KR970003491Y1 - Optical pick-up - Google Patents
Optical pick-up Download PDFInfo
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- KR970003491Y1 KR970003491Y1 KR2019940018023U KR19940018023U KR970003491Y1 KR 970003491 Y1 KR970003491 Y1 KR 970003491Y1 KR 2019940018023 U KR2019940018023 U KR 2019940018023U KR 19940018023 U KR19940018023 U KR 19940018023U KR 970003491 Y1 KR970003491 Y1 KR 970003491Y1
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- KR
- South Korea
- Prior art keywords
- laser beam
- prism
- optical pickup
- recording medium
- optical
- Prior art date
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Classifications
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
- G11B7/135—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
- G11B7/1359—Single prisms
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
- G11B7/135—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
- G11B7/1362—Mirrors
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
- G11B7/135—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
- G11B7/1395—Beam splitters or combiners
Abstract
내용없음.None.
Description
제1도는 종래 광픽업의 광학계를 도시한 개략도.1 is a schematic diagram showing an optical system of a conventional optical pickup.
제2도는 종래 광픽업의 포커스 에러신호 검출과정을 예시한 참고도.2 is a reference diagram illustrating a focus error signal detection process of a conventional optical pickup.
제3도는 본 고안에 따른 광픽업의 광하계를 도시한 개략도.3 is a schematic diagram showing an optical system of the optical pickup according to the present invention.
제4도는 본 고안에 따른 광픽업이 포커스 에러신호 검출과정을 예시한 참고도.4 is a reference diagram illustrating a focus error signal detection process of an optical pickup according to the present invention.
* 도면의 주요부분에 대한 부호의 설명* Explanation of symbols for main parts of the drawings
11 : 레이저 다이오드 12 : 회절격자11 laser diode 12 diffraction grating
13 : 프리즘 14 : 빔분할면13 prism 14 beam splitting surface
15 : 대물렌즈 16 : 광기록매체15: objective lens 16: optical recording medium
17 : 반사면 18 : 2분할 포토다이오드17: reflection surface 18: two-split photodiode
본 고안은 광기록매체에 정보를 광학적으로 기록하거나 기록된 정보를 광학적으로 재생하는 광픽업에 관한 것이다.The present invention relates to an optical pickup for optically recording information on an optical recording medium or optically reproducing the recorded information.
일반적으로 광픽업은 광기록매체에 레이저빔을 주사하고 광기록매체로부터 반사되는 레이저빔을 검출하여 정보의 광학적 기록 또는 재생동작을 수행하는 것으로, LDP(laser disk player, CDP(compack disk player), MODD(magnetic optical disk driver)등에 사용된다.In general, an optical pickup scans a laser beam on an optical recording medium and detects a laser beam reflected from the optical recording medium to perform optical recording or reproducing of information. An LDP (laser disk player, a CDP (compack disk player), It is used for a magnetic optical disk driver (MODD).
종래의 광픽업은 제1도에 도시되어 있는 바와같이, 레이저 광원인 레이저다이오드(1)의 전방에 레이저 다이오드(1)로부터 발생된 레이저빔을 반사 및 투과시키는 빔분할면(3)이 일측에 형성된 프리즘(2)이 설치된다. 그리고 프리즘(2)의 상부에는 대물렌즈(4)가 설치되고, 프리즘(2)의 하면에는 제1, 제2 다분할 포토 다이오드(5)(6)가 소정간격을 두고 설치되고, 프리즘(2)의 상면에는 반사면(7)이 형성된다.In the conventional optical pickup, as shown in FIG. 1, the beam splitting surface 3 for reflecting and transmitting the laser beam generated from the laser diode 1 in front of the laser diode 1, which is a laser light source, is provided on one side. The formed prism 2 is installed. The objective lens 4 is provided above the prism 2, and the first and second multi-segment photodiodes 5 and 6 are provided on the lower surface of the prism 2 at predetermined intervals, and the prism 2 is provided. The reflective surface 7 is formed on the upper surface of the ().
이와 같이 구성된 종래의 광픽업은, 레이저 다이오드(1)로부터 조사된 레이저빔이 프리즘(2)의 빔분할면(3)에 의해 반사되고, 빔분할면(3)에 의해 반사된 레이저빔은 대물렌즈(4)에 의해 집속되어 광기록매체(8)에 포커싱되게 된다.In the conventional optical pickup configured as described above, the laser beam irradiated from the laser diode 1 is reflected by the beam splitting surface 3 of the prism 2, and the laser beam reflected by the beam splitting surface 3 is the objective. The lens 4 is focused and focused on the optical recording medium 8.
