KR19990066690A - Focused optical system generating near field, optical pickup and optical disk drive employing the same, and optical disk - Google Patents

Focused optical system generating near field, optical pickup and optical disk drive employing the same, and optical disk Download PDF

Info

Publication number
KR19990066690A
KR19990066690A KR1019980019876A KR19980019876A KR19990066690A KR 19990066690 A KR19990066690 A KR 19990066690A KR 1019980019876 A KR1019980019876 A KR 1019980019876A KR 19980019876 A KR19980019876 A KR 19980019876A KR 19990066690 A KR19990066690 A KR 19990066690A
Authority
KR
South Korea
Prior art keywords
near field
laser light
optical system
optical
reflection
Prior art date
Application number
KR1019980019876A
Other languages
Korean (ko)
Inventor
이철우
정종삼
이용훈
연철성
서중언
정영민
신동호
조건호
성평용
유장훈
Original Assignee
윤종용
삼성전자 주식회사
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 윤종용, 삼성전자 주식회사 filed Critical 윤종용
Priority to US09/196,111 priority Critical patent/US6266315B1/en
Priority to EP05001525A priority patent/EP1538614A3/en
Priority to BR9806979-9A priority patent/BR9806979A/en
Priority to PCT/KR1998/000371 priority patent/WO1999027532A1/en
Priority to CA002278416A priority patent/CA2278416C/en
Priority to RU99118228/28A priority patent/RU2169400C2/en
Priority to KR1019980050086A priority patent/KR100346397B1/en
Priority to EP98959226A priority patent/EP0954859B1/en
Priority to CNB988032341A priority patent/CN1133996C/en
Priority to DE69836202T priority patent/DE69836202T2/en
Priority to JP52820299A priority patent/JP4198763B2/en
Priority to IDW990904A priority patent/ID23169A/en
Priority to TW087119418A priority patent/TW419596B/en
Priority to MYPI98005306A priority patent/MY122310A/en
Publication of KR19990066690A publication Critical patent/KR19990066690A/en
Priority to HK00103062A priority patent/HK1024088A1/en

Links

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
    • G11B7/1387—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector using the near-field effect
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/10—Beam splitting or combining systems
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
    • G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
    • G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
    • G11B11/10532—Heads
    • G11B11/10541—Heads for reproducing
    • G11B11/10543—Heads for reproducing using optical beam of radiation
    • G11B11/10547—Heads for reproducing using optical beam of radiation interacting with the magnetisation of an intermediate transfer element, e.g. magnetic film, included in the head
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
    • G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
    • G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
    • G11B11/10582—Record carriers characterised by the selection of the material or by the structure or form
    • G11B11/10584—Record carriers characterised by the selection of the material or by the structure or form characterised by the form, e.g. comprising mechanical protection elements
    • 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
    • G11B7/085—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam into, or out of, its operative position or across tracks, otherwise than during the transducing operation, e.g. for adjustment or preliminary positioning or track change or selection
    • G11B7/0857—Arrangements for mechanically moving the whole head
    • G11B7/08576—Swinging-arm positioners
    • 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
    • G11B7/0901—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 for track following only
    • 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
    • G11B7/0908—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 for focusing only
    • 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
    • G11B7/122—Flying-type heads, e.g. analogous to Winchester type in magnetic recording
    • 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
    • G11B7/22—Apparatus or processes for the manufacture of optical heads, e.g. assembly
    • 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
    • G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
    • G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
    • G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
    • G11B11/1055—Disposition or mounting of transducers relative to record carriers
    • G11B11/10552—Arrangements of transducers relative to each other, e.g. coupled heads, optical and magnetic head on the same base
    • G11B11/10554—Arrangements of transducers relative to each other, e.g. coupled heads, optical and magnetic head on the same base the transducers being disposed on the same side of the carrier
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
    • G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
    • G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
    • G11B11/1055—Disposition or mounting of transducers relative to record carriers
    • G11B11/10556—Disposition or mounting of transducers relative to record carriers with provision for moving or switching or masking the transducers in or out of their operative position
    • G11B11/10567—Mechanically moving the transducers
    • G11B11/10569—Swing arm positioners
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
    • G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
    • G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
    • G11B11/1055—Disposition or mounting of transducers relative to record carriers
    • G11B11/1058—Flying heads
    • 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
    • G11B2007/13725—Catadioptric lenses, i.e. having at least one internal reflective surface

Landscapes

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

Abstract

광픽업은 광원으로부터 입사하는 레이저광을 이용하여 니어필드를 발생하는 집속광학계를 구비한다. 집속광학계는, 광원 쪽에 위치한 표면에 형성된 굴절부 및 제 1반사부와, 디스크 쪽에 표면에 형성된 니어필드형성부 및 제 2반사부를 포함한다. 굴절부는 광원 쪽으로부터 입사하는 레이저광을 굴절시키며, 제 2반사부는 굴절부에 의해 굴절된 레이저광을 제 1반사부 쪽으로 반사시키고, 제 1반사부는 제 2반사부에서 반사된 레이저광을 니어필드형성부의 집광면에 집속시킨다. 그 결과로, 니어필드(near field)를 형성하는 광스폿이 니어필드형성부의 디스크 쪽 집광면 상에 형성된다. 따라서, 본 발명에 따른 집속광학계는 니어필드를 형성하는 기존의 집속광학계광학계에서 사용되는 레이저빔보다 적은 빔직경을 갖는 레이저빔을 사용하면서도 니어필드를 형성시키는 광스폿의 크기를 줄일 수 있다. 그러므로, 본 발명에 따른 광픽업은 10Gbit/inch2이상의 면 기록밀도를 갖는 광디스크에 정보를 기록하거나 재생할 수 있으며, 디스크 또는 광픽업의 움직임에 의해 입사빔기울어짐이 발생하는 경우에도, 디스크에 대한 정보의 기록 또는 재생을 정확히 할 수 있다. 또한, 그 조립 및 조립된 광학계의 조정이 용이한 효과가 있다.The optical pickup includes a focusing optical system that generates a near field using laser light incident from a light source. The focusing optical system includes a refracting portion and a first reflecting portion formed on the surface located on the light source side, and a nearfield forming portion and a second reflecting portion formed on the surface on the disk side. The refracting portion refracts laser light incident from the light source side, the second reflecting portion reflects the laser light refracted by the refracting portion toward the first reflecting portion, and the first reflecting portion reflects the laser light reflected from the second reflecting portion near field. It focuses on the condensing surface of the formation part. As a result, light spots forming near fields are formed on the disk-side light collecting surface of the near field forming portion. Accordingly, the focused optical system according to the present invention can reduce the size of the light spot for forming the near field while using a laser beam having a beam diameter smaller than that of the conventional focused optical system for forming the near field. Therefore, the optical pickup according to the present invention can record or reproduce information on an optical disk having a plane recording density of 10 Gbit / inch 2 or more, and even when incident beam tilt occurs due to the movement of the disk or optical pickup, Information can be recorded or reproduced accurately. In addition, there is an effect that the assembly and adjustment of the assembled optical system are easy.

Description

니어필드를 발생하는 집속광학계와, 이를 채용한 광픽업 및 광디스크드라이브, 및 광디스크Focused optical system generating near field, optical pickup and optical disk drive employing the same, and optical disk

본 발명은 니어필드(near field)를 발생하는 집속광학계, 이를 채용한 광픽업 및 광디스크드라이브, 그리고, 이것들에 의해 정보가 기록 또는 재생되는 디지털저장매체에 관한 것이다.BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a focused optical system for generating a near field, an optical pickup and an optical disk drive employing the same, and a digital storage medium on which information is recorded or reproduced.

광기록/재생장치의 기록용량을 늘이기 위한 여러 가지 방법들이 연구되고 있으며, 그 기본은 사용되는 광의 파장을 줄이는 것과 사용되는 대물렌즈의 개구수(NA)를 높임으로써 집광 스폿의 크기를 줄이는 것이다. 개구수를 높임으로써 집광 스폿의 크기를 줄이는 집속광학계를 도 1을 참조하여 설명한다.Various methods for increasing the recording capacity of the optical recording / reproducing apparatus have been studied, and the basis thereof is to reduce the size of the condensing spot by reducing the wavelength of light used and increasing the numerical aperture (NA) of the objective lens used. A focusing optical system for reducing the size of the focusing spot by increasing the numerical aperture will be described with reference to FIG. 1.

도 1에 보여진 집속광학계는 니어필드를 이용하여 집광 스폿의 크기를 줄이는 것으로, 종래의 비구면 렌즈(1) 및 고체함침렌즈(solid immersion lens)라고도 불리는 구면렌즈(2)를 구비한다. 이러한 집속광학계를 광디스크(4)를 위한 대물렌즈로 사용하는 경우, 슬라이더(slider; 3)는 디스크(4)의 표면에 대해 구면렌즈(2)를 이동시키며, 구면렌즈(2)와 디스크(4)간의 거리를 100nm 미만으로 유지시킨다. 비구면렌즈(1)는 광원(미도시)으로부터 출사된 레이저광을 굴절시키며, 구면렌즈(2)는 비구면렌즈(1)에 의해 굴절된 레이저광을 디스크(4) 쪽에 위치한 면의 안쪽에 집광시킨다. 레이저광이 집광되는 구면렌즈(2)의 표면은 니어필드를 형성하며, 그 결과로, 니어필드를 통해 디스크(4)에 정보가 기록되거나 디스크(4)로부터 정보가 읽혀진다.The converging optical system shown in FIG. 1 uses a near field to reduce the size of the condensing spot, and includes a conventional aspherical lens 1 and a spherical lens 2 also called a solid immersion lens. When using this focused optical system as an objective lens for the optical disc 4, a slider 3 moves the spherical lens 2 with respect to the surface of the disc 4, and the spherical lens 2 and the disc 4 Keep the distance between the cells below 100 nm. The aspherical lens 1 refracts the laser light emitted from a light source (not shown), and the spherical lens 2 condenses the laser light refracted by the aspherical lens 1 to the inside of the surface located on the disk 4 side. . The surface of the spherical lens 2 on which the laser light is focused forms a near field, and as a result, information is recorded on or read from the disk 4 through the near field.

구면렌즈(2)를 구성하는 매질이 굴절률 "n"을 갖는 경우, 구면렌즈(2)의 내부에서, 레이저광이 집광되는 각도는 크게 되며 레이저광의 운동량(momentum)이 줄어들어, 결과적으로 레이저광의 파장은 λ/n으로 감소하는 효과가 발생한다. 따라서, 개구수(NA)는 NA/λ로 상승하게 된다. 그러므로, 구면렌즈(2)의 표면 내부에서 최종적으로 형성되는 광스폿의 크기는 NA/n에 비례하며, 그 결과, 구면렌즈(2)의 매질이 갖는 굴절률(n)을 이용하여 스폿의 크기를 줄일 수 있다.When the medium constituting the spherical lens 2 has a refractive index "n", the angle at which the laser light is focused inside the spherical lens 2 becomes large and the momentum of the laser light is reduced, resulting in the wavelength of the laser light. Has the effect of decreasing to [lambda] / n. Therefore, the numerical aperture NA rises to NA / λ. Therefore, the size of the light spot finally formed inside the surface of the spherical lens 2 is proportional to NA / n. As a result, the size of the spot is determined by using the refractive index n of the medium of the spherical lens 2. Can be reduced.

