JPS5792439A - Optical recorder and reproducer - Google Patents
Optical recorder and reproducerInfo
- Publication number
- JPS5792439A JPS5792439A JP16742580A JP16742580A JPS5792439A JP S5792439 A JPS5792439 A JP S5792439A JP 16742580 A JP16742580 A JP 16742580A JP 16742580 A JP16742580 A JP 16742580A JP S5792439 A JPS5792439 A JP S5792439A
- Authority
- JP
- Japan
- Prior art keywords
- focus
- signal
- focus control
- turn
- comparator
- 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
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
- G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
- G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
- G11B7/0945—Methods for initialising servos, start-up sequences
Landscapes
- Moving Of The Head For Recording And Reproducing By Optical Means (AREA)
Abstract
PURPOSE:To secure focus control by providing a means of starting, stopping and restarting the focus drawing operation of irradiating light according to the states of a focus control signal and a guide-track traverse signal. CONSTITUTION:When a signal FON is inputted to a terminal K, switches 24 and 26 turn on between terminals p2 and r2, and p3 and r3, allowing an aperture lens to approach a disk. When a focus error signal DI increases above the Vthl of a comparator and the disk is judged to be within focus drawing range, the signal Q1 of an FF29 goes down to an L to turn off switches 26 and 26, and a switch 22 turns on between terminals p1 and r1 to turn on a focus control loop I. As a recording material surface is brought under focus control, a guide- track traverse signal inputted to a terminal S decreases below the set value Vth2 of the comparator 37 and the delay pulse G of a delay pulse generating circuit 31 is intercepted by an AND gate 34 to hold a focus-controlled state, but when the signal S is high, the focus drawing operation is repeated through the output of the gate 34, thus performing the focus control securely.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP55167425A JPH0644347B2 (en) | 1980-11-27 | 1980-11-27 | Optical recording / reproducing device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP55167425A JPH0644347B2 (en) | 1980-11-27 | 1980-11-27 | Optical recording / reproducing device |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS5792439A true JPS5792439A (en) | 1982-06-09 |
JPH0644347B2 JPH0644347B2 (en) | 1994-06-08 |
Family
ID=15849454
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP55167425A Expired - Lifetime JPH0644347B2 (en) | 1980-11-27 | 1980-11-27 | Optical recording / reproducing device |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0644347B2 (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6148133A (en) * | 1984-08-15 | 1986-03-08 | Hitachi Ltd | Optical disc device |
JPS6149107A (en) * | 1984-08-15 | 1986-03-11 | Mitsubishi Heavy Ind Ltd | Condenser vacuum reduction trip interlock circuit using pressure switch of steam turbine |
JPS6168735A (en) * | 1984-09-10 | 1986-04-09 | Nakamichi Corp | Focus servo actuation device for optical recording and reproduction |
JPH0513242A (en) * | 1991-06-29 | 1993-01-22 | Hitachi Ferrite Ltd | Rotary transformer |
EP0618569A1 (en) * | 1993-04-02 | 1994-10-05 | Sony Corporation | Focusing servo system and focus servo acquisition enable method |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS54128707A (en) * | 1978-03-27 | 1979-10-05 | Mca Disco Vision | Focus servo device |
-
1980
- 1980-11-27 JP JP55167425A patent/JPH0644347B2/en not_active Expired - Lifetime
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS54128707A (en) * | 1978-03-27 | 1979-10-05 | Mca Disco Vision | Focus servo device |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6148133A (en) * | 1984-08-15 | 1986-03-08 | Hitachi Ltd | Optical disc device |
JPS6149107A (en) * | 1984-08-15 | 1986-03-11 | Mitsubishi Heavy Ind Ltd | Condenser vacuum reduction trip interlock circuit using pressure switch of steam turbine |
JPS6168735A (en) * | 1984-09-10 | 1986-04-09 | Nakamichi Corp | Focus servo actuation device for optical recording and reproduction |
JPH0513242A (en) * | 1991-06-29 | 1993-01-22 | Hitachi Ferrite Ltd | Rotary transformer |
EP0618569A1 (en) * | 1993-04-02 | 1994-10-05 | Sony Corporation | Focusing servo system and focus servo acquisition enable method |
US5745450A (en) * | 1993-04-02 | 1998-04-28 | Sony Corporation | Focusing servo system and focus servo acquisition enable with multiple velocity acquisition modes |
US5912867A (en) * | 1993-04-02 | 1999-06-15 | Sony Corporation | Focusing servo system with focus servo acquisition enable which is operational within a predetermined time after the start of the movement of an objective lens |
Also Published As
Publication number | Publication date |
---|---|
JPH0644347B2 (en) | 1994-06-08 |
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