Patent ID: 7158157

Claim:
A light emitting device comprising: a plurality of light emitting elements; a voltage source for supplying voltages to the plurality of light emitting elements; means for calculating an accumulation of one of light emission periods and gradation levels of each of the plurality of light emitting elements based on video signals for controlling the light emission periods of the plurality of light emitting elements; means for storing the calculated accumulation of one of light emission periods and gradation levels of each of the plurality of light emitting elements; means for storing data on a time-varying luminance characteristic of the plurality of light emitting elements; means for determining an amount of luminance variation compared to an initial luminance of each of the plurality of light emitting elements based on the data on the time-varying luminance characteristic of the plurality of light emitting elements and the calculated accumulation of at least one selected from the group consisting of the light emission periods and the gradation levels of the plurality of light emitting elements; means for correcting the voltages supplied from the voltage source to the plurality of light emitting elements to return a luminance of one of the plurality of light emitting elements to an initial luminance; and means for correcting the video signals in a manner to compensate for a difference between the amount of luminance variation compared to an initial luminance of the one of the plurality of light emitting elements and an amount of luminance variation compared to an initial luminance of each of the other light emitting elements than the one of the plurality of light emitting elements, thereby correcting the gradation level of each of the other light emitting elements than the one of the plurality of light emitting elements.