JPS57113424A - Locked-track detector of recorded-information reader - Google Patents
Locked-track detector of recorded-information readerInfo
- Publication number
- JPS57113424A JPS57113424A JP18817580A JP18817580A JPS57113424A JP S57113424 A JPS57113424 A JP S57113424A JP 18817580 A JP18817580 A JP 18817580A JP 18817580 A JP18817580 A JP 18817580A JP S57113424 A JPS57113424 A JP S57113424A
- Authority
- JP
- Japan
- Prior art keywords
- signal
- level
- locked
- track
- gate
- 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)
- Moving Of The Head For Recording And Reproducing By Optical Means (AREA)
Abstract
PURPOSE:To detect a locked-track with extremely simple costitution by detecting the locked-track according to the level of a reproduction signal by a pickup. CONSTITUTION:The sums of outputs of the counter elements 1a and 1b, and 1c and 1d of a photodetector 1 are supplied to two inputs of a differential amplifier 2, whose output (a) is a focus servo error signal. An in-focus detector 6, when the signal (a) exceeds a certain level, generates and supplies a low-level defocusing detection signal (d) to one input of an AND gate 7. Further, the total of the outputs of the photodetector 1 is obtained by an amplifier 8 to generate a reproduction RF signal (b), and an RF envelope level detector 9 generates a high-level detection signal (c) when said signal has a low level within prescribed level range. This signal (c) is supplied to the other input of the gate 7, whose gate output (e) is used as a locked-track detection signal to drive a locked-track resetting circuit 30, and also used as a control signal for a gain control amplifier 3.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP18817580A JPS57113424A (en) | 1980-12-29 | 1980-12-29 | Locked-track detector of recorded-information reader |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP18817580A JPS57113424A (en) | 1980-12-29 | 1980-12-29 | Locked-track detector of recorded-information reader |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS57113424A true JPS57113424A (en) | 1982-07-14 |
JPS6353617B2 JPS6353617B2 (en) | 1988-10-25 |
Family
ID=16219067
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP18817580A Granted JPS57113424A (en) | 1980-12-29 | 1980-12-29 | Locked-track detector of recorded-information reader |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS57113424A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0083838A2 (en) * | 1981-12-31 | 1983-07-20 | Magnetic Peripherals Inc. | Focusing initialisation control system |
JPS5956231A (en) * | 1982-09-27 | 1984-03-31 | Sony Corp | Optical disc player |
-
1980
- 1980-12-29 JP JP18817580A patent/JPS57113424A/en active Granted
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0083838A2 (en) * | 1981-12-31 | 1983-07-20 | Magnetic Peripherals Inc. | Focusing initialisation control system |
JPS5956231A (en) * | 1982-09-27 | 1984-03-31 | Sony Corp | Optical disc player |
JPH0438054B2 (en) * | 1982-09-27 | 1992-06-23 | Sony Corp |
Also Published As
Publication number | Publication date |
---|---|
JPS6353617B2 (en) | 1988-10-25 |
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