Patent ID: 8106928

Claim:
An image display method of an image display device having respective single-color light sources corresponding to at least two primary color image signals, the method comprising: extracting a white color component from the primary color image signals; calculating time periods to display the white color component corresponding to each of the primary color image signals based on a calculated ratio of the lowest minimum gradient to a highest possible gradient of the primary color image signals and periods to display the primary color images; defining the longest of the calculated time periods to display the white color component corresponding to the primary color image signals as the period to display the white color component, where the defined longest time period is selected from the calculated time periods that include at least two different time periods; converting the primary color image signals into shortened primary color image signals and a white color image signal based on the period to display the white color component by reducing periods to display the primary color image signals according to the period to display the white color component to obtain the periods to display the shortened primary color image signals, obtaining a linear combination of the shortened primary color image signals and the white color image signal by combining the shortened primary color image signals and the white color image signal without overlapping the primary color image signals and the white color image signal, and generating the shortened primary color image signals and the white color image signal by temporally scaling the linear combination of the shortened primary color image signals and the white color image signal such that a sum of the periods to display the shortened primary color image signals and the white color image signal is equal to a period of a frame; and driving the single-color light sources together during a period to display the white color image signal and sequentially driving the single-color light sources during periods to display the shortened primary color image signals, wherein scaling the linear combination of the shortened primary color image signals and the white color image signal is performed by increasing the periods to display the shortened primary color image signals and the white color image signal with a predetermined ratio.