KR19990029512U - Beam deflector - Google Patents

Abstract

Disclosed is a beam deflecting device which is employed for recording / reproducing a hologram memory and the like and finely adjusts an incident angle of a beam incident on a recording medium.

The disclosed beam deflecting device includes a base, a rotating arm rotatably installed on the base, a mirror member provided on a rotating shaft of the rotating arm, and installed on one side of the rotating arm to rotate the rotating arm with respect to the rotating shaft to enter the mirror member. Beam deflection means for deflecting the beam, and an encoder for detecting the deflection direction of the deflected beam by detecting the angle of rotation of the pivoting arm.

Since the beam deflecting device can finely adjust the rotation of the pivoting arm provided with the mirror member on its rotating shaft, the beam incident on the mirror member can be deflected at a fine angle.

In addition, since the rotational angle of the rotational arm, that is, the deflection angle of the incident beam, can be sensed using a general optical pickup, an inexpensive beam deflection device can be configured.

Description

Beam deflector

The present invention relates to a beam deflecting device, and more particularly, to a beam deflecting device which is used when recording / reproducing a hologram memory and the like, to finely adjust an incident angle of a beam incident on a recording medium.

In general, when overlapping recording or reproducing an information signal while precisely changing the angle of incidence of a beam on a recording medium such as a hologram memory, a beam deflecting device that allows fine adjustment of the angle of incidence of an incident beam incident on the recording medium, that is, galvano. Adopt a meter.

Conventional beam deflection apparatus comprises a step motor and a mirror provided on the rotation shaft of the step motor. When driving the step motor, the mirror is rotated, thereby changing the reflection direction of the beam incident on the mirror. In this case, the direction of the reflected beam, that is, the deflection direction of the beam, may be known by counting the number of driving pulses driving the step motor.

This beam deflector is difficult to deflect the beam at a fine angle when the step motor is used as it is. In addition, when the mechanical reduction device is adopted to increase the resolution, it takes a long time to change the direction of the beam when the deflection range of the beam is wide.

Further, a beam deflector employing an acoustic optical device (AOD) deflects the beam by passing an incident beam through the acoustic optical device. The beam deflection direction then depends on the vibration frequency applied to the acoustooptic device.

As described above, the beam deflecting device employing the acoustooptic device can adjust the beam deflection direction at high speed, but has a disadvantage of low light efficiency and high price.

The present invention has been made to solve the above problems, the object of the present invention is to provide a beam deflecting device which can deflect the beam at a fine angle and low cost.

1 is an exploded perspective view schematically showing a beam deflector according to an embodiment of the present invention;

2 is an assembled cross-sectional view of FIG.

<Description of the symbols for the main parts of the drawings>

1 ... base 10 ... swivel arm

20 Mirror member 30 Beam deflection means

31.Support member 35 ... Rotating actuator

36.Magnetic member 37 ... Coil member

40.Encoder 41 ... Reflection

50 ... optical pickup 53 ... light source

54.Photodetector 55 ... Light path converting means

57 Objective lens 61.

Beam deflection apparatus according to the present invention for achieving the above object, the base; A pivot arm rotatably installed on the base; A mirror member provided on a rotation axis of the pivot arm; Beam deflecting means installed on one side of the pivoting arm to rotate the pivotal arm with respect to the rotational axis to deflect the beam incident on the mirror member; And an encoder which detects a rotational angle of the pivoting arm and detects a deflection direction of the deflected beam.

Here, the beam deflecting means, the support member rotatably supporting the pivot arm above the pivot arm, and coupled to the base; And a rotating actuator installed on the supporting member and the rotating arm to rotate the rotating arm with respect to the supporting member.

The encoder comprises: a reflecting plate provided on the pivoting arm and having a stripe pattern repeatedly formed; And an optical pickup for irradiating light onto the reflecting plate and counting the number of pattern movements of the reflecting plate according to the rotation of the rotating arm to detect the rotating angle of the rotating arm.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is an exploded perspective view schematically showing a beam deflector according to an embodiment of the present invention, Figure 2 is an assembled cross-sectional view of FIG.

Referring to the drawings, the beam deflecting device includes a base 1, a rotating arm 10 rotatably installed on the base 1, a mirror member 20 provided on a rotating shaft of the rotating arm 10, It comprises a beam deflection means 30 for deflecting the beam incident on the mirror member 20, and an encoder 40 for detecting the deflection direction of the deflected beam.

