Image signal backlight brightness control devices and methods therefor

The invention discloses a controlling device and method of video signal aphototropism brightness, which comprises the following parts: analytical mode, decision mode, storage mode, synergistic mode and aphototropism control mode, wherein the analytical mode picks characteristic brilliance; the decision mode builds corresponding list of output-input image at characteristic brilliance and index adjusting pattern, which obtains the level pulse closing quantity of the characteristic brilliance; the synergistic mode switches the input signal of image into output signal; the aphototropism control mode rolls out the pulse breadth adjusting signal to adjust aphototropism according to the level pulse closing quantity. The invention can increase the contrast of panel to lessen aphototropism and leaking influence, which reduces the power consumption effect greatly.