Optical disc recording and reproducing device

Abstract

Abstract PURPOSE:To set an optimum recording condition by applying recording while the intensity of a laser beam is changed sequentially so as to obtain the laser beam intensity when the pulse width of a reproduced signal reaches a prescribed width. CONSTITUTION:A control circuit 5 gives a data to a D/A converter to change sequentially the laser drive current, a laser driver 3 drives the laser 21 of an optical pickup 2 in response to an analog signal and the recording with a prescribed frequency and sequentially different laser beam intensity is applied to a rotary optical recording disc 1. Thus, the recording pit (a) at a period t1 is the shortest and that at a period t5 is the longest. In order to apply the optimum recording where the duty ratio of the reproducing signal is 50%, it is decided that the laser beam strength is to be P3 and the information is recorded with the laser beam strength of P3.

Inventors

• 👤 Shigemi Maeda
• 👤 茂己 前田
• 👤 Toshihisa Deguchi
• 👤 出口　敏久
• 👤 Takeshi Yamaguchi
• 👤 毅 山口
• 👤 Shozo Kobayashi
• 👤 省三 小林

Bibliographic Details