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:
Jul. 11, 2006
Filed:
Jun. 13, 2003
Sumito Nishioka, Ikoma-gun, JP;
Nobuo Ogata, Nara, JP;
Sumito Nishioka, Ikoma-gun, JP;
Nobuo Ogata, Nara, JP;
Sharp Kabushi Kaisha, Osaka, JP;
Abstract
An optical pickup includes a semiconductor laser for emitting light at a wavelength λand a semiconductor laser for emitting light at a different wavelength λfrom the wavelength λThe light at the wavelength λtransmitted through an objective lens forms a light-collecting spot on an optical disk to record/reproduce information thereon. The light at the wavelength λtransmitted through the objective lens forms a light-collecting spot on an optical disk to record/reproduce information thereon, the two optical disks having different substrate thicknesses. Between the semiconductor laser and the objective lens is there provided a combination-type diffractive element fabricated by combining two raw materials having different refractive index behaviors in relation to wavelength at a combining plane shaped as a grating. The structure facilitates good recording/reproduction on the two types of recording media irrespective of the reproduction wavelengths or substrate thicknesses of the recording media.