KR20000009846A - Optical pickup - Google Patents
Optical pickup Download PDFInfo
- Publication number
- KR20000009846A KR20000009846A KR1019980030497A KR19980030497A KR20000009846A KR 20000009846 A KR20000009846 A KR 20000009846A KR 1019980030497 A KR1019980030497 A KR 1019980030497A KR 19980030497 A KR19980030497 A KR 19980030497A KR 20000009846 A KR20000009846 A KR 20000009846A
- Authority
- KR
- South Korea
- Prior art keywords
- reflected
- beam splitter
- light source
- optical pickup
- disk
- Prior art date
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Classifications
-
- 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
-
- 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
- G11B7/1372—Lenses
- G11B7/1374—Objective lenses
-
- 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
- G11B7/1372—Lenses
- G11B7/1378—Separate aberration correction lenses; Cylindrical lenses to generate astigmatism; Beam expanders
Abstract
Description
본 발명은 광픽업에 관한 것으로서, 더욱 상세하게는 파장이 다른 복수의 광원으로부터의 광을 디스크에 집광하는 장치에 있어서, 복수의 빔스플리터를 모듈화하여 일체로 제작함으로써, 구성이 간소화되는 광픽업에 관한 것이다.BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup, and more particularly, in an apparatus for condensing light from a plurality of light sources having different wavelengths onto a disk, wherein the plurality of beamsplitters are modularized and integrally manufactured to provide an optical pickup. It is about.
일반적으로 2광원 광픽업 광학계는 1매의 평판 광분할기(flat beam splitter)와 1매의 육면 광분할기(cubic beam splitter)를 사용한다. 도 1은 종래 2광원 광픽업에 관한 것으로서, DVD(Digital video disc)용 파장이 650nm 인 레이저다이오드를 제1광원(1)으로 사용하는 광은 평판 빔스플리터(3)에서 반사되고, CD(Compact Disc)용 파장이 780nm 인 레이저다이오드를 제2광원(2)으로 사용하는 광은 육면 빔스플리터(4)의 반사면에서 반사되어져 각각 콜리메이터렌즈(5)로 입사되어져 렌즈(6)를 거쳐 광디스크(7)로 집속되어 진다. 광디스크(7)에서 집속후 반사되어진 광은 렌즈(6)와 콜리메이터렌즈(5), 평판 및 육면 빔스플리터(3)(4)에서 투과되고 센서렌즈를 거쳐 포토다이오드(8)로 집속되어진다.In general, a two-light optical pickup optical system uses one flat beam splitter and one cubic beam splitter. FIG. 1 relates to a conventional two-light source optical pickup, wherein light using a laser diode having a wavelength of 650 nm for a DVD (Digital Video Disc) as the first light source 1 is reflected by the flat panel beam splitter 3, and compact CD (Compact). Light using a laser diode having a wavelength of 780 nm as the second light source 2 is reflected at the reflecting surface of the six-sided beam splitter 4 and is incident on the collimator lens 5 to pass through the lens 6 to the optical disc ( 7) are concentrated. The light reflected by the optical disk 7 after being focused is transmitted through the lens 6, the collimator lens 5, the flat plate and the six-sided beam splitter 3, 4, and is focused on the photodiode 8 via the sensor lens.
그러나 종래의 광학계는 육면 빔스플리터의 가격이 다른 광학소자에 비해 고가이므로 시스템의 구성 비용상승의 문제가 있으며, 비축상으로 2광원을 입사시켜 광분할을 이루는 홀로그램 빔스플리터의 경우 광원의 파장 변화에 의해 광학계의 전체 광축의 흔들림이 발생한다. 보통의 레이저 다이오드의 경우 시스템의 주변온도의 변화에 대해 ± 20nm 정도의 파장가변이 발생하며 이 경우 중심설계 파장에 대해 설계되어진 비축상의 홀로그램을 사용하는 경우 보통 광학계의 출사쪽에서 0.2도 이상의 광축 틸트가 발생하며 이로인해 디스크 상에서의 광 스팟의 형상의 저하 문제외에 포토다이오드에 떨어지는 광의 위치가 파장에 따라 달라짐으로 4분할 포토다이오드를 사용하여 각 분할면에 떨어지는 광 스팟의 광량변화를 이용하여 광 디스크의 포커싱 에러를 잡지 못하게 된다. 또한 복수의 빔스플리터를 사용함으로 부품수가 증가되고 조립오차가 증가되어 제품의 신뢰성이 저하되는 등의 단점이 있다.However, in the conventional optical system, the price of the six-sided beam splitter is higher than that of other optical elements, and thus, there is a problem in the construction cost of the system. This causes shaking of the entire optical axis of the optical system. In the case of a normal laser diode, a wavelength variation of about 20 nm occurs with respect to the change of the ambient temperature of the system. In this case, when using a non-axial hologram designed for the central design wavelength, an optical axis tilt of 0.2 degrees or more is usually observed at the emission side of the optical system. In addition to the problem of deterioration of the shape of the optical spot on the disk, the position of the light falling on the photodiode depends on the wavelength. You will not catch the focusing error. In addition, the use of a plurality of beam splitters has the disadvantage of increasing the number of parts and the assembly error is increased and the reliability of the product.
