KR100297765B1 - Optical pickup for high density recording/playback - Google Patents

Optical pickup for high density recording/playback Download PDF

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Publication number
KR100297765B1
KR100297765B1 KR1019980014991A KR19980014991A KR100297765B1 KR 100297765 B1 KR100297765 B1 KR 100297765B1 KR 1019980014991 A KR1019980014991 A KR 1019980014991A KR 19980014991 A KR19980014991 A KR 19980014991A KR 100297765 B1 KR100297765 B1 KR 100297765B1
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KR
South Korea
Prior art keywords
optical
light
recording medium
solid immersion
immersion lens
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KR1019980014991A
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Korean (ko)
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KR19990081194A (en
Inventor
조건호
유장훈
이철우
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윤종용
삼성전자 주식회사
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Priority to KR1019980014991A priority Critical patent/KR100297765B1/en
Publication of KR19990081194A publication Critical patent/KR19990081194A/en
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Publication of KR100297765B1 publication Critical patent/KR100297765B1/en

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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
    • G11B7/1372—Lenses
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/29—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the position or the direction of light beams, i.e. deflection
    • 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
    • G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
    • G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
    • G11B7/095—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following specially adapted for discs, e.g. for compensation of eccentricity or wobble
    • G11B7/0956—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following specially adapted for discs, e.g. for compensation of eccentricity or wobble to compensate for tilt, skew, warp or inclination of the disc, i.e. maintain the optical axis at right angles to the disc
    • 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
    • G11B7/13—Optical detectors therefor
    • 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
    • G11B7/1384—Fibre optics

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  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Nonlinear Science (AREA)
  • General Physics & Mathematics (AREA)
  • Optical Head (AREA)

Abstract

PURPOSE: An optical pickup for high density recording/playback is provided to compact structure, to be insensible to the tilt of an incident light, and to obtain high numerical aperture by adopting a single lens. CONSTITUTION: An optical pickup includes an optical module(21) for exiting a light and receiving the light reflected onto a recording medium and a solid immersion lens member(30) placed on a light path between the optical module and the recording medium. The solid immersion lens member includes a first solid immersion lens portion(31) having a planar surface(31a) facing the recording medium and a specific refractive index and a second solid immersion lens portion(33) having a specific refractive index. The refractive index of the second solid immersion lens portion is larger than that of the first solid immersion lens portion. The solid immersion lens member forms a light spot on the writing surface of the recording medium by focusing incident lights. Since a curved surface(33a) of the second solid immersion lens portion is oval, spherical aberration is restrained. A boundary surface(35) of the first and second solid immersion lens portions is non-spherical. Thus, coma aberration due to the tilt of an incident light is avoided.

Description

고밀도 기록/재생 가능한 광픽업장치High density recording / playback optical pickup

본 발명은 광픽업장치에 관한 것으로, 상세하게는 실(Solid Immersion Lens: SIL)를 채용하여 고밀도로 정보를 기록/재생할 수 있는 고밀도 기록/재생 가능한 광픽업장치에 관한 것이다.BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup apparatus, and more particularly, to an optical pickup apparatus capable of recording / reproducing information at high density by employing a solid immersion lens (SIL).

고밀도로 정보를 기록/재생하는 장치로 종래에는 도 1에 도시된 바와 같은 광픽업장치가 제안된 바 있다. 도 1을 참조하면, 광모듈(1)에서 출사된 광은 광편향부재(5)를 통해 실(10)에 입사되고, 이 실(10)에 의해 집속되어 디스크(19)의 기록면 상에 광스폿을 형성한다.As an apparatus for recording / reproducing information at a high density, a conventional optical pickup apparatus as shown in FIG. 1 has been proposed. Referring to FIG. 1, the light emitted from the optical module 1 is incident on the chamber 10 through the optical deflecting member 5, is focused by the chamber 10, and is lighted on the recording surface of the disk 19. Form a spot.

