Patent ID: 8427513

Claim:
A display device which has a display unit in which pixels which have light emitting elements that self-emit light according to an electric current amount and pixel circuits for controlling an electric current applied to the light emitting elements according to video signals, scanning lines which supply selection signals for selecting the pixels that are caused to emit light to the pixels in a predetermined scanning cycle, and data lines which supply the video signals to the pixels are arranged into a matrix pattern, the display device comprising: an average value calculation unit which inputs video signals having linear characteristic and calculates an average value of signal levels of the video signals having linear characteristic in each of the pixels; an average value storage unit which sequentially stores the average values calculated by the average value calculation unit; a still image judging unit which judges whether a still image is displayed on a present screen by dividing the display unit into a plurality of regions and judging whether a still image is displayed on each of the plurality of regions based on a difference between the average value stored in the average value storage unit and a last average value; a storage unit that stores a value for respective regions of the plurality of regions, wherein when the still image judging unit judges that a still image is displayed on a respective one of the plurality of regions, the value is increased by a first predetermined amount, and when the still image judging unit judges that a moving image is displayed on the respective one of the plurality of regions, the value is decreased by a second predetermined amount; a coefficient calculation unit which, when it is judged that a still image is displayed on the present screen as a result of the judgment in the still image judging unit, calculates coefficients for reducing luminance of an image displayed on the display unit based on the value; and a coefficient multiplying unit which multiplies the video signals by the coefficients calculated by the coefficient calculation unit, wherein when the still image judging unit judges that the still image is displayed on at least one of the plurality of regions, the still image judging unit judges that the still image is displayed on the entire screen, and wherein coefficients for reducing luminance for the respective one of the plurality of regions is decreased as the value is increased beyond a first threshold, and coefficients for reducing luminance for the entire screen are decreased as the value is increased beyond a second threshold which is higher than the first threshold.