| 摘要 |
A pulse-width modulated backlight control for a video display restarts the pulse-width modulated pulse train on occurrence of a video refresh pulse. In order to prevent an undesirable momentary increase in brightness in the event that the last pulse of the pre-refresh pulse train occurs too close to the first pulse of the post-refresh pulse train relative to the normal pulse interval, the width of the first pulse following refresh may be reduced from a first value determined by the desired brightness to a second value that bears the same proportion to the first value that the interval between the beginning of the previous pulse and the occurrence of the refresh pulse bore to the normal pulse interval. In that way, the duty cycle during the shortened pulse interval is the same as during a normal pulse interval, avoiding or minimizing perceptible increase in backlight brightness.
|
