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:
Jul. 08, 2014
Filed:
May. 23, 2011
Yoshiyuki Kurokawa, Sagamihara, JP;
Takayuki Ikeda, Atsugi, JP;
Hikaru Tamura, Zama, JP;
Munehiro Kozuma, Isehara, JP;
Masataka Ikeda, Atsugi, JP;
Yoshiyuki Kurokawa, Sagamihara, JP;
Takayuki Ikeda, Atsugi, JP;
Hikaru Tamura, Zama, JP;
Munehiro Kozuma, Isehara, JP;
Masataka Ikeda, Atsugi, JP;
Semiconductor Energy Laboratory Co., Ltd., Atsugi-shi, Kanagawa-ken, JP;
Abstract
Influence of external light is suppressed. With a photodetector including a photodetector circuit which generates a data signal in accordance with illuminance of incident light and a light unit which overlaps with the photodetector circuit, a first data signal is generated by the photodetector circuit when the light unit is in an ON state, a second data signal is formed by the photodetector circuit when the light unit is in an OFF state, and the first data signal and the second data signal are compared, so that a difference data signal that is data of a difference between the two compared data signals is generated.