그러나, 도 1의 집속광학계는, 별도로 제작된 비구면렌즈(1) 및 구면렌즈(2)를 구비하므로, 소망된 광학적 특성을 갖도록 조립 또는 조정하는데 어려움이 있다. 그리고, 3mm 이상의 빔직경을 갖는 입사 레이저광을 필요로 하므로, 수광부를 포함한 모든 광부품의 크기가 커지게 된다. 뿐만 아니라, 이동하는 광픽업 또는 회전하는 광디스크의 흔들림에 의해, 레이저빔이 광디스크에 대한 정상적인 각도로부터 벗어나는 입사빔기울어짐이 발생하는 경우, 정상적으로 신호를 기록 또는 재생하기 곤란하다. 더욱이, 현재 사용가능한 레이저다이오드광원의 광파장은 600nm 부근이 가장 짧은 것이며, 대물렌즈의 개구수도 현재로는 대략 0.6 이다. 따라서, 0.6이상의 개구수가 필요한 경우, 광픽업의 성능은 입사빔기울어짐 등에 매우 민감하게 되어, 광기록/재생장치의 상용화를 위해 이러한 집속광학계를 사용하기에는 많은 어려움이 따른다.However, since the focusing optical system of FIG. 1 includes separately produced aspherical lens 1 and spherical lens 2, there is a difficulty in assembling or adjusting to have desired optical characteristics. In addition, since an incident laser light having a beam diameter of 3 mm or more is required, the size of all the optical parts including the light receiving portion is increased. In addition, it is difficult to record or reproduce a signal normally when an incident beam tilt occurs in which the laser beam deviates from a normal angle with respect to the optical disk by the shaking of the moving optical pickup or the rotating optical disk. Moreover, the light wavelength of the laser diode light source currently available is the shortest around 600 nm, and the numerical aperture of the objective lens is also approximately 0.6 at present. Therefore, when a numerical aperture of 0.6 or more is required, the performance of the optical pickup becomes very sensitive to incident beam tilting, and the like, and it is difficult to use such a focused optical system for commercialization of the optical recording / reproducing apparatus.

따라서, 본 발명의 목적은 새로운 광학계를 이용하여 니어필드를 발생함으로써, 입사빔 기울어짐에 대해 우수한 성능을 가지며 광부품의 소형화가 가능하면서도 집광 스폿의 크기를 줄일 수 있는, 집속광학계를 제공함에 있다.Accordingly, an object of the present invention is to provide a condensing optical system that generates a near field using a new optical system, which has excellent performance against incident beam inclination, and can reduce the size of a condensing spot while miniaturizing an optical component. .

본 발명의 다른 목적은 전술의 집속광학계를 채용한 광픽업을 제공함에 있다.Another object of the present invention is to provide an optical pickup employing the above-mentioned focused optical system.

본 발명의 또 다른 목적은 전술의 집속광학계를 성형하기 위한 금형방법에 있다.Still another object of the present invention is a mold method for molding the above-mentioned focusing optical system.

본 발명의 또 다른 목적은 전술의 집속광학계를 채용한 광디스크드라이브를 제공함에 있다.Still another object of the present invention is to provide an optical disk drive employing the above-mentioned focused optical system.

도 1은 니어필드를 발생하는 종래의 집속광학계를 설명하기 위한 도면,1 is a view for explaining a conventional focusing optical system for generating a near field;

도 2는 본 발명의 바람직한 일 실시예에 따른 집속광학계를 설명하기 위한 도면,2 is a view for explaining a focusing optical system according to an embodiment of the present invention;

도 3a-3c는 도 2에 보여진 집속광학계를 광자기디스크를 위해 변형한 집속광학계를 설명하기 위한 도면,3A and 3C are diagrams for explaining a focusing optical system in which the focusing optical system shown in FIG. 2 is modified for a magneto-optical disk;

도 4a-4c는 도 3a에 보여진 집속광학계가 광디스크의 표면위에 에어베어링을 형성하도록 변형한 예들을 설명하기 위한 도면,4A and 4C are diagrams for explaining examples in which the focusing optical system shown in FIG. 3A is modified to form an air bearing on the surface of an optical disc;

도 5는 도 2에 보여진 집속광학계의 제조방법을 설명하기 위한 도면,5 is a view for explaining a method of manufacturing the focusing optical system shown in FIG.

도 6은 도 3a의 집속광학계를 채용한 광픽업의 광학계를 보여주는 도면,6 is a view illustrating an optical system of an optical pickup employing the focusing optical system of FIG. 3A;

도 7은 도 2 집속광학계를 광픽업에서 조립하기에 적합하도록 변형한 예를 보여주는 도면,FIG. 7 is a diagram illustrating an example in which the focused optical system of FIG. 2 is modified to be suitable for assembling in an optical pickup;

도 8 내지 도 10b는 본 발명에 따른 집속광학계를 채용한 광디스크드라이브의 구조도들.8 to 10b are structural diagrams of an optical disk drive employing a focused optical system according to the present invention;

도 11은 도 8내지 도 10b에 보여진 광디스크드라이브들에 사용되는 플렉서(flexure)를 설명하기 위한 도면,FIG. 11 is a view for explaining a flexure used in the optical disk drives shown in FIGS. 8 to 10B;

도 12a는 도 8내지 도 10b에 보여진 광디스크드라이브가 정보를 기록 또는 재생하는 광디스크를 설명하기 위한 도면,12A is a diagram for explaining an optical disc in which the optical disc drive shown in FIGS. 8 to 10B records or reproduces information;

도 12b는 도 12a에 보여진 재생층을 갖는 광디스크 대신에 니어필드형성부의 표면에 재생층을 갖는 집속광학계를 나타낸 도면.FIG. 12B shows a condensing optical system having a reproducing layer on the surface of the nearfield forming portion instead of the optical disc having the reproducing layer shown in FIG. 12A;

*도면의 주요 부분에 대한 부호의 설명* Explanation of symbols for the main parts of the drawings

10 : 레이저광 20,40 : 집속광학계10: laser light 20, 40: focused optical system

30,50 : 집광소자 33,41 : 니어필드형성부30,50 condensing element 33,41 near field forming part

100,110 ; 디스크 201,311,401,511 : 굴절부100,110; Disc 201,311,401,511: Refraction

203,313,403,513 : 반사부 331,411,531 : 집광면203,313,403,513: Reflector 331,411,531: Condensing surface

본 발명의 목적을 달성하기 위한, 입사하는 레이저광을 이용하여 니어필드(near field)를 발생하는 집속광학계는, 광원 쪽에 위치한 표면에 형성된 굴절부 및 제 1반사부와, 대상물 쪽에 위치한 제 2반사부 및 니어필드형성부를 포함하며, 니어필드를 형성하는 광스폿이 상기 니어필드형성부에 형성되도록, 상기 굴절부는 광원 쪽으로부터 입사하는 레이저광을 굴절시키며, 상기 제 2반사부는 상기 굴절부에 의해 굴절된 레이저광을 상기 제 1반사부 쪽으로 반사시키고, 상기 제 1반사부은 상기 제 2반사부에서 반사된 레이저광을 상기 니어필드형성부에 집속시킨다.In order to achieve the object of the present invention, a focusing optical system that generates a near field using incident laser light includes a refractive part and a first reflecting part formed on a surface located on a light source side, and a second reflection located on an object side. And a near field forming portion, wherein the refracting portion refracts laser light incident from the light source side such that a light spot forming a near field is formed in the near field forming portion, and the second reflecting portion is formed by the refracting portion. The refracted laser light is reflected toward the first reflecting portion, and the first reflecting portion focuses the laser light reflected by the second reflecting portion on the near field forming portion.

또한, 본 발명의 목적을 달성하기 위한, 광픽업은, 광원; 및 상기 광원으로부터 입사하는 레이저광을 이용하여 니어필드를 발생하는 집속광학계를 포함하며, 상기 집속광학계는 광원 쪽에 위치한 표면에 형성된 굴절부 및 제 1반사부와, 디스크 쪽에 위치한 표면에 형성된 제 2반사부 및 니어필드형성부를 포함하며, 니어필드를 형성하는 광스폿이 상기 니어필드형성부에 형성되도록, 상기 굴절부는 광원 쪽으로부터 입사하는 레이저광을 굴절시키며, 상기 제 2반사부는 상기 굴절부에 의해 굴절된 레이저광을 상기 제 1반사부 쪽으로 반사시키고, 상기 제 1반사부은 상기 제 2반사부에서 반사된 레이저광을 상기 니어필드형성부에 집속시킨다.In addition, the optical pickup for achieving the object of the present invention, the light source; And a focusing optical system for generating a near field by using the laser light incident from the light source, wherein the focusing optical system includes a refracting part and a first reflecting part formed on a surface located on the light source side, and a second reflection formed on a surface located on the disk side. And a near field forming portion, wherein the refracting portion refracts laser light incident from the light source side such that a light spot forming a near field is formed in the near field forming portion, and the second reflecting portion is formed by the refracting portion. The refracted laser light is reflected toward the first reflecting portion, and the first reflecting portion focuses the laser light reflected by the second reflecting portion on the near field forming portion.

상술한 집속광학계들은 소망된 광학적 특성을 갖도록 조립 또는 조정이 용이하며, 집속광학계가 갖는 구경보다 작은 빔직경의 레이저광을 이용하여 상술한 종래의 집속광학계가 제공하는 개구수보다 훨씬 큰 개구수를 제공한다. 따라서, 종래의 집속광학계에 의해 형성되는 광스폿보다 작은 사이즈를 갖는 광스폿을 형성하므로, 현존하는 광기록매체보다 훨신 높은 면기록밀도를 갖는 피트부조광디스크, 상변화광디스크 또는 광자기디스크에 사용할 수 있다.The above-mentioned focusing optical systems are easy to assemble or adjust to have desired optical characteristics, and use a laser beam having a beam diameter smaller than the aperture of the focusing optical system to achieve a numerical aperture much larger than that provided by the conventional focusing optical system. to provide. Therefore, since the optical spot having a smaller size than the optical spot formed by the conventional converging optical system is formed, it can be used for a pit auxiliary optical disk, a phase change optical disk, or an optical magnetic disk having a much higher surface recording density than existing optical recording media. have.

