adjustment screw 36 is displaced in the axial direction. There is no. For this reason, according to the present invention, when performing the flange back adjustment, there is a feature that the flange back adjustment can be accurately performed without changing the axial position of the imaging element 9 due to the external force in the axial direction.
[0019]
Even if the flange back adjustment screw 36 moves in the axial direction due to the rotation of the screw, the flange back adjustment knob 39 always keeps a fixed position. For this reason, even if the flange back adjustment knob 39 is small, it has a feature that it always maintains a position where it can be easily operated with a finger.
[0020]
When the flange back adjustment screw 36 is operated beyond the adjustable range, if the screw is screwed deeply, the frame 33 and the flange back adjustment screw 36 come into contact with each other and stop. The flange back adjustment knob 39 comes into contact and stops. Therefore, there is a feature that the flange back adjustment screw 36 does not move beyond the adjustable range, and for example, the flange back adjustment screw 36 does not come off due to excessive loosening.
[0021]
Embodiment 3 FIG.
FIG. 9 shows the third embodiment and is an exploded perspective view of a flange back adjusting screw portion. As shown in the figure, the flange back adjustment screw 36 is screwed into the frame 33, and the oval hole 39 a of the flange back adjustment knob 39 is fitted with the oval projection 36 a of the flange back adjustment screw 36. A coil spring 41 is inserted coaxially with the flange back adjustment screw 36, and the coil spring 41 is compressed between the flange back adjustment screw 36 and the frame 33. The reaction force of the coil spring 41 causes the flange back adjustment screw 36 to be offset by the play of the screw.
[0022]
In this structure, the reaction force of the coil spring 41 is the same as the direction in which the cylindrical cam 30 presses the flange back adjustment screw 36. Therefore, even if the screw is loose, the cylindrical cam 30 and the flange back adjustment screw 36 come into contact with each other. The flange-back adjusting screw 36 does not move in the axial direction when the contact is made or when there is no contact. Therefore, even when the image sensor 9 is repeatedly moved by the image sensor moving mechanism 20, the position of the image sensor 9 in the optical axis direction at the time of photographing does not change.
[0023]
Further, the flange back adjusting screw 36, the coil spring 41, and the frame 33 are pressed against each other by the reaction force of the coil spring 41 to generate appropriate friction, so that the flange back adjusting screw 36 does not rotate carelessly. In addition, even when the image pickup device 9 is repeatedly moved by the image pickup device moving mechanism 20, the position of the image pickup device 9 in the optical axis direction at the time of photographing does not change.
[0024]
Embodiment 4 FIG.
FIG. 10 shows the fourth embodiment, and is an exploded perspective view of a flange back adjusting screw portion. As shown in the figure, the flange back adjustment screw 36 is screwed into the frame 33, and the oval hole 39a of the flange back adjustment knob 39 is fitted with the oval projection 36a of the flange back adjustment screw. A coil spring 41 is inserted coaxially with the flange back adjustment screw 36. A knurl is cut on the outer periphery of the flange back adjustment knob 39, and a ball plunger 42 is fixed to the frame 33 so as to fit with the knurl.
[0025]
In this structure, when the flange back adjustment knob 39 rotates, the ball plunger 42 and the knurled groove on the outer periphery of the flange back adjustment knob 39 are stabilized at the fitting position, so that the flange back adjustment screw 36 may rotate carelessly. In addition, even when the image sensor 9 is repeatedly moved by the image sensor moving mechanism 20, the position of the image sensor 9 in the optical axis direction at the time of photographing does not change.
[0026]
Further, when turning the flange back adjustment knob 39 with a finger, a click feeling is felt at a position where the ball plunger 42 and the knurled groove of the flange back adjustment knob 39 are fitted, so that it can be used as a guide for fine adjustment. There is a feature.
[0027]
【The invention's effect】
In the video camera according to the present invention, when the power is not turned on, the image pickup device mounted on the image pickup device holder is retracted into the container of the radiation shielding material, and the image pickup device is placed on the optical axis of the lens only when the power is turned on. An image sensor moving mechanism having a driving device for moving the image sensor to a predetermined position, and an adjusting screw that is provided in parallel in the linear movement direction of the image sensor moving mechanism and adjusts the flange back by applying the image sensor holder to the end face. Provided between the image sensor holder and the drive device, and a spring that absorbs a change in position when the flange back is adjusted, so that the image sensor is moved by the image sensor moving mechanism, The operation of positioning the lens at a predetermined position on the optical axis of the lens again can be stably performed.
[Brief description of the drawings]
FIG. 1 shows the first embodiment, and is an external perspective view of a CCD camera as viewed obliquely from the front.
FIG. 2 shows the first embodiment, and is an external perspective view of the CCD camera as viewed obliquely from behind.
FIG. 3 shows the first embodiment, and is an exploded perspective view showing a CCD camera.
FIG. 4 shows the first embodiment, and is a cross-sectional view showing a CCD camera.
FIG. 5 is a view showing the first embodiment, and is a perspective view showing an image pickup device moving mechanism of the CCD camera.
FIG. 6 shows the first embodiment, and is a cross-sectional view showing an image pickup device moving mechanism of the CCD camera.
FIG. 7 shows the second embodiment and is an exploded perspective view showing an image pickup device moving mechanism of the CCD camera.
FIG. 8 shows the second embodiment and is a perspective view showing an image pickup device moving mechanism of the CCD camera.
FIG. 9 shows the third embodiment and is an exploded perspective view showing an image pickup device moving mechanism of the CCD camera.
FIG. 10 is a diagram illustrating the fourth embodiment, and is an exploded perspective view illustrating an image pickup device moving mechanism of the CCD camera.
[Explanation of symbols]
Reference Signs List 1 CCD camera, 2 camera case, 3 front panel, 4 camera units, 5 latches, 6 lenses, 7 power / control connector, 8 video connector, 9 image sensor, 10 camera board, 11-14, 16 neutron moderator , 17-19 γ-ray shielding material, 20 image sensor moving mechanism, 21 solenoid, 22 motor, 23 gear plate, 24 latch, 25 gear A, 26 gear B, 27 gear C, 28 rack, 29 drive pin, 30 cylindrical cam , 31 guide rod, 32 CCD board, 33 frame, 34 sleeve, 35 spring, 36 flange back adjustment screw, 37 limit switch, 38 return spring, 39 flange back adjustment knob, 40 knob holding bracket, 41 spring, 42 ball plunger.

