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:
Nov. 15, 2011
Filed:
Oct. 25, 2007
Hiroki Awakura, Hitachinaka, JP;
Akihito Akai, Yokohama, JP;
Yoshiki Kurokawa, Tokyo, JP;
Naoki Takada, Yokohama, JP;
Goro Sakamaki, Fuchu, JP;
Hiroki Awakura, Hitachinaka, JP;
Akihito Akai, Yokohama, JP;
Yoshiki Kurokawa, Tokyo, JP;
Naoki Takada, Yokohama, JP;
Goro Sakamaki, Fuchu, JP;
Renesas Electronics Corporation, Kanagawa, JP;
Abstract
A display brightness control circuit of a liquid crystal display device includes a logarithmic-linear converting circuit for converting an illuminance signal having a logarithmic relationship with incident light into a linear signal. When an output of an external light sensor is a logarithmic signal, the logarithmic signal is converted into a linear signal through the logarithmic-linear converting circuit, and when an output of the external light sensor is a linear signal, the logarithmic-linear converting circuit is not involved. The logarithmic-linear converting circuit corresponds to an exponential circuit which is an inverse function of a logarithm log. Further, when even the same logarithmic output illuminance sensor is different in input-output characteristics, setting of the abovementioned exponential circuit can be changed.