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:
Feb. 02, 1999
Filed:
Jul. 30, 1996
Katsuhiro Koike, Tsurugashima, JP;
Yoshiyuki Tsukai, Tsurugashima, JP;
Pioneer Electronic Corporation, Tokyo, JP;
Abstract
A bifocal crystal optic lens made of a uniaxial crystal comprising two surfaces having a same axis, at least one of the two surfaces being a spherical surface or an aspherical surface. An optical system for an optical pickup device includes; a crystal optic lens consisting of a first lens body made of a transparent uniaxial crystal and a second lens body made of a transparent optical material selected from a second uniaxial crystal and an optical isotropic material, the first and second lens bodies joining via a spherically or aspherically curved interface; and an objective lens aligned with the crystal optic lens in a same optical axis of an incident ray. This optical system for the optical pickup device is capable of making simultaneously two focal points in the same axis, so as to simplify preferably the structure of the compatible video optical disc player for CD and SD to minimize the size thereof, thereby providing a relatively low cost for the manufacture thereof.