Optical disk

Abstract

Abstract PURPOSE:To surely obtain the reproducing signals for tracking and of pits by specifying the depth of guide grooves and the depth of the pits in the optical disk previously recorded with information data by the pits between the guide grooves to a specific ratio of the wavelength of reproducing light. CONSTITUTION:The information data can be recorded and reproduced as the pits 4 by a magneto-optical means on the lands 3 of the optical disk 1 formed with the guide grooves 2 for tracking. The relation of the depth of the pits 4 and the signal quantity of a track cross signal STCS and push pull signal SPP changes to the sinusoidal shape in which the former indicates the max. value at lambda/4 and the latter exhibits the min. value at lambda/8 and the max. 3lambda/8 with respect to a change from 0 to lambda/2 of the wavelength lambda of the light beam for reproducing. The influence of the duty of the information data of the pits is eliminated and the signal quantity of the signals STCS and SPP is assured by selecting the depth of the guide grooves 2 at lambda/8 to lambda/4 and the depth of the pits 4 at lambda/4 to lambda/2.

Inventors

• 👤 Fusaaki Endou
• 👤 惣銘 遠藤
• 👤 Masanobu Yamamoto
• 👤 眞伸 山本

Bibliographic Details