JPS55157135A - Information reader - Google Patents

Information reader

Info

Publication number
JPS55157135A
JPS55157135A JP6144379A JP6144379A JPS55157135A JP S55157135 A JPS55157135 A JP S55157135A JP 6144379 A JP6144379 A JP 6144379A JP 6144379 A JP6144379 A JP 6144379A JP S55157135 A JPS55157135 A JP S55157135A
Authority
JP
Japan
Prior art keywords
signal
recording medium
light beam
splitter
separated
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.)
Granted
Application number
JP6144379A
Other languages
Japanese (ja)
Other versions
JPS6223378B2 (en
Inventor
Kazuo Shigematsu
Manabu Yamamoto
Masahiro Oshima
Kiichi Kamiyanagi
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.)
Hitachi Ltd
Original Assignee
Hitachi Ltd
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 Hitachi Ltd filed Critical Hitachi Ltd
Priority to JP6144379A priority Critical patent/JPS55157135A/en
Publication of JPS55157135A publication Critical patent/JPS55157135A/en
Publication of JPS6223378B2 publication Critical patent/JPS6223378B2/ja
Granted legal-status Critical Current

Links

Landscapes

  • Optical Recording Or Reproduction (AREA)
  • Optical Head (AREA)

Abstract

PURPOSE: To detect reproduced signals of a good SN ratio independently of the surface state of a recording medium, by irradiating a light beam to information existence regions close to each other on the recording medium.
CONSTITUTION: Light beam 20 from reproducing light source 1 is irradiated onto recording medium as light beams 30A and 30B superposed onto each other partially after separated into two light beams 20A and 20B different in deflection state by splitter 2. In this case, this light beam is set to the same direction, the right-angle direction, the 45° direction, and so on for tracks by the angle of splitter 2. Two reflection lights 40A and 40B from medium 12 are separated by semitransparent mirror 6 and polarizing prism 7 and are led to photodetectors 8A and 8B respectively, and detection outputs 50A and 50B are supplied to differential amplifier 9, and output signal 60 detects information signal 70, and signal 80 obtained by causing signal 60 to pass through LPF11 becomes a tracking signal to drive mirror 4. As a result, reproduced signals of a good SN ratio are always detected.
COPYRIGHT: (C)1980,JPO&Japio
JP6144379A 1979-05-21 1979-05-21 Information reader Granted JPS55157135A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP6144379A JPS55157135A (en) 1979-05-21 1979-05-21 Information reader

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP6144379A JPS55157135A (en) 1979-05-21 1979-05-21 Information reader

Publications (2)

Publication Number Publication Date
JPS55157135A true JPS55157135A (en) 1980-12-06
JPS6223378B2 JPS6223378B2 (en) 1987-05-22

Family

ID=13171204

Family Applications (1)

Application Number Title Priority Date Filing Date
JP6144379A Granted JPS55157135A (en) 1979-05-21 1979-05-21 Information reader

Country Status (1)

Country Link
JP (1) JPS55157135A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59127243A (en) * 1983-01-11 1984-07-23 Matsushita Electric Ind Co Ltd Optical recording and reproducing device
JPH02192042A (en) * 1989-01-19 1990-07-27 Nec Corp Optical disk device
JPH0426940A (en) * 1990-05-21 1992-01-30 Matsushita Electric Ind Co Ltd Master disk preparing device for optical disk
JPH06203398A (en) * 1981-03-31 1994-07-22 Discovision Assoc Tracking device
JP2019523403A (en) * 2016-07-29 2019-08-22 シャンハイ マイクロ エレクトロニクス イクイプメント（グループ）カンパニー リミティド Diffraction grating measuring device

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5295203A (en) * 1976-02-05 1977-08-10 Mitsubishi Electric Corp Information reproduction apparatus

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5295203A (en) * 1976-02-05 1977-08-10 Mitsubishi Electric Corp Information reproduction apparatus

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06203398A (en) * 1981-03-31 1994-07-22 Discovision Assoc Tracking device
JPS59127243A (en) * 1983-01-11 1984-07-23 Matsushita Electric Ind Co Ltd Optical recording and reproducing device
JPH0570212B2 (en) * 1983-01-11 1993-10-04 Matsushita Electric Ind Co Ltd
JPH02192042A (en) * 1989-01-19 1990-07-27 Nec Corp Optical disk device
JPH0426940A (en) * 1990-05-21 1992-01-30 Matsushita Electric Ind Co Ltd Master disk preparing device for optical disk
JP2019523403A (en) * 2016-07-29 2019-08-22 シャンハイ マイクロ エレクトロニクス イクイプメント（グループ）カンパニー リミティド Diffraction grating measuring device

Also Published As

Publication number Publication date
JPS6223378B2 (en) 1987-05-22

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