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. 11, 1997
Filed:
May. 15, 1995
Taro Takekoshi, Nagano-ken, JP;
Masatoshi Yonekubo, Nagano-ken, JP;
Seiko Epson Corporation, Tokyo, JP;
Abstract
An optical head for use in an optical recording apparatus contains a lens element that permits independent setting of the magnification and numerical aperture for a forward optical system and a rearward optical system. The optical head includes a light beam emitting assembly that emits a beam of light and a light beam separating assembly. A light beam focusing element focuses a forward light beam onto an optical recording medium. The light beam emitted from the light beam emitting assembly follows a forward optical path passing through the light beam separating assembly as a non-diffracted light beam and is focused onto the optical recording medium. A rearward light beam is reflected from the optical recording medium and follows a rearward optical path passing through the focusing element and the light beam separating assembly such that the rearward light beam is deflected to a light detection device. The lens element is positioned in at least one of the forward optical path and the rearward optical path.