JPH03165332A - Focusing servo device - Google Patents

Focusing servo device

Info

Publication number
JPH03165332A
JPH03165332A JP30416589A JP30416589A JPH03165332A JP H03165332 A JPH03165332 A JP H03165332A JP 30416589 A JP30416589 A JP 30416589A JP 30416589 A JP30416589 A JP 30416589A JP H03165332 A JPH03165332 A JP H03165332A
Authority
JP
Japan
Prior art keywords
offset
focusing
correcting voltage
reproducing operation
error signal
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
JP30416589A
Inventor
Akira Kawano
Original Assignee
Matsushita Graphic Commun Syst 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 Matsushita Graphic Commun Syst Inc filed Critical Matsushita Graphic Commun Syst Inc
Priority to JP30416589A priority Critical patent/JPH03165332A/en
Publication of JPH03165332A publication Critical patent/JPH03165332A/en
Application status is Pending legal-status Critical

Links

Abstract

PURPOSE: To make address crosstalk distortion sufficiently small by setting a correcting voltage properly, then performing control to the best focusing state in reproducing operation for either of a data area and an address area, and obtaining an excellent data error rate.
CONSTITUTION: An offset adding circuit 17 and an offset switching circuit 18 are added to a conventional device. When the ADDG signal from an external control system which is not shown in a figure indicates address area reproducing operation, a switching circuit 18 generates a correcting voltage for canceling the offset quantity at the focusing point of a focusing error signal, but when data area reproducing operation is indicated, a corresponding correcting voltage is generated and supplied to an offset adding circuit 17. The adding circuit 17 adds the correcting voltage to the focusing error signal FE4 to generate and supply a focusing error signal FE5 whose offset is canceled to a driving circuit 11, thereby driving a coil 12. Thus, the error rate of data is held excellently and the address crosstalk distortion can be reduced sufficiently.
COPYRIGHT: (C)1991,JPO&Japio
JP30416589A 1989-11-22 1989-11-22 Focusing servo device Pending JPH03165332A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP30416589A JPH03165332A (en) 1989-11-22 1989-11-22 Focusing servo device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP30416589A JPH03165332A (en) 1989-11-22 1989-11-22 Focusing servo device

Publications (1)

Publication Number Publication Date
JPH03165332A true JPH03165332A (en) 1991-07-17

Family

ID=17929832

Family Applications (1)

Application Number Title Priority Date Filing Date
JP30416589A Pending JPH03165332A (en) 1989-11-22 1989-11-22 Focusing servo device

Country Status (1)

Country Link
JP (1) JPH03165332A (en)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6278732A (en) * 1985-10-01 1987-04-11 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
JPS6278732A (en) * 1985-10-01 1987-04-11 Olympus Optical Co Ltd Optical information recording and reproducing device

Similar Documents

Publication Publication Date Title
JPH0482037A (en) Method and device for recording and/or reproducing
JPS6052960A (en) Disk reproducer
JPS60251724A (en) Receiver for identifying program
JPH01149684A (en) Method and device for automatically obtaining and correcting frame position error at the time of film scanning
JPH04356816A (en) Buffer circuit
JPS5498517A (en) Reproducer for information signal
JPS573164A (en) Microcomputer control device
JPS5693318A (en) Electron beam exposure device
JPH04315898A (en) Semiconductor integrated circuit
JPS5335508A (en) Automatic tracking controller
GB1320272A (en) Process cont'ol system
JPS5936487A (en) Magnetic reproducer
JPS5585905A (en) Gain compensating device for servo control circuit through current negativeefeedback
JPH03213827A (en) Driving device for electrophoresis display panel
JPS5375828A (en) Semiconductor circuit
JPH02103775A (en) Loop gain control system for spindle servo loop
JPH03237680A (en) Semiconductor memory device
JPS52119946A (en) Drive system for thermal recording unit
JPH0243688A (en) Image processor
JPS54132120A (en) Reproduction device of video signal
JPS61208614A (en) Bimorph driver for bimorph head
JPS6446240A (en) Disk device
JPS63276738A (en) Magnetic recording and reproducing device
JPS5317315A (en) Reproducer
KR980004795A (en) Tracking control circuit and control method for digital video recording / reproduction device using bit error rate