Patent ID: 8400391

Claim:
A method for displaying an image on a display device having first and second light sources, the method comprising: providing a video signal to the display device, the video signal comprising first and second video frames, each video frame comprising first and second sub-frames corresponding to the respective first and second light sources, the first and second sub-frames having adjustable on-times, and thus adjustable pulse-widths, for the first and second light sources; operating the first light source during the first sub-frame of the first video frame to generate a first plurality of first light emission pulses, each of the first plurality of first light emission pulses having a first on-time and thus a first pulse-width, the first pulse-width equal to a minimum pulse-width, a maximum pulse-width, or a pulse-width between the minimum pulse-width and the maximum pulse-width; operating the first light source during the first sub-frame of the second video frame to generate a second plurality of first light emission pulses, each of the second plurality of first light emission pulses having a second on-time and thus a second pulse-width, the second pulse-width equal to the minimum pulse-width, the maximum pulse-width, or a pulse-width between the minimum pulse-width and the maximum pulse-width, the second on-time being different from the first on-time, whereby the second pulse-width is different from the first pulse-width; supplying a constant peak current to the first light source at least when the first pulse-width and the second pulse-width are equal to a pulse-width between the minimum pulse-width and the maximum pulse-width, wherein the difference in the first pulse-width and the second pulse-width varies the brightness of the first light source; and selectively varying the peak current supplied to the first light source when either the first pulse-width or the second pulse-width is not equal to a pulse-width between the minimum pulse-width and the maximum pulse-width, to thereby further vary the brightness of the first light source.