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:
Apr. 27, 2010
Filed:
Sep. 11, 2007
Minoru Watanabe, Fukushima-ken, JP;
Mitsuru Kano, Fukushima-ken, JP;
Minoru Fujiwara, Fukushima-ken, JP;
Minoru Watanabe, Fukushima-ken, JP;
Mitsuru Kano, Fukushima-ken, JP;
Minoru Fujiwara, Fukushima-ken, JP;
Alps Electric Co., Ltd., Tokyo, JP;
Abstract
An illuminance sensor is formed as a current output type sensor that outputs a current which increases or decreases in an analog manner corresponding to an increasing or decreasing change of the illuminance. A light-emitting device is connected with a detection resistor that detects a current flowing through a light-emitting device. A driving control circuit has a light-emitting device driver that outputs to the light-emitting device a voltage for holding a voltage, which is obtained when a current flowing through the light-emitting device and a current detected by the illuminance sensor flows through the detection resistor, in a predetermined value all the time. The light-emitting device emits a large amount of light in a dark place and emits a small amount of light in a bright place.