JPS5532245A - Optical recorder and reproducing device - Google Patents

Optical recorder and reproducing device

Info

Publication number
JPS5532245A
JPS5532245A JP10407678A JP10407678A JPS5532245A JP S5532245 A JPS5532245 A JP S5532245A JP 10407678 A JP10407678 A JP 10407678A JP 10407678 A JP10407678 A JP 10407678A JP S5532245 A JPS5532245 A JP S5532245A
Authority
JP
Japan
Prior art keywords
condenser lens
photo detectors
light
recording
reproducing
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
JP10407678A
Other languages
Japanese (ja)
Other versions
JPS616450B2 (en
Inventor
Sadao Mizuno
Yoshikazu Goto
Yasuhisa Fukushima
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.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co 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 Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Priority to JP10407678A priority Critical patent/JPS5532245A/en
Publication of JPS5532245A publication Critical patent/JPS5532245A/en
Publication of JPS616450B2 publication Critical patent/JPS616450B2/ja
Granted legal-status Critical Current

Links

Landscapes

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

Abstract

PURPOSE: To control a device so that a beam spot will be constant as small as possible in recording while it is a little bit larger in reproducing, by providing two kinds of methods of detecting a distance between a condenser lens and recording medium.
CONSTITUTION: Light reflected by information track 13 of recording medium 12 is passed through condenser lens 10 and then detected by photo detectors 17 and 18, and 15 and 16 for focal-distance control. In order to equalize the quantities of detected light of photo detectors 17 and 18, condenser lens 10 is vertically moved, thereby keeping a light spot constant as small as possible in recording. In reproducing, change-over switch 23 is switched to supply an output difference between photo detectors 15 and 16 to condenser lens control circuit 31 via differential amplifier 23, so that the light spot will be a little bit larger than that in recording. Photo detectors 19 and 20 make comparison between respective quantities of light to allow the beam spot to scan on information track 13 accurately.
COPYRIGHT: (C)1980,JPO&Japio
JP10407678A 1978-08-25 1978-08-25 Optical recorder and reproducing device Granted JPS5532245A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP10407678A JPS5532245A (en) 1978-08-25 1978-08-25 Optical recorder and reproducing device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP10407678A JPS5532245A (en) 1978-08-25 1978-08-25 Optical recorder and reproducing device

Publications (2)

Publication Number Publication Date
JPS5532245A true JPS5532245A (en) 1980-03-06
JPS616450B2 JPS616450B2 (en) 1986-02-26

Family

ID=14371051

Family Applications (1)

Application Number Title Priority Date Filing Date
JP10407678A Granted JPS5532245A (en) 1978-08-25 1978-08-25 Optical recorder and reproducing device

Country Status (1)

Country Link
JP (1) JPS5532245A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2518295A1 (en) * 1981-12-11 1983-06-17 Philips Nv SYSTEM FOR DETECTING OPTICAL FOCUSING DEFECTS
JPS61158038A (en) * 1984-12-29 1986-07-17 Nec Home Electronics Ltd Focus servo circuit

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2518295A1 (en) * 1981-12-11 1983-06-17 Philips Nv SYSTEM FOR DETECTING OPTICAL FOCUSING DEFECTS
JPS61158038A (en) * 1984-12-29 1986-07-17 Nec Home Electronics Ltd Focus servo circuit

Also Published As

Publication number Publication date
JPS616450B2 (en) 1986-02-26

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