OPTICAL-DISK REPRODUCTION EQUIPMENT AND OPTICAL- DISK REPRODUCTION PROCESS Russian patent published in 2003 - IPC

FIELD: optical-disk reproduction process. SUBSTANCE: main data recorded in the form of marks or spaces are coded in limited field length. Auxiliary data are modulated in direction of mark or space length. Reproduction facility is designed to illuminate marks or spaces residing on optical disk and to generate reproduction signal in response to signal reflected from optical disk. Binary coding facility is designed for binary coding of reproduced disk. Equipment also incorporates sync signal generating facility. Mark/space detection is effected according to sync signal coming from its generating facility. Bias reducing facility provides for eliminating bias of signal after its retrieval and storage. There is also demodulating facility intended for demodulating auxiliary data in response to bias-free signal passed through retrieval and storage. EFFECT: reduced number of marks (spaces), enhanced precision of auxiliary-data modulation, reduced auxiliary-data signal-to-noise ratio. 14 cl, 7 dwg