JPH07120809A - Filter disk device and optical instrument incorporating the same - Google Patents

Abstract

PURPOSE:To effectively arrange a disk position detecting photosensor for setting the filter of a filter disk having plural filters on an optical axis. CONSTITUTION:A group of three reflection type photosensors 7a, 7b and 7c are provided diagonally in the direction of the rotary shaft of the filter disk 1 and reflectors 9a1-9a3, 9b1-9d3... are stuck to groups of three V-shaped holes 1b1-1b3, 1c1-1c3... with prescribed relations among filters 4a-4d respectively so as to obtain an ON-OFF signal for selecting the filter in relation to the reflection type photosensors 7a, 7b and 7c. Moreover, in the detection of the position of a disk, when a position detecting means detects a specific position during the drive of the disk, it is newly driven up to a target position from the specific position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter disc device mounted on a part of a photographing system, and more particularly to a filter disc device having a photosensor used for detecting the position of the filter disc and an optical device incorporating the filter disc device. is there.

[0002]

2. Description of the Related Art Conventionally, in a color television camera or the like, a filter disc accommodating various filters such as a color temperature conversion filter, an infrared cut filter, or a color filter used at the time of photographing is arranged in a part of the photographing system. is doing. Then, a filter suitable for the photographing condition is appropriately selected by rotating a motor from a filter disc, for example, and is mounted in the optical path of the photographing system. As a result, the shooting conditions are optimized.

9 to 11 show an example of a conventional filter disc device. That is, the disk-shaped filter disks 1 and 2 of the same shape are rotatably supported on the same shaft 3, and a plurality of filters 4a, 4b and 4 such as a density filter and a color temperature conversion filter are equally spaced in the circumferential direction.
c and 4d are arranged, and gear parts 1a and 2a are provided on the outer peripheral edges thereof, respectively, and the selected filter is located on the optical axis O of the photographing system. Further, the gears 1a and 2a on the outer peripheral edges of the filter discs 1 and 2 are meshed with gears 5a and 6a provided integrally with the motors 5 and 6, respectively.

Further, three reflective photosensors 7a, 7b, 7c and 8a, 8b, 8 for detecting the filter position of the filter discs 1 and 2 are provided, relative to the outer peripheral portions thereof.
c are provided so as to be displaced in the radial direction, and three sets of three reflectors 9a1, 9a2, 9a3, 9b are provided on the outer peripheral surface between the filters of the filter disks 1 and 2.
1, 9b2, 9b3, 9c1, 9c2, 9c3, 9d
1, 9d2 and 9d3 are adhered so as to be parallel to the positions facing the reflective photosensors 7a, 7b, 7c and 8a, 8b, 8c when the disc is rotated. However,
In some places, the reflector is removed so that digital signals (for example, 0 for OFF and 1 for ON) can be obtained. In the illustrated filter disc 1, the portions 9b2, 9c1, 9d1 and 9d2 have the reflector removed.

In the conventional example having the above configuration, when a filter position command signal (for example, the filter 4a of the filter disk 1) is input to a filter disk drive circuit (not shown), a digital signal preset by the reflection type photosensor 7 is inputted. The motor 5 is energized until (for example, 1, 1, 1) is detected, the rotation of the motor output shaft is transmitted to the filter disc 1 via the gear 5a and is rotated, and when the reflection type photo sensor 7 detects a signal, the motor is rotated. The power supply to 5 is stopped and the filter 4a of the filter disc 1 is set on the optical axis O.

Next, as shown in FIG. 12, a motor (driving section) is used as a filter detecting means to be selected in a conventional television camera incorporating the above-described filter disk device (only the filter disk 1 is used). The control unit 11 includes five and three reflective photosensors 7a, 7b, and 7c.
, A set of three reflectors 9a1 to 9a3 provided between the filters of the filter disc 1, respectively.
..On / off combination of photosensors 7a, 7b, and 7c with respect to. (Reflector 9 does not have a black circle)
The rotation of the filter disc 1 is controlled by the above, or the rotation position of the disc is set from the output using a potentiometer. Regarding the on / off relationship of the photosensors 7a, 7b, and 7c depending on the type of filter, the filter 4a is off, off, on, and the filter 4
b is on, on, on, filter 4c is on, off,
On, the filter 4d is off, on, on.

