OPTICAL INFORMATION RECORDING MEDIUM, AND METHOD AND APPARATUS FOR RECORDING AND REPRODUCTION

摘要

Two thin-film information layers (2, 4) are deposited on a substrate (1), and they produce optically detectable changes when irradiated with a beam of light (7). A separation layer (3), which is transparent to the wavelength of the beam (7), is formed between the information layers (2, 4). Each of the information layers (2, 4) comprises sector regions, which includes circumferentially divided sector address parts (9, 13) and data areas (8, 12) for recording information signals. Management regions (10, 14) are also provided to record identification information on the deviations in the circumference direction between the sector address parts (9, 13). Depending on identification information on deviations, the amplification gain or slice level for reproduction is switched to decrease demodulation errors. Stable data recording can be achieved by switching the recording power depending on the gate signal.