본 발명의 다른 목적을 달성하기 위한, 광원 쪽에 위치한 표면에 형성된 굴절부 및 제 1반사부와, 디스크 쪽에 위치한 표면에 형성된 제 2반사부 및 니어필드형성부를 포함하며, 니어필드를 형성하는 광스폿이 상기 니어필드형성부에 형성되도록, 상기 굴절부는 광원 쪽으로부터 입사하는 레이저광을 굴절시키며, 상기 제 2반사부는 상기 굴절부에 의해 굴절된 레이저광을 상기 제 1반사부 쪽으로 반사시키고, 상기 제 1반사부은 상기 제 2반사부에서 반사된 레이저광을 상기 니어필드형성부에 집속시키는, 집속광학계를 위한 금형을 제조하기 위한 방법은, 상기 굴절부 및 제 1반사부를 위한 상부금형을 제조하는 단계를 포함하며,To achieve another object of the present invention, a light spot including a refractive portion and a first reflection portion formed on the surface located on the light source side, a second reflection portion and a near field forming portion formed on the surface located on the disk side, and forming a near field The refracting portion refracts laser light incident from the light source side so that the near field forming portion is formed, and the second reflecting portion reflects the laser light refracted by the refracting portion toward the first reflecting portion, The method for manufacturing a mold for a focusing optical system, wherein the first reflector focuses the laser light reflected by the second reflector on the near field forming unit, includes: manufacturing an upper mold for the refraction unit and the first reflection unit; Including;

상기 상부금형제조단계는, 금형원판을 컷팅하여 금형원판에 상기 제 1반사부의 표면을 조형하는 단계; 상기 굴절부의 조형을 위한 굴절부금형을 제조하는 단계; 제 1반사부의 표면이 조형된 금형원판에 상기 굴절부금형을 삽입하기 위한 개구를 형성하는 단계; 및 상기 금형원판에 형성된 개구에 상기 굴절부금형을 삽입하는 단계를 포함한다.The upper mold manufacturing step may include forming a surface of the first reflection part on a mold disc by cutting a mold disc; Manufacturing a refractive mold for molding the refractive portion; Forming an opening for inserting the refractive portion mold in the mold disc having the surface of the first reflection portion molded; And inserting the refractive portion mold into the opening formed in the mold disc.

본 발명의 다른 목적을 달성하기 위한, 니어필드를 재생에 이용하는 광디스크드라이브는, 광원; 광디스크; 니어필드가 형성되는 니어필드형성면을 가지며, 상기 광디스크와 자신의 사이에 상기 광디스크로부터의 신호재생에 유효한 니어필드를 형성하기 위한 에어베어링을 발생하는 슬라이더; 상기 슬라이더를 지지하기 위한 피봇(pivot)점의 주위를 지지하는 플렉서(flexure); 및 상기 광원 쪽에 위치한 표면에 형성된 굴절부 및 제 1반사부와, 디스크 쪽에 위치한 표면에 형성된 제 2반사부 및 니어필드형성부를 포함하며, 상기 굴절부는 광원 쪽으로부터 입사하는 레이저광을 굴절시키며, 상기 제 2반사부는 상기 굴절부에 의해 굴절된 레이저광을 상기 제 1반사부 쪽으로 반사시키고, 상기 제 1반사부은 상기 제 2반사부에서 반사된 레이저광을 상기 니어필드형성부에 집속시키고, 상기 광원으로부터 입사하는 레이저광을 이용하여 상기 슬라이더의 니어필드형성면에 니어필드를 발생하는 집속광학계를 포함한다.In order to achieve another object of the present invention, an optical disc drive using near field for reproduction includes a light source; Optical disks; A slider having a near field forming surface on which a near field is formed and generating an air bearing between the optical disk and itself to generate a near field effective for signal reproduction from the optical disk; A flexure supporting a circumference of a pivot point for supporting the slider; And a refraction portion and a first reflection portion formed on the surface located on the light source side, a second reflection portion and a near field forming portion formed on the surface located on the disk side, wherein the refraction portion refracts laser light incident from the light source side, The second reflecting portion reflects the laser light refracted by the refracting portion toward the first reflecting portion, and the first reflecting portion focuses the laser light reflected by the second reflecting portion on the near field forming portion, and the light source And a focusing optical system for generating a near field on the near field forming surface of the slider by using the laser light incident therefrom.

이하 첨부된 도면들을 참조하여 본 발명의 실시예들을 상세히 설명한다.Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

도 2를 참조하면, 본 발명의 일 실시예에 따른 집속광학계(20)는 자신의 광원(미도시)쪽의 표면에 위치한 굴절부(201) 및 제 1반사부(203)와, 집속광학계(20)의 광디스크(100)쪽 표면에 위치한 니어필드형성부(204) 및 제 2반사부(205)를 구비한다. 이하로는 설명의 명료함을 위해, 광원쪽에 위치한 반사부를 제 1반사부, 디스크쪽에 위치한 반사부를 제 2반사부로 정한다. 굴절부(201)는 광원으로부터 입사하는 광을 굴절시키며, 제 1 및 제 2반사부들(203 및 205)은 입사하는 광을 반사시킨다. 니어필드형성부(204)는 광투과특성을 갖는 부분으로 광디스크(100)에 대한 정보의 기록 그리고/또는 재생에 이용되는 니어필드를 형성한다. 굴절부(201) 및 니어필드형성부(204)는 집속광학계(20)의 광학적 축을 포함하는 부분들이며, 제 1반사부(203)는 굴절부(201)의 바깥쪽에 위치하고, 제 2반사부(205)는 니어필드형성부(204)의 바깥쪽에 위치한다. 니어필드형성부(204) 및 제 2반사부(205)로 구성된 광디스크(100) 쪽 표면은 평면 또는 평면에 가까운 곡면 형상을 갖는다.Referring to FIG. 2, the focusing optical system 20 according to an exemplary embodiment of the present invention may include a refracting part 201 and a first reflecting part 203 located on a surface of a light source (not shown) thereof, and a focusing optical system ( And a near field forming portion 204 and a second reflecting portion 205 located on the surface of the optical disc 100 side of the optical disc 100. In the following description, for the sake of clarity, the reflection part located on the light source side and the reflection part located on the disc side are defined as the second reflection part. The refraction unit 201 refracts the light incident from the light source, and the first and second reflection parts 203 and 205 reflect the incident light. The near field forming unit 204 forms a near field used for recording and / or reproducing information on the optical disc 100 as a portion having light transmission characteristics. The refracting portion 201 and the near field forming portion 204 are portions including the optical axis of the focusing optical system 20, and the first reflecting portion 203 is located outside the refracting portion 201 and the second reflecting portion ( 205 is located outside the near field forming portion 204. The optical disc 100 side surface formed of the near field forming portion 204 and the second reflecting portion 205 has a flat surface or a nearly curved surface.

굴절부(201)는 광디스크(100)쪽으로 들어간 구면 형상을 갖는 것으로, 광원 쪽으로부터 입사하는 레이저광(10)을 발산하는 형태로 굴절시킨다. 제 1반사부(203)는 비구면 형상을 갖는 것으로, 굴절부(201)에 의해 굴절된 다음 제 2반사부(205)에서 반사된 레이저광(10)을 제 2반사부(205)의 중심부분에 위치한 니어필드형성부(204) 쪽으로 반사시킨다. 제 1반사부(203)는 또한 외부로부터 그 표면으로 들어오는 외부광을 반사시킨다. 제 2반사부(205) 또한 외부광 및 제 1반사부(203)에서 반사된 다음 입사하는 레이저광을 반사시킨다.The refraction portion 201 has a spherical shape that enters the optical disc 100 and is refracted in a form of diverging the laser light 10 incident from the light source side. The first reflecting portion 203 has an aspherical shape, and the laser beam 10 refracted by the refracting portion 201 and reflected by the second reflecting portion 205 is divided into a central portion of the second reflecting portion 205. Reflect toward the near field forming unit 204 located in. The first reflecting portion 203 also reflects external light coming into the surface from the outside. The second reflector 205 also reflects the external light and the laser light that is incident after being reflected by the first reflector 203.

이와 같은 집속광학계(20)에서, 반사부들(203, 205)은 코팅등에 의해 전반사특성이 부여된다. 그러나, 니어필드형성부(204)는 광투과특성을 갖도록 반사코팅을 하지 않는다. 또한, 굴절부(201)의 구경(aperture)이 집속광학계(20)의 구경보다 충분히 작도록 설계된다. 즉, 굴절부(201)가 제 1반사부(203)에 비해 집속광학계(20)의 광원쪽 표면을 차지하는 비율이 훨씬 적도록 설계된다. 그리고, 제 1반사부(203)에서 반사된 레이저광의 대부분이 니어필드형성부(204)에 집속되도록 설계된다. 따라서, 도 2의 집속광학계(20)는 굴절부(201)를 통해 입사하는 레이저광(10)의 대부분을 니어필드형성부(204)에 광스폿으로 집광시킨다. 이 실시예에서, 굴절부(201)의 구경 즉, 레이저광(10)의 축에 수직한 굴절부(201)의 폭은 대략 0.8mm이다. 니어필드형성부(204)에 집광되는 광스폿은 대략 0.35μm의 크기를 가지며, "감쇠필드(evanescent field)"라고도 하는 니어필드를 형성한다. 잘 알려진 것처럼, 니어필드는 광의 한 파장이내에 존재하는 전자기장이다. 그러므로, 집속광학계(20)의 니어필드형성부(204)로부터 레이저광(10)의 한 파장만큼의 거리 이내에 광디스크(100)의 표면을 위치시키면, 니어필드를 통해 니어필드형성부(204)의 근처에 위치한 광디스크(100)의 정보기록면 부분에 정보를 기록하거나 또는 그로부터 정보를 읽어낼 수 있게 된다. 바람직하게는, 집속광학계(20)의 니어필드형성부(204)의 표면과 광디스크(100)의 집속광학계(20) 쪽 표면간의 거리는 100nm 미만이다.In the focusing optical system 20, the reflection parts 203 and 205 are given total reflection characteristics by coating or the like. However, the near field forming unit 204 does not perform reflection coating so as to have a light transmission characteristic. Further, the aperture of the refraction portion 201 is designed to be sufficiently smaller than the aperture of the focusing optical system 20. That is, the refraction portion 201 is designed to have a much smaller ratio of occupying the light source side surface of the focusing optical system 20 than the first reflection portion 203. And, most of the laser light reflected by the first reflecting portion 203 is designed to focus on the near field forming portion 204. Therefore, the focusing optical system 20 of FIG. 2 condenses most of the laser light 10 incident through the refracting portion 201 to the near field forming portion 204 as a light spot. In this embodiment, the aperture of the refracting portion 201, that is, the width of the refracting portion 201 perpendicular to the axis of the laser light 10 is approximately 0.8 mm. The light spots focused on the near field forming unit 204 have a size of approximately 0.35 μm and form a near field, also called an “evanescent field”. As is well known, nearfields are electromagnetic fields that exist within one wavelength of light. Therefore, if the surface of the optical disc 100 is positioned within a distance of one wavelength of the laser light 10 from the near field forming portion 204 of the focusing optical system 20, the near field forming portion 204 is formed through the near field. Information can be recorded on or read from the information recording surface portion of the optical disc 100 located nearby. Preferably, the distance between the surface of the near field forming portion 204 of the focusing optical system 20 and the surface of the focusing optical system 20 of the optical disk 100 is less than 100 nm.

