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. 09, 2013
Filed:
Dec. 23, 2010
Masaaki Kurebayashi, Ebina, JP;
Shinji Fujita, Yokohama, JP;
Osamu Kawamae, Kawasaki, JP;
Hitachi-LG Data Storage, Inc., Tokyo, JP;
Hitachi Consumer Electronics Co., Ltd., Tokyo, JP;
Abstract
There is provided a method of calculating the degradation over time of the quality of data recorded on an optical disk in a short time. In the method, when user data is recorded on a data area, a test signal including a component in which the signal level is smaller than a reference value, is recorded on a test area. Then, the test signal is reproduced from the test area when a predetermined time has passed, to calculate the quality degradation of the user data from the evaluation result. Alternatively, every time when the user data is recorded/reproduced on/from the data area, the test signal is recorded/reproduced repeatedly on/from the test area. Then, the test signal is reproduced from the test area at a predetermined timing, to calculate the quality degradation of the user data from the evaluation result.