그리고 광기록매체(8)로부터 반사된 레이저빔은 프리즘(2)의 빔분할면(3)을 투과하여 제1, 제2 다분할 포토다이오드(5)(6)중 제1다분할 포토다이오드(5)로 먼저 조사되고, 제1다분할 포토다이오드(5)로부터 반사된 레이저빔이 프리즘(2)의 상면에 형성된 반사면(7)에 의해 제2다분할 포토다이오드(6)로 조사됨으로써 빔싸이즈법(beam size method)에 의해 제2도에 도시된 바와같은 방식으로 포커스 에러신호를 검출하게 된다. 즉, 제2a도는 대물렌즈가 광기록매체와 가까운 경우이고, 제2c도는 대물렌즈가 광기록매체와 멀어진 경우이며, 제2b도는 포커스가 일치하는 상태를 나타낸다.The laser beam reflected from the optical recording medium 8 penetrates through the beam splitting surface 3 of the prism 2 so that the first divided photodiode of the first and second multi-segment photodiodes 5 and 6 is formed. 5) and the laser beam reflected from the first multi-segment photodiode 5 is irradiated to the second multi-segment photodiode 6 by the reflecting surface 7 formed on the upper surface of the prism 2. The focus error signal is detected in a manner as shown in FIG. 2 by the beam size method. That is, FIG. 2A shows a case where the objective lens is close to the optical recording medium, FIG. 2C shows a case where the objective lens is far from the optical recording medium, and FIG. 2B shows a state where the focus is in agreement.
그러나 이와 같이 구성된 종래의 광픽업은, 2개의 다분할 포토다이오드를 사용하므로 광학계가 복잡하여 광픽업의 소형 경향화가 어렵고, 원가가 상승하게 되는 문제점이 있었다.However, in the conventional optical pickup configured as described above, since two multi-divided photodiodes are used, the optical system is complicated, which makes it difficult to reduce the size of the optical pickup and increase the cost.
본 고안은 상술한 바와 같은 문제점을 감안하여 안출된 것으로서, 소형 경량화 및 원가를 줄일 수 있도록 개량된 광픽업을 제공하는데 그 목적이 있다.The present invention has been made in view of the above-described problems, and an object thereof is to provide an improved optical pickup to reduce the size and weight and to reduce the cost.
상기의 목적을 달성하기 위하여 본 고안은 레이저빔 발생수단과, 상기 레이저빔 발생수단으로부터 조사된 레이저빔의 경로를 변경시키는 빔분할면이 일측에 형성된 프리즘과, 상기 빔분할면에 의해 경로가 변경된 레이저빔을 광기록매체로 집속시키는 빔집속수단을 구비하여 된 광픽업에 있어서, 상기 프리즘의 하면에 빔분할면을 투과한 레이저빔의 절반을 반사시키는 반사면이 형성되고, 상기 프리즘의 상면에 상기 반사면에 의해 반사되는 레이저빔으로부터 포커스 에러신호를 검출하는 2분할 포토다이오드가 설치된 점에 그 특징이 있다.In order to achieve the above object, the present invention provides a laser beam generating means, a prism formed on one side of a beam splitting surface for changing a path of a laser beam irradiated from the laser beam generating means, and whose path is changed by the beam splitting surface. In an optical pickup including beam focusing means for focusing a laser beam onto an optical recording medium, a reflecting surface for reflecting half of the laser beam passing through the beam splitting surface is formed on the lower surface of the prism, and on the upper surface of the prism. A characteristic feature is that a two-segment photodiode is provided for detecting a focus error signal from the laser beam reflected by the reflecting surface.
따라서 본 고안 광픽업은 포토다이오드의 수를 줄일 수 있게 됨에 따라 광학계가 간단하여 소형 경량화가 가능하고 원가를 절감할 수 있게 된다.Therefore, the optical pickup of the present invention can reduce the number of photodiodes, so that the optical system is simple, so that the size and weight can be reduced and the cost can be reduced.
이하 첨부된 도면을 참조하여 본 고안에 따른 바람직한 실시예를 상세하게 설명한다.Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.
본 고안에 따른 광픽업은 제3도에 도시되어 있는 바와같이, 레이저빔 발생수단인 레이저 다이오드(11)의 전방에 회절격자(12)와, 빔분할면(14)이 일측에 형성된 프리즘(13)이 동일한 광축상에 설치되고, 프리즘(13)의 상부에는 빔분할면(14)에 의해 반사된 레이저빔을 집속하여 광기록매체(16)로 조사하는 빔집속수단인 대물렌즈(15)가 설치된다.In the optical pickup according to the present invention, as shown in FIG. 3, a prism 13 having a diffraction grating 12 and a beam splitting surface 14 on one side in front of the laser diode 11 as a laser beam generating means. Is installed on the same optical axis, and the objective lens 15, which is a beam focusing means for focusing the laser beam reflected by the beam splitting surface 14 and irradiating the optical recording medium 16, on the prism 13, Is installed.