또한, 도 2의 집속광학계(20)는 굴절부(201)만을 통해 입사하는 레이저광(10)을 사용한다. 그러므로, 도 1의 집속광학계에 비하여 훨씬 작은 빔직경을 갖는 레이저광만으로 소망된 크기의 광스폿을 얻을 수 있다. 사용되는 레이저광(10)의 직경은 바람직하게는 1mm 미만이므로, 도 2의 집속광학계(20)는, 광픽업에 사용되는 경우, 도 1의 집속광학계에 비하여 수광부를 포함한 모든 광부품의 크기를 작게 할 수 있다. 또한, 이 집속광학계(20)는 3mm의 빔직경을 갖는 레이저빔을 사용하는 기존의 광픽업에서 그대로 사용할 수 도 있다.In addition, the focusing optical system 20 of FIG. 2 uses the laser light 10 incident through only the refraction unit 201. Therefore, compared to the focused optical system of Fig. 1, only a laser beam having a much smaller beam diameter can obtain an optical spot of a desired size. Since the diameter of the laser beam 10 to be used is preferably less than 1 mm, the condensing optical system 20 of FIG. 2 has the size of all optical components including the light receiving unit as compared to the condensing optical system of FIG. 1 when used for optical pickup. It can be made small. In addition, the focusing optical system 20 may be used as it is in the conventional optical pickup using a laser beam having a beam diameter of 3 mm.

이와 같은 도 2의 집속광학계(20)는 피트부조(emboss-pit) 광디스크와, 기록 및 재생 둘 다가 가능한 상변화(phase-change) 광디스크를 위한 광픽업에 사용된다.This focusing optical system 20 of FIG. 2 is used for optical pickup for an emboss-pit optical disc and a phase-change optical disc capable of both recording and playback.

도 3a-3c는 도 2의 집속광학계를 광자기(magneto-optical)디스크를 위해 사용하기에 적합하도록 변형한 예들을 보여준다. 도 3a에 보여진 집속광학계(30)는 집광소자(31) 및 니어필드형성부(33)를 포함한다. 니어필드형성부(33)는 집속광학계(30)의 광자기디스크(110) 쪽 표면의 광학적 중심과 동일한 중심을 갖도록 형성되는 것으로, 원통형상을 갖는다. 집광소자(31)는 집속광학계(30)의 광원쪽 표면을 구성하는 굴절부(311) 및 제 1반사부(313)와, 니어필드형성부(33)가 차지하는 부분을 제외한 집광소자(31)의 광자기디스크(110) 쪽 표면을 형성하는 제 2반사부(315)를 포함한다.3A-3C show examples of modification of the focusing optical system of FIG. 2 to be suitable for use for magneto-optical discs. The focusing optical system 30 shown in FIG. 3A includes a light collecting element 31 and a near field forming unit 33. The near field forming unit 33 is formed to have the same center as the optical center of the surface of the magneto-optical disk 110 side of the focusing optical system 30 and has a cylindrical shape. The light collecting element 31 is a light collecting element 31 except for a portion occupied by the refractive portion 311 and the first reflecting portion 313 and the near field forming portion 33 constituting the light source side surface of the focusing optical system 30. And a second reflection portion 315 forming a surface of the magneto-optical disk 110.

니어필드형성부(33)는 광자기디스크(110)에 대한 자기기록/재생을 위해 사용되는 자석코일(magnet coil)을 부착하기에 적합한 두께 및 형상을 갖는다. 여기서, 니어필드형성부(33)의 두께는 집광소자(31)의 제 2반사면(315)으로부터 튀어나온 니어필드형성부(33)의 높이이다. 제 2반사면(315)은 외부 또는 내부에서의 입사하는 광을 반사시키는 반사특성을 가지며, 이러한 반사특성은 금속코팅을 통해 주어진다.The near field forming unit 33 has a thickness and a shape suitable for attaching a magnet coil used for magnetic recording / reproducing to the magneto-optical disk 110. Here, the thickness of the near field forming portion 33 is the height of the near field forming portion 33 protruding from the second reflecting surface 315 of the light converging element 31. The second reflecting surface 315 has a reflection characteristic that reflects incident light from the outside or the inside, and this reflection characteristic is given through a metal coating.

굴절부(311)는 입사하는 레이저광(10)을 발산하는 형태로 굴절시키며, 제 2반사부(315)는 굴절부(311)에 의해 굴절된 레이저광을 제 1반사부(313) 쪽으로 반사시킨다. 제 1반사부(313)는 제 2반사부(315)에 의해 반사된 다음 입사하는 레이저광을 니어필드형성부(33) 쪽으로 반사시킨다. 도 3a의 집속광학계에 의해 최종적으로 집광되는 광스폿은 광자기디스크(110) 쪽에 위치한 니어필드형성부(33)의 집광면(331)에 형성된다. 그러므로, 굴절부(311) 및 제 1반사부(313)는 도 2의 굴절부(201) 및 제 1반사부(203)의 곡률들로부터 약간 달라진 곡률을 갖는다. 제 2반사부(315)의 경우, 도 2에 보여진 집속광학계(20)의 광디스크(100) 쪽 표면과 마찬가지로 평면 또는 평면에 가까운 곡면 형상을 갖는다.The refracting part 311 refracts the laser beam 10 incident thereto, and the second reflecting part 315 reflects the laser light refracted by the refracting part 311 toward the first reflecting part 313. Let's do it. The first reflecting portion 313 reflects the laser light incident after being reflected by the second reflecting portion 315 toward the near field forming portion 33. The light spot finally focused by the focusing optical system of FIG. 3A is formed on the condensing surface 331 of the near field forming portion 33 located on the magneto-optical disk 110 side. Therefore, the refraction portion 311 and the first reflection portion 313 have a curvature slightly different from the curvatures of the refraction portion 201 and the first reflection portion 203 of FIG. 2. In the case of the second reflecting portion 315, the surface of the second optical reflector 315 has a flat surface or a near surface similar to that of the optical disk 100 side surface of the focusing optical system 20 shown in FIG.

광스폿이 형성되는 집광면(331)으로 진행하는 레이저광의 량은 니어필드형성부(33)의 두께에 의존하며, 니어필드형성부(33)의 두께가 얇을수록 많은 레이저광이 집광면(331)에 도달한다. 그러므로, 제 1반사부(313)가 굴절부(311)를 통해 입사한 레이저광(10)의 30% 미만을 블로킹(blocking)하는 경우, 이 정도 비율 이상을 제 2반사부(315)가 블로킹하지 않도록 니어필드형성부(33)의 두께가 정해진다.The amount of laser light traveling to the condensing surface 331 where the light spot is formed depends on the thickness of the near field forming portion 33. The thinner the thickness of the near field forming portion 33 is, the more laser light is collected on the condensing surface 331. ) Therefore, when the first reflecting portion 313 blocks less than 30% of the laser light 10 incident through the refraction portion 311, the second reflecting portion 315 blocks more than this ratio. The thickness of the near field forming part 33 is determined so as not to be.

집광소자(31) 및 니어필드형성부(33) 둘 다가 굴절률 "1.84"인 매질로 제작된 경우, 도 3a 집속광학계의 설계를 위해 시험한 결과에 따르면, 니어필드형성부(33)의 두께는, 바람직하게는 대략 0.1∼0.2mm의 범위를 가지며, 보다 바람직하게는 대략 0.13mm이다. 그 두께가 0.13mm인 경우, 제 2면에서 니어필드형성부(33)의 집광면(331)이 차지하는 영역의 직경은 0.5mm이다. 이와 같은 조건들을 만족하도록 니어필드형성부(33)를 설계한 경우, 집속광학계(30)는 개구수 1.5, 초점거리 0.477mm, 및 제 2면의 유효직경 3.4mm를 가지며, 입사 레이저광(10)의 빔직경은 0.78mm이면 충분하다. 그러므로, 상술한 도 3a의 집속광학계를 광픽업에 이용하면 10Gbit/inch2이상의 면기록밀도로 광자기디스크에 정보를 기록 또는 재생할 수 있다. 굴절률 "1.58"을 갖는 매질을 이용하여 니어필드형성부(33)를 제조하는 경우, 집광소자(31)는 개구수 1.1을 갖도록 설계될 수 있다.When both the light collecting element 31 and the near field forming portion 33 are made of a medium having a refractive index of "1.84", the thickness of the near field forming portion 33 is determined according to the result of the test for the design of the focused optical system of FIG. 3A. Preferably it is about 0.1-0.2 mm, More preferably, it is about 0.13 mm. When the thickness is 0.13 mm, the diameter of the area occupied by the condensing surface 331 of the near field forming portion 33 in the second surface is 0.5 mm. When the nearfield forming unit 33 is designed to satisfy such conditions, the focusing optical system 30 has a numerical aperture 1.5, a focal length of 0.477mm, and an effective diameter of 3.4mm on the second surface, and the incident laser light 10 ), The beam diameter of 0.78 mm is sufficient. Therefore, when the above-mentioned converging optical system of Fig. 3A is used for optical pickup, information can be recorded or reproduced on the magneto-optical disc with a plane recording density of 10 Gbit / inch 2 or more. When the near field forming portion 33 is manufactured using a medium having a refractive index of "1.58", the light collecting element 31 may be designed to have a numerical aperture 1.1.

도 3b는 도 3a의 집속광학계(30)로부터 변형된 집속광학계(40)를 도시한다. 도 3b에 보여진 집속광학계(40)는 단일 광학소자로 제작되는 것으로, 집속광학계(40)의 광원(미도시)쪽 표면에 광원 쪽으로 볼록한 굴절부(401)를 구비한다. 굴절부(401)는 입사하는 레이저광(10)을 집속광학계(40) 내부에 초점(FP)이 형성되도록 수렴시키는 형태로 굴절시킨다. 평면 또는 평면에 가까운 곡면 형상의 제 2반사부(405)는 굴절부(401)에 의해 굴절된 레이저광(10)을 제 1반사부(403) 쪽으로 반사시키며, 제 1반사부(403)는 제 2반사부(405)로부터 입사하는 레이저광을 원형평판 형상을 갖는 니어필드형성부(41)쪽으로 반사시킨다. 이러한 도 3b의 집속광학계(40)는 굴절부(401)가 도 3a의 굴절부(311)의 반대쪽으로 볼록한 것을 제외하면 도 3a의 집속광학계와 거의 동일한 구조를 갖는다. 그러므로, 제 1반사부(403)에 의해 반사된 레이저광(10)은 니어필드형성부(41)의 집광면(411)에서 광스폿으로 집광된다.FIG. 3B shows the focusing optical system 40 modified from the focusing optical system 30 of FIG. 3A. The focusing optical system 40 shown in FIG. 3B is made of a single optical element, and includes a refracting part 401 convex toward the light source on the light source (not shown) surface of the focusing optical system 40. The refraction unit 401 refracts the incident laser light 10 to converge to form the focal point FP inside the focusing optical system 40. The planar or near-surface curved second reflector 405 reflects the laser light 10 refracted by the refracting unit 401 toward the first reflector 403, and the first reflector 403 The laser light incident from the second reflecting portion 405 is reflected toward the near field forming portion 41 having a circular flat plate shape. The focused optical system 40 of FIG. 3B has a structure almost the same as that of the focused optical system of FIG. 3A except that the refracting unit 401 is convex to the opposite side of the refracting unit 311 of FIG. 3A. Therefore, the laser light 10 reflected by the first reflecting portion 403 is condensed into the light spot on the light collecting surface 411 of the near field forming portion 41.

