Patent ID: 6788627
Filing Date: 2004-09-07
Classification: G11B

Abstract:
An optical recording and reproducing apparatus for optically recording and reproducing information, comprising:an optical head having (1) means of condensing light into a medium provided with first areas having dent portions or groove portions and substantially flat second areas, and (2) means of detecting signals from said medium, and tilt correction means of correcting the relative angle between said medium and the axis of light outgoing from said condensing means of said optical head, wherein while said medium is subjected to focus servo-control by using a light spot formed by said condensing means, said tilt correction means is operated so that a value based on the difference between the detection level of the reflected light in said first areas and the detection level of the reflected light in said second areas among the detection levels of light reflected by said medium and received and detected by said signal detection means becomes virtually maximal, thereby to correct said relative angle.