그리고 프리즘(13)의 하면에는 본 고안의 특징에 따라 광기록매체(16)로부터 반사되고 프리즘(13)의 빔분할면(14)을 투과한 레이저빔중 절반은 투과시키고 절반은 반사시키는 나이프에지(knife edge)역할을 하는 반사면(17)이 형성되고, 프리즘(13)의 상면에는 반사면(17)에 의해 반사된 절반의 레이저빔으로부터 포커스 에러신호를 검출하는 2분할 포토다이오드(18)가 설치된다.On the lower surface of the prism 13, a knife edge reflecting half of the laser beam transmitted from the optical recording medium 16 and transmitted through the beam splitting surface 14 of the prism 13 and reflecting half of the prism 13 is reflected. A reflective surface 17 serving as a (knife edge) is formed, and a two-sided photodiode 18 for detecting a focus error signal from a half of the laser beam reflected by the reflective surface 17 is formed on the upper surface of the prism 13. Is installed.
이와 같이 구성된 본 고안에 따른 광픽업의 작용을 설명하면 다음과 같다.Referring to the operation of the optical pickup according to the present invention configured as described above are as follows.
먼저 레이저빔 발생수단인 레이저 다이오드(11)로부터 조사된 레이저빔이 회절격차(12)를 통과하면서 0차±1차의 레이저빔으로 분리되고, 프리즘(13)의 빔분할면(14)에 의해 상방으로 반사된 후 대물렌즈(15)에 의해 집속되어 광기록매체(16)에 포커싱하게 된다.First, the laser beam irradiated from the laser diode 11, which is a laser beam generating means, is separated into a laser beam of 0 order ± 1 order while passing through the diffraction gap 12, and by the beam splitting surface 14 of the prism 13 After reflecting upward, the light is focused by the objective lens 15 to focus on the optical recording medium 16.
그리고 광기록매체(16)로부터 반사된 레이저빔은 프리즘(13)의 빔분할면(14)를 투과하여 프리즘(13)의 하면에 형성된 나이프 에지(knife edge)역할을 하는 반사면(17)에 의해 절반은 투과되고 나머지 절반의 레이저빔이 반사되어 프리즘(13)의 상면에 설치된 2분할 포토다이오드(18)로 조사되게 됨에 따라 나이프 에이지법(knife edge mothod)에 의해 제4도에 도시된 바와같은 방식으로 포커스 에러신호를 검출하게 된다. 즉, 제4a도는 대물렌즈가 광기록매체와 가까운 경우이고, 제4c도는 대물렌즈가 광기록매체와 가까운 경우이며, 제4b도는 포커스가 일치하는 상태를 나타낸다.The laser beam reflected from the optical recording medium 16 passes through the beam splitting surface 14 of the prism 13 to the reflecting surface 17 serving as a knife edge formed on the lower surface of the prism 13. Half of which is transmitted and the other half of the laser beam is reflected and irradiated to a two-segment photodiode 18 mounted on the upper surface of the prism 13, as shown in FIG. 4 by knife edge method. In the same manner, the focus error signal is detected. That is, FIG. 4A shows a case where the objective lens is close to the optical recording medium, and FIG. 4C shows a case where the objective lens is close to the optical recording medium, and FIG. 4B shows a state where the focus is in agreement.
이상에서 설명한 본 고안 광픽업에 의하면 하나의 2분할 포토다이오드를 사용하므로 종래 2개의 포토다이오드를 사용하던 방식에 비하여 광학계가 간단하여 광픽업의 소형 경량화가 가능하고, 원가를 절감할 수 있게 된다.According to the inventive optical pickup described above, the optical splitter is simpler than the conventional two-type photodiode, and thus the optical pickup can be reduced in size and the cost can be reduced.
Claims (1)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR2019940018023U KR970003491Y1 (en) | 1994-07-21 | 1994-07-21 | Optical pick-up |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR2019940018023U KR970003491Y1 (en) | 1994-07-21 | 1994-07-21 | Optical pick-up |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| KR960006076U KR960006076U (en) | 1996-02-17 |
| KR970003491Y1 true KR970003491Y1 (en) | 1997-04-17 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| KR2019940018023U KR970003491Y1 (en) | 1994-07-21 | 1994-07-21 | Optical pick-up |
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| Country | Link |
|---|---|
| KR (1) | KR970003491Y1 (en) |
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1994
- 1994-07-21 KR KR2019940018023U patent/KR970003491Y1/en not_active IP Right Cessation
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| Publication number | Publication date |
|---|---|
| KR960006076U (en) | 1996-02-17 |
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