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, 2000
Filed:
Mar. 05, 1998
Kenji Yamamoto, Tokyo, JP;
Isao Ichimura, Kanagawa, JP;
Fumisada Maeda, Tokyo, JP;
Toshio Watanabe, Kanagawa, JP;
Akira Suzuki, Kanagawa, JP;
Kiyoshi Ohsato, Chiba, JP;
Sony Corporation, Tokyo, JP;
Abstract
This invention intends to provide an optical pickup of which it is possible to limit aberrations within a tolerable limit without incorporating a special device for that purpose even if errors arise in thickness of component lenses of a two-lens system constituting an element of the pickup. This object is achieved by providing an optical pickup incorporating a two-lens system with first and second lenses 13 and 14 being arranged in the following manner: the first lens has a first surface 15 to receive a laser beam radiated from a semiconductor laser and a second surface 16 to direct the laser beam transmitted from the first surface 15 towards the second lens 14; the second lens 14 has a third surface 17 to receive the light flux transmitted from the second surface 16 and a fourth surface 18 to direct the light flux transmitted from the third surface 17 towards an optical disc placed opposite thereto; and the first and fourth surfaces are used as a reference during positioning.