JP2001197338A - Optical filter device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical filter device in which a disk for supporting a filter can be exchanged only by removing the supporting member of a color separation prism from a base frame by constituting a supporting member for supporting the color separation prism and a driving unit to a half-sprit structure to make one of the divided supporting member support a color separation prism and the other supporting member support the driving unit, in the optical filter device provided with a filter-supporting disk, the color separation prism and the driving unit. SOLUTION: A supporting plate for supporting the color separation prism 16 and the driving unit 18 of the optical filter device 10 is constituted by half- split structure to make one of the supporting plates support the prism 16 and the other supporting plate 70 support the unit 18. Then, the filter disk 145 is exchanged only by detaching the plate 36 from the base frame 12 without detaching the plate 70 from the frame 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical filter device mounted on a camera such as a broadcast video camera, and more particularly, to rotating a filter supporting disk having a plurality of filters so that a desired filter can be photographed on an optical axis. The present invention relates to an optical filter device located above.

[0002]

2. Description of the Related Art A broadcast video camera separates white light of a photographed object into light of three colors of RGB by a color separation prism, receives each light by a CCD, and outputs electric light output from the CCD. The image is formed by combining the signals. An optical filter device that arranges special effect filters such as an ND filter, a CC filter, and an infrared filter in front of the color separation prism, and adjusts the amount of light and characteristics of light incident on the color separation prism according to shooting conditions. Some are provided.

The conventional optical filter device 1 shown in FIG.
The base frame 2 is provided with a filter disk (filter support disk) 3, a color separation prism 4, and a drive unit 5 indicated by broken lines in FIG. The rotation axis 3A of the filter disk 3 is supported by the base frame 2,
The plurality of filters described above are provided around the rotation shaft 3A. On the other hand, the color separation prism 4 and the drive unit 5 are supported by a common support plate 6, and are mounted at predetermined positions on the base frame 2 via the support plate 6.

The drive unit 5 includes a motor 7, a gear train 8,
A gear 8A disposed at the end of the gear train 8 is meshed with a gear 3B engraved on the outer periphery of the filter disk 3. Therefore, when the motor 7 is driven, the driving force is transmitted from the gear 8A of the gear train 8 to the gear 3B, so that the filter disk 3 rotates and a desired filter is placed on the optical axis of the color separation prism 4. Is located.

The amount of rotation of the filter disk 3 is determined by the gear train 8
The ON / OFF of the motor 7 is controlled by a controller (not shown) based on the position information output from the potentiometer 9. That is, the motor 7 is
When F is performed, the filter is positioned on the optical axis of the color separation prism 4.

Incidentally, in the optical filter device 1, the filter disk 3 may be replaced with a filter disk having a different optical characteristic depending on the photographing situation. In such a case, first, the support plate 6 is removed from the base frame 2, and the filter disc 3 exposed thereby is removed from the base frame 2. After this, a replacement filter disk is attached to the base frame 2,
Finally, the support plate 6 is mounted on the base frame 2. Thus, the replacement work of the filter disk is completed.

[0007]

However, the conventional optical filter device 1 has a drawback that the drive unit 5 is detached from the base frame 2 when the filter disk is replaced, so that it takes time to replace the filter disk. .

The present invention has been made in view of such circumstances, and an object of the present invention is to provide an optical filter device having a structure in which a filter supporting disk can be easily replaced.

[0009]

In order to achieve the above object, the present invention provides a filter comprising a base frame rotatably provided via a rotary shaft and a plurality of filters disposed around the rotary shaft. A support disc, a color separation prism supported via a support member detachably attached to a base frame, and a filter supported by the support member and rotating the filter support disc to photograph a desired filter In an optical filter device including a motor and a drive unit including a gear positioned on the optical axis, the support member is configured in a two-part structure, and the color separation prism is supported on one of the divided support members. At the same time, the drive unit is supported by the other support member, and by removing the one support member from the base frame, replacement of the filter support disk is performed. Characterized by being realized.

