The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 13, 1993
Filed:
May. 21, 1991
Jun Kanehira, Tokyo, JP;
Naoyuki Ueno, Tokyo, JP;
Olympus Optical Co., Ltd., Tokyo, JP;
Abstract
According to the present invention, recording laser beam is shot from a semiconductor laser to form a mark set which comprises a pair of marks on the track of an optical recording medium in the track width direction thereof and first information which has been coded corresponding to the interval between the paired marks in the mark set is recorded on the track of the optical recording medium. At the same time, the plural mark sets are formed on the track of the optical recording medium in the track length direction thereof and second information which has been coded corresponding to the interval between these mark sets is recorded on the track of the optical recording medium. The track of the optical recording medium is scanned in the track width direction thereof with reproducing laser beam shot from a semiconductor laser and .+-. first-order diffraction beam of an optical interference pattern which is created from the paired marks in the mark set thus scanned is detected to reproduce the first information. At the same time, the track is scanned in the track length direction thereof with the reproducing laser beam and zero-order diffraction beam of an optical interference pattern which changes corresponding to the interval between the plural mark sets thus scanned is detected to reproduce the second information.