JPH0316693B2 - - Google Patents
Info
- Publication number
- JPH0316693B2 JPH0316693B2 JP56034825A JP3482581A JPH0316693B2 JP H0316693 B2 JPH0316693 B2 JP H0316693B2 JP 56034825 A JP56034825 A JP 56034825A JP 3482581 A JP3482581 A JP 3482581A JP H0316693 B2 JPH0316693 B2 JP H0316693B2
- Authority
- JP
- Japan
- Prior art keywords
- reflectance
- circuit
- focus
- laser beam
- detection circuit
- 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.)
- Expired - Lifetime
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
- Automatic Focus Adjustment (AREA)
- Optical Recording Or Reproduction (AREA)
- Optical Head (AREA)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56034825A JPS57186238A (en) | 1981-03-10 | 1981-03-10 | Focusing mechanism |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56034825A JPS57186238A (en) | 1981-03-10 | 1981-03-10 | Focusing mechanism |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57186238A JPS57186238A (en) | 1982-11-16 |
| JPH0316693B2 true JPH0316693B2 (enrdf_load_stackoverflow) | 1991-03-06 |
Family
ID=12424970
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56034825A Granted JPS57186238A (en) | 1981-03-10 | 1981-03-10 | Focusing mechanism |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS57186238A (enrdf_load_stackoverflow) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS632123A (ja) * | 1986-06-20 | 1988-01-07 | Sanyo Electric Co Ltd | 光学式記録及び若しくは再生装置 |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5517818A (en) * | 1978-07-20 | 1980-02-07 | Mitsubishi Electric Corp | Procedure of focus initialization setting in optical recording unit and its equipment |
-
1981
- 1981-03-10 JP JP56034825A patent/JPS57186238A/ja active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57186238A (en) | 1982-11-16 |