SUPER-HIGH RESOLUTION OPTICAL DISK AND REPRODUCTION METHOD OF SUPER-HIGH RESOLUTION OPTICAL DISK

摘要

PROBLEM TO BE SOLVED: To realize super-high resolution reproduction by making an effective beam spot smaller than a reproduced beam spot. ;SOLUTION: A photocromism layer 2 is changed to deep color when an optical disk is irradiated with ultraviolet rays and the temp. of the disk rises and the photocromism layer 2 is changed to light color when the optical disk is irradiated with the reproduced laser beam. A forward region of the disk entering the inside of the reproduced beam spot 7 is turned to a low temp. region 8 and a backward region is turned to a high temp. region 9 when the optical disk is moved by rotation. Consequently, the photocromism layer 2 with light color in the high temp. region 9 functions as an aperture and the photocromism layer 2 with heavy color in the low temp. region 8 functions as a mask, thereby making the effective aperture region smaller than a spot 7 and thus the super-high resolution reproduction is realized.;COPYRIGHT: (C)1998,JPO