| 摘要 |
A contrast ratio promotion method for a display device is provided. The display device contains a back light module having a brightness and has a maximum luminance. The contrast ratio promotion method comprises the steps of continuously receiving a picture signal during each unit time, continuously calculating a ratio of a luminance of a picture corresponding to the picture signal to the maximum luminance, where the ratio is defined as an instant relative luminance, setting a first ratio, a first buffer time and a first adjusting time, and gradually reducing the brightness of the back light module to a minimum brightness during the first adjusting time when a first cumulated time for the respective consecutive plural instant relative luminances being smaller than the first ratio is longer than the first buffer time. |
