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:
Dec. 14, 2010
Filed:
May. 21, 2007
Noriaki Nishi, Tokyo, JP;
Hiroaki Mizuma, Tokyo, JP;
Motoi Kimura, Kanagawa, JP;
Kenji Yamamoto, Kanagawa, JP;
Masatoshi Nishino, Tokyo, JP;
Noriaki Nishi, Tokyo, JP;
Hiroaki Mizuma, Tokyo, JP;
Motoi Kimura, Kanagawa, JP;
Kenji Yamamoto, Kanagawa, JP;
Masatoshi Nishino, Tokyo, JP;
Sony Corporation, Tokyo, JP;
Abstract
The light intensity of a light beam emitted from a light source is appropriately controlled when the light beam is transmitted through a variable optical coupling efficiency device in an optical head. During a read mode, the light beam from the light source is incident on an optical disk at an intensity relatively weaker than that of the light source. By switching the optical coupling efficiency of the variable optical coupling efficiency device between a write mode and a read mode, the light intensity directed to an optical recording medium is substantially varied from the write mode to the read mode. This arrangement eliminates the need for substantially increasing the optical output power ratio of the light source of write power to read power.