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:
Aug. 01, 2006
Filed:
Jun. 18, 2003
Tatsuo Ohta, Tokyo, JP;
Tatsuo Ohta, Tokyo, JP;
Konica Opto Corporation, Tokyo, JP;
Abstract
An optical lens for condensing a light emitted from a laser light source on an optical recording medium, the light having a wavelength λwithin a wavelength range from 400 nm to 440 nm, comprises: a light incident side lens surface disposed on a side which the light emitted from the laser light source enters, the light incident side lens surface comprising a peripheral part having an angle θ of 45 degrees or more, where the θ is an angle formed by a normal line at a position on each lens surface and an optical axis; and a first anti-reflection film formed on the light incident side lens surface, the first anti-reflection film having a film thickness which is set so that a wavelength λat which a reflectance of the light entering a central part having the angle θ of zero degrees, of the light incident side lens surface at an angle of zero degrees has a local minimum value, satisfies λand 420 nm≦λ≦680 nm.