상기 광모듈(1)은 광을 생성 출사하는 광원(미도시)과, 입사광의 진행 경로를 변환하는 수단(미도시)과, 상기 디스크(19)의 기록면에서 반사되는 광을 수광하는 광검출기(미도시) 등을 포함한다.The optical module 1 includes a light source (not shown) for generating and outputting light, a means (not shown) for converting a traveling path of incident light, and a photodetector for receiving light reflected from a recording surface of the disk 19 ( Not shown).

상기 광편향부재(5)는 도시된 바와 같이 반사부재로서, 실(10)에 입사되는 광의 입사각을 미세하게 바꾸어줌으로써 디스크(19) 상에 맺혀지는 광스폿의 위치를 조금씩 바꾸어가며 미세 트랙킹을 한다.The optical deflecting member 5 is a reflecting member as shown in the drawing. By slightly changing the incident angle of light incident on the seal 10, the optical deflection member 5 slightly changes the position of the light spot formed on the disk 19. .

상기 실(10)은 디스크(19)의 회전에 따른 공기(air) 베어링 효과에 의해 상기 디스크(19)에 대해 부상되는 슬라이더(15)에 의해 지지된다. 이 실(10)의 상기 광모듈(1)을 향하는 면은 소정 곡률을 갖는 곡면(10a)으로 형성되어 입사광을 집속하며, 상기 디스크(19)를 향하는 면은 상기 디스크(19)에 근접되도록 평면(10b)을 이룬다. 실제, 디스크(19)의 회전에 따른 공기 베어링 효과에 의해 디스크(19)의 회전시에 상기 실(10)의 평면(10b)과 디스크(19) 사이의 간격은 수십 nm 이내가 된다.The seal 10 is supported by a slider 15 which floats against the disk 19 by the air bearing effect of the rotation of the disk 19. The surface facing the optical module 1 of the seal 10 is formed as a curved surface 10a having a predetermined curvature to focus incident light, and the surface facing the disk 19 is planar to be close to the disk 19. (10b). In fact, due to the air bearing effect of the rotation of the disk 19, the distance between the disk 10 and the plane 10b of the seal 10 at the time of rotation of the disk 19 is within several tens of nm.

한편, 디스크(19)에 맺혀지는 광스폿의 크기는 수학식 1과 같이 나타낼 수 있다.On the other hand, the size of the light spot formed on the disk 19 can be represented by the equation (1).

여기서, λ 는 광원에서 출사되는 광의 파장, NA 는 광집속수단의 개구수이다.here, λ Is the wavelength of light emitted from the light source, NA Is the numerical aperture of the light focusing means.

그러므로, 고밀도 기록/재생을 위헤 광스폿의 크기를 줄이기 위해서는 광의 파장을 줄이거나 및/또는 개구수를 크게 해야 한다. 그러나, 이론상 공기중에서 얻을 수 있는 최대 개구수는 1이 된다.Therefore, in order to reduce the size of the light spot for high density recording / reproduction, the wavelength of the light must be reduced and / or the numerical aperture must be large. In theory, however, the maximum numerical aperture that can be obtained in air is 1.

한편, 상기 실(10)의 평면(10b)이 디스크(19)에 거의 근접되므로, 실(10)의 굴절율을 nSIL 이라 할 때, 실(10) 및 디스크(19)내에서의 광의 파장은 이 되고, 이를 수학식 1과 비교하면, 결과적으로 광원에서 출사되는 광의 파장 λ 에 대해 실(10)의 개구수가 1 이상이 되어, 광스폿의 크기를 줄일 수 있다. 여기서, 상기 실(10)은 실질상 상기 디스크(19)의 기록면을 보호하는 보호막과 대략 같은 굴절율을 갖도록 마련된다.On the other hand, since the plane 10b of the seal 10 is close to the disk 19, the refractive index of the seal 10 is increased. n SIL In this regard, the wavelength of light in the seal 10 and the disk 19 is When compared with Equation 1, the wavelength of the light emitted from the light source as a result λ In contrast, the numerical aperture of the seal 10 becomes 1 or more, so that the size of the light spot can be reduced. Here, the seal 10 is provided to have substantially the same refractive index as the protective film protecting the recording surface of the disc 19.

