Optical recording and reproducing system

Abstract

Abstract PURPOSE: To make it possible to record information with a high density by an arbitrary information modulation system, by forming previously a groove on the recording medium so that groove may be orgthogonal to the main scanning direction and by detecting the modulation beam from this groove in distinction from modulation dependent upon information and by using the modulation beam for the synchronizing or position signal. CONSTITUTION: In recording medium 1, grooves 3 are formed radially regularly on disc-form base 2, and photosensitive recording material 4 is caused to adhere to all the surface. Recording medium 1 is rotated, and laser light 5 modulated by information is condensed onto recording material 4 to record information. When the output of laser light 5 for no formation of 8 bits is the photosensitive threshold level or less of recording material 4, the reflection light in this part is subjected to intensity modulation each time laser light 5 moves across radial groove 3, and therefore, this modulation can be uses as a synchronizing signal. For reproducing, a reflection type disc is suitable to this system, and the depth of radial grooves 3 is set to a value other than integral multiples of λ/4 for wave length λ of the beam for reproducing. COPYRIGHT: (C)1981,JPO&Japio

Inventors

• 👤 Masaharu Sakamoto
• 👤 Kiichi Kato

Bibliographic Details