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JPS6443818A - Optical information recording and reproducing device - Google Patents

Optical information recording and reproducing device

Info

Publication number
JPS6443818A
JPS6443818A JP20003687A JP20003687A JPS6443818A JP S6443818 A JPS6443818 A JP S6443818A JP 20003687 A JP20003687 A JP 20003687A JP 20003687 A JP20003687 A JP 20003687A JP S6443818 A JPS6443818 A JP S6443818A
Authority
JP
Japan
Prior art keywords
changed
time
servo
gain
power
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
JP20003687A
Other languages
Japanese (ja)
Inventor
Satoshi Shikichi
Shigeto Kanda
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.)
Canon Inc
Original Assignee
Canon Inc
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 Canon Inc filed Critical Canon Inc
Priority to JP20003687A priority Critical patent/JPS6443818A/en
Publication of JPS6443818A publication Critical patent/JPS6443818A/en
Pending legal-status Critical Current

Links

Landscapes

  • Automatic Focus Adjustment (AREA)
  • Optical Recording Or Reproduction (AREA)

Abstract

PURPOSE:To attain the stable tracking and/or focusing servo by switching the amplification degree of an amplifier in a servo loop in accordance with the change of the power of an optical spot in an optical information recording and reproducing device. CONSTITUTION:When recording information is changed to '1' and '0' the power of a light source is also changed to 'PH' and 'PL'. A pit is not formed at the time of 'PL' and at the time of 'PH', it is formed. thus, signals A and B from photoelectric converting elements 115-A and 115-B are changed to 'VL' and 'VH' in proportion to a light source power P. At such a time, in order to keep constantly the open loop gain of an auto-tracking, the gain of amplifiers 302-A and 302-B is switched by a signal C. As such a result, the gain goes to be constant and a stable servo action can be realized. The same control can be executed even concerning the auto-focusing servo.
JP20003687A 1987-08-12 1987-08-12 Optical information recording and reproducing device Pending JPS6443818A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP20003687A JPS6443818A (en) 1987-08-12 1987-08-12 Optical information recording and reproducing device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP20003687A JPS6443818A (en) 1987-08-12 1987-08-12 Optical information recording and reproducing device

Publications (1)

Publication Number Publication Date
JPS6443818A true JPS6443818A (en) 1989-02-16

Family

ID=16417757

Family Applications (1)

Application Number Title Priority Date Filing Date
JP20003687A Pending JPS6443818A (en) 1987-08-12 1987-08-12 Optical information recording and reproducing device

Country Status (1)

Country Link
JP (1) JPS6443818A (en)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61126637A (en) * 1984-11-21 1986-06-14 Olympus Optical Co Ltd Optical information recording and reproducing device

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61126637A (en) * 1984-11-21 1986-06-14 Olympus Optical Co Ltd Optical information recording and reproducing device

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