One end of the pivot arm 10 is formed with a wall portion 11 having a cross-sectional shape of "c", and the mirror member 20 between the upper and lower flanges 11a and 11b of the wall portion 11. Is installed. In addition, hemispherical grooves 12 are formed on the upper and lower surfaces of the upper and lower flanges 11a and 11b, which are aligned with the mirror member 20, respectively. The pivot arm 10 is formed by a ball 15 fitted between a groove 12 formed in the lower flange and a hemispherical groove 13 formed in the base 1 corresponding to the groove 12. It is rotatably coupled to the base 1. Therefore, the mirror member 20 is located on the rotation axis of the pivot arm 10.

The beam deflecting means 30 is installed on the support member 31 coupled to the base 1, the support member 31 and the pivot arm 10, and the pivot arm 30 with respect to the support member 31. And a rotating actuator 35 for rotating 10).

The support member 31 is supported by a block 32 installed in the base 1 through the pivot arm 10 and is spaced apart from the base 1 by a predetermined distance. The support member 31 penetrates the block 32 and is coupled to the base 33 by a screw 33. And a hemispherical groove 34 is formed in the lower surface of the support member 31 on the rotary shaft, the ball is fitted between the groove 34 and the hemispherical groove 12 formed on the upper surface of the upper flange (11a). The rotating arm 10 is rotatably supported by the upper side of the rotating arm 10 by (17).

The rotating actuator 35 includes a magnet member 36 installed on one side of the support member 31 and a coil member 37 installed on the pivot arm 10 so as to face the magnet member 36. do. When a current is applied to the coil member 37, a magnetic force line is formed around the coil arm 37. As a result, the rotation arm 10 is rotated by the interaction with the magnetic force line generated by the magnet member 36. Here, the magnet member 36 may be installed on the pivot arm 10, and the coil member 37 may be installed on the support member 31.

The encoder 40 detects a rotation angle of the pivot arm 10 and detects a deflection direction of the beam deflected by the beam deflection means 30. To this end, the encoder 40 is installed on the pivoting arm 10 and the reflecting plate 41 repeatedly formed with a stripe pattern, and irradiates light onto the reflecting plate 41 and the The optical pickup 50 detects the rotation angle of the pivoting arm 10 by counting the number of pattern shifts of the reflector 41 from the optical signal reflected by the reflector 41 according to rotation.

The pattern of the reflecting plate 41 is formed by forming a stripe-shaped reflecting portion and a non-reflecting portion or a track and a groove having a pitch of about 1.6 μm or less in parallel or radially. Here, a part of a normal optical disk can be cut out and used as the reflecting plate 41.

The optical pickup 50 includes a light source 53 for generating and outputting light, an optical path converting means 55 for converting a traveling path of incident light, an objective lens 57 for focusing incident light, and the objective lens 57 And an actuator for adjusting the distance between the reflector 41 and the photodetector 54 which is reflected by the reflector 41 and receives light through the objective lens 57 and the light path converting means 55. And a determination unit 61 for determining a rotation angle of the rotation arm 10 from the detection signal of the photodetector 54. Here, the light source 53, the light path converting means 55, the objective lens 57 and the photodetector 54 are compactly installed in the housing 51.

The light path converting means 55 is disposed on the light path between the light source 53 and the reflector plate 41. 2 is a hologram in which the light path conversion means 55 transmits the light incident from the light source 53 toward the light source 53 and the light incident from the light reflector 41 is diffracted and directed toward the photodetector 54. The example provided with an element is shown. In this case, since the photodetector 54 may be disposed on the same substrate 52 as the light source 53, as shown, the light source 53, the photodetector 54, and the optical path converting means 55. ) Can be formed as a module. On the other hand, the light path conversion means 55 may be provided with a beam splitter for transmitting or reflecting the incident light.

The objective lens 57 is disposed on an optical path between the optical path converting means 55 and the reflecting plate 41 to focus incident light. In this case, the actuator is configured such that the light incident on the objective lens 57 can be focused on the reflecting plate 41, that is, the distance between the objective lens 57 and the reflecting plate 41 is the objective lens 57. Adjust to the focal length of.

As shown in FIGS. 1 and 2, the actuator is provided on the base 1 so as to face the focusing coil member 56 and the focusing coil member 56 installed to surround the outer circumference of the housing 51. It consists of a magnet member 58 provided. At this time, the magnet member 58 is installed in the yoke 59. The actuator is installed in the housing 51 by the interaction between the magnetic force lines generated by the focusing coil member 56 and the magnetic force lines generated by the magnet member 58 according to the current applied to the focusing coil member 56. The light source 53, the optical path changing means 55, the photodetector 54 and the objective lens 57 are adjusted in the optical axis direction.

On the other hand, the housing 51 is elastically coupled to the base 1 by a spring 65 coupled to the base 1 via the block 65 in the optical axis direction in accordance with the adjustment of the actuator It is provided to be movable.