이와 같이, 실(10)을 채용하면 실질상 광스폿이 공기중에 노출되지 않게 되고(디스크(19) 회전시 공기 베어링 효과에 의한 실(10)의 평면(10b)과 디스크(19) 사이의 간격이 수십 nm 이내이므로), 이에 따라 개구수가 1 이상이 되어 광스폿의 크기를 줄일 수 있기 때문에 정보신호를 고밀도로 기록/재생할 수 있다.As such, when the seal 10 is employed, the optical spot is not substantially exposed to the air (the space between the plane 10b of the seal 10 and the disc 19 due to the air bearing effect when the disc 19 rotates). Since the numerical aperture becomes 1 or more, thereby reducing the size of the light spot, the information signal can be recorded / reproduced with high density.

그러나, 상기한 바와 같이, 하나의 곡면(10a)을 갖는 실(10)은 구면수차와 코마수차를 동시에 제거할 수 없다. 즉, 상기 실(10)의 광모듈(1)을 향하는 곡면(10a)을 도 2에 도시된 바와 같이 타원곡면으로 형성하면, 구면수차를 제거하여 회절 한계의 광스폿을 형성할 수 있다. 하지만, 이와 같이 구면수차를 제거한 타원곡면(10a)은 코마수차가 제거되는 아베(abbe)의 사인 조건(sine condition)을 만족시키지 못해 입사광의 틸트에 너무 취약하게 되고, 틸트된 입사광에 대해 상기 실(10)에 의해 집속되는 광( S1 )은 도 2 및 도 3에 도시된 바와 같이 코마수차가 발생된다. 한편, 상기 실(10)의 곡면(10a)을 반구면으로 하면 코마수차는 제거되지만, 이 경우, 디포커스(defocus)와 구면수차가 문제가 된다.However, as described above, the seal 10 having one curved surface 10a cannot simultaneously remove spherical aberration and coma aberration. That is, when the curved surface 10a toward the optical module 1 of the seal 10 is formed as an elliptic curved surface as shown in FIG. 2, spherical aberration may be removed to form an optical spot having a diffraction limit. However, the elliptic curved surface 10a in which spherical aberration is removed in this way does not satisfy the sine condition of abbe from which coma aberration is removed, and thus becomes too vulnerable to the tilt of incident light, and the seal for tilted incident light. Light focused by (10) S 1 ), Coma aberration is generated as shown in FIGS. 2 and 3. On the other hand, if the curved surface 10a of the seal 10 is a hemispherical surface, coma aberration is eliminated. In this case, defocus and spherical aberration become a problem.

그러므로, 상기한 바와 같은 실(10)을 채용한 광픽업장치는 틸트에 민감하게 코마수차가 발생되기 때문에 실질상 조립이 어렵다.Therefore, the optical pickup device employing the seal 10 as described above is practically difficult to assemble because coma aberration is sensitive to tilt.

한편, 종래에는 도 4에 도시된 바와 같이 상기 광모듈(1)과 실(10) 사이에 별도의 집광용 대물렌즈(7)를 추가로 채용한 광픽업장치가 제안된 바 있다. 이 경우, 구면수차와 코마수차는 상기 대물렌즈(8)에 의해 제거되며, 상기 실(10)은 개구수를 크게 하는 역할을 하게 된다.On the other hand, conventionally, as shown in Figure 4 has been proposed an optical pickup device that further employs a separate condenser objective lens 7 between the optical module 1 and the seal 10. In this case, spherical aberration and coma aberration are removed by the objective lens 8, and the seal 10 serves to increase the numerical aperture.

그러나, 이러한 구조를 갖는 광기록/재생 장치는 2매의 렌즈(7)(10)를 채용하므로 장치의 구성이 복잡하고 대형화되는 문제가 있다.However, since the optical recording / reproducing apparatus having such a structure employs two lenses 7 and 10, there is a problem that the configuration of the apparatus is complicated and enlarged.

