Laser control circuit for optical information recording and reproducing device

Abstract

Abstract PURPOSE:To record with a stable laser light quantity, by performing control on a light quantity at time of non-modulation, storing a control signal in a memory means, and emitting light based on the control signal stored at time of non-podulation, at time of modulation. CONSTITUTION:At time of recording, an erasing operation is performed in advance regardless of whether a data is already recorded or not, and the direction of magnetization is regulated. Therefore, a track is erased with an erasing light quantity larger than a reproducing light quantity, and by which feedback control is performed, based on a signal from a controller 12. At this time, a controlled voltage signal based on the light quantity is sent to a RAM13 in the controller 12, then it is stored. Immediately after that, the controlled voltage signal at time of erasing by which erasure is performed on the same track based on a recording operation command issued from the controller 12, is read out from the RAM13, and is sent to a laser quantity control circuit 3, and the recording of a pulse is performed with the same light quantity at time of erasure. In such way, it is possible to perform the recording with a stable controlled light quantity at time of erasure.

Inventors

• 👤 Saburo Funada
• 👤 船田　三郎

Bibliographic Details