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:
Oct. 09, 2001
Filed:
Apr. 14, 1999
Shigeki Yamazaki, Hitachinaka, JP;
Hiroyuki Minamura, Kokubunji, JP;
Hisataka Sugiyama, Kodaira, JP;
Tetsuya Fushimi, Hitachinaka, JP;
Makoto Itagaki, Yokohama, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An optical disc apparatus having at least two optical condenser lens for recording and reproducing information of an optical disc, comprising: means for discriminating the optical disc; means for reading control information in a ROM area which is formed in an inner periphery of said optical disc; means for conducting focus control in a RAM area which is formed outside of said ROM area; means for conducting adjustment in amplitude of a reproduced signal from an inner periphery of said RAM area; means for conducting a pre-writing (a sample-writing); means for conducting test-writing in the inner periphery of said RAM area; means for conducting test-writing in an outer periphery of said RAM area; and means for conducting adjustment in amplitude of a reproduced signal from the outer periphery of said RAM area, wherein said means conducts the respective operations sequentially, thereby making said optical disc in reproducible and recorable condition, with a short time period and with a smooth confirmation operation.