According to the present invention, the support member for supporting the color separation prism and the drive unit is formed in a two-part structure, and one of the divided support members supports the color separation prism.
Since the drive unit is supported by the other support member and the one support member is removed from the base frame, the filter support disk can be replaced. Therefore, the filter support disk can be easily replaced.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the optical filter device according to the present invention will be described below in detail with reference to the accompanying drawings.

As shown in FIGS. 1 to 4, an optical filter device 10 according to an embodiment comprises a base frame 12, a filter disk 14
(See FIG. 5), a color separation prism 16, and a drive unit 18.

The base frame 12 is formed in a rectangular shape as shown in FIG. 1, and a lens mount 20 is provided on the front side thereof. A photographing lens 22 indicated by a two-dot chain line in FIG. 2 is detachably mounted on the lens mount 20.

A shaft 34 for supporting the front filter disk 14A and the rear filter disk 14B of the filter disk 14 is formed on the rear surface of the base frame 12, as shown in FIG. The front filter disk 14A can be replaced.

A support plate 36 for the color separation prism is mounted on the back side of the base frame 12 as shown in FIG.
The color separation prism 16 is fixed via a mounting plate 38. The support plate 36 is formed in a rectangular shape as shown in FIG. 3, and positioning holes 40, 40 are formed in these two places. These holes 40, 40 are formed in the base frame 1 shown in FIG.
The support plate 36 is attached to a predetermined position of the base frame 12 by being fitted into two pins 42, 42 protruding from FIG. 2, and the four screws 32, 32 shown in FIG. 3
The support plate 36 is fixed to the base frame 12 by screwing into the screw holes 46, 46.

The color separation prism 1 supported by the support plate 36
Reference numeral 6 includes first, second, and third prisms 48, 50, and 52 for decomposing the subject light from the photographing lens 22 into R, G, and B components as shown in FIG. The first prism 48 and the second prism 50 are provided to be slightly separated from each other so as to form an air layer on their opposing surfaces. Further, a first dichroic surface is formed on the opposing surface on the first prism 48 side, and R light and G light are transmitted by the first dichroic surface and B light is reflected. The reflected B light is totally reflected by the total reflection surface of the first prism 48 and the first prism 4
8 to the exit end 54. This emission end 54 has a C for B light.
The CD 56 is fixed via the holder 58.

The second prism 50 and the third prism 52 are joined to each other via a second dichroic surface formed therebetween. Among the R light and the G light transmitted through the first dichroic surface, the R light is reflected by the second dichroic surface, and the reflected R light is totally reflected by the total reflection surface of the second prism 50, and the second prism The light is guided to the exit end 60 of the light source 50. An R light CCD 62 is fixed to the emission end 60 via a holder 58. on the other hand,
The G light that has passed through the second dichroic surface is
The light is guided to the emission end 64 of the prism 52. This emission end 6
4, a G light CCD 66 is fixed via a holder 58.

As shown in FIGS. 2 and 3, on the rear side of the base frame 12 and above the color separation prism 16, a driving unit support plate 70 is provided.
The drive unit 18 is supported by the support plate 70. The support plate 70 is fixed to the back surface of the base frame 12 by four screws 72, 72,... As shown in FIGS. Further, as shown in FIG.
Is formed in a concave-convex fitting structure, and by this structure, intrusion of dust through the joint 74 is prevented. Therefore, the support plate 36 and the support plate 70 have the function of a dustproof cover. The support plate 36 is formed to be larger than the support plate 70, so that the support plate 3
6 is removed from the base frame 12, the filter disc 1
Most of 4B is exposed as shown in FIG. 5, so that the replacement work of the rear filter disk 14B can be performed.

