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:
Feb. 24, 2015
Filed:
May. 10, 2012
Eishi Oda, Osaka, JP;
Michiaki Takeda, Osaka, JP;
Hiroyoshi Kure, Osaka, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
Light leakage and black float are reduced in dark ambient while a perception of high contrast is achieved when a backlight is divided into a plurality of areas and backlight brightness is controlled depending on a video signal corresponding to each area. An area active control portion () divides a video signal into a plurality of areas and outputs a first feature value for each area. An LED control portion () acquires a first brightness for each divided area of an LED backlight () depending on the first feature value of each area, and acquires a second brightness for each area that is acquired by uniformly multiplying a specific multiplying factor acquired depending on the lighting ratio of the LED backlight () with respect to the first brightness within a range where a total value of the LED driving current does not exceed a predetermined permissible current value. When the lighting ratio of the LED backlight () is at or below a predetermined value, the second brightness is reduced in accordance with ambient lighting detected by a photosensor () to acquire a third brightness.