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:
Sep. 05, 1995
Filed:
Dec. 17, 1993
Toshiki Aoi, Saku, JP;
TDK Corporation, Tokyo, JP;
Abstract
With a dye recording layer having an index of refraction n of 2.0 to 2.6 formed on a substrate, that portion of the recording layer disposed in a groove is used as a recording track by restricting the groove to a width W.sub.G of 0.38 to 0.45 .mu.m and a depth D.sub.G of 1000 to 1700 .ANG. and that portion of the recording layer in the groove to a thickness T.sub.G of at least 2000 .ANG. for 2.0.ltoreq.n.ltoreq.2.3 or to W.sub.G of 0.38 to 0.45 .mu.m, D.sub.G of 1000 to 2300 .ANG., and T.sub.G of at least 2500 .ANG. for 2.3<n.ltoreq.2.6. Reproduction is performed by means of a CD player which is adapted to perform tracking control by detecting a tracking error signal by the differential phase technique. There is obtained a tracking control loop gain of -2 dB or higher relative to that of commercially available CD, ensuring stable and accurate tracking control.