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:
Jan. 07, 2014
Filed:
Mar. 02, 2007
Shin-ichi Uehara, Tokyo, JP;
Masao Imai, Tokyo, JP;
Shin-ichi Uehara, Tokyo, JP;
Masao Imai, Tokyo, JP;
NLT Technologies, Ltd., Kanagawa, JP;
Abstract
A light source apparatus has two or more light sources that have different light-emission spectra and that can be controlled independently, and also has light sensors for detecting the quantity of light emitted by the light sources. The light sensors are composed of one type of light sensor that is not provided with a color filter for selecting the wavelength of received light, and the light sensors are sensitive to wavelength ranges that are sufficiently broad to simultaneously receive light in red, green, and blue wavelength ranges. A control circuit controls the two or more light sources to emit light in a time sequential fashion, and compares reference data with the output values of the light sensors to control the quantity of light emitted by the light sources by means of a light source drive circuit. It is thereby possible to reduce the cost and size of a light source apparatus that is capable of correcting changes in hue.