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:
Jul. 27, 1999
Filed:
Apr. 06, 1998
Pioneer Electronic Coporation, Tokyo, JP;
Abstract
The irradiation device irradiates, at the time of recording main information, a first light beam having a first power and a second light beam having a second power on the pre-pits in a time-divisional manner. The light receiving device receives a reflected light of the first light beam from the pre-pits to produce a first light-receipt signal, and receives a reflected light of the second light beam from the pre-pits to produce a second light-receipt signal. The first detector detects the pre-pits based on the first light-receipt signal to produce a first detection signal, and the second detector detects the pre-pits based on the second light-receipt signal to produce a second detection signal. Then, the processor produces a logical sum of the first detection signal and the second detection signal to output a pre-pit detection signal. Therefore, the pre-pits can be correctly detected in both cases where the first light beam and the second light beam is irradiated, and all pre-pits on the storage medium may be detected to obtain the recording information.