JPS6476539A - Device for detecting abnormality of focus servo - Google Patents
Device for detecting abnormality of focus servoInfo
- Publication number
- JPS6476539A JPS6476539A JP23526187A JP23526187A JPS6476539A JP S6476539 A JPS6476539 A JP S6476539A JP 23526187 A JP23526187 A JP 23526187A JP 23526187 A JP23526187 A JP 23526187A JP S6476539 A JPS6476539 A JP S6476539A
- Authority
- JP
- Japan
- Prior art keywords
- focus servo
- abnormality
- recording medium
- detect
- read
- 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
Landscapes
- Optical Recording Or Reproduction (AREA)
- Automatic Focus Adjustment (AREA)
Abstract
PURPOSE:To accurately detect the abnormality of focus servo in a short time by reading data pre-formatted on a recording medium, and judging a case where the data is impossible to be discriminated within a prescribed time as the abnormality of the focus servo. CONSTITUTION:An SMD signal reproduced by a head in a recording are reproducing mechanism 16 is read, and the value SMD1 is stored in a RAM15. Next, a timer with a time (t) to detect the abnormality of the focus servo is started, and the SMD signal is read again, and the value SMD2 is stored in the RAM15, then, the values SMD1 is compared with the SMD2. Thus, the data pre-formatted on the recording medium is read, and the case where the data is impossible to be discriminated within the prescribed time is judged as the abnormality of the focus servo. In such a way, it is possible to detect the abnormality of the focus servo in a short time and accurately in spite of the eccentricity of the recording medium or the ON/OFF of tracking servo.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP62235261A JPH0778895B2 (en) | 1987-09-18 | 1987-09-18 | Focus servo abnormality detection device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP62235261A JPH0778895B2 (en) | 1987-09-18 | 1987-09-18 | Focus servo abnormality detection device |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS6476539A true JPS6476539A (en) | 1989-03-22 |
JPH0778895B2 JPH0778895B2 (en) | 1995-08-23 |
Family
ID=16983466
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP62235261A Expired - Fee Related JPH0778895B2 (en) | 1987-09-18 | 1987-09-18 | Focus servo abnormality detection device |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0778895B2 (en) |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5942672A (en) * | 1982-09-02 | 1984-03-09 | Toshiba Corp | Disc device |
-
1987
- 1987-09-18 JP JP62235261A patent/JPH0778895B2/en not_active Expired - Fee Related
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5942672A (en) * | 1982-09-02 | 1984-03-09 | Toshiba Corp | Disc device |
Also Published As
Publication number | Publication date |
---|---|
JPH0778895B2 (en) | 1995-08-23 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
LAPS | Cancellation because of no payment of annual fees |