DISK AND DISK REPRODUCING METHOD

摘要

PURPOSE: To reproduce the optical disk recorded at a density higher than that recorded according to the standard format. CONSTITUTION: The beam having a wavelength of 695nm and emitted from a semiconductor laser 1 is converged and applied to the recording track of the disk 8 recorded with the density four times as dense as the one prescribed in the standard format, using an objective lens 7 having the number of aperture of 0.6. The reflected light is split by the beam splitter 4 and led to the photoreceptor element 12 to output a photoelectrically converted signal. As for the disk 8 to be reproduced is according to some specifications such that in which the track pitch is about half of the standard one and the pit length is more than half of the standard one or contrarily the track pitch is larger than half of the standard one and the pit length is about a half of the standard one.