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:
Nov. 20, 2007
Filed:
Nov. 30, 2004
Hisatoshi Baba, Yokohama, JP;
Hisatoshi Baba, Yokohama, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An optical information recording/reproducing apparatus is provided that condenses a light flux from a light source on an optical recording medium and effects recording/reproduction and comprises a light source; an objective lens; a spherical aberration generating mechanism; a sensor for receiving light reflected by an optical recording medium and converting the light into an electric signal; an equalization filter for effecting waveform equalization of an output from the sensor in accordance with a predetermined partial response characteristic; a quality evaluating circuit for measuring reproduction quality of an output signal from the equalization filter; and an adaptive equalization circuit for sequentially updating a coefficient for the equalization filter, wherein while the update of the coefficient for the equalization filter by the adaptive equalization circuit is stopped, the spherical aberration generating mechanism is driven on the basis of the reproduction quality measured by the quality evaluating circuit.