[0007]

However, in the above-described conventional filter disk device, since the reflection type photosensor is arranged in parallel to the rotating direction of the filter disk, there is a possibility that it may be reflected on the filter and pick up an erroneous signal. was there. For this reason, the reflection type photosensor must be arranged outside the circumference φχ around which the filter moves, and there is a drawback that the device becomes large.

On the other hand, in the filter disc position detecting means of the above-mentioned conventional example, one position detecting means or a plurality of position detecting means is used for all the filters in the filter disc, and one of the on / off combinations is set. It is necessary to allocate them, and in both cases, a large number of position detecting means are required, and there is a drawback that the cost becomes high if a potentiometer is used. Also, if the final position of some filters is not detected, the encoder is
Since a phase encoder is used, an error occurs due to the influence of a slight vibration due to a mechanical mechanism, and when the operation between filters that does not detect the final position is repeated, the error accumulates and causes a malfunction.

A first object of the present invention is to provide a filter disk device which eliminates the above-mentioned drawbacks of the filter disk device of the prior art and can downsize the device even if a photosensor for detecting the filter disk rotational position is provided. To do.

The present invention eliminates the drawbacks of the filter disk position detecting means in the above-mentioned conventional optical equipment, simplifies the means, and provides an optical equipment provided with filter disk position detecting means having no detection error. The purpose is 2.

[0011]

In order to achieve the above-mentioned first object, the first invention is to provide one or two filter discs provided with a plurality of filters on the circumference as a part of a photographing system. In a filter disc device in which a predetermined filter is provided on the optical axis of the photographing system by rotating the filter disc, a photosensor for detecting the position of the filter disc is arranged in the rotation axis direction of the filter disc. It is arranged diagonally.

In order to achieve the above-mentioned second object, a second
Of the invention, in an optical device having a filter disk which is provided with a plurality of filters on the circumference and can be driven electrically, and a pulse generator for detecting the rotation amount of the filter disk, and the number of output pulses of the pulse generator are counted. Counter, position detecting means for detecting a specific position of the filter disc, position setting means for setting a target position of the filter disc, and calculating means for performing calculation from the output of the position setting means and the current position of the filter disc, And a drive unit that drives the filter disc in accordance with the calculation result of the calculation unit, and when the position detection unit detects a specific position while driving the filter disc, the filter disk is newly driven from the specific position to the target position. To do.

[0013]

In the filter disk device having the above construction, the photosensor can be disposed in the portion which has conventionally been a dead space, so that the space can be effectively used.

The optical device having the filter disk device having the above-mentioned configuration uses the signal of the position setting means during driving of the filter disk, thereby reducing the number of position detecting means,
Prevent errors from accumulating.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the first invention will be described below with reference to FIGS. The component names 1 to 9d3 are the same as those in FIGS. 9 and 10 in the above-mentioned conventional example. In this example, the filter 4 of the filter discs 1 and 2
On the surface between a, 4b, 4c, and 4d, a set of three V-shaped holes 1b1, 1b2, 1 is obliquely provided with respect to the direction of the rotation axis 3.
b3, 1c1, 1c2, 1c3, 1d1, 1d2, 1d
3, 1e1, 1e2, 1e3 and 2b1, 2b2, 2b
3, 2c1, 2c2, 2c3, 2d1, 2d2, 2d
3, 2e1, 2e2, 2e3 are provided, and a reflector 9a such as a reflecting mirror or a reflecting paint is provided on one surface of each V-shaped hole.
1, 9a2, 9a3, 9b1, 9b2, 9b3, 9c
1, 9c2, 9c3, 9d1, 9d2, 9d3 are provided. Then, a set of three reflective photosensors 7a, 7b, 7c is arranged at a position parallel to the reflector 9, that is, obliquely with respect to the directions of the rotation axes 3 of the filter disks 1 and 2.
And 8a, 8b, 8c are arranged so that the projection light from the reflection type photosensors 7a, 7b, 7c and 8a, 8b, 8c is reflected by the reflector 9 and received. A digital signal (for example, 0 for off, 1 for on)
There is also a portion where a part of the reflector 9 is removed so as to remove. Other configurations are the same as those of the above-mentioned conventional example.

