JPH06258583A - Chopper - Google Patents

Abstract

PURPOSE:To provide a chopper which is wearless because this chopper has no sliding parts, and to prevent shortening of its life by the trouble due to occurring of wear by constituting the driving part of a voice coil motor moving back and forth and fixing the reciprocating part of this voice coil motor to a shutter plate. CONSTITUTION:This chopper has a shutter plate 10 disposed as to cross the optical path between a light source and a photodetector, and a driving part mechanically connected to the shutter plate 10 and cuts the luminous flux advancing on the optical path intermittently by driving the shutter plate 10 with the driving part. This driving part is constituted of the voice coil motor 20 moving back and forth and the reciprocating part of the voice coil motor 20 is fixed to the shutter plate 10. Since the shutter plate 10 is driven by the driving part consisting of the voice coil motor 20 in such a manner that there are no sliding parts as admitted with a revolving motor type and crank type and, therefore, the wear at the time of using the device does not arise.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chopper suitable for high-speed imaging and high-speed light detection, and more particularly to a chopper which is mechanically driven by being driven by a driving unit.

[0002]

2. Description of the Related Art Conventionally, as an example of a chopper, for example,
There is known a so-called rotary shutter device as described in JP-A-61-114231. In this rotary shutter device, a disc provided with a slit is disposed as a shutter plate between a subject (light source) and an image pickup element (light receiving element), and the disc is used as a rotation motor (for example, a DC motor or a pulse). The disc is rotated by a motor or the like) to allow the light to pass when the slit of the disk coincides with the luminous flux, and to block the light when the slit does not coincide. Further, Japanese Patent Application Laid-Open No. 62-65569 describes a shutter device which intermittently interrupts a light beam by reciprocally moving a plate member which is a shutter plate by a drive unit having a crank mechanism.

[0003]

By the way, the above-mentioned 2
Each of the two shutter devices (choppers) has a sliding part between the rotary shaft of the rotary motor and the bearing or between the crank shaft and the bearing. There is a problem of causing wear. When the chopper is used for a long period of time or continuously and a large amount of wear is caused, it causes a failure and has a short life. This wear is generally dealt with by applying a lubricant to the sliding portion. However, when the chopper is mounted on a spacecraft and used, fluid such as a lubricant cannot be used, and therefore the wear has not been prevented, and the chopper cannot be used for a long term or continuously. There is a problem.

An object of the present invention is to provide a chopper which does not cause wear and does not cause a failure due to wear or a shortened life.

Another object of the present invention is to provide a chopper which can be mounted on a spacecraft and used continuously for a long period of time.

[0006]

According to the present invention, there is provided a shutter plate arranged so as to cross an optical path between a light source and a light receiving element, and a drive section mechanically connected to the shutter plate. Then, in the chopper that drives the shutter plate by the drive unit to interrupt the light flux traveling on the optical path, the drive unit includes a reciprocating voice coil motor,
A chopper is obtained in which the reciprocating portion of the voice coil motor is fixed to the shutter plate.

Further, according to the present invention, the reciprocating portion of the voice coil motor is fixed to a leaf spring fixed to a supporting body without a sliding portion, and without a sliding portion. The chopper is obtained which is characterized by being supported by.

According to the present invention, there is further provided the chopper characterized by comprising an oscillator for generating a vibration signal for controlling the reciprocating movement of the voice coil motor.

[0009]

Since the chopper according to the present invention has a structure in which the shutter plate is driven by the drive unit composed of the voice coil motor, it does not have a sliding portion as seen in the rotary motor type or the crank type. Therefore, no wear occurs when using the device.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A chopper according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a vertical sectional view showing a chopper according to this embodiment. In FIG. 1, the present apparatus has a slit 11
And a voice coil motor 20 as a drive unit. The voice coil motor 20 is arranged in a yoke 21, a permanent magnet 22 fixed on the bottom surface of the yoke 21, a spring holder 23 fixed on the opening end surface of the yoke 21, and a gap between the yoke 21 and the permanent magnet 22. Coil fixed to coil holder 25
And the coil holder 25 by being bridge-fixed to the spring holder 23.
And a leaf spring 24 supporting the. Leaf spring 24
Attaches the coil holder 25 and the coil 26 to the yoke 21.
The coil holder 25 can be bent so as to have a degree of freedom in the direction of the arrow a, while the coil holder 25 is held at the center of the gap between the permanent magnet 22 and the permanent magnet 22. The shutter plate 10 is fixed to the upper part of the coil holder 25, and the shutter plate 10 is movable in the arrow a direction together with the coil holder 25.

Next, with reference to FIG. 2 in combination, the present invention will be described in more detail based on an application example of the present apparatus.

FIG. 2 is a perspective view showing a case where the chopper according to this embodiment is applied to an infrared image pickup device. In FIG. 2, this chopper is installed so that its shutter plate 10 crosses the optical path between the infrared imaging element 100 and the condensing optical system 110 in the infrared imaging device. Further, an oscillator (not shown) is connected to the coil 26 (FIG. 1) of the voice coil motor 20 of the present apparatus, and a vibration signal can be applied to the coil 26. Image object 2 now
The infrared ray of 00 is focused on the focusing optical system 110. The condensed light flux travels on the optical path toward the infrared imaging element 100. Here, when the oscillator is turned on, the coil 2
6 and the coil holder 25 (FIG. 1), the shutter plate 10 moves up and down. In vertical movement, when the slit 11 (FIG. 1) provided on the shutter plate 10 matches the light flux, the light flux passes through the slit 11 and is received by the infrared imaging device 100. It is shielded and is not received by the infrared imaging device 100.

If the oscillation frequency of the oscillator can be adjusted, the interval and speed at which the luminous flux is intermittently set can be freely set. That is, the chopper according to the present invention is suitable for use in an imaging device mounted on a spacecraft to cut 1 / f of observation noise by repeating blocking and transmission of observation light reaching an image sensor at a frequency f. .

[0015]

In the chopper according to the present invention, the driving portion thereof is composed of a reciprocating voice coil motor, and the reciprocating portion of this voice coil motor is fixed to the shutter plate and has no sliding portion. No wear occurs during use, and there is no risk of breakdown or shortened life due to wear.

Since no lubricant for preventing wear is required, it can be mounted on a spacecraft, and
It can be used for a long time and continuously.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a chopper according to an embodiment of the present invention.

FIG. 2 is a perspective view showing an application example of the apparatus shown in FIG. 1 to an infrared imaging device.

[Explanation of symbols]

 10 Shutter Plate 11 Slit 20 Voice Coil Motor 21 Yoke 22 Permanent Magnet 23 Spring Holder 24 Leaf Spring 25 Coil Holder 26 Coil 100 Infrared Imaging Device 110 Condensing Optical System 200 Imaging Object

Claims (3)

[Claims] 1. A shutter plate arranged so as to cross an optical path between a light source and a light receiving element, and a drive unit mechanically connected to the shutter plate. The shutter plate is driven by the drive unit. In the chopper that drives and interrupts the light flux that travels on the optical path, the drive unit is composed of a reciprocating voice coil motor, and the reciprocating portion of the voice coil motor and the shutter plate are fixed to each other. A chopper characterized by that. 2. The reciprocating portion of the voice coil motor is fixed to a leaf spring fixed to a supporting body without a sliding portion and without a sliding portion, and is supported by the supporting body. The chopper according to claim 1, wherein: 3. The chopper according to claim 1, further comprising an oscillator that generates a vibration signal that controls the reciprocating movement of the voice coil motor.