The drive unit 18 supported on the support plate 70
Is composed of a first unit 18A and a second unit 18B as shown in FIG. First unit 18A
Is a drive unit for driving the front filter disk 14A shown in FIG. 6, and comprises a motor 76A, a gear train 78A, and a potentiometer 80A as shown in FIG. On the other hand, the second unit 18B is a drive unit for driving the rear filter disk 14B in FIG. 6, and includes a motor 76B, a gear train 78B, and a potentiometer 80B as shown in FIG.

The motor 76A and the potentiometer 80A of the first unit 18A are fixed to a bracket 84 fixed to the support plate 70 by screws 82. Motor 76A
The spindle 86A is disposed through the bracket 84, and a driving gear 88 constituting a gear train 78A is provided at the tip of the spindle 86A.
A is attached. The gear 88A is connected via a driven gear 90A to a gear 92A indicated by a dotted line in FIG. 6, and the gear 92A is meshed with a gear 15A engraved on the outer periphery of the front filter disk 14A.

As a result, when the motor 76A is driven, the driving force is transmitted to the gear 15A via the gear train 78A, so that the front filter disk 14A is rotated.
A desired filter attached to the front filter disk 14A is located on the imaging optical axis.

The amount of rotation of the front filter disk 14A is detected by a potentiometer 80A having a gear 94A meshed with the gear 88A of FIG. ON / OFF of the motor 76A is controlled by a controller (not shown) based on the position information output from the potentiometer 80A. That is, when the motor 76A is turned off based on the position information, the filter of the front filter disk 14A is positioned on the photographing optical axis.

The motor 76B and the potentiometer 80B of the second unit 18B are also fixed to the bracket 84. A spindle 86B of the motor 76B is also disposed through the bracket 84, and a driving gear 88B constituting a gear train 78B is attached to a tip of the spindle 86B. The gear 88B is connected via a driven gear 90B to a gear 92B shown by a two-dot chain line in FIG. .

Thus, when the motor 76B is driven, the driving force is transmitted to the gear 15B via the gear train 78B, so that the rear filter disk 14B is rotated.
A desired filter attached to the rear filter disk 14B is located on the photographing optical axis.

The amount of rotation of the rear filter disk 14B is detected by a potentiometer 80B having a gear 94B meshed with the gear 88B of FIG. ON / OFF of the motor 76B is controlled by a controller (not shown) based on the position information output from the potentiometer 80B. That is, when the motor 76B is turned off based on the position information, the filter of the rear filter disk 14B is positioned on the photographing optical axis.

As shown in FIG. 5, the rear filter disk 14B has a disk-shaped substrate. The rear filter disk 14B has circular openings 100, 100,...
And three of these openings 10
Special effect filters 102 such as ND filters, CC filters, and infrared filters are attached to 0, 100, and 100 via a pair of holders 104, 104, respectively. No filter is attached to the remaining one opening 100, so that the subject light from the taking lens 22 is directly incident on the color separation prism 16. Note that the structure of the front filter disk 14A is the same as the structure of the rear filter disk 14B, and a description thereof will be omitted.

Next, a method of replacing the filter disk 14 in the optical filter device 10 configured as described above will be described.

First, in the state of FIG. 3, the screws 32, 32 fixing the support plate 36 for the color separation prism are loosened.
The support plate 36 is removed from the base frame 12. Thereby, the filter disk 14B after the filter disk 14 is exposed as shown in FIG.

Next, the rear filter disk 14B is pulled out from the rotating shaft 34 and removed from the base frame 12. At this time, since there is a space S between the rear filter disk 14B and the drive unit support plate 70 for pulling out the rear filter disk 14B as shown in FIG. 6, the rear filter disk 14B is removed from the base frame 12 without any problem. be able to.

Next, after inserting the upper part of the new rear filter disc 14B to be replaced into the space S, the rear filter disc 14B is fitted into the rotating shaft 34, and the gear 15B of the rear filter disc 14B is moved upward in FIG. The gear 92B is attached to the base frame 12 by meshing with the gear 92B indicated by a two-dot chain line. Then, the support plate 36 is attached to the original position of the base frame 12, and is fixed to the base frame 12 with the screws 44. Thus, the replacement work of the rear filter disk 14B is completed. As another replacement method, the filter is replaced by loosening the filter mounting screw 103, removing the holder 104, and fastening a new holder holding the replacement filter to the filter disk with the filter mounting screw 103. You may make it.