도 3c는 도 3a에 보여진 집속광학계(30)의 다른 변형을 도시한다. 도 3c의 집속광학계(50)는 집광소자(51) 및 니어필드형성부(53)로 구성되며, 집광소자(51)는, 오목한 형상을 갖는 굴절부(511), 비구면형상의 제 1반사부(513), 및 평면 또는 평면에 가까운 곡면 형상의 제 2반사부(515)를 구비한다. 니어필드형성부(53)는 집광소자(51)의 광학적 축을 중심을 포함하는 형태로 집광소자(51)의 광자기디크스(110) 쪽 표면에 형성되며, 그 광학적 축이 집광소자(51)의 광학적 축과 일치하며 광원(미도시) 쪽을 향한 면이 볼록한 원통 형상을 갖는다. 이 니어필드형성부(53)의 면(531)은 입사 레이저광(10)이 최종 광스폿으로 집광되는 집광면이 된다. 굴절부(511)는 입사하는 레이저광(10)을 발산하는 형태로 굴절시키며, 광자기디크스(110) 쪽에 위치한 제 2반사부(515)는 굴절부(511)에 의해 굴절된 레이저광을 제 1반사부(513) 쪽으로 반사시킨다. 제 1반사부(513)는 제 2반사부(515)로부터 반사된 레이저광(10)을 니어필드형성부(53)의 집광면(531)에 집광시킨다. 그 결과, 집광면(531)에 집광되는 광스폿에 의해 니어필드가 형성된다.FIG. 3C shows another variant of the focusing optical system 30 shown in FIG. 3A. The converging optical system 50 of FIG. 3C is composed of a light collecting element 51 and a near field forming portion 53, and the light collecting element 51 includes a concave portion 511 having a concave shape and an aspheric first reflecting portion. 513, and a second reflective portion 515 having a flat surface or a near surface shape. The near field forming part 53 is formed on the surface of the magneto-optical disk 110 side of the light collecting element 51 in a form including the optical axis of the light collecting element 51 as a center, and its optical axis is the light collecting element 51. The surface facing the light axis (not shown) is convex in the convex cylindrical shape. The surface 531 of the near field forming portion 53 serves as a condensing surface in which the incident laser light 10 is collected as a final light spot. The refracting unit 511 refracts the incident laser light 10, and the second reflecting unit 515 located on the magneto-optical dike 110 side receives the laser light refracted by the refracting unit 511. Reflected toward the first reflecting portion 513. The first reflecting portion 513 condenses the laser light 10 reflected from the second reflecting portion 515 on the condensing surface 531 of the near field forming portion 53. As a result, a near field is formed by the light spot focused on the condensing surface 531.

니어필드형성부(53)는 집광소자(51)보다 높은 굴절률을 갖도록 설계되어, 니어필드형성부(53)로 입사하는 레이저광은 니어필드형성부(53)에 의해 더욱 수렴된다. 그러므로, 집광면(531)에 형성되는 광스폿의 크기는 도 3a의 집속광학계가 형성시키는 광스폿 크기의 절반이 된다. 집광소자(51)는 대략 1.55인 굴절률을 갖는 일반 광학유리로 제작되며, 니어필드형성부(53)는 대략 3인 굴절률을 갖는 갈륨비소(GaAs)로 제작된다.The near field forming unit 53 is designed to have a higher refractive index than the light collecting element 51, so that the laser light incident on the near field forming unit 53 is further converged by the near field forming unit 53. Therefore, the size of the light spot formed on the condensing surface 531 is half the size of the light spot formed by the converging optical system of FIG. 3A. The light collecting element 51 is made of general optical glass having a refractive index of approximately 1.55, and the near field forming portion 53 is made of gallium arsenide (GaAs) having a refractive index of approximately 3.

상술한 도 3a-3c의 집속광학계들은 피트부조 광디스크, 상변화 광디스크 및 광자기디스크 모두에 사용할 수 있다.The focusing optical systems of FIGS. 3A-3C described above can be used for both the pit-assisted optical disk, the phase change optical disk, and the magneto-optical disk.

도 4a-4c는 본 발명에 따른 집속광학계들을 채용한 광헤드들을 보여준다.4A-4C show optical heads employing focused optical systems in accordance with the present invention.

도 4a는 도 3a의 니어필드형성부(33) 대신에 슬라이더(slider, 65)를 집광소자(31)의 디스크쪽 표면에 부착한 광헤드(60)를 보여준다. 슬라이더(65)는 집광소자(31) 보다 더 높은 굴절률을 갖는 매질로 된 것으로, 접착제 등을 이용하여 집광소자(31)의 디스크쪽 표면에 부착된다. 이 슬라이더(65)는 광자기디스크(110)의 회전이동에 대하여 상대적으로 앞쪽에 위치한 돌출부(651), 및 집광소자(31)의 광학축과 동일한 광학축을 갖는 니어필드형성부(653)를 구비한다. 니어필드형성부(653)의 디스크쪽 표면은 집광소자(31)에 의해 레이저광(10)이 집광되어, 니어필드를 형성한다. 돌출부(651)는 광자기디스크(110)가 회전하는 경우, 슬라이더(65)와 광자기디스크(110) 사이에 에어베어링을 형성한다.4A shows an optical head 60 in which a slider 65 is attached to the disk side surface of the light collecting element 31 instead of the near field forming portion 33 of FIG. 3A. The slider 65 is made of a medium having a higher refractive index than the light collecting element 31, and is attached to the disk side surface of the light collecting element 31 using an adhesive or the like. This slider 65 has a projection 651 located relatively forward with respect to the rotational movement of the magneto-optical disk 110, and a nearfield forming portion 653 having the same optical axis as the optical axis of the light converging element 31. As shown in FIG. do. On the disk-side surface of the near field forming portion 653, the laser light 10 is collected by the light collecting element 31 to form a near field. The protrusion 651 forms an air bearing between the slider 65 and the magneto-optical disk 110 when the magneto-optical disk 110 rotates.

도 4b는 도 3a에 보여진 집속광학계(30)를 집광소자(71)와 슬라이더(75A)를 갖도록 변형한 광헤드(70A)를 보여준다. 집광소자(71)와 슬라이더(75A)는 동일한 굴절률을 갖는 매질들로 만들어지며, 이 것들과 동일한 굴절률을 갖는 접착제에 의해 접착된다. 도 4b에서, 711은 굴절부, 713은 제 1반사부, 715는 제 2반사부, 751A는 돌출부, 753은 니어필드형성부이다.FIG. 4B shows the optical head 70A in which the focusing optical system 30 shown in FIG. 3A is modified to have the light collecting element 71 and the slider 75A. The light collecting element 71 and the slider 75A are made of media having the same refractive index, and are bonded by an adhesive having the same refractive index as these. In Fig. 4B, reference numeral 711 denotes a refraction portion, 713 a first reflection portion, 715 a second reflection portion, 751A a protrusion portion, and 753 a near field forming portion.

도 4c는 도 4b에 보여진 슬라이더(75A)와는 다른 형상을 갖는 슬라이더(75B)를 갖는 광헤드(70B)를 보여준다. 도 4c에 보여진 소자들은 도 4b에서의 동일한 참조번호를 갖는 소자들과 동일한 형상 및 기능을 갖는다. 슬라이더(75B)는 광자기디스크(110)에 대한 정보의 기록/재생을 위한 자석코일(77)을 형성하기 위한 홈을 갖는다.FIG. 4C shows an optical head 70B having a slider 75B having a different shape than the slider 75A shown in FIG. 4B. The elements shown in FIG. 4C have the same shape and function as those with the same reference numerals in FIG. 4B. The slider 75B has a groove for forming a magnet coil 77 for recording / reproducing information on the magneto-optical disk 110.

도 5는 전술한 집속광학계들 또는 집광소자들의 제조방법을 설명하기 위한 도면이다. 설명의 명료함을 위해, 도 2에 보여진 집속광학계의 제조방법을 예를 들어 설명한다. 도 2에 보여진 집속광학계(20)의 형상을 만들기 위해 금형을 이용한다. 집속광학계(20)를 성형하기 위해, 금형들(151 및 155)로 구성된 상부금형 및 하부금형(157)이 사용된다. 상부금형을 제작하기 위해, 굴절부(201) 및 제 1반수부(203)를 위해 충분한 두께를 갖는 금형원판을 컷팅하여 제 1반사부(203)의 성형을 위한 금형(151)을 제작하며, 굴절부(201)의 성형을 위한 금형(155)은 별도로 제작한다. 이 때, 제 1반사부(203)의 표면을 조형하기 위한 금형(151)의 내측표면은 다이아몬드컷팅 등을 통해 제작되며, 그런 다음에 금형(155)을 삽입하기 위한 개구(153)를 만든다. 일단 금형들(151 및 153)이 제작되면, 금형(151)의 개구(153)에 금형(153)을 삽입하여, 완전한 상부금형이 되게 한다. 이러한 방법을 이용하여 상부금형을 제작하면, 다이아몬드컷팅만을 이용하여 상부금형을 제작함에 의해 발생하는 문제 즉, 굴절부(201)와 제 1반사부(203)가 만나는 부분이 라운드진 형태가 되는 문제를 피할 수 있다. 다음으로, 상부금형과 하부금형(157)을 결합한 다음 이 금형들을 이용하여 원하는 굴절률의 매질로부터 집속광학계(20)를 성형한다. 금형을 통해 집속광학계(20)의 형상이 제작되면, 이 집속광학계(20)의 표면은 코팅처리되어, 제 1 및 제 2반사부들(203 및 205)은 반사특성을 갖게되며, 굴절부(201)는 굴절특성을 갖게 되고, 니어필드형성부(204)는 광투과특성을 갖게 된다.5 is a view for explaining a method of manufacturing the above-mentioned focusing optical systems or light collecting elements. For clarity of explanation, the manufacturing method of the focused optical system shown in FIG. 2 will be described by way of example. A mold is used to make the shape of the focused optical system 20 shown in FIG. To mold the focusing optical system 20, an upper mold and a lower mold 157 consisting of molds 151 and 155 are used. In order to manufacture the upper mold, a mold disc having a sufficient thickness for the refractive portion 201 and the first half portion 203 is cut to produce a mold 151 for forming the first reflective portion 203. The mold 155 for forming the refracting portion 201 is manufactured separately. At this time, the inner surface of the mold 151 for molding the surface of the first reflecting portion 203 is made through diamond cutting or the like, and then an opening 153 for inserting the mold 155 is made. Once the molds 151 and 153 are fabricated, the mold 153 is inserted into the opening 153 of the mold 151 to be a complete upper mold. When the upper mold is manufactured using this method, a problem caused by manufacturing the upper mold using only diamond cutting, that is, a problem in which the portion where the refracting portion 201 and the first reflecting portion 203 meet is rounded. Can be avoided. Next, the upper mold and the lower mold 157 are combined, and then the focusing optical system 20 is formed from the medium having the desired refractive index by using the molds. When the shape of the focusing optical system 20 is manufactured through a mold, the surface of the focusing optical system 20 is coated, so that the first and second reflecting portions 203 and 205 have reflective characteristics, and the refractive portion 201 ) Has a refractive characteristic, and the near field forming unit 204 has a light transmitting characteristic.