본 발명은 상기한 바와 같은 점을 감안하여 안출된 것으로, 1매의 렌즈를 채용하여 간단하고 컴팩트한 구조를 가지면서도 입사광의 틸트에 둔감하고 고 개구수를 갖는 고밀도 기록/재생 가능한 광픽업장치를 제공하는데 그 목적이 있다.SUMMARY OF THE INVENTION The present invention has been made in view of the above, and has a simple and compact structure employing a single lens and has a high density recording / reproducing optical pickup device which is insensitive to the tilt of incident light and has a high numerical aperture. The purpose is to provide.

도 1은 종래의 고밀도 기록/재생 가능한 광픽업장치의 일예를 보인 구성도,1 is a block diagram showing an example of a conventional high-density recording / reproducing optical pickup apparatus;

도 2는 도 1의 실을 확대 도시한 도면,2 is an enlarged view of the yarn of FIG. 1;

도 3은 도 1의 실에 의해 집속된 광스폿을 개략적으로 보인 도면,3 is a view schematically showing a light spot focused by the yarn of FIG. 1,

도 4는 종래의 고밀도 기록/재생 가능한 광픽업장치의 다른예를 보인 구성도,4 is a block diagram showing another example of a conventional high-density recording / reproducing optical pickup apparatus;

도 5는 본 발명의 일 실시예에 따른 고밀도 기록/재생 가능한 광픽업장치의 구성을 개략적으로 보인 도면,5 is a view schematically showing a configuration of an optical pickup apparatus capable of recording / reproducing high density according to an embodiment of the present invention;

도 6은 도 5의 실부재를 확대 도시한 도면,6 is an enlarged view of the seal member of FIG. 5;

도 7은 본 발명에 따른 실부재의 구체적인 설계예를 보인 도면,7 is a view showing a specific design example of a seal member according to the present invention;

도 8은 도 7의 실부재에 의해 집속된 광스폿을 개략적으로 보인 도면,8 is a view schematically showing a light spot focused by the seal member of FIG. 7;

도 9는 본 발명의 다른 실시예에 따른 고밀도 기록/재생 가능한 광픽업장치의 구성을 개략적으로 보인 도면.9 is a schematic view showing the configuration of a high-density recording / reproducing optical pickup apparatus according to another embodiment of the present invention.

<도면의 주요부분에 대한 부호의 설명><Description of the symbols for the main parts of the drawings>

19...기록매체 21...광모듈19 ... Recording medium 21 ... Optical module

25...광편향부재 30...실부재25 ... light deflection member 30 ... real member

31...제1실부 31a...평면1st room 31a ... flat

33...제2실부 33a...곡면33 2nd part 33a

35...경계면 37...슬라이더35 ... border 37 ... slider

40...광섬유40 ... optical fiber

상기 목적을 달성하기 위하여 본 발명은, 광을 생성 출사하고 기록매체에서 반사되는 광을 수광하는 광모듈과; 상기 광모듈과 상기 기록매체 사이의 광경로 상에 배치되어 입사광을 집속시켜 상기 기록매체의 기록면에 광스폿이 형성되도록 하는 실(Solid Immersion Lens)부재;를 구비하는 고밀도 기록/재생 가능한 광픽업장치에 있어서, 상기 실부재는, 상기 기록매체에 근접되도록 상기 기록매체를 향하는 면이 평면을 이루며 소정 굴절율을 갖는 제1실부와; 상기 제1실부보다 큰 굴절율을 가지며 상기 제1실부의 상기 광모듈 쪽에 일체로 형성되고 상기 광모듈을 향하는 면이 곡면을 이루는 제2실부;를 포함하는 것을 특징으로 한다.In order to achieve the above object, the present invention provides an optical module for generating and emitting light and receiving light reflected from a recording medium; A high density recording / reproducing optical pickup apparatus, comprising: a solid immersion lens member disposed on an optical path between the optical module and the recording medium to focus incident light to form an optical spot on a recording surface of the recording medium; The seal member of claim 1, further comprising: a first seal portion having a predetermined refractive index with a plane facing the recording medium so as to be close to the recording medium; And a second chamber part having a refractive index greater than that of the first chamber part and integrally formed on the optical module side of the first chamber part and having a curved surface facing the optical module.

