JPH0244185B2 - - Google Patents

Description

[Detailed Description of the Invention] When a television camera is used to take pictures using an optical filter, star-shaped beams are created in the video scene, images are overlapped, etc. When photographing a scene with special effects such as rotation around the center, a rotating filter device is used that inserts a desired filter into the optical axis of a television camera and rotates the filter around the optical axis.

In the past, there have been many scenes shot with such special effects, but no simple special effects device has been proposed. For example, as shown in FIG. 1, a very large special effects device 3 is inserted between the lens device 1 and the main body 2 of a television camera,
The actual situation was that this was remotely controlled using the operation unit 4 to take pictures.

However, such conventional special effects devices have various drawbacks as described below.

(1) Since the special effects device 3 is large and heavy, the center of gravity of the camera shifts, and the balance of the cam head must therefore be readjusted.

(2) The strength of the tripod 5 must also be considerably strong.
A large tripod is required.

(3) By installing the special effects device 3,
Since the distance between the lens device 1 and the main body 2 increases significantly and the tracking becomes inconsistent, it is necessary to take measures to correct this.

(4) Depending on the function of the special effects device 3, the amount of light incident on the image pickup tube may be attenuated, and consideration must be given to correction and lighting for this purpose.

(5) Since the special effects device 3 is complicated and expensive,
It is economically difficult to install and use it on all television cameras.

(6) The power supply section must be equipped with a separate power supply.

(7) Since television cameras are subject to restrictions for reasons (1) to (6), filming must also be subject to restrictions.

An object of the present invention is to solve the various drawbacks of the conventional television camera described above, and to be able to be constructed so small and lightweight that it can be easily incorporated into the place where the filter device was installed in the conventional television camera. It is an object of the present invention to provide a rotary filter device that can be manufactured at low cost and that can selectively achieve various special effects through simple operations.

The rotary filter device of the present invention includes: a first disc rotatably pivoted about an axis; a first rotation mechanism that rotates the first disc in both forward and reverse directions; a plurality of filters each rotatably mounted on a plate and connected to the first rotation mechanism;
The absolute position of the first disc is constantly detected, compared with the position of any filter specified to be inserted into the optical path from among the plurality of filters, and the rotation direction is determined according to the difference. a first drive control circuit that controls a first rotation mechanism to rotate the first disc so as to rotate the first disc; a first drive control circuit that is rotatably mounted on the first disc about the axis; a second disc drivingly connected to a second disc, a second rotation mechanism that simultaneously rotates the plurality of filters by rotating the disc in both forward and reverse directions, and a second rotation mechanism connected to the second rotation mechanism; and a second drive control circuit for controlling the second rotational direction and rotational speed, the flattened lens being entirely disposed in the space between the rear of the lens mount and the color separation prism in the camera head housing of the television camera. It is characterized by its shape.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIGS. 2a and 2b are a plan view and a side view showing the structure of an embodiment of a rotary filter device according to the present invention. A filter disk 10 is rotatably attached to a frame 11 via a shaft 12. In FIG. 2a, frame 11 is shown in phantom. A spur gear 10a is formed on the outer periphery of this filter disk 10. A first gear 13 that meshes with the gear of this filter disk is provided, a second gear 14 with a small diameter is attached to the shaft of this first gear, and a third gear 15 that meshes with this second gear is provided. , this third gear
Attach it to the output shaft of the motor 16. Further, a fourth gear 17 that meshes with the third gear 15 is provided, and this fourth gear is connected to the rotary type potentiometer 1.
It is fixed to the drive shaft 19 of 8.

On the other hand, a fifth gear 20 is rotatably mounted on the filter disc 10 concentrically with the shaft 12, and this fifth gear is connected to a seventh gear 22 via a sixth gear 21. A seventh gear is fixed to the drive shaft 24 of the second motor 23.

A plurality of circular filters 30a to 30f, six in this example, are respectively attached to the filter disk 10 so as to be freely rotatable. In this example, these six filters are a blind plate, a transparent glass, an ND filter, a mirage, a linear focus, and a cross. Each filter 30a to 30
Gears 31a to 31f are fixed to the outer periphery of f, and these gears are meshed with the fifth gear 20.

According to the rotary filter device configured as described above, by driving the first motor 16, the gears 15-
By rotating the filter disk 10 via the filter 14-13-10a, any one of the filters 30a to 30f can be inserted into the optical axis OP. Also,
By driving the second motor 23, the gear 22
-21-20-31a-31f, all filters 30a to 30f can be rotated simultaneously.

FIG. 3 is a perspective view showing a filter unit holding a filter 30a. The filter 30a is fixed to a filter ring 32, for example, with an adhesive, and a spur gear 31a is formed at the lower end of the filter ring 32. There is a groove 3 on the upper outer wall.
3 is formed. This groove 33 is for rotatably holding the filter unit on the filter disk 10, as will be described later.

