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:
Oct. 17, 2000
Filed:
Sep. 24, 1998
Hiroshi Kawamura, Tokyo, JP;
Sony Corporation, Tokyo, JP;
Abstract
A recording/reproducing apparatus for recording and/or reproducing the information on or from an optical recording medium by illuminating laser light on it using a double-lens type objective lens unit made up of at least a first lens and a second lens. The apparatus includes a light source for radiating laser light, a first lens for converging the laser light radiated from the light source, a second lens arranged between the first lens and the optical recording medium, a detection unit for detecting the sort of the recording medium and a piezoelectric element for causing relative movement between the first and second lenses for varying the distance between the two lenses in the direction along the optical axis. Specifically, the second lens is moved by a movement unit responsive to the results of detection by the detection unit to vary the separation between the first and second lenses. This increases the numerical aperture NA and reduces the effect of aberration to enable high-density recording and/or reproduction of information signals.