Claims (6)

When the power is not turned on, the image sensor mounted on the image sensor holder is retracted into the radiation shielding container, and the image sensor is moved to a predetermined position on the optical axis of the lens only when the power is turned on. An image pickup device moving mechanism having a device;
An adjusting screw that is provided in parallel in the linear movement direction of the image sensor moving mechanism and adjusts the flange back by applying the image sensor holder to an end face,
A spring that is provided between the image sensor holder and the driving device and absorbs a change in position when the flange back is adjusted,
A video camera comprising: The image pickup device moving mechanism has a guide rod for guiding the linear movement of the image pickup device. When the image pickup device is moved to a shooting position, the surface perpendicular to the guide rod of the image pickup device holder is formed by the flange back adjustment screw. The video camera according to claim 1, wherein the video camera is performed by contacting the end surface. The adjusting screw is composed of a screw portion and a knob portion, the screw portion and the knob portion are fixed only in the rotation direction, and the structure is such that the axial direction is freely movable, and then the knob portion is fixed to the frame only in the axial direction. The video camera according to claim 1, wherein the video camera is supported to rotate freely. A knob holding member having a claw portion for fixing the knob portion of the adjusting screw to the frame is provided, and a groove is provided on the knob portion side surface of the adjusting screw so that the knob portion does not drop off in the axial direction. The video camera according to claim 3, wherein the claw portion of the holding metal fitting and the groove of the knob portion of the adjusting screw are fitted. 4. The video camera according to claim 3, wherein a spring is arranged coaxially with the screw portion of the adjusting screw to apply a preload to the screw portion. 4. The video camera according to claim 3, wherein a ball plunger is provided on the frame, a knurl is cut around the knob portion of the adjusting screw, and the ball plunger is pressed against the knurl.

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