여기서, 상기 곡면은 타원형 곡면인 것이 바람직하다.Here, the curved surface is preferably an elliptical curved surface.

또한, 상기 제1 및 제2실부의 경계면은 비구면으로 형성된 것이 바람직하다.In addition, the interface between the first and second chamber portions is preferably formed as an aspheric surface.

본 발명의 다른 특징에 따르면, 상기 광모듈과 실부재 사이에 광을 전송하는 광섬유;가 더 구비된다.According to another feature of the invention, there is further provided; an optical fiber for transmitting light between the optical module and the seal member.

이하, 첨부된 도면들을 참조하면서 본 발명에 따른 바람직한 실시예들을 상세히 설명한다.Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

도 5는 본 발명의 일 실시예에 따른 고밀도 기록/재생 가능한 광픽업장치의 구성을 개략적으로 보인 도면이고, 도 6은 도 5의 실부재를 확대 도시한 측면도이다.FIG. 5 is a view schematically showing a configuration of an optical pickup apparatus capable of recording / reproducing high density according to an embodiment of the present invention, and FIG. 6 is an enlarged side view of the seal member of FIG. 5.

도면을 참조하면, 본 발명에 따른 고밀도 기록/재생 가능한 광픽업장치는 광을 출사하고 기록매체(19)에서 반사되는 광을 수광하는 광모듈(21)과, 상기 광모듈(21)과 기록매체(19) 사이의 광경로 상에 배치된 실(Solid Immersion Lens)부재(30)를 포함하여 구성된다.Referring to the drawings, the high-density recording / reproducing optical pickup apparatus according to the present invention comprises an optical module 21 for emitting light and receiving light reflected from the recording medium 19, the optical module 21 and the recording medium. It comprises a seal (Solid Immersion Lens) member 30 disposed on the optical path between the (19).

상기 광모듈(21)로는 통상의 광픽업장치에 채용되는 광모듈이 채용될 수 있다. 즉, 상기 광모듈(21)은 광을 생성 출사하는 광원(미도시)과, 입사광의 진행 경로를 변환하는 광경로변환수단(미도시)과, 기록매체(19)에서 반사되고 상기 광경로변환수단을 경유한 광을 수광하는 광검출기(미도시)를 포함한다. 상기 광경로변환수단으로는 입사광을 투과 및/또는 반사시키는 (편광)빔스프리터 또는 상기 광원에서 출사된 광을 투과시키고 상기 기록매체(19)에서 반사되어 입사되는 광은 회절 투과시켜 상기 광검출기를 향하도록 하는 홀로그램소자를 채용할 수 있다.As the optical module 21, an optical module employed in a conventional optical pickup device may be employed. That is, the optical module 21 includes a light source (not shown) for generating and outputting light, an optical path converting means (not shown) for converting a traveling path of incident light, and a reflection of the optical path on the recording medium 19. And a photodetector (not shown) for receiving light via the means. The light path converting means includes a (polarized) beam splitter for transmitting and / or reflecting incident light or a light emitted from the light source, and diffracted and transmitted light reflected from the recording medium 19 to detect the photodetector. It is possible to employ a hologram element for directing.

