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. 20, 2004
Filed:
Mar. 26, 2001
Tetsuji Kawashima, Kanagawa, JP;
Futoshi Tsukada, Kanagawa, JP;
Kunihiko Miyake, Kanagawa, JP;
Shinji Ohta, Kanagawa, JP;
Masazumi Shiozawa, Tokyo, JP;
Sony Corporation, Tokyo, JP;
Abstract
An optical disc having a power calibration area for calibrating the power of a data recording laser beam. The power calibration area is provided at an inner peripheral part of the disc and has test areas and count areas. The test areas are provided to accomplish trial writing of data, and the count areas are provided to record data representing the use condition of the test areas. Data is recorded on the optical disc, while calibrating the data recording laser beam. The number of the test areas is increased in accordance with an increase in the recording density of the optical disc. The optical disc may be a double-density CD. In this case, the disc has 800 to 1200 test areas. The test areas have the smallest possible size, and the count areas are provided in the smallest possible number. Therefore, the disc can have sufficiently large data regions. Thus, the power of the data recording laser beam can be therefore adjusted many times. The amount of data that can be recorded on the optical disc therefore increase.