Patent ID: 7893916

Claim:
A method for compensating the luminance of a backlight module adapted for use in a display device that displays video data, comprising: sensing a light intensity of a backlight module; calculating a difference parameter based on the sensed light intensity and a preset luminance; and adjusting the video data according to the calculated difference parameter, wherein the method for calculating the difference parameters for red light, green light, and blue light further comprises: calculating S 1 , S 2 , and S 3 using the formulae listed below, wherein S 1 , S 2 , and S 3 respectively represent the difference parameters for red light, green light and blue light, V m (R), V m (G), and V m (B) respectively represent light intensities of the red light, the green light, and the blue light sensed by a red light sensor, a green light sensor, and a blue light sensor, V rr , V gr , and V br respectively represent the light intensities of the red light, the green light, and the blue light sensed by a light sensor when a fixed driving current is continuously driving a red LED, V rg , V gg , and V bg respectively represent the light intensities of the red light, the green light, and the blue light sensed by the light sensor when the fixed driving current is continuously driving a green LED, V rb , V gb , and V bb respectively represent the light intensities of the red light, the green light, and the blue light sensed by the light sensor when the fixed driving current is continuously driving a blue LED, V r — dark , V g — dark , V b — dark respectively represent the light intensities of the red light, the green light, and the blue light sensed by the light sensor when the red LED, the green LED, and the blue LED are turned off, PWM(R), PWM(G), and PWM(B) respectively represent predetermined periods for lighting the red LED, the green LED, and the blue LED, and [ ⁢ ( V r ⁢ ⁢ r - V r_dark ) ⁢ PWM ⁡ ( R ) , ( V r