CARRIER FOR OPTICAL INFORMATION RECORDING

摘要

PURPOSE:To adjust an optical recording and reproducing system speedily and accurately by providing a signal track part consisting of recessed and projected pits dedicated to reproduction and a groove track part for recording and reproduction on a substrate, and providing a recording thin film over them. CONSTITUTION:Signals of frequencies f1, f2 and f3 are recorded on mutually adjacent tracks. Track lines of recessed and projected pit signal lines 1 and 2 are provided at the innermost and outermost circumferential parts of a disk. A recording and reproduction part 3 for information is provided at a disk intermediate part surrounded by said signal parts 1 and 2. A thin film for information recording is vapor-deposited over the entire area of the signal parts 1 and 2 and recording and reproduction part 3. This substrate is made of transparent acryl and tracks consisting of the signal parts 1 and 2 having the recessed and projected pit are provided thereupon; when the width d1 of the recessed and projected bit signal and the diameter d2 of irradiation laser spot light are set to be d1