상기 실부재(30)는 입사광을 집속시켜 상기 기록매체(19)의 기록면에 광스폿이 형성되도록 한다. 본 실시예에 있어서, 상기 실부재(30)는 상기 기록매체(19)에 근접되도록 상기 기록매체(19)를 향하는 면이 평면(31a)을 이루며 소정 굴절율( n1 )을 갖는 제1실부(31)와, 상기 제1실부(31)의 상기 광모듈(21) 쪽에 일체로 형성되며 소정의 굴절율( n2 )을 갖는 제2실부(33)를 포함한다.The seal member 30 focuses incident light so that an optical spot is formed on the recording surface of the recording medium 19. In the present exemplary embodiment, the seal member 30 has a surface 31a facing the recording medium 19 so as to be close to the recording medium 19 and has a predetermined refractive index. n 1 ) Is formed integrally with the first chamber 31 and the optical module 21 side of the first chamber 31 and has a predetermined refractive index ( n 2 The second chamber part 33 which has () is included.

상기 제2실부(33)는 상기 제1실부(31)보다 큰 굴절율( n2>n1 )을 가지며, 입사광을 집속할 수 있도록 상기 광모듈(21)을 향하는 면이 곡면(33a)으로 이루어진다. 이때, 상기 곡면(33a)은 도 6에 도시된 바와 같이, 타원형 곡면인 것이 바람직하다. 이 경우, 상기 곡면(33a)이 타원형 곡면이므로 구면수차를 억제할 수 있다.The second chamber part 33 has a refractive index greater than that of the first chamber part 31. n 2 > n 1 ) And a surface facing the optical module 21 is configured to be a curved surface 33a so as to focus incident light. At this time, the curved surface 33a is preferably an elliptical curved surface, as shown in FIG. In this case, since the curved surface 33a is an elliptical curved surface, spherical aberration can be suppressed.

또한, 굴절율이 서로 다른 상기 제1 및 제2실부(31)(33)가 만나는 경계면(35)은 입사광의 틸트에 따른 코마수차를 상쇄할 수 있도록 비구면으로 형성되는 것이 바람직하다. 따라서, 도 6에 도시된 바와 같이 실부재(30)에 비스듬이 입사되어 집속된 광은 코마수차가 거의 발생하지 않게 된다.In addition, the interface 35 where the first and second seal portions 31 and 33 having different refractive indices meet is preferably formed as an aspherical surface so as to cancel coma aberration according to the tilt of the incident light. Therefore, as shown in FIG. 6, oblique incidence is incident on the seal member 30 so that coma aberration hardly occurs.

도 7은 본 발명에 따른 실부재(30)의 구체적인 설계예로써, 이 실부재(30)는 개구수가 1이 되도록 제1 및 제2실부(31)(33)를 설계한 도면이다. 이와 같이 마련된 실부재(30)에 입사되는 광은 집속되어 도 8에 도시된 바와 같은 광스폿( S2 )을 형성한다.7 is a specific design example of the seal member 30 according to the present invention, in which the seal member 30 is designed to have the first and second seal portions 31 and 33 to have a numerical aperture of 1. FIG. The light incident on the seal member 30 prepared as described above is focused to a light spot as shown in FIG. S 2 ).

상기한 바와 같은 실부재(30)는 상기 제2실부(33)의 곡면(33a)이 타원형 곡면이므로 구면수차가 거의 발생하지 않으며, 또한 상기 굴절율이 상대적으로 큰 제2실부(33)와 굴절율이 상대적으로 작은 제1실부(31)의 경계면(35)이 비구면이므로, 입사광의 틸트에 따른 코마수차가 거의 발생하지 않는다.In the seal member 30 as described above, since the curved surface 33a of the second seal portion 33 is an elliptical curved surface, almost no spherical aberration occurs, and the second seal portion 33 having a relatively high refractive index and a refractive index are relatively high. Since the boundary surface 35 of the relatively small first seal portion 31 is an aspherical surface, coma aberration hardly occurs due to the tilt of the incident light.

