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:
Jan. 29, 2013
Filed:
Mar. 09, 2012
Tohru Hotta, Nagano, JP;
Ryoichi Kawasaki, Gunma, JP;
Kenji Kan, Saitama, JP;
Hiroyuki Shindo, Tokyo, JP;
Tohru Hotta, Nagano, JP;
Ryoichi Kawasaki, Gunma, JP;
Kenji Kan, Saitama, JP;
Hiroyuki Shindo, Tokyo, JP;
Sanyo Electric Co., Ltd., Osaka, JP;
Sanyo Optec Design Co., Ltd., Tokyo, JP;
Abstract
An optical pickup apparatus includes an objective lens having a numeric aperture and an incident face. An antireflection coating is formed on the incident face. A collimating lens converts laser light from a laser diode into parallel light, and causes the parallel light to be made incident on the incident face through the antireflection coating. The thickness of the antireflection coating causes a transmittance of laser light that enters the objective lens to be: set at a first predetermined transmittance value, when the numeric aperture is between zero and a first predetermined numeric aperture value; set to correlate linearly with the numeric aperture when the numeric aperture is between the first predetermined numeric aperture value and a second predetermined numeric aperture value; and set at a second predetermined transmittance value, when the numeric aperture is between the second predetermined numeric aperture value and a third predetermined numeric aperture value.