Here, the actuator is described and illustrated to adjust the light source 53, the optical path converting means 55, the photodetector 54, and the objective lens 57 installed in the housing 51 in the optical axis direction, but is not limited thereto. Do not. That is, the light source 53, the light path converting means 55 and the photodetector 54 are fixed in position with respect to the base 1, and the actuator is provided to adjust only the objective lens 57 in the optical axis direction. It is also possible. In this case, the objective lens 57 and the focusing coil member 56 are elastically coupled to the base 1 by a spring 63.

The determination unit 61 counts the number of pattern movements of the reflecting plate 41, that is, the number of traversed tracks, from the detection signal of the photodetector 54, that is, the angle of rotation of the pivoting arm 10, that is, the mirror member 20. The deflection direction of the beam incident on and deflected by the beam is determined.

The optical pickup 50 as described above is employed in a disc player or the like to use a general optical pickup for recording and reproducing information signals of a recording medium.

Hereinafter, the operation of the beam deflector according to the embodiment of the present invention will be described with reference to FIGS. 1 and 2.

First, when a current is applied to the coil member 37, the rotating arm 10 is applied to the base 1 and the support member 31 by the magnetic force between the coil member 37 and the magnet member 36. It rotates about a rotation shaft, and the mirror member 20 installed on the rotation shaft is rotated accordingly.

As the pivoting arm 10 is rotated, the light incident on the reflecting plate 41 provided on the pivoting arm 10 on the optical pickup 50 side traverses a pattern, for example, a track, and thus the reflecting plate 41. The reflected light signal is changed. The photodetector 54 detects the light reflected from the reflector plate 41, and the determination unit 61 counts the number of movements of the pattern according to the detection signal of the photodetector 54 to determine the rotational arm 10. Detect the angle of rotation That is, the deflection direction of the beam incident and reflected on the mirror member 20 is sensed.

At this time, when the current applied to the coil member 37 is adjusted, the rotation angle of the rotation arm 10 is finely adjusted, and the detection signal of the encoder 40 is used to determine the rotation angle of the rotation arm 10. Since the minute change can be known, the deflection of the beam by the mirror member 20 can be precisely adjusted, and the deflection direction of the beam can be precisely controlled.

Since the beam deflecting device as described above can finely adjust the rotation of the pivoting arm provided with the mirror member on the rotational axis by the pivoting actuator, the beam incident on the mirror member can be deflected at a fine angle.

In addition, since the rotational angle of the rotational arm, that is, the deflection angle of the incident beam, can be sensed using a general optical pickup, an inexpensive beam deflection device can be configured.

In addition, since the rotating arm is adjusted by adjusting the current applied to the rotating actuator, the deflection direction of the beam can be changed at high speed.

Claims (6)

A base; A pivot arm rotatably installed on the base; A mirror member provided on a rotation axis of the pivot arm; Beam deflecting means installed on one side of the pivoting arm to rotate the pivotal arm with respect to the rotational axis to deflect the beam incident on the mirror member; And an encoder for detecting a deflection direction of the deflected beam by detecting a rotation angle of the pivot arm. The method of claim 1, wherein the beam deflecting means, A support member rotatably supporting the pivot arm above the pivot arm and coupled to the base; And a rotating actuator installed on the supporting member and the rotating arm to rotate the rotating arm with respect to the supporting member. The rotary actuator of claim 2, wherein A magnet member installed on one side of the support member and the pivot arm; And a coil member installed on the other side opposite to the magnet member to rotate the pivot arm by interaction with a magnetic force line generated by the magnet member in accordance with an applied current. The method of claim 1, wherein the encoder, A reflection plate installed on the pivot arm and having a stripe pattern repeatedly formed; And an optical pickup for irradiating light onto the reflecting plate and counting the number of pattern movements of the reflecting plate according to the rotation of the rotating arm to detect the rotating angle of the rotating arm. The method of claim 4, wherein the optical pickup, A light source for generating and emitting light; Optical path converting means disposed on an optical path between the light source and the reflecting plate to convert a propagation path of incident light; An objective lens disposed on an optical path between the optical path converting means and the reflecting plate to focus incident light; An actuator for adjusting a distance between the objective lens and the reflecting plate so that light incident on the objective lens is formed on the reflecting plate; A photodetector that is reflected by the reflector and receives light through the actuator and the light path converting means; And a determining unit which counts the number of pattern movements of the reflecting plate from the detection signal of the photodetector to determine the rotation angle of the pivoting arm. 6. The beam deflecting device according to claim 5, wherein the light path converting means is a hologram element for transmitting light incident from the light source toward the light detector and diffracting and transmitting light incident from the reflector toward the photodetector. .