FIG. 4 is a cross-sectional view of the filter disk 10 and a portion of the filter unit. Straight line A-A is axis 1
2, and is also the center of rotation of the filter disk. A filter disk 10 and a fifth gear 20 are rotatably mounted on this shaft 12 via spacers 34 to 40. When installing the filter unit, attach the filter ring 32 to the filter disc 10.
Insert the gears 20 and 31a from below into the drilled hole.
mesh with. In this state, the filter ring stopper 41 is inserted into the groove 33 of the filter ring 32 and fixed to the filter disc 10 with the screw 42. In this way, the filter unit can be detachably attached to the filter disc 10. The filter ring 32 is made of brass with a surface treatment such as black matte plating to prevent diffuse reflection of light, and the sliding contact area with the filter disc 10 is made of molybdenum disulfide (M _p S ₂ ) based material. Applying film treatment,
It is intended to act as a dry lubricant. The filter disk 10 is an aluminum plate subjected to surface treatment such as black alumite to prevent diffuse reflection of light.

The above-described rotary filter device of the present invention is mounted in the front part of the camera head housing of a television camera, that is, between the rear part of the lens mount and the color separation prism, as shown in FIG. That is, the main body frame 4
It can be freely inserted and removed along a guide rail (not shown) attached to the main body frame 45 into the gap between the lens mount 46 attached to the color separation prism 47 and the glass plate 48 disposed on the incident side of the color separation prism 47. do it like this. Conventionally, a filter disk equipped with an ND filter or a color temperature conversion filter has been inserted into this space, but the rotary filter device of the present invention can be inserted in place of this filter disk. Therefore, the distance between the lens system and each image pickup tube does not increase at all, and no tracking problem occurs at all. Also, the above void is usually 10 to 15
Since the thickness of the rotary filter device of the present invention is approximately 1 mm, the thickness of the rotary filter device of the present invention is also kept within this range.

FIG. 6 shows an example of a drive control circuit for the above-mentioned rotary filter device.

A local/remote switch 51 is provided so that the filter disk 10 can be rotated from either the camera head side or the camera control unit side, but the figure shows the case of remote operation.

A resistor is connected between each contact of the position rotary switch 52, and -3V is applied to one end of this resistor, and 4.5V is applied to the other end. The contacts of the rotary switch 52 obtain a partial voltage of this voltage and transfer it to the IC.
Here, the voltage is compared with the voltages from other input terminals, and if there is no potential difference, there is no output, so no voltage is applied to the motor circuit, and the first motor 16 does not rotate.

Other input terminals of circuit 53 and rotary switch 5
Potential difference between comparison voltages from 2 (temporarily set to positive potential)
If it exists, the output becomes a negative potential, so the transistor 54 becomes conductive, and the base potential of the transistor 55 decreases, so the transistor 55 is turned off.
Also, at this time, the transistor 56 is turned off, the transistor 57 is turned on, and the output circuit becomes -12V, and a current flows from the earth to the motor 16 to the switch 58 to the transistor 57 to -12V, and the motor 16 rotates. If the input of the circuit 53 is at a negative potential, the transistors 55 and 56 become conductive, and a current flows from +12V to the transistor 55 to the switch 58 to the motor 16 to the ground, causing the motor 16 to rotate in the opposite direction.

Potentiometer 18 directly connected to motor 16
The divided voltage from the rotary switch 52 is led to the circuit 53, and the output of the circuit 53 disappears when the potential difference with the divided voltage from the rotary switch 52 disappears, so the transistor 55
Alternatively, since the emitter 57 becomes zero potential, no voltage is applied to the motor 16 and the motor 16 stops. The contacts A to F of the rotary switch 52 correspond to the stop positions of the filters 30a to 30f attached to the filter disc 10, and the circuit of this embodiment is an example of a circuit when six filters are mounted. In this case, the control method, voltage, and stopping position of the filter disks should be selected according to the number of filters mounted.

The motor 23 is a motor for rotating the filters 30a to 30f, and the switch 59 is a selection switch for rotating clockwise, rotating counterclockwise, and stopping.
It is always stopped, that is, connected to the earth. It is sufficient for this switch 59 to be a push button switch or a switch with a home position.
When set to RIGHT, the +12V potential is passed through the switch 59 - variable resistor 60 - switch 61 - relay contact 62 -> circuit 63, and a negative potential is generated at its output, so the motor 23 rotates at a rotation speed proportional to the output voltage of the circuit 63. and rotates in the direction of rotation according to its polarity.

To stop the rotation, the switch 59 may be set to the STOP position so that the output of the circuit 63 is eliminated. The speed control switch 61 changes the rotation speed of the motor 23, and the inter-terminal resistance thereby adjusts the rotation speed of the motor 23, and the variable resistor 60 is a resistance for fine adjustment. This rotation fine adjustment variable resistor 60 is necessary to match the filter rotation speed of each camera when shooting special effects using multiple cameras, or to obtain the filter rotation speed required by the video. It is a great resistance.

There is also a speed control on the camera control unit side, but since it is the same circuit, its description is omitted.

Transistor 64 is a transistor for local/remote switching, and is normally placed on the camera head side. When local/remote switch 51 is set to local (indicating operation on the camera head side), transistor 64 becomes conductive and relay 65 operates. , so that the rotation of the filter disk and filter ring can be controlled by the circuit on the camera head side. This relay 65 makes relay contacts 62, 66, 67
to drive.

