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:
Mar. 21, 2017
Filed:
Nov. 27, 2012
Hitachi Consumer Electronics Co., Ltd., Tokyo, JP;
Tatsuro Ide, Tokyo, JP;
Hitachi Consumer Electronics Co., Ltd., Tokyo, JP;
Abstract
To provide an optical information recording and reproducing apparatus capable of correct positioning, in an optical information recording and reproducing apparatus which branches a light beam into reference light and signal light to cause interference and records an obtained interference fringe as a hologram on an optical information recording medium and reproduces the hologram recorded by applying the reference light onto the optical information recording medium, the apparatus has an image pickup element which detects reproduction light passing through an aperturein reproduction light obtained by applying the reference light onto the optical information recording medium and generates a reproduction signal, photo detectors, andthat are different from the image pickup element and detect reproduction light applied on a location on the periphery of the aperture, and a computing unit which computes a position error signal based on outputs from the photo detectors.