Patent ID: 8842140
Filing Date: 2014-09-23
Classification: G02F,G09G,H04N

Abstract:
1. A liquid crystal display device comprising: an image writing portion that writes an image signal onto a liquid crystal panel in accordance with a given clock signal; a backlight source having a plurality of sub-light-sources arranged in rows in correspondence to a plurality of display areas in a vertical direction of the liquid crystal panel; a backlight control portion that executes a backlight scanning that causes each of the sub-light-sources to sequentially and repeatedly execute an intermittent turning-on action consisting of an action of a given consecutive turning-off period and an action of a given consecutive turning-on period in connection with an image signal writing action by the image signal writing portion; and an interpolation image generating portion that generates an interpolation image signal based on two or more consecutive frame images, wherein the image writing portion writing an image signal onto the liquid crystal panel in synchronization with a vertical synchronization signal having a frequency n times (n represents an integer of 2 or larger one) a frame frequency of a video signal containing the image signal, the image writing portion, when in a first multi-speed drive mode, executing an interpolation image insertion process in which the interpolation image signal generated by the interpolation image generating portion is inserted between frames and is written onto the liquid crystal panel, and, when in a second multi-speed drive mode, the image writing portion executing an overlapped image output process in which the same frame image is written onto the liquid crystal panel n times in a row, and wherein the backlight control portion matches an execution cycle of the intermittent turning-on action in the backlight scanning to a cycle of the vertical synchronization signal when the image writing portion executes the first multi-speed drive mode, while increasing the execution cycle of the intermittent turning-on action in the backlight scanning to a cycle longer than the cycle of the vertical synchronization signal or invalidates the backlight scanning when the image writing portion executes the second multi-speed drive mode; an interpolation image precision determining portion that determines whether precision of an interpolation image signal generated by the interpolation image generating portion is equivalent to preset precision, wherein even when the image writing portion executes the first multi-speed drive mode, if the interpolation image precision determining portion determines the precision of the interpolation image signal to be not equivalent to the preset precision, the backlight control portion increases an execution cycle of the intermittent turning-on action in the backlight scanning to a cycle longer than a cycle of the vertical synchronization signal or invalidates the backlight scanning.