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:
Nov. 16, 1999
Filed:
Nov. 13, 1997
Hisatoshi Kawamura, Iwaki, JP;
Jiro Ueki, Fuchu, JP;
Alpine Electronics, Inc., , JP;
Abstract
An apparatus for playing back an optical recording medium automatically and quickly identifies the kind of optically recorded disc (CD or DVD) loaded in the apparatus. After a disc to be checked has been loaded in the apparatus, the disc is first driven in a DVD servo mode. If a peak value of a focus error signal detected in this mode is larger than a threshold value, the checked disc is recognized as a DVD. If the detected peak value of the focus error signal is smaller than the threshold value, the checked disc is thereafter driven in a CD servo mode. The checked disc is recognized as a CD if a peak value of a focus error signal detected in this mode is larger than a threshold value, which may be different from the above-mentioned threshold value.