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:
Dec. 01, 1998
Filed:
Jun. 23, 1997
TEAC Corporation, Tokyo, JP;
Abstract
CD-ROMS of poor quality, such as those having eccentric center holes or uneven weight distributions circumferentially, tend to overload b tracking and focusing servos and to invite read errors and retries. Each CD-ROM on being loaded into a CD-ROM drive is therefore checked as to its quality preparatory to reading. The disk is first rotated at eight times the standard audio CD speed, with both tracking and focusing servo gains set at matching values. If then at least either servo malfunctions, the disk is of poor quality, fit for reading at four or two times the standard audio CD speed. If both servos function normally, on the other hand, then the disk quality is rechecked at the same speed as before but with the servo gains lowered six decibels. A malfunctioning of at least either servo at this time indicates that the disk is of intermediate quality, to be read at eight times the standard audio CD speed. On the other hand, if both servos still function normally, the disk Is of good quality, suitable for reading at 12 times the standard audio CD speed.