JPS57150147A - Optical type recorder and reproducer - Google Patents
Optical type recorder and reproducerInfo
- Publication number
- JPS57150147A JPS57150147A JP3495881A JP3495881A JPS57150147A JP S57150147 A JPS57150147 A JP S57150147A JP 3495881 A JP3495881 A JP 3495881A JP 3495881 A JP3495881 A JP 3495881A JP S57150147 A JPS57150147 A JP S57150147A
- Authority
- JP
- Japan
- Prior art keywords
- circuit
- recording
- focus control
- converging lens
- film
- 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
Abstract
PURPOSE:To prevent a converging lens from being collided with a recorded disc and to achieve focus control surely on a recording material film, by using an output of an optical beam converging state detecting means to distinguish a protective film surface not having a recording film form the recording material surface. CONSTITUTION:A reflected light of a beam converged on a recording surface of a recording disc 1 irradiates a 4-split photodetector 13, two portions of outputs are inputted to a differential amplifier 16 via synthesis circuits 14 and 15, and the outputs operate a converging lens driving element 21 via a compensation circuit 17, a gain converting circuit 18, a switch 19 and a driving circuit 20. If focus control is inoperative, a signal is given to a counter circuit 25 and an AND circuit 31 from an instruction generating circuit 26, and a counter circuit 25 counts 1 when an optical beam converging point approaches a protective layer and a recording member layer, a comparison circuit 27 compares the result of count with the 2 of a numeral setting circuit 28, and when they are coincident, a switch circuit 19 is operative via an AND circuit 31. Thus, the collision between a converging lens 9 and the recording disc 1 can be prevented and the focus control on the recording film can be performed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3495881A JPS57150147A (en) | 1981-03-10 | 1981-03-10 | Optical type recorder and reproducer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3495881A JPS57150147A (en) | 1981-03-10 | 1981-03-10 | Optical type recorder and reproducer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57150147A true JPS57150147A (en) | 1982-09-16 |
| JPH0316691B2 JPH0316691B2 (en) | 1991-03-06 |
Family
ID=12428654
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3495881A Granted JPS57150147A (en) | 1981-03-10 | 1981-03-10 | Optical type recorder and reproducer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS57150147A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6052933A (en) * | 1983-09-02 | 1985-03-26 | Nippon Kogaku Kk <Nikon> | Focus servo draw-in device of optical disk device |
| JPS61122934A (en) * | 1984-11-16 | 1986-06-10 | Matsushita Electric Ind Co Ltd | Focus position control device |
| JPH01162110U (en) * | 1988-04-27 | 1989-11-10 | ||
| US5477514A (en) * | 1993-09-07 | 1995-12-19 | Matsushita Electric Industrial Co., Ltd. | Control apparatus for controlling focusing, accessing and spindle rotating circuits to operate simultaneously |
| EP1274075A3 (en) * | 2001-06-15 | 2003-10-29 | Lg Electronics Inc. | High-density disk recording medium having a reflecting surface and manufacturing method thereof |
| KR100462259B1 (en) * | 1995-10-18 | 2005-04-06 | 소니 가부시끼 가이샤 | Focus drive circuit and focus search method based on the relative positional relationship between the disc and the objective lens |
-
1981
- 1981-03-10 JP JP3495881A patent/JPS57150147A/en active Granted
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6052933A (en) * | 1983-09-02 | 1985-03-26 | Nippon Kogaku Kk <Nikon> | Focus servo draw-in device of optical disk device |
| JPS61122934A (en) * | 1984-11-16 | 1986-06-10 | Matsushita Electric Ind Co Ltd | Focus position control device |
| JPH0470698B2 (en) * | 1984-11-16 | 1992-11-11 | Matsushita Electric Ind Co Ltd | |
| JPH01162110U (en) * | 1988-04-27 | 1989-11-10 | ||
| US5477514A (en) * | 1993-09-07 | 1995-12-19 | Matsushita Electric Industrial Co., Ltd. | Control apparatus for controlling focusing, accessing and spindle rotating circuits to operate simultaneously |
| KR100462259B1 (en) * | 1995-10-18 | 2005-04-06 | 소니 가부시끼 가이샤 | Focus drive circuit and focus search method based on the relative positional relationship between the disc and the objective lens |
| EP1274075A3 (en) * | 2001-06-15 | 2003-10-29 | Lg Electronics Inc. | High-density disk recording medium having a reflecting surface and manufacturing method thereof |
| US7761887B2 (en) | 2001-06-15 | 2010-07-20 | Lg Electronics Inc. | Recording medium having a reflector to prevent traveling of beam to recording layer |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0316691B2 (en) | 1991-03-06 |
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