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. 29, 2006
Filed:
Nov. 26, 2003
Shigehiro Yamada, Yamatokooriyama, JP;
Takashi Itoh, Nara, JP;
Nobumasa Kaneko, Nara, JP;
Kazunori Matsubara, Nara, JP;
Shigehiro Yamada, Yamatokooriyama, JP;
Takashi Itoh, Nara, JP;
Nobumasa Kaneko, Nara, JP;
Kazunori Matsubara, Nara, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
An optical pick-up apparatus and a semiconductor laser apparatus which can suppress reduction of optical utilization efficiency for the laser light emitted from the semiconductor laser element. When a laser light which is emitted from a laser element for DVD and whose polarization direction is perpendicular to a direction of a groove of the polarization grating is incident on the polarization grating, the polarization grating does not diffract the laser light and transmits the laser light as zero-order diffraction light. Consequently, all of the laser light emitted from the laser element for DVD can be used for reading information signal of DVD and detecting FES and TES. This enables reduction of optical utilization efficiency arising by diffracting action of a grating used for detecting TES of CD in a conventional optical pick-up apparatus to be suppressed.