In this embodiment having the above construction, a filter disc drive circuit (not shown) is provided with a filter position command signal (for example, filter disc filter 4).
When a) is input, the reflective photosensors 7a, 7b, 7
c is a preset digital signal (for example, 1, 1,
The motor 5 is energized until 1) is detected, the rotational force is transmitted to the filter disk 1 via the gear 5a and rotated, and the motor 5 is energized when the reflective photosensors 7a, 7b, 7c detect a signal. To finish. In this series of movements, as shown in FIG. 4, the filters 4a to 4d may pass within the operating range of the reflective photosensors 7a to 7c, but the reflective photosensors 7a to 7c are not Since the projection light from the photosensors 7a to 7c is obliquely arranged with respect to the direction of the rotation axis, the light projected toward the photosensors 7a to 7c goes to a direction in which the photosensors 7a to 7c cannot detect even if the light is reflected by the filter. It doesn't pick up the signal.

In this embodiment, a motor is used as a drive source for the filter disc, but a cylindrical ultrasonic motor or the like may be used.
It goes without saying that an appropriate motor may be used. Further, instead of electric driving, manual driving may be used, and in this case, a position sensor may be used to detect the filter position. Further, in this embodiment, the filter disk is composed of two pieces, but it goes without saying that it may be composed of one piece.

Next, one embodiment of the second invention will be described with reference to FIGS. FIG. 5 is a block diagram of a disk drive unit of a television camera having the filter disk device of this embodiment. In FIG. 5, reference numeral 21 denotes a filter disk having four kinds of filters 22a, 22b, 22c and 22d on its circumference, and a detection plate 23 for determining the position of a certain optical filter is provided on the surface thereof. And is rotatable about the shaft 24. 25
a and 25b are position detectors for detecting the detection plate 23 to determine the position of the filter disc 21, 26 is a drive unit using an ultrasonic motor for rotating the filter disc 21, and 27 is a filter disc 21. Is a pulse encoder that outputs a pulse according to the operation of.

28 is a filter select switch for determining a target optical filter, 29 is a command value output to the drive unit 26 by using the data of the filter select switch 28 and the position detectors 25a and 25b, and the filter disk 21. , A counter 30 for counting the output pulses of the pulse encoder 27, 31
Is a start switch for starting the operation of the filter disc 21, 32a and 32b are command values calculated by the microcomputer 29 and the filter select switch 28 in the previous operation.
The memory 33 stores the state of No. 3, and 33 is a comparator that constantly compares the memory 32a and the counter 30 and outputs a stop signal to the drive unit 26 when they match.

The structure of the pulse encoder 27 is shown in FIG.
27a is a light emitting portion, 27b is a light receiving portion, 27c.
Is a slit, and 21a is a reflecting portion formed on the filter disk 21.

In this embodiment having the above structure, the light emitting section 2
The light emitted from 7a passes through the slit 27c, and the reflection portion 21
When reflected by a and returned to the light receiving unit 27b, a pulse is generated and the counter 30 counts the pulse. However, if the slit 27c slightly vibrates due to the influence of a mechanical mechanism while the filter disc 21 is not rotating, a pulse is generated, and the counter 30 counts even if the filter disc 21 is not rotating. It causes the error to occur due to up.

Therefore, it is necessary to eliminate this error. The operation will be described with reference to the flowchart of FIG. First, in step 1, when the power is turned on, the filter disk 21 rotates, and if the position detector 25a does not detect the detection plate 23, the operation is continued, and the position detector 25a
If the detection plate 23 is detected, the stop signal is output to the drive unit 26 and the motor stops. In step 2, it waits until the start switch 31 is turned on. If it is turned on, go to step 3.

In step 3, the state of the filter select switch 28 is input to the microcomputer 29. When the filter selected by the filter select switch 28 is a filter whose position can be detected by the position detectors 25a and 25b, the filter disc 21 is rotated until the detection plate 23 is detected by the position detectors 25a and 25b. The stop signal is output to 26, and the filter disk 2
Stop 1 This makes it possible to eliminate the error.

Next, in step 4, the data of the filter select switch 28 (for example, the fourth filter 22) is selected.
d) and the currently selected filter number (previous command value or initial value stored in the memory 32a. For example, the second filter 22b) is used to calculate the rotation direction and movement amount of the filter disk 21 ( For example, 1000 pulses counterclockwise). At this time, as shown in FIG. 4, the filter disc 21 is rotated clockwise when the first filter 22a is changed to the second filter 22b, and is counterclockwise when changed from the first filter 22a to the fourth filter 22d. Rotate with the shortest distance.

In step 5, a start signal is output to the drive section 26 to rotate the filter disk 21. If neither of the position detectors 25a and 25b detects the detection plate 23 in step 6, the process proceeds to step 9, and the command value (currently 1000) stored in the counter 30 and the memory 32a in step 9 is set. The comparison is performed by the comparator 33. On the other hand, if either of the position detectors 25a and 25b detects the detection plate 23 in step 6, the counter 3 is detected in step 7.
Clear 0. By this step, at the previous driving, even if there is an error, the error is canceled.