On the other hand, the indicator lamp 68 is turned on to indicate that it is a local operation.

As shown in FIG. 2, the mechanical system that rotates the filters 30a/30f is such that the driving force of a gear 22 connected to a shaft 24 of a motor 23 is transmitted to a gear 21.
This is transmitted to gear 20. This gear 20 meshes with gears 31a to 31f carved on the outer edge of a plurality of filter rings 33 mounted on the filter disc 10, and rotates the filters 30a to 30f fitted in the filter rings to produce special effects. You can take pictures of

Note that the switches 58, 69 to 71 shown in FIG.
is an on/off switch, and the filter disk 10
And it is turned off when manually rotating the filters 30a to 30f. Further, the voltage divider driven by the switch 72 is installed in the camera head section for position control, and is selected by the relay contact 67.

A little over one rotation is sufficient for the filter disk 10 in terms of its function, and it is desirable to switch the filter in less than one second, so in this embodiment, the rotation speed of the filter disk 10 is selected to be 30 rpm. However, there are countless combinations of this rotation speed if the gear ratio is selected appropriately, and the key is to select the filter switching time that satisfies the required performance by selecting the gear ratio. Further, since the potentiometer 18 only needs to be slid from one end to the other end during a little more than one rotation of the filter disc 10, the gear 15,
A gear ratio of 17 may be adopted to meet this requirement.

Filters for various purposes such as ultraviolet absorption, color correction, color temperature conversion, special effects, and bright line spectrum suppression are commercially available. Just select and use. In the embodiment described above,
Special effects were shot using six types of special effect filters: blind plate, clear through, ND, mirage, linear focus, and cross. Special effect filters such as cloth, color, etc. may also be used.
All you have to do is prepare these filters in advance and select the filter configuration that suits your photographic needs.Also, you can replace them by loosening the fixing screw 42 screwed onto the filter disc 10 and removing the filter ring stopper 4.
You can easily replace it by removing 1. The rotary filter device with any desired filter attached thereto is mounted at a predetermined position within the camera head via a guide rail or the like, fixed with screws, and connected to the electrical system via a connector.

If the rotary filter device of the present invention is installed, it may make it difficult to take pictures if a conventional ND filter and color temperature conversion filter are required. A filter device is separately prepared in which two filter disks 81 and 82 are rotatably mounted on a frame 83, and these filter disks are rotated by a motor, which implements only a conversion filter and omit a filter rotation mechanism. , the rotary filter device may be replaced depending on the purpose.

Note that the present invention is not limited to the above-mentioned example, and many modifications and applications are possible. For example, in the embodiment described above, six filters were mounted on one filter disk, and each was rotated by two control electrical systems, but two filters were placed back to back, and one control electrical system was added. By additionally rotating two filters clockwise and counterclockwise, a combined special effect can be photographed. Alternatively, by arranging two filter discs back to back and providing four control electrical systems, the number of combinations of filters will further increase and new special effects can be expected. In addition, although the above embodiment was applied to a television camera, it can also be applied to an optical camera, that is, a movie camera, or to a filter for a theater spotlight. You can expect new lighting effects. Furthermore, in the above-described embodiment, the rotation of the filter disk and the rotation of each filter was performed by a power transmission mechanism using gears, but rollers, belts,
A power transmission mechanism such as a chain may also be used.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the configuration of a television camera incorporating a conventional special effects device, FIGS. FIG. 3 is a perspective view showing the filter unit, FIG. 4 is a sectional view showing the filter unit and filter disk assembled together, and FIG. 5 is a view showing the rotary filter device of the present invention being inserted into a television camera. A diagrammatic plan view showing the position, FIG. 6 is a circuit diagram showing the configuration of an example of the drive control circuit of the rotary filter device of the present invention, and FIG. 7 is the ND
FIG. 2 is a perspective view showing a filter device in which two filter disks loaded with a filter and a color filter are combined. 10... Filter disk, 11... Frame, 12...
Axis, 10a, 13, 14, 15, 20, 21, 2
2, 31a to 31f... Gears, 16, 23... Motors, 30a to 30f... Filters.

Claims (1)

[Claims] 1. A first disc rotatably pivoted about an axis, a first rotation mechanism that rotates the first disc in both forward and reverse directions, and rotatably attached to each of the first discs. a plurality of filters connected to the first rotation mechanism, constantly detecting the absolute position of the first disc, and an arbitrary filter designated to be inserted into the optical path from among the plurality of filters. a first drive control circuit that controls a first rotation mechanism to rotate the first disk in a rotation direction determined according to a difference between the position of the disk and the first disk; a second disc attached to the first disc and drivingly connected to the plurality of filters; and a second disc that simultaneously rotates the plurality of filters by rotating the second disc in both forward and reverse directions. a rotation mechanism, and a second drive control circuit connected to the second rotation mechanism to control the rotation direction and rotation speed of the second disk; A rotating filter device characterized by having a flat shape so that it can be placed in a space between the rear part of a mount and a color separation prism.