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. 03, 1998
Filed:
May. 22, 1996
Tadashi Takeda, Nagano-ken, JP;
Kenji Fukui, Tokyo, JP;
Ricardo Musashi Okamoto, Tokyo, JP;
Hiroyuki Wada, Tokyo, JP;
Nippon Steel Corporation, Tokyo, JP;
Abstract
A displacement detecting device for optical head is disclosed which is capable of stably generating displacement detecting signals without being affected by fluctuation of wavelength of light emitted from a light source. The displacement detecting device is provided for use in an optical head which comprises a optical sensor for reading information recorded on an optical information recording medium by irradiating the optical information recording medium with light from a light source and detecting reflected light from the irradiated surface of the recording medium as well as detecting focus displacement and track displacement by utilizing diffracted light of the reflected light. The optical sensor is provided with wavelength fluctuation component detector for detecting wavelength fluctuation components in the reflected light. At least one of a focus displacement detecting signal and a track displacement detecting signal is compensated for based on a wavelength fluctuation detecting signal generated by the wavelength fluctuation component detector, thereby enabling the displacement detection to be stably performed without being affected by fluctuation of the wavelength of light emitted from a light source.