In step 8, the filter specified by detecting the detection plate 23 (for example, the first filter 22a) to the filter set by the filter select switch 28 (for example, the second filter 22b).
The moving amount up to (currently 500) is output to the memory 32a. By doing so, errors will not be accumulated even if the filters having no position detecting means are repeatedly operated.

Next, in step 9, the comparator 33 compares the counter 30 with the value output to the memory 32a. If the two values are equal, the process is repeated from step 6. If the two values are equal, the process proceeds to step 10. In step 10, a stop signal is output from the comparator 33 to the drive unit 26, the motor stops, the data of the filter select switch 28 is transferred to the memory 32b, and the process returns to step 2.

[0028]

As described above, according to the first aspect of the present invention, the photosensor used for detecting the position of the filter disc is arranged obliquely with respect to the direction of the rotation axis of the filter disc. Since it can be installed in a different place, the device can be downsized.

A second aspect of the invention is, as described above, a pulse generator for detecting the rotation amount of the filter disk, and a counter for counting the number of output pulses of the pulse generator.
By providing the position detecting means for detecting the specific position of the filter disc and the position setting means for setting the target position of the filter disc, the number of the position detecting means can be reduced by using the signal of the position setting means during the driving of the filter disc. It is possible to reduce the cost, prevent the error from accumulating, and reduce the cost.

[Brief description of drawings]

FIG. 1 is a front view of a main part of a filter disk device according to an embodiment of the first invention.

FIG. 2 is a side view thereof.

FIG. 3 is an enlarged cross-sectional view taken along the line AA of FIG.

FIG. 4 is an enlarged sectional view taken along line BB in FIG. 1 when rotated.

FIG. 5 is a main part configuration diagram of a television camera incorporating a filter disk device of an embodiment according to the second invention.

FIG. 6 is a schematic configuration diagram of the pulse encoder.

FIG. 7 is a flowchart illustrating the operation of the microcomputer.

FIG. 8 is an explanatory diagram of the rotation direction of the filter disc.

FIG. 9 is a front view of a main part of a conventional filter disk device.

FIG. 10 is a side view thereof.

11 is an enlarged cross-sectional view taken along the line CC of FIG.

FIG. 12 is a main part configuration diagram of a television camera including a filter disk device of a conventional example.

[Explanation of symbols]

1, 2, 21 ... Filter discs, 1b1-1b
3, 1c1 to 1c3, 1d1 to 1d3, 1e1 to 1e
3, 2b1-2b3, 2c1-2c3, 2d1-2d
3, 2e1 to 2e ... V-shaped hole, 3 ... Shaft serving as rotation center, 4a, 4b, 4c, 4d, 22a, 22b, 22
c, 22d ··· filter, 5, 6 ·· motor, 7a,
7b, 7c, 8a, 8b, 8c ... Reflective photosensor, 9a1-9a3, 9b1-9b3, 9c1-9c
3, 9d1-9d3 ... Reflector, 23 ... Detection plate, 25
a, 25b .. Position detector, 26 .. Drive unit, 27 ..
Pulse encoder, 28 ... Filter select switch, 29 ... Microcomputer, 30 ... Counter, 31 ... Start switch, 32a, 32b ... Memory, 33 ...
Comparator.

Claims (2)

[Claims] 1. One or two filter discs provided with a plurality of filters on the circumference are provided in a part of a photographing system,
In a filter disc device in which a predetermined filter is positioned on the optical axis of the photographing system by rotating the filter disc, a photosensor for detecting the position of the filter disc is slanted with respect to the filter disc rotation axis direction. A filter disc device characterized in that the filter disc device is arranged in. 2. An optical device having a plurality of filters and having a filter disc that can be driven electrically, and a pulse generator that detects the rotation amount of the filter disc and a counter that counts the number of output pulses of the pulse generator. Position detecting means for detecting a specific position of the filter disk, position setting means for setting a target position of the filter disk, calculating means for calculating from the output of the position setting means and the current position of the filter disk, and the calculating means. A drive unit for driving the filter disc in accordance with the calculation result of the means, and when the position detecting means detects a specific position while driving the filter disc, the filter disc is newly driven from the specific position to the target position. Optical equipment with a built-in filter disk device.