도 6은 일반적인 광픽업의 광학계에 도 3a에 보여진 집속광학계(30)를 채용한 광학계를 도시한다. 도 6에서, 대략 600nm 파장의 레이저광원(61)으로부터 출사되는 레이저광(10)은 시준렌즈(63)에 의해 시준렌즈(63)의 광축에 평행하도록 시준(collimation)된 다음 빔분할기(65)로 입사한다. 빔분할기(65)는 입사하는 레이저광(10)을 반사거울(67)쪽으로 투과시킨다. 반사거울(67)은 빔분할기(65)로부터 입사된 레이저광(10)을 집속광학계(30)의 굴절부(311)쪽으로 반사시키도록 배열된다. 집속광학계(30)의 굴절부(311), 제 1반사부(313), 제 2반사부(315) 및 니어필드형성부(33)는 반사거울(67)로부터 입사하는 레이저광(10)에 대하여 도 3a에 관련하여 설명한 광학적특성들을 발휘하며, 그 결과 집광면(331)에 광스폿이 형성된다. 집속광학계(30)와 디스크(110)간의 간격은 공기 베어링에 의해 유지되며, 이 간격은 100nm 미만이 된다. 집광면(331)에 형성된 광스폿은 니어필드를 발생한다. 이 니어필드가 디스크(110)의 정보기록층에 의해 변경되며, 이러한 변경을 나타내는 반사광은 반사거울(67) 및 빔분할기(65)에서 차례로 반사된 다음, 검출렌즈(69)로 입사한다. 검출렌즈(69)는 빔분할기(65)로부터 입사하는 광을 광검출기(71)의 수광면으로 전달한다.FIG. 6 shows an optical system employing the focusing optical system 30 shown in FIG. 3A as an optical system of a general optical pickup. In FIG. 6, the laser light 10 emitted from the laser light source 61 having a wavelength of approximately 600 nm is collimated by the collimating lens 63 so as to be parallel to the optical axis of the collimating lens 63, and then the beam splitter 65. Incident The beam splitter 65 transmits the incident laser light 10 toward the reflection mirror 67. The reflection mirror 67 is arranged to reflect the laser light 10 incident from the beam splitter 65 toward the refracting portion 311 of the focusing optical system 30. The refracting portion 311, the first reflecting portion 313, the second reflecting portion 315, and the near field forming portion 33 of the focusing optical system 30 are incident on the laser light 10 incident from the reflecting mirror 67. With respect to the optical characteristics described with respect to FIG. 3A, a light spot is formed on the light collecting surface 331. The spacing between the focusing optical system 30 and the disk 110 is maintained by the air bearing, which is less than 100 nm. Light spots formed on the light collecting surface 331 generate near fields. This near field is changed by the information recording layer of the disc 110, and the reflected light indicating such a change is reflected by the reflecting mirror 67 and the beam splitter 65 in turn, and then enters the detection lens 69. The detection lens 69 transmits the light incident from the beam splitter 65 to the light receiving surface of the photodetector 71.

상술한 도 6의 광픽업을 광자기디스크(110)를 위해 사용되도록 제작하는 경우, 검출렌즈(69) 및 광검출기(71) 사이의 위치에 별도의 편광빔분할기를 구비하며, 광검출기(71) 대신에 두 개의 광검출기들을 구비한다. 별도의 편광빔분할기는 검출렌즈(69)를 투과한 광을 선형편광의 두 성분들로 분할하며 분할된 두 성분의 선형편광들은 두 광검출기에 의해 각각 검출된다.When the optical pickup of FIG. 6 described above is manufactured to be used for the magneto-optical disk 110, a separate polarization beam splitter is provided at a position between the detection lens 69 and the photodetector 71, and the photodetector 71. Are provided with two photodetectors instead. The separate polarization beam splitter divides the light transmitted through the detection lens 69 into two components of linear polarization, and the linear polarizations of the divided two components are detected by the two photodetectors, respectively.

도 7a-7c는 도 2 내지 도 4c에 관련하여 설명한 집속광학계들을 광픽업에서 사용하기에 적합한 형태로 변형한 것을 설명하기 위한 도면으로, 특히, 도 2의 집속광학계(30)로부터 변형된 집속광학계들(20a 및 20b)을 도시한다. 도 7a는 돌출부(220)를 구비한 집속광학계(20a)를 보여주며, 도 7b는 지지부(230)를 구비한 집속광학계(20b)를 그리고, 도 7c는 집속광학계(20a 또는 20b)의 투영도를 보여준다. 참조번호 10은 레이저광이다.7A and 7C are diagrams for explaining the modification of the focusing optical systems described with reference to FIGS. 2 through 4C in a form suitable for use in an optical pickup. In particular, the focusing optical system modified from the focusing optical system 30 of FIG. 2a and 20b are shown. FIG. 7A shows a condensing optical system 20a having a protrusion 220, FIG. 7B shows a condensing optical system 20b having a support 230, and FIG. 7C shows a projection view of the condensing optical system 20a or 20b. Shows. Reference numeral 10 is a laser light.

도 7a에 보여진 돌출부(220)는 집속광학계(20a)의 굴절부(201) 및 제 1반사부(203)가 만나는 부분에 위치하며 반사거울(67a) 쪽으로 돌출한 형상을 갖는다. 도 7b의 지지부(230)는 돌출부(220)와 마찬가지로 집속광학계(20b)의 굴절부(201) 및 제 1반사부(203)이 만나는 부분에 위치하며, 집속광학계(20b)와 만나는 지지부(230)의 표면이 집속광학계의 광축에 수직한 방향에 나란하도록 굴절부와 바깥쪽부분이 만나는 부분을 깎아냄으로써 형성된다. 집속광학계(20a 및 20b)의 광축방향에서 본 돌출부(220) 및 지지부(230)의 모양은 도 7c에서 보인 것처럼 환형띠의 형상을 갖는다.The protrusion 220 shown in FIG. 7A is positioned at a portion where the refracting portion 201 and the first reflecting portion 203 of the focusing optical system 20a meet and have a shape protruding toward the reflective mirror 67a. The support part 230 of FIG. 7B is located at a portion where the refracting part 201 and the first reflecting part 203 of the focusing optical system 20b meet, similar to the protrusion 220, and the support part 230 which meets the focusing optical system 20b. ) Is formed by scraping off the portion where the refracting portion and the outer portion meet so that the surface of the) is parallel to the direction perpendicular to the optical axis of the focusing optical system. The shapes of the protrusions 220 and the supports 230 seen in the optical axis directions of the focusing optical systems 20a and 20b have the shape of annular bands as shown in FIG. 7C.

도 8 및 도 9는 일반적인 하드디스크드라이브에 본 발명에 따른 집속광학계의 광픽업을 구성한 광디스크드라이브들을 보여준다. 도 8은 피트부조 광디스크 및 상변화광디스크를 위한 광디스크드라이브를 보여주는 도면으로, 참조번호 80은 베이스, 81은 레이저다이오드, 82는 시준렌즈, 83은 빔분할기, 84는 반사거울, 85A는 본 발명에 따른 도 2의 집속광학계, 86은 디스크, 87은 검출렌즈, 88은 광검출기, 89A는 스윙아암(swing arm), 그리고 90은 스윙암액츄에이터이다.8 and 9 illustrate optical disk drives in which an optical pickup of a condensing optical system according to the present invention is configured on a general hard disk drive. 8 is a view showing an optical disk drive for a pit relief optical disk and a phase change optical disk, reference numeral 80 is a base, 81 is a laser diode, 82 is a collimating lens, 83 is a beam splitter, 84 is a reflecting mirror, and 85A is 2, 86 is a disk, 87 is a detection lens, 88 is a photodetector, 89A is a swing arm, and 90 is a swing arm actuator.

도 9는 피트부조 광디스크, 상변화광디스크 및 광자기디스크를 위한 광디스크드라이브를 보여주는 도면으로, 표기된 참조번호들은 도 8의 대응하는 것과 동일한 구성요소를 나타낸다. 참조번호 85B는 도 3a 내지 도 3c에 보여진 집속광학계, 88A는 S-편광성분을 검출하기 위한 광검출기이며 88B는 P-편광성분을 검출하기 위한 광검출기이고, 91은 편광빔분할기이다.FIG. 9 shows an optical disc drive for a pit relief optical disc, a phase change optical disc and a magneto-optical disc, in which the reference numerals denote the same components as the corresponding ones of FIG. 8. Reference numeral 85B denotes a condensing optical system shown in FIGS. 3A to 3C, 88A is a photodetector for detecting S-polarized components, 88B is a photodetector for detecting P-polarized components, and 91 is a polarization beam splitter.

본 발명에 따른 집속광학계를 채용한 광픽업의 광학계는 도 6에 관련하여 설명되었다. 따라서, 이 기술분야의 당업자에게는 도 8 및 도 9에 도시한 광디스크드라이브의 광학계 및 그 기능은 자명하므로, 도 8 및 도 9에 도시된 광디스크드라이브의 동작설명은 생략한다.The optical system of the optical pickup employing the focused optical system according to the present invention has been described with reference to FIG. 6. Therefore, the optical system and the function of the optical disc drive shown in Figs. 8 and 9 are obvious to those skilled in the art, and thus the description of the operation of the optical disc drive shown in Figs. 8 and 9 is omitted.

