KR970060091A

KR970060091A - An optical pickup device using a liquid crystal plate

Info

Publication number: KR970060091A
Application number: KR1019960001642A
Authority: KR
Inventors: 오평희; 이명숙
Original assignee: 오평희
Priority date: 1996-01-26
Filing date: 1996-01-26
Publication date: 1997-08-12

Abstract

본 발명은 액정판(6)을 써서 광속의 크기(Beam Size)를 조절하는 광픽업(Optical Pick Up)장치에 관한 것이다. 종래의 액정판(6)을 쓴 광학계에서는 편광판을 써서 레이저 다이오드(1)에서 나온 빛을 투과 또는 흡수시키는 액정표시형을 썼기 때문에 두께가 균일한 결정형 편광판을 써야하므로 비용이 매우 크다. 그래도 액정층(32)에 이방성 염료를 넣어 빛을 흡수하고 투과하는 GH형(Gust Host Mode)을 써서 편팡판(9)을 쓰지 않는 방법이 제기되었지만, 빛의 투과율과 명암대비율이 낮아서 빛의 세기가 큰 광원을 써야되고 검출기에서 나온 신호의 해석이 어려워 실용화가 되지 않았다.The present invention relates to an optical pick-up apparatus for adjusting a beam size by using a liquid crystal plate (6). In the optical system using the conventional liquid crystal plate 6, since a liquid crystal display type which transmits or absorbs the light emitted from the laser diode 1 is used by using a polarizing plate, the cost is very high since a uniform polarized crystal polarizing plate must be used. However, a method of not using the unfolded plate 9 by using the GH type (Gust Host Mode) in which anisotropic dye is added to the liquid crystal layer 32 to absorb and transmit light has been proposed. However, since the transmittance of light and the contrast ratio are low, It is difficult to interpret the signal from the detector because it is necessary to use a light source having a large intensity.

또한 액정배열을 이용한 액정홀로그램방식으로 편광판(9)을 대신하는 방식도 나왔지만 선폭이 0.5㎛ 이하이기 때문에 생산성이 떨어졌다. 본 발명에서는 종래의 편광판 대신에 평면형 편광광속분할기(Polarizing Beam Splitter Plate)를 써서 비용을 줄였다.In addition, although a method of replacing the polarizing plate 9 with a liquid crystal hologram system using a liquid crystal array has been proposed, the productivity is lowered because the line width is 0.5 탆 or less. In the present invention, a planar polarizing beam splitter plate is used instead of the conventional polarizing plate to reduce the cost.

또한 액정판의 아래기판에 유전체층을 입혀 편광광속분할기의 기능과 편광을 변조하는 두 기능을 갖는 액정판을 구성하여 비용을 줄였다.In addition, a liquid crystal plate having two functions of applying a dielectric layer to the substrate below the liquid crystal plate and modulating the function of the polarized light beam splitter and the polarization is reduced, thereby reducing the cost.

본 발명의 액정판(6)을 쓴 광픽업장치는 CD를 읽을 수 있는 DVD(Digital Video Disk)의 광픽업장치등에 쓰일 수 있다.The optical pickup device using the liquid crystal plate 6 of the present invention can be used for an optical pickup device of a DVD (Digital Video Disk) that can read CDs.

Description

An optical pickup device using a liquid crystal plate

본 내용은 요부공개 건이므로 전문내용을 수록하지 않았음Since this is a trivial issue, I did not include the contents of the text.

제2도는 본 발명의 광픽업장치의 한 예.2 is an example of the optical pickup device of the present invention.

제5도는 액정판의 전극모양.5 shows an electrode shape of the liquid crystal plate.

제6도는 본 발명에서 쓴 액정판의 구조.6 shows the structure of the liquid crystal plate used in the present invention.

Claims

In which the light emitted from the laser diode 1 is irradiated to the optical storage element 8 through the light beam splitter 3 and the liquid crystal plate 6 so that the glass substrate surface of the liquid crystal plate is opposed to the laser diode light 5 And adjusts the size of the light flux of the laser beam irradiated toward the optical storage element 8 by utilizing the function of the polarization beam splitter of various dielectric layers having different refractive indexes on the substrate below the liquid crystal plate 6. [

The optical pickup apparatus according to claim 1, wherein the display type of the liquid crystal plate (6) is an ECB.

The optical pickup apparatus of claim 1, wherein the liquid crystal plate is in front of or behind the beam splitter.

In which the light emitted from the laser diode 1 is irradiated to the optical storage element 8 through the beam splitter 3 and the liquid crystal plate 6 and the planar polarized beam splitter transmits or reflects the light passing through the liquid crystal plate And adjusts the size of the light flux of the laser diode irradiated toward the optical storage element (8).

※ Note: It is disclosed by the contents of the first application.