한편, 상기한 바와 같은 실부재(30)는 도 5에 도시된 바와 같이 슬라이더(37)에 의해 지지되며, 이 실부재(30) 및 슬라이더(37)는 기록매체(19)의 회전시에 디스크형 기록매체(19)의 회전에 따른 공기(air) 베어링 효과에 의해 상기 기록매체(19)에 대해 부상된다. 여기서, 상기 실부재(30)를 채용함에 의한 개구수가 커지는 효과는 도 1을 참조하면서 설명한 종래기술과 실질상 동일하므로 그 설명을 생략한다.On the other hand, the seal member 30 as described above is supported by the slider 37 as shown in Fig. 5, and the seal member 30 and the slider 37 are discs when the recording medium 19 is rotated. Due to the air bearing effect of the rotation of the recording medium 19, the recording medium 19 is floated. Here, since the effect of increasing the numerical aperture by employing the seal member 30 is substantially the same as the prior art described with reference to Figure 1, the description thereof will be omitted.

한편, 본 발명은 상기 광모듈(21)과 실부재(30) 사이의 광경로 상에 입사광의 틸트를 조정하는 광편향부재(25)를 더 구비하는 것이 바람직하다. 이 광편향부재(25)는 반사부재로서, 이 광편향부재(25)를 회동시키면, 실부재(30)에 입사되는 광의 입사각을 미세하게 바꾸어줄 수 있으므로 기록매체(19) 상에 맺혀지는 광스폿의 위치를 조금씩 바꾸어가며 미세 트랙킹을 할 수 있다.On the other hand, the present invention preferably further comprises an optical deflection member 25 for adjusting the tilt of the incident light on the optical path between the optical module 21 and the seal member 30. The optical deflecting member 25 is a reflecting member. When the optical deflecting member 25 is rotated, the incident angle of the light incident on the seal member 30 can be minutely changed, so that the light is formed on the recording medium 19. Fine tracking can be done by changing the position of the spot little by little.

상기한 바와 같이 굴절율이 서로 다른 제1 및 제2실부(31)(33)를 갖는 실부재(30)를 채용하면, 종래에 1매의 실(도 1의 10)을 채용한 광픽업장치에 비해 입사광의 틸트에 따른 코마수차에 둔감해지며, 이에 따라 조립이 쉽고 또한 입사광의 틸트에 의한 트랙킹 영역을 넓힐 수 있다.As described above, when the seal member 30 having the first and second seal portions 31 and 33 having different refractive indices is employed, a conventional optical pickup apparatus employing one seal (10 in FIG. 1) is employed. On the other hand, it is insensitive to coma aberration due to the tilt of the incident light, and thus, it is easy to assemble and widen the tracking area due to the tilt of the incident light.

한편, 본 발명의 다른 실시예에 따르면, 도 8에 도시된 바와 같이, 광모듈(21)과 실부재(30) 사이의 광경로 상에 광을 전송하는 광섬유(40)를 더 구비할 수 있다. 이 광섬유(40)는 상기 광모듈(21)쪽에서 입사되는 광을 전송하여 상기 실부재(30)를 향하도록 하며, 상기 기록매체(19)에서 반사되고 상기 실부재(30)를 경유한 광을 전송하여 상기 광모듈(21)에서 검출되도록 한다.Meanwhile, according to another embodiment of the present invention, as shown in FIG. 8, the optical fiber 40 may be further provided on the optical path between the optical module 21 and the seal member 30. . The optical fiber 40 transmits light incident from the optical module 21 toward the seal member 30, and reflects the light reflected from the recording medium 19 and through the seal member 30. Transmission to be detected by the optical module 21.

이와 같이, 광모듈(21)과 실부재(30) 사이의 광경로 상에 광섬유(40)를 구비하는 경우, 광픽업장치의 조립이 용이하고, 미세 트랙킹 영역이 넓어지게 된다.As such, when the optical fiber 40 is provided on the optical path between the optical module 21 and the seal member 30, the optical pickup device may be easily assembled and the micro tracking area may be widened.

상기한 바와 같은 본 발명에 따른 고밀도 기록/재생 가능한 광픽업장치는 서로 다른 굴절율을 갖는 제1 및 제2실부로 이루어진 1매의 실부재를 채용하므로, 간단하고 컴팩트한 구조를 가지며 코마수차의 영향이 크게 줄어들어 입사광의 틸트에 둔감하며, 미세 트랙킹 영역이 넓어지게 된다.As described above, the high-density recording / reproducing optical pickup apparatus according to the present invention employs a single seal member composed of first and second seal portions having different refractive indices, and thus has a simple and compact structure and influences of coma aberration. This greatly reduces and is insensitive to the tilt of the incident light, and the fine tracking area is widened.

