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:
Jun. 23, 2009
Filed:
Oct. 14, 2003
Sakuya Tamada, Tokyo, JP;
Sakuya Tamada, Tokyo, JP;
Sony Corporation, Tokyo, JP;
Abstract
An optical recording medium master disc exposure apparatus comprises a modulating meansfor modulating intensity of light from an exposure light sourcein response to recording information and a focusing optical systemfor focusing the light modulated by this modulating meanson a photoresiston an optical recording medium master discto thereby pattern-expose the photoresistin response to recording information. The exposure light sourceis composed of a ultrashort wave pulse laser with a repetitive frequency of an integral multiple ranging from 1 time to 20 times as high as the clock frequency of recording information. This optical recording medium master disc apparatus includes an external synchronizing mechanism to vary the resonator length of this ultrashort wave pulse laser to mode-lock the repetitive frequency of the ultrashort wave pulse laser in synchronism with the clock frequency to cause the ultrashort wave pulse laser to emit pulses, and hence miniscule pits can be formed with high accuracy.