도 10a 및 10b는 도 4a 내지 4c에 보인 광헤드를 이용하는 광디스크드라이브를 설명하기 위한 도면이다. 참조번호 85C는 도 4a 내지 4c에 보인 집광소자(31 또는 71)와 동일한 집광소자, 89B는 스윙아암, 92는 자석, 93은 보이스코일모터, 94는 요크, 95는 도 4a 내지 도 4c에 보인 슬라이더(65, 75A 또는 75B)와 동일한 슬라이더, 96은 서스팬션(suspension), 97은 스핀들모터이다. 도 10a 및 도 10b에 보여진 광디스크드라이브에 광자기디스크를 사용하는 경우, 도 9에 보여진 광검출기들(88A 및 88B)과 편광빔분할기(91)를 추가로 설치하여 사용한다.10A and 10B are diagrams for explaining an optical disk drive using the optical head shown in FIGS. 4A to 4C. Reference numeral 85C denotes the same light collecting element as the light collecting element 31 or 71 shown in Figs. 4A to 4C, 89B is a swing arm, 92 is a magnet, 93 is a voice coil motor, 94 is a yoke, 95 is shown in Figs. 4A to 4C. The same slider as the sliders 65, 75A or 75B, 96 is a suspension and 97 is a spindle motor. When the magneto-optical disk is used for the optical disk drive shown in FIGS. 10A and 10B, the photodetectors 88A and 88B and the polarization beam splitter 91 shown in FIG. 9 are additionally installed and used.

도 11a 내지 11c는, 도 10a 및 10b에 보여진 집광소자(85C)를 서스팬션(96)에 매달기 위한 플렉서(flexure, 98)를 설명하기 위한 도면들이다. 플렉서(98)는 도 11a에 보인 것처럼, 집광소자(85C)를 붙들기 위한 홀더(981)와, 돌기(983)를 구비한다. 플렉서(98)는 도 11b에 보인 것처럼 서스팬션(96)에 의해 스윙아암(89B)에 고정된다. 돌기(983)는 자신을 중심으로 플렉서(98)가 피봇(pivot)운동을 하게 한다. 도 11c는 도 10b에 보여진 집광소자(85C), 슬라이더(95) 및 서스팬션(96)에 더하여, 집광소자(85C)를 확대하여 보여준다. 도 11c는 도 11a에 보여진 플렉서(98)와는 달리, 피봇운동점이 되는 돌기(983)가 홀더(981)에 형성된 예를 보여준다.11A to 11C are diagrams for explaining a flexure 98 for hanging the light collecting element 85C shown in FIGS. 10A and 10B to the suspension 96. As shown in Fig. 11A, the flexure 98 includes a holder 981 for holding the light collecting element 85C and a protrusion 983. The flexure 98 is fixed to the swing arm 89B by the suspension 96 as shown in FIG. 11B. The protrusion 983 causes the flexure 98 to pivot about itself. FIG. 11C shows an enlarged view of the light collecting element 85C in addition to the light collecting element 85C, the slider 95 and the suspension 96 shown in FIG. 10B. FIG. 11C shows an example in which the projection 983, which is a pivot point, is formed in the holder 981, unlike the flexure 98 shown in FIG. 11A.

디스크의 회전에 의해 슬라이더(95)와 디스크사이에 발생하는 에어베이링이 광디스크다라이버 제작상의 공차나 다른 요인들에 의해 균일하지 않게되는 경우에도, 플렉서(98)는 슬라이더(95)에서의 니어필드를 형성하는 표면이 광디스크의 표면과 항상 일정한 간격을 유지하는 것을 보장한다.Even if the air bearing generated between the slider 95 and the disc due to the rotation of the disc is not uniform due to the tolerances or other factors in the manufacturing of the optical disc driver, the flexure 98 may be removed from the slider 95. It is ensured that the surface forming the nearfield is always kept at a constant distance from the surface of the optical disc.

도 12a는 본 발명에서 사용되는 광자기디스크(110)의 단층구조를 보여준다. 미합중국특허번호 5,202,880호 공보는 니어필드를 정보의 기록 그리고/또는 재생에 이용하는 니어필드기록방식을 위한 광디스크의 단층구조를 개시한다. 이 문헌에 따르면, 니어필드기록방식을 위한 광디스크는 기판위에 반사층, 제 1유전체층, 기록층(memory layer), 제 2유전체층 및 보호코팅(overcoat)층을 적층한 단층구조를 갖는다. 보호코팅층의 바깥쪽 표면에는, 헤드를 운반하는 슬라이더가 광디스크의 표면에 대한 손상없이 원할하게 미끄러져 갈 수 있도록 하기 위한 윤활유가 발라져있다. 본 발명에서 사용되는 광자기디스크(110)는 위의 문헌에서 언급된 단층구조를 갖는 광디스크의 기록층(memory layer)과 제 2유전체층 사이에 원하는 신호만 증폭시키는 재생층(readout layer)을 더 구비한다. 이 재생층은 1995년 8월 30일부터 9월 1일까지 일본국의 가나자와(kanazawa)시에서 개최된 "INTERNATIONAL SYMPOSIUM ON OPTICAL MEMORY 1995"의 기술개요(technical digest)의 페이지 27-28에서 개시되어 있다.12A shows a single layer structure of the magneto-optical disk 110 used in the present invention. U.S. Patent No. 5,202,880 discloses a tomographic structure of an optical disc for a nearfield recording method using nearfield for recording and / or reproduction of information. According to this document, an optical disc for a near field recording method has a single layer structure in which a reflective layer, a first dielectric layer, a memory layer, a second dielectric layer, and an overcoat layer are laminated on a substrate. On the outer surface of the protective coating layer, lubricant is applied to allow the slider for carrying the head to slide smoothly without damaging the surface of the optical disc. The magneto-optical disk 110 used in the present invention further includes a readout layer for amplifying only a desired signal between the recording layer and the second dielectric layer of the optical disk having the single-layer structure mentioned in the above document. do. This regeneration layer is described on pages 27-28 of the technical digest of "INTERNATIONAL SYMPOSIUM ON OPTICAL MEMORY 1995" held in Kanazawa City, Japan, from August 30 to September 1, 1995. have.

도 12b는 전술한 미국특허공보에서 개시된 광디스크를 그대로 사용하는 대신에 전술한 재생층을, 슬라이더(95)에서 니어필드를 형성하는 광디스크쪽 표면에 형성한 경우를 보여준다.FIG. 12B shows a case where the above-described reproduction layer is formed on the surface of the optical disc that forms the near field in the slider 95 instead of using the optical disc disclosed in the above-described US Patent Publication.

상술한 바와 같이, 본 발명에 따른 니어필드를 형성하는 집속광학계 및 이를 채용한 광픽업은 니어필드를 형성하는 기존의 집속광학계에서 사용되는 레이저빔보다 적은 빔직경을 갖는 레이저빔을 사용하면서도 니어필드를 형성시키는 광스폿의 크기를 줄일 수 있다. 따라서, 본 발명에 따른 광픽업은 10Gbit/inch2 이상의 면 기록밀도를 갖는 광디스크에 정보를 기록하거나 재생할 수 있으며, 디스크 또는 광픽업의 움직임에 의해 입사빔기울어짐이 발생하는 경우에도, 디스크에 대한 정보의 기록 또는 재생을 정확히 할 수 있다. 또한, 그 조립 및 조립된 광학계의 조정이 용이한 효과가 있다. 이에 더하여, 본 발명에 따른 집속광학계는 종래의 여타 광학계 즉, 렌즈 또는 반사경을 사용하는 경우에 비하여, 매우 우수한 각도특성(필드특성)을 제공하면서도 개구수를 높일 수 있으며, 따라서, 이러한 필드특성이 요구되는 고밀도 노광장치(stepper) 및 현미경 등에도 사용할 수 있다.As described above, the focused optical system for forming the near field and the optical pickup employing the same according to the present invention use a near-field while using a laser beam having a beam diameter smaller than that of the conventional focused optical system for forming the near field. It is possible to reduce the size of the light spot to form a. Accordingly, the optical pickup according to the present invention can record or reproduce information on an optical disk having a plane recording density of 10 Gbit / inch 2 or more, and the information on the disk even when incident beam tilt occurs due to the movement of the disk or optical pickup. Can accurately record or play back. In addition, there is an effect that the assembly and adjustment of the assembled optical system are easy. In addition, the focusing optical system according to the present invention can increase the numerical aperture while providing very excellent angular characteristics (field characteristics), compared with other conventional optical systems, that is, lenses or reflectors. It can also be used for the required high density stepper and microscope.

Claims (4)