또한, 1 이상의 고 개구수를 가질 수 있으므로 광스폿의 크기를 줄일 수 있어서, 정보신호의 고밀도 기록/재생이 가능하다.In addition, since it can have one or more high numerical apertures, the size of the optical spot can be reduced, and high density recording / reproducing of the information signal is possible.

Claims (5)

광을 생성 출사하고 기록매체에서 반사되는 광을 수광하는 광모듈과;An optical module for generating and emitting light and receiving light reflected from a recording medium; 상기 광모듈과 상기 기록매체 사이의 광경로 상에 배치되어 입사광을 집속시켜 상기 기록매체의 기록면에 광스폿이 형성되도록 하는 실(Solid Immersion Lens)부재;를 구비하는 고밀도 기록/재생 가능한 광픽업장치에 있어서,A high density recording / reproducing optical pickup apparatus, comprising: a solid immersion lens member disposed on an optical path between the optical module and the recording medium to focus incident light to form an optical spot on a recording surface of the recording medium; To 상기 실부재는,The seal member, 상기 기록매체에 근접되도록 상기 기록매체를 향하는 면이 평면을 이루며 소정 굴절율을 갖는 제1실부와;A first seal portion having a predetermined refractive index with a plane facing the recording medium so as to be close to the recording medium; 상기 제1실부보다 큰 굴절율을 가지며 상기 제1실부의 상기 광모듈 쪽에 일체로 형성되고 상기 광모듈을 향하는 면이 곡면을 이루는 제2실부;를 포함하는 것을 특징으로 하는 고밀도 기록/재생 가능한 광픽업장치.And a second chamber portion having a refractive index greater than that of the first chamber portion and integrally formed on the optical module side of the first chamber portion and having a curved surface facing the optical module. Device. 제1항에 있어서, 상기 곡면은 타원형 곡면인 것을 특징으로 하는 고밀도 기록/재생 가능한 광픽업장치.The optical pickup apparatus of claim 1, wherein the curved surface is an elliptical curved surface. 제1항에 있어서, 상기 제1 및 제2실부의 경계면은 비구면으로 형성된 것을 특징으로 하는 고밀도 기록/재생 가능한 광픽업장치.The optical pickup apparatus of claim 1, wherein an interface between the first and second chamber portions is formed as an aspherical surface. 제1항에 있어서, 상기 광모듈과 실부재 사이의 광경로 상에 입사광의 틸트를 조정하는 광편향부재;가 더 구비된 것을 특징으로 하는 고밀도 기록/재생 가능한 광픽업장치.The optical pickup apparatus of claim 1, further comprising an optical deflecting member configured to adjust a tilt of incident light on an optical path between the optical module and the seal member. 제1항 내지 제4항 중 어느 한 항에 있어서, 상기 광모듈과 실부재 사이에 광을 전송하는 광섬유;가 더 구비된 것을 특징으로 하는 고밀도 기록/재생 가능한 광픽업장치.The optical pickup apparatus according to any one of claims 1 to 4, further comprising an optical fiber for transmitting light between the optical module and the seal member.
KR1019980014991A 1998-04-27 1998-04-27 Optical pickup for high density recording/playback KR100297765B1 (en)

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Publication number Priority date Publication date Assignee Title
KR100366154B1 (en) * 2000-11-15 2002-12-31 송태선 Optical pickup apparatus for read/write heads in high density optical storages

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KR100378601B1 (en) * 2000-01-27 2003-03-31 한국전자통신연구원 Optical multi-recording apparatus using solid immersion lens

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100366154B1 (en) * 2000-11-15 2002-12-31 송태선 Optical pickup apparatus for read/write heads in high density optical storages

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