Tracking lead-in device

Abstract

Abstract PURPOSE:To attain always stable tracking lead-in by detecting a relative speed between a beam spot and an information track and executing the tracking lead- in under the condition of a sufficiently low relative speed. CONSTITUTION:When the relative speed between the beam spot 11 and a guide groove for tracking is reduced down to a certain value, the output of a monostable multivibrator is turned to the ''0'' level. At the starting of the device or under the OFF state of a tracking servo at the end of accessing to the track, a tracking lead-in instruction is inputted from an external controller to a lead-in control circuit 9 through a signal line 10. The output of the monostable multivibrator 8 is monitored, and when the output is turned to the ''0'' level, a switch 4 is closed and the state is continuously kept. Thus, the tracking lead-in can be executed at the time of the low relative speed, so that the tracking lead-in can be attained always stably.

Inventors

• 👤 Hiroshi Inada
• 👤 稲田　博司

Bibliographic Details