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:
Aug. 16, 2005
Filed:
Feb. 16, 2001
Nobuo Ogata, Nara, JP;
Nobuo Ogata, Nara, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
An optical recording medium is arranged such that respective information recorded on lands and grooves are reproducible by either of a light beam of a first wavelength λand a light beam of a second wavelength λwhich is shorter than the first wavelength λ. The groove depth d of the optical recording medium is such that tracking error signals of not less than a predetermined level can be ensured for respective wavelengths λand λwithout generating distortion in waveform, irrespectively of differences in receiving light sensitivity of a photodetector provided in a optical pickup devices for use in recording and reproducing information on and from such optical recording medium.