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. 03, 2001
Filed:
Jan. 11, 1999
Hisao Watanabe, Sagamihara, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
The present invention provides an exposure apparatus of an optical disc master plate for exposing a photoresist master plate and writing-in a DVD-R format, and a method of exposing an optical disc master plate. The exposure apparatus of the optical disc master plate can cause both the wobble signal and the land pre-pit signal to precisely synchronize with each other and to output the synchronized signals by use of a formatter. The formatter can facilitate the design of a separation element for electrically separating an analog circuit and a digital circuit from each other and a circumferential circuit thereof. The formatter of the optical disc exposing apparatus operates on the basis of the predetermined basic clock signal Fclk. The formatter is provided with a wobble signal generating circuit which generates a wobble signal and a land pre-pit signal generating circuit which operates on the basis of the same basic clock signal Fclk and generates a land pre-pit signal. The wobble signal generating circuit is provided with a frequency dividing circuit for dividing the frequency of the basic clock signal Fclk and operates on the basis of the frequency-divided clock signal.