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:
Sep. 11, 2012
Filed:
Dec. 05, 2008
Teruhiro Shiono, Osaka, JP;
Yoshiharu Kobayashi, Osaka, JP;
Takashi Mihara, Hyogo, JP;
Panasonic Corporation, Osaka, JP;
Abstract
The present invention contributes to getting a reproduction/recording operation done with stability on an information recording medium by utilizing an absorption edge shifting phenomenon. An apparatusaccording to the present invention includes: a light sourcefor emitting a laser beam; a lensfor condensing the beam onto an information recording medium; and a photodetectorfor detecting light reflected from the medium, of which a recording layer includes a material that absorbs the beam at an increasing absorptance as the absorption edge of a light absorption spectrum shifts, with a rise in temperature, toward a longer wavelength range as a result of a band-to-band transition of electrons. The apparatusof this invention further includes: a wavelength detecting sectionfor detecting at least one of the wavelength of the beam and its variation; a temperature sensing sectionfor sensing at least one of the temperature of the mediumor its ambience and its variation; and a control sectionfor controlling the power of the light sourcebased on the respective outputs of the wavelength detecting sectionand the temperature sensing section