Patent ID: 8674926
Filing Date: 2014-03-18
Classification: G09G

Abstract:
1. An image display device, comprising: an optical modulation element having a plurality of pixels; light sources illuminating the optical modulation element, each of which is independently controlled; a light source control value setting section detecting, in an input image data, a maximum grayscale value among grayscales of the input image data corresponding to pixels included in a pixel area associated with each of the light sources, and determining a brightness control value for each light source corresponding to the maximum grayscale value; a light source driving section determining a voltage value corresponding to the brightness control value for each pixel area, driving a respective one of the light sources at the brightness control values, and controlling lighting of the respective light source to a brightness corresponding to the maximum grayscale value for the corresponding pixel areas; an optical sensor provided on an area of each pixel of the optical modulation element to detect a numerical value for each pixel; an illumination detection section determining an illumination data for each pixel of the optical modulation element based on the detected numerical value for each pixel; a grayscale control section determining corrected grayscales from the grayscales of the input image data and the illumination data for each pixel of the optical modulation element, and using the corrected grayscales to output a transmittance control value which controls transmittance of the optical modulation element; and an optical modulation driving section using the transmittance control value to control the transmittance of the optical modulation element for each pixel of the image display device, wherein when determining the illumination data to determine the corrected grayscales, the light source control value setting section inputs one entire frame's worth of image data, detects the maximum grayscales for each light source, and determines brightness control values which control illumination of the light source corresponding to the maximum grayscales, the grayscale control section performs black display control so as to display black in all pixels of the optical modulation element during both a first correction processing period and a second correction processing period to determine the corrected grayscales, and the light source driving section turns all of the light sources off during the first correction processing period, and lights each of the light sources according to the brightness control values during the second correction processing period in synchronization with the black display control, the second correction processing period being a period following the first correction processing period.