JPS643841A - Magneto-optical reproducing device - Google Patents

Magneto-optical reproducing device

Info

Publication number
JPS643841A
JPS643841A JP62158092A JP15809287A JPS643841A JP S643841 A JPS643841 A JP S643841A JP 62158092 A JP62158092 A JP 62158092A JP 15809287 A JP15809287 A JP 15809287A JP S643841 A JPS643841 A JP S643841A
Authority
JP
Japan
Prior art keywords
signal
diameter
magneto
effective
photodetectors
Prior art date
Legal status (The legal status 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 status listed.)
Pending
Application number
JP62158092A
Other languages
Japanese (ja)
Inventor
Toru Sekiguchi
Yoshihiro Sasaki
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEC Corp
Original Assignee
NEC Corp
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 NEC Corp filed Critical NEC Corp
Priority to JP62158092A priority Critical patent/JPS643841A/en
Publication of JPS643841A publication Critical patent/JPS643841A/en
Pending legal-status Critical Current

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

Landscapes

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

Abstract

PURPOSE:To make the whole signal incident on the effective photodetection surface of a photodetector and to improve the SN ratio of signal detection by selecting the numerical aperture of a condenser lens so that the diameter of the signal light is smaller than the effective photodetection diameter of the photodetector. CONSTITUTION:Condenser lenses 10A and 10B are so designed that an expression I holds for the numerical aperture NA, where lambda is the wavelength of laser light, (w) the diameter of the effective photodetection surfaces of photodetectors 11A and 11B, and (k) a constant nearly equal to 1. Consequently, the whole signal light is incident on the effective photodetection surfaces of the photodetectors 11A and 11B and playback signal light is converted into an electric signal without any waste, thereby reproducing the signal from a magneto-optical recording medium 6 with an excellent SN ratio.
JP62158092A 1987-06-24 1987-06-24 Magneto-optical reproducing device Pending JPS643841A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP62158092A JPS643841A (en) 1987-06-24 1987-06-24 Magneto-optical reproducing device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP62158092A JPS643841A (en) 1987-06-24 1987-06-24 Magneto-optical reproducing device

Publications (1)

Publication Number Publication Date
JPS643841A true JPS643841A (en) 1989-01-09

Family

ID=15664122

Family Applications (1)

Application Number Title Priority Date Filing Date
JP62158092A Pending JPS643841A (en) 1987-06-24 1987-06-24 Magneto-optical reproducing device

Country Status (1)

Country Link
JP (1) JPS643841A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1991011806A1 (en) * 1990-01-31 1991-08-08 Sony Corporation Magneto-optical recording/reproducing apparatus

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS628347A (en) * 1985-07-03 1987-01-16 Nec Corp Optomagnetic recording and reproducing device

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS628347A (en) * 1985-07-03 1987-01-16 Nec Corp Optomagnetic recording and reproducing device

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1991011806A1 (en) * 1990-01-31 1991-08-08 Sony Corporation Magneto-optical recording/reproducing apparatus

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