입사하는 레이저광을 이용하여 니어필드(near field)를 발생하는 집속광학계에 있어서,In a focused optical system that generates a near field using incident laser light, 광원 쪽에 위치한 표면에 형성된 굴절부 및 제 1반사부와, 대상물 쪽에 위치한 제 2반사부 및 니어필드형성부를 포함하며,A refractive part and a first reflection part formed on a surface located on the light source side, and a second reflection part and a near field forming part located on the object side, 니어필드를 형성하는 광스폿이 상기 니어필드형성부에 형성되도록, 상기 굴절부는 광원 쪽으로부터 입사하는 레이저광을 굴절시키며, 상기 제 2반사부는 상기 굴절부에 의해 굴절된 레이저광을 상기 제 1반사부 쪽으로 반사시키고, 상기 제 1반사부은 상기 제 2반사부에서 반사된 레이저광을 상기 니어필드형성부에 집속시키는 집속광학계.The refracting portion refracts laser light incident from the light source side so that a light spot forming a near field is formed in the nearfield forming portion, and the second reflecting portion reflects the laser light refracted by the refracting portion in the first reflection. And a first reflecting portion to focus the laser light reflected by the second reflecting portion to the near field forming portion. 광픽업에 있어서,In the optical pickup, 광원; 및Light source; And 상기 광원으로부터 입사하는 레이저광을 이용하여 니어필드를 발생하는 집속광학계를 포함하며,It includes a focusing optical system for generating a near field using the laser light incident from the light source, 상기 집속광학계는 광원 쪽에 위치한 표면에 형성된 굴절부 및 제 1반사부와, 디스크 쪽에 위치한 표면에 형성된 제 2반사부 및 니어필드형성부를 포함하며,The focusing optical system includes a refraction portion and a first reflection portion formed on the surface located on the light source side, a second reflection portion and a near field forming portion formed on the surface located on the disk side, 니어필드를 형성하는 광스폿이 상기 니어필드형성부에 형성되도록, 상기 굴절부는 광원 쪽으로부터 입사하는 레이저광을 굴절시키며, 상기 제 2반사부는 상기 굴절부에 의해 굴절된 레이저광을 상기 제 1반사부 쪽으로 반사시키고, 상기 제 1반사부은 상기 제 2반사부에서 반사된 레이저광을 상기 니어필드형성부에 집속시키는, 광픽업.The refracting portion refracts laser light incident from the light source side so that a light spot forming a near field is formed in the nearfield forming portion, and the second reflecting portion reflects the laser light refracted by the refracting portion in the first reflection. And the first reflecting portion focuses the laser light reflected by the second reflecting portion to the near field forming portion. 광원 쪽에 위치한 표면에 형성된 굴절부 및 제 1반사부와, 디스크 쪽에 위치한 표면에 형성된 제 2반사부 및 니어필드형성부를 포함하며, 니어필드를 형성하는 광스폿이 상기 니어필드형성부에 형성되도록, 상기 굴절부는 광원 쪽으로부터 입사하는 레이저광을 굴절시키며, 상기 제 2반사부는 상기 굴절부에 의해 굴절된 레이저광을 상기 제 1반사부 쪽으로 반사시키고, 상기 제 1반사부은 상기 제 2반사부에서 반사된 레이저광을 상기 니어필드형성부에 집속시키는, 집속광학계를 위한 금형을 제조하기 위한 방법에 있어서,Refractive portions and the first reflecting portion formed on the surface located on the light source side, and the second reflection portion and the near field forming portion formed on the surface located on the disk side, so that the light spot forming the near field is formed in the near field forming portion, The refraction portion refracts laser light incident from the light source side, and the second reflection portion reflects the laser light refracted by the refraction portion toward the first reflection portion, and the first reflection portion reflects the second reflection portion. A method for manufacturing a mold for a focused optical system, wherein the focused laser light is focused on the near field forming unit. 상기 굴절부 및 제 1반사부를 위한 상부금형을 제조하는 단계를 포함하며,Manufacturing an upper mold for the refraction portion and the first reflection portion, 상기 상부금형제조단계는,The upper mold manufacturing step, 금형원판을 컷팅하여 금형원판에 상기 제 1반사부의 표면을 조형하는 단계;Cutting the mold disc to form a surface of the first reflection portion on the mold disc; 상기 굴절부의 조형을 위한 굴절부금형을 제조하는 단계;Manufacturing a refractive mold for molding the refractive portion; 제 1반사부의 표면이 조형된 금형원판에 상기 굴절부금형을 삽입하기 위한 개구를 형성하는 단계; 및Forming an opening for inserting the refractive portion mold in the mold disc having the surface of the first reflection portion molded; And 상기 금형원판에 형성된 개구에 상기 굴절부금형을 삽입하는 단계를 포함하는 금형제조방법.And inserting the refractive portion mold into the opening formed in the mold disc. 니어필드를 재생에 이용하는 광디스크드라이브에 있어서,In an optical disc drive using nearfield for reproduction, 광원;Light source; 광디스크;Optical disks; 니어필드가 형성되는 니어필드형성면을 가지며, 상기 광디스크와 자신의 사이에 상기 광디스크로부터의 신호재생에 유효한 니어필드를 형성하기 위한 에어베어링을 발생하는 슬라이더;A slider having a near field forming surface on which a near field is formed and generating an air bearing between the optical disk and itself to generate a near field effective for signal reproduction from the optical disk; 상기 슬라이더를 지지하기 위한 피봇(pivot)점의 주위를 지지하는 플렉서(flexure); 및A flexure supporting a circumference of a pivot point for supporting the slider; And 상기 광원 쪽에 위치한 표면에 형성된 굴절부 및 제 1반사부와, 디스크 쪽에 위치한 표면에 형성된 제 2반사부 및 니어필드형성부를 포함하며, 상기 굴절부는 광원 쪽으로부터 입사하는 레이저광을 굴절시키며, 상기 제 2반사부는 상기 굴절부에 의해 굴절된 레이저광을 상기 제 1반사부 쪽으로 반사시키고, 상기 제 1반사부은 상기 제 2반사부에서 반사된 레이저광을 상기 니어필드형성부에 집속시키고, 상기 광원으로부터 입사하는 레이저광을 이용하여 상기 슬라이더의 니어필드형성면에 니어필드를 발생하는 집속광학계를 포함하는 광디스크드라이브.A refracting portion and a first reflecting portion formed on the surface located on the light source side, a second reflecting portion and a near field forming portion formed on the surface located on the disk side, wherein the refracting portion refracts laser light incident from the light source side, The second reflecting portion reflects the laser light refracted by the refracting portion toward the first reflecting portion, and the first reflecting portion focuses the laser light reflected by the second reflecting portion on the near field forming portion, and And a focusing optical system for generating a near field on the near field forming surface of the slider using the incident laser light.
KR1019980019876A 1997-11-22 1998-05-29 Focused optical system generating near field, optical pickup and optical disk drive employing the same, and optical disk KR19990066690A (en)

Priority Applications (15)

Application Number Priority Date Filing Date Title
US09/196,111 US6266315B1 (en) 1997-11-22 1998-11-20 Catadioptric optical system, optical pickup and optical disk drive employing the same, and optical disk
EP98959226A EP0954859B1 (en) 1997-11-22 1998-11-21 Catadioptric optical system, optical pickup and optical disk drive employing the same, and optical disk
CNB988032341A CN1133996C (en) 1997-11-22 1998-11-21 Catadioptric optical system, optical pickup and optical disk drive employing the same, and optical disk
PCT/KR1998/000371 WO1999027532A1 (en) 1997-11-22 1998-11-21 Catadioptric optical system, optical pickup and optical disk drive employing the same, and optical disk
CA002278416A CA2278416C (en) 1997-11-22 1998-11-21 Catadioptric optical system, optical pickup and optical disk drive employing the same, and optical disk
RU99118228/28A RU2169400C2 (en) 1997-11-22 1998-11-21 Catadioptric optical system, for optical reproducing head and optical-disk memory; optical disk
KR1019980050086A KR100346397B1 (en) 1997-11-22 1998-11-21 Catadioptric optical system and optical pickup employing catadioptric optical system and optical disk drive and optical disk
EP05001525A EP1538614A3 (en) 1997-11-22 1998-11-21 Catadioptric optical system, optical pickup and optical disk drive employing the same, and optical disk
BR9806979-9A BR9806979A (en) 1997-11-22 1998-11-21 Catadioptric optical system, optical pickup and optical disk unit employing the same, and optical disk
DE69836202T DE69836202T2 (en) 1997-11-22 1998-11-21 CATADIOPTRIC OPTICAL SYSTEM, OPTICAL HEAD, OPTICAL PLATE DRIVE WITH THE SYSTEM AND OPTICAL PLATE
JP52820299A JP4198763B2 (en) 1997-11-22 1998-11-21 Catadioptric optical system, optical pickup and optical disk drive using the same
IDW990904A ID23169A (en) 1997-11-22 1998-11-21 CATALOPTRIC OPTICAL SYSTEMS, OPTICAL PICKUPS AND DRIVE OPTICAL DISK DRIVES, THE SAME, AND OPTICAL DISK
TW087119418A TW419596B (en) 1997-11-22 1998-11-23 Catadioptric optical system, optical pickup and optical disk drive employing the same, and optical disk
MYPI98005306A MY122310A (en) 1997-11-22 1998-11-23 Catadioptric optical system, optical pickup and optical disk drive employing the same, and optical disk.
HK00103062A HK1024088A1 (en) 1997-11-22 2000-05-23 Catadioptric optical system, optical pickup and optical disk drive employing the same

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
KR101997062146 1997-11-22
KR19970062146 1997-11-22

Publications (1)

Publication Number Publication Date
KR19990066690A true KR19990066690A (en) 1999-08-16

Family

ID=65899617

Family Applications (2)

Application Number Title Priority Date Filing Date
KR1019980019876A KR19990066690A (en) 1997-11-22 1998-05-29 Focused optical system generating near field, optical pickup and optical disk drive employing the same, and optical disk
KR1019980050086A KR100346397B1 (en) 1997-11-22 1998-11-21 Catadioptric optical system and optical pickup employing catadioptric optical system and optical disk drive and optical disk

Family Applications After (1)

Application Number Title Priority Date Filing Date
KR1019980050086A KR100346397B1 (en) 1997-11-22 1998-11-21 Catadioptric optical system and optical pickup employing catadioptric optical system and optical disk drive and optical disk

Country Status (1)

Country Link
KR (2) KR19990066690A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100530170B1 (en) * 1999-03-30 2005-11-22 삼성전자주식회사 optical pick-up system using near-field
KR100548236B1 (en) * 1998-11-26 2006-04-20 엘지전자 주식회사 High density data recording / playback cartridge

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100414662B1 (en) * 2001-04-04 2004-01-07 임경화 Head structure of optical disc system

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0226647B1 (en) * 1985-12-17 1991-05-29 Ibm Deutschland Gmbh Read/write head for optical disks
US5031976A (en) * 1990-09-24 1991-07-16 Kla Instruments, Corporation Catadioptric imaging system
JPH07176070A (en) * 1993-12-20 1995-07-14 Matsushita Electric Ind Co Ltd Floating optical head and optical recording and reproducing device
JPH09265053A (en) * 1996-03-28 1997-10-07 Mitsubishi Electric Corp Two-visual-field optical device
US5986995A (en) * 1998-07-06 1999-11-16 Read-Rite Corporation High NA catadioptric focusing device having flat diffractive surfaces

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100548236B1 (en) * 1998-11-26 2006-04-20 엘지전자 주식회사 High density data recording / playback cartridge
KR100530170B1 (en) * 1999-03-30 2005-11-22 삼성전자주식회사 optical pick-up system using near-field

Also Published As

Publication number Publication date
KR19990045487A (en) 1999-06-25
KR100346397B1 (en) 2002-10-25

Similar Documents

Publication Publication Date Title
JP4198763B2 (en) Catadioptric optical system, optical pickup and optical disk drive using the same
EP0727777B1 (en) Optical pickup device
JP3319686B2 (en) Two-position imaging objective lens for optical pickup
US6266315B1 (en) Catadioptric optical system, optical pickup and optical disk drive employing the same, and optical disk
JPH09237431A (en) Objective lens device, optical pickup device utilizing the same and manufacture of objective lens
RU99118228A (en) CATADIOPTRICAL OPTICAL SYSTEM, OPTICAL PLAYBACK HEAD AND STORAGE ON OPTICAL DISKS USING THIS SYSTEM, AND OPTICAL DISK
KR19990080234A (en) Optical pickup with catadioptric objectives
JP2003123307A (en) Optical head and disk device
JP3521770B2 (en) Optical head and optical disk device
WO2000002199A1 (en) Spherical aberration correction using flying lens and method
KR100346397B1 (en) Catadioptric optical system and optical pickup employing catadioptric optical system and optical disk drive and optical disk
JPWO2002063619A1 (en) Optical storage device
JP3524539B2 (en) Optical recording / playback system lens
JP2001184707A (en) Optical pickup and optical disk drive
JPWO2002091370A1 (en) Optical device and information recording and / or reproducing device using the same
JP2990067B2 (en) Optical information recording / reproducing device
KR100400543B1 (en) Lens for optical recording and reproducing system
KR19990072653A (en) Near field type optical storage medium and optical data storage system therefor
KR100400545B1 (en) Lens for optical recording and reproducing system
KR100400544B1 (en) Lens for optical recording and reproducing system
JPH11110767A (en) Optical pickup device
KR100268385B1 (en) Optical focusing system of a paraboloid reflector and high-density optical recording and reproduction apparatus using the same
JPH10247338A (en) Optical pickup device
KR100438571B1 (en) Lens for optical recording and reproducing system
KR100562338B1 (en) Optical pickup apparatus