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:
Apr. 25, 2006
Filed:
Jun. 22, 2004
Yasuo Kitaoka, Ibaraki, JP;
Ken'ichi Kasazumi, Takatsuki, JP;
Katsuhiko Kumagawa, Neyagawa, JP;
Kazuhisa Yamamoto, Takatsuki, JP;
Hidenori Wada, Sakai, JP;
Yasuo Kitaoka, Ibaraki, JP;
Ken'ichi Kasazumi, Takatsuki, JP;
Katsuhiko Kumagawa, Neyagawa, JP;
Kazuhisa Yamamoto, Takatsuki, JP;
Hidenori Wada, Sakai, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
Laser beams respectively emitted from a SHG blue laser unit and a red semiconductor laser unit that have photo detectors respectively are turned into parallel lights by a collimator lens and then coupled by a dielectric multi-layer film mirror so as to be propagated on the same optical axis. The dielectric multi-layer film mirror is configured so as to transmit light with a wavelength of 500 nm or shorter and reflect light with a wavelength of 500 nm or longer for both P wave and S wave. The lights that are transmitted and reflected by the dielectric multi-layer film mirror pass through a polarizing hologram and a phase variable wave plate and are focused on an optical disk by an objective lens. In this manner, a simple configuration can realize a compatibility with many types of optical disks and a stable signal detection even when using a polarizing optical detection system.