Therefore, according to the optical filter device 10 of the present embodiment, the support plate for supporting the color separation prism 16 and the drive unit 18 has a double structure composed of the support plates 36 and 70. The filter disk 14 can be replaced without removing the 18 from the base frame 12. Therefore, as compared with the conventional optical filter device 1 of FIG. 8 in which the filter disc 3 cannot be replaced without removing the drive unit 5, the filter disc 14
Replacement becomes easy.

Further, in the conventional optical filter device 1 shown in FIG. 8, when the gear 8A meshes with the gear 3B,
Even if B rotates slightly and meshes with the gear 8A in a state where the position of the gear 3B is shifted, the meshing state is blinded by the support plate 6 so that it is not noticed. In this case, since the position information output from the potentiometer 9 and the actual position of the filter disk 3 are displaced, there occurs a problem that the filter disk 3 does not stop at an accurate position.

On the other hand, in the optical filter device 10 of the present embodiment, when the gear 15B is engaged with the gear 92, the rear filter disk 14B is exposed.
In other words, the gear can be engaged with the rear filter disk 14B while looking directly at the gear, so that the gear 15B can be accurately engaged with the gear 92B. Therefore, the rear filter disk 14B can be stopped at an accurate position.

In the present embodiment, the replacement work of the rear filter disc 14B has been described. However, when the front filter disc 14A is replaced together with the rear filter disc 14B, the replacement work is performed in the same manner as the above replacement work. do it. Further, even if the front plate 24 of the base frame 12 is removed from the rear plate 26, the two filter disks 14
A and 14B can be exchanged together. Further, when replacing only the front filter disk 14A, the base frame 1
The second front plate 24 is removed from the rear plate 26 to perform the replacement operation.

[0035]

As described above, according to the optical filter device of the present invention, the support member for supporting the color separation prism and the drive unit is formed in a two-part structure, and one of the divided support members has a color. The filter support disk can be replaced by supporting the disassembly prism, supporting the drive unit on the other support member, and removing one support member from the base frame, making it easy to replace the filter support disk. Become.

[Brief description of the drawings]

FIG. 1 is a front view of an optical filter device according to an embodiment.

FIG. 2 is a right side view of the optical filter device shown in FIG.

FIG. 3 is a rear view of the optical filter device shown in FIG. 1;

FIG. 4 is a top view of the optical filter device shown in FIG. 1;

FIG. 5 is a rear view when the support plate for the color separation prism is removed from the optical filter base frame.

FIG. 6 is a sectional view of the optical filter device taken along line 6-6 in FIG. 5;

FIG. 7 is a structural diagram of a color separation prism provided in the optical filter device.

FIG. 8 is a structural diagram of a conventional optical filter device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Optical filter apparatus, 12 ... Base frame, 14 ... Filter disk, 16 ... Color separation prism, 18 ... Drive unit, 36 ... Color separation prism support plate, 70 ... Drive unit support plate, 76A, 76B ... Motor, 78A, 78B
... gear train, 80A, 80B ... potentiometer, 102
…filter

Claims (1)

[Claims] 1. A filter supporting disk rotatably provided on a base frame via a rotating shaft and having a plurality of filters disposed around the rotating shaft, and a supporting member detachably attached to the base frame. A color separation prism supported through the support member, and a drive unit including a motor and a gear supported by the support member and rotating the filter support disk to position a desired filter on a photographing optical axis. In the optical filter device, the support member is configured to have a two-part structure, and the one of the divided support members supports the color separation prism, and the other support member supports the drive unit. An optical filter device, wherein the filter supporting disk can be replaced by removing the supporting member from the base frame.