본 발명은 종래의 문제점을 감안하여 개발한 것으로서, 본 발명의 목적은 파장이 다른 복수의 광원으로부터의 광을 디스크에 집광하는 장치에 있어서, 복수의 빔스플리터를 모듈화하여 일체로 제작함으로써, 구성이 간소화되고 조립공차가 줄어들어 제품의 신뢰성이 향상되는 광픽업을 제공함에 있다.SUMMARY OF THE INVENTION The present invention was developed in view of the conventional problems, and an object of the present invention is to provide a device for condensing light from a plurality of light sources having different wavelengths onto a disk, wherein the plurality of beam splitters are modularized to be manufactured integrally. It provides an optical pickup that simplifies and reduces assembly tolerances to improve product reliability.
도 1은 종래 광픽업의 개략도,1 is a schematic diagram of a conventional optical pickup,
도 2는 본 발명 광픽업의 개략도,2 is a schematic diagram of an optical pickup of the present invention;
도 3은 본 발명 빔스플리터의 단면도.3 is a cross-sectional view of the present invention beamsplitter.
<도면의 주요부분에 대한 부호의 설명><Description of the symbols for the main parts of the drawings>
10 : 제1광원 11 : 제2광원10: first light source 11: second light source
12 : 빔스플리터 12a,b,c,d,e : 제1,2,3,4,5면12: beam splitter 12a, b, c, d, e: first, second, third, fourth, fifth
13 : 콜리메이터렌즈 14 : 렌즈13: collimator lens 14: lens
15 : 디스크 16 : 포토다이오드15: disc 16: photodiode
상기 목적을 달성하기 위하여 본 발명은 제1면에서 제5면으로 구성된 단일체의 빔스플리터가 구비되고 제1광원이 상기 빔스플리터의 제1면, 제2면, 제3면 및 제4면을 순차적으로 투과 및 반사되며, 제2광원이 상기 빔스플리터의 제4면, 제3면 및 제5면을 순차적으로 투과 및 반사되며, 상기 빔스플리터를 통과한 빔이 콜리메이터렌즈를 거쳐 디스크 쪽으로 빔을 집광시키는 렌즈로 주사되며, 상기 디스크에서 반사된 빔이 상기 주사경로의 역으로 반사되어져 포토다이오드로 집광되도록 구성된다.In order to achieve the above object, the present invention is provided with a single beam splitter composed of a first surface to a fifth surface, and the first light source sequentially the first surface, the second surface, the third surface and the fourth surface of the beam splitter. And a second light source is sequentially transmitted and reflected through the fourth, third and fifth surfaces of the beam splitter, and the beam passing through the beam splitter focuses the beam toward the disc through the collimator lens. And a beam reflected from the disk is reflected to the reverse of the scanning path to be focused onto the photodiode.
이하 본 발명의 바람직한 실시예를 첨부 도면에 따라 상세히 설명하면 다음과 같다.Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
도 2는 본 발명 제1실시예의 광픽업의 개략도 이다. DVD(Digital video disc)용 파장이 650m 인 레이저다이오드를 제1광원(10)으로 사용하는 광은 빔스플리터(12)에 의해 투과/반사되고, CD(Compact Disc)용 파장이 780nm 인 레이저다이오드를 제2광원(11)으로 사용하는 광은 빔스플리터(12)에 의해 투과/반사된어져 각각 콜리메이터렌즈(13)로 입사되어지고 렌즈(14)를 거쳐 광디스크(15)로 집속되어 진다. 광디스크(15)에서 집속후 반사되어진 광은 렌즈(14)와 콜리메이터렌즈(13), 빔스플리터(12)에서 투과되고 센서렌즈를 거쳐 포토다이오드(16)로 집속되어진다.2 is a schematic diagram of an optical pickup of a first embodiment of the present invention. Light using a laser diode having a wavelength of 650 m for a DVD (Digital Video disc) as the first light source 10 is transmitted / reflected by the beam splitter 12 and a laser diode having a wavelength of 780 nm for a CD (Compact Disc) is used. The light used as the second light source 11 is transmitted / reflected by the beam splitter 12 to be incident on the collimator lens 13 and focused on the optical disk 15 via the lens 14. The light reflected after focusing on the optical disk 15 is transmitted through the lens 14, the collimator lens 13, and the beam splitter 12, and is focused onto the photodiode 16 via the sensor lens.
