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. 28, 1998
Filed:
Apr. 14, 1997
Fumisada Maeda, Tokyo, JP;
Isao Ichimura, Kanagawa, JP;
Kenji Yamamoto, Saitama, JP;
Kiyoshi Ohsato, Chiba, JP;
Toshio Watanabe, Kanagawa, JP;
Sony Corporation, , JP;
Abstract
An optical pickup device for condensing the light from a light source on a signal recording surface of an optical recording medium, such as an optical disc. A semi-spherical lens of the optical pickup device has a surface 9b facing an optical disc 20 and has a pre-set refractive index. The optical pickup device also has a slider 12 adapted for securing the lens 9 and for being in sliding contact with an optical disc 20, and a spring plate 13 adapted for thrusting and supporting the slider in sliding contact with the optical disc 20. With the optical pickup device, high density reproduction may be realized, while the tolerance value for warping during disc molding or the tolerance value for warping due to moisture absorption may be increased. In addition, the production yield and the degree of freedom in selecting the disc materials may be improved.