Patent ID: 7748854
Filing Date: 2010-07-06
Classification: G03B,H04N

Abstract:
1. An image display device comprising: a light source; a light source driving unit for controlling a driving power of the light source; a light source driving-level calculating unit for calculating a driving level of the light source and outputting the driving level of the light source to the light source driving unit, the light source driving-level calculating unit providing a variable driving power in a certain period of time; a diaphragm for adjusting a quantity of light of the light source; a diaphragm control unit for controlling a narrowing amount of the diaphragm; a diaphragm control-level calculating unit for outputting the narrowing amount to the diaphragm control unit responsive to the variable driving power supplied from the light source driving-level calculating unit; a liquid crystal panel for modulating light of the light source; a liquid crystal driving unit for driving the liquid crystal panel; a liquid crystal video signal processing unit for converting an input video signal into a signal for driving the liquid crystal panel; and a projection lens for expanding and projecting an image of the liquid crystal panel, wherein the light source driving-level calculating unit generates a repeatedly varying fluctuation in the driving power corresponding to the variable driving power in the certain period, and the diaphragm control-level calculating unit controls the diaphragm so as to cancel brightness fluctuation of the light source corresponding to the fluctuation of the driving power and wherein either only the diaphragm is interlocked with the input video signal when the driving power of the light source is a predetermined power or more, or only the driving power of the light source is interlocked with the input video signal when the driving power of the light source is smaller than the predetermined power.