빔스플리터(12)는 제1면(12a), 제2면(12b), 제3면(12c), 제4면(12d) 및 제5면(12e)으로 구성된다. 제1면은 제1광원(12a)의 투과면이고, 제2면은 제1광원의 반사 및 투과면 이며, 제3면은 제2광원의 반사 및 투과면임과 동시에 제1광원의 투과면이다. 그리고 제4면은 제2광원의 투과면이고 제5면은 제1,2광원의 투과 및 반사면으로 구성된다. 이때 제2면의 기울어진 각(θ1)은 광이 디스크에 반사되어 도아올 때 전반사가 일어나지 않는 각도록 구성되며, 제1면의 기울어진 각(θ2)은 제2면에서 반사되어 광축에 평행하도록 구성된 각도 이다.The beam splitter 12 is composed of a first surface 12a, a second surface 12b, a third surface 12c, a fourth surface 12d and a fifth surface 12e. The first surface is the transmission surface of the first light source 12a, the second surface is the reflection and transmission surface of the first light source, and the third surface is the reflection and transmission surface of the second light source and the transmission surface of the first light source. . The fourth surface is a transmissive surface of the second light source and the fifth surface is composed of transmissive and reflective surfaces of the first and second light sources. At this time, the inclination angle θ1 of the second surface is configured so that total reflection does not occur when light is reflected on the disk and the inclination angle θ2 is reflected from the second surface and is parallel to the optical axis. It is an angle configured to.
이와 같이 구성된 본 발명은 제1광원(10)을 사용하여 광 픽업을 작동시킬 때 광원이 빔스플리터(12)의 제1,2,3,4면(12a)(12b)(12c)(12d)을 순차적으로 거친 다음 콜리메이터렌즈(13)를 거쳐 렌즈(14)에 주사되고 이후 광이 집속된 상태로 디스크(15)에 스팟으로 형성된다. 그리고 제2광원(11)이 작동되면 빔스플리터(12)의 제4,3,5면(12d)(12c)(12e)을 순차적으로 거친 뒤 콜리메이터렌즈(13)와 렌즈(14)를 거쳐 디스크(15)에 집속되며 이후 재반사 되어 포토다이오드(16)에 수렴된다.According to the present invention configured as described above, the first, second, third and fourth surfaces 12a, 12b, 12c, and 12d of the beam splitter 12 when the light source is operated using the first light source 10 are operated. After sequentially passing through the collimator lens 13 is scanned to the lens 14 is formed as a spot on the disk 15 in the state where the light is focused. When the second light source 11 is operated, the beams are sequentially passed through the fourth, third, and fifth surfaces 12d, 12c, and 12e of the beam splitter 12, and then through the collimator lens 13 and the lens 14. Focused at (15) and then reflected back to converge on the photodiode (16).
상기한 바와 같이 본 발명에 따르면, 650nm 및 780nm의 파장을 갖는 두 개의 광원을 이용하여 광픽업을 구성할 때 평판 빔스플리터와 육면 빔스플리터를 조합하여 모듈화 함으로써, 한 개의 빔스플리터를 사용함으로 조립공수 및 조립오차가 줄며 특히 부품수의 감소로 생산성이 향상되는 등의 효과가 있다.As described above, when constructing an optical pickup using two light sources having wavelengths of 650 nm and 780 nm, the flat beam splitter and the six-sided beam splitter are combined and modularized, thereby using one beam splitter. And assembling errors are reduced, and in particular, productivity is improved by reducing the number of parts.
Claims (2)
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KR1019980030497A KR20000009846A (en) | 1998-07-29 | 1998-07-29 | Optical pickup |
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KR1019980030497A KR20000009846A (en) | 1998-07-29 | 1998-07-29 | Optical pickup |
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Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR20030080592A (en) * | 2002-04-09 | 2003-10-17 | 삼성전자주식회사 | Compatible optical pickup |
KR100859702B1 (en) * | 2006-12-18 | 2008-09-23 | 도시바삼성스토리지테크놀러지코리아 주식회사 | Optical pickup apparatus using aniso-CBS |
-
1998
- 1998-07-29 KR KR1019980030497A patent/KR20000009846A/en not_active Application Discontinuation
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR20030080592A (en) * | 2002-04-09 | 2003-10-17 | 삼성전자주식회사 | Compatible optical pickup |
KR100859702B1 (en) * | 2006-12-18 | 2008-09-23 | 도시바삼성스토리지테크놀러지코리아 주식회사 | Optical pickup apparatus using aniso-CBS |
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