Optical recording medium having offset-compensating areas

U.S. Patent Number: 5268887

Abstract: A optical recording medium having guide grooves which are parallel or substantially parallel, tracks formed among the guide grooves, offset-compensating areas spaced apart in lengthwise direction of the guide grooves and separating each of the tracks into portions, first pits formed in each portion of each of the tracks and arranged in a center line of the track, and second pits formed in the offset-compensating areas and extending in the center line of the tracks. Also disclosed herein is an optical recording apparatus for applying a light beam to the optical recording medium as defined above, thereby to record data on the medium and reproduce data there from. In the apparatus, two tracking error signals, which represent the distance between the center of a light spot formed on the medium and the center line of a target track, are generated from diffracted light beams from any one of the guide grooves and the offset-compensating area adjacent to the guide groove. The first tracking error signal is corrected in accordance with the second tracking signal, and the position of the light spot is controlled in accordance with the first tracking error signal thus corrected.

Inventors: Honguh; Yoshinori (Yokohama, JP), Murakami; Teruo (Yokohama, JP)

Assignee: Kabushiki Kaisha Toshiba (Kawasaki, JP)

Application Number: 07/943,125

Issued: 1993-12-07

Expired: 2005-12-07

Classes: 369/44.13 ; 369/275.3; 369/275.4; 369/44.26

Field of search: 369/44.13,44.26,44.34,44.11,275.1,275.3,275.4,109,44.28,44.32

Click the image above to view patent images at uspto.gov within a frame.

Click here for the fulltext page on uspto.gov within a frame.