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:
Nov. 20, 2007
Filed:
Mar. 10, 2003
Hisaji Oyake, Tokyo, JP;
Tatsuya Kato, Tokyo, JP;
Hajime Utsunomiya, Tokyo, JP;
Masanori Shibahara, Tokyo, JP;
Kenji Yoneyama, Tokyo, JP;
Hisaji Oyake, Tokyo, JP;
Tatsuya Kato, Tokyo, JP;
Hajime Utsunomiya, Tokyo, JP;
Masanori Shibahara, Tokyo, JP;
Kenji Yoneyama, Tokyo, JP;
TDK Corporation, Tokyo, JP;
Abstract
The present invention relates to a method for processing a photoresist-coated board, a method for manufacturing a stamper for a recording medium and a method for manufacturing a recording medium which can form a fine raised and depressed pattern having a uniform width after development even in the case where a laser beam having a relatively long wavelength is used for forming pre-pits on a recording medium with high accuracy. A photoresist-coated boardis constituted by laminating a light absorption layerand a photosensitive material layeron a glass substratein this order and is exposed to a laser beamby condensing the laser beamonto the photosensitive material layer, thereby forming a raised and depressed pattern corresponding to pre-pits on the the photosensitive material layer. When the length of a pre-pit to be formed is shorter than 4 T, for example, the duty ratio of the pulse signal train input to the light modulatoris varied within a range from about 50% to 65% so that a pulse signal train having a higher duty ratio is generated as the length of a pre-pit to be formed becomes longer and the power of a laser beam is modulated by the thus generated pulse signal train. On the other hand, when the length of a pre-pit to be formed is equal to or longer than 4 T, for example, a pulse signal train having a constant duty ratio is generated independently of the length of the pre-pit to be formed and the power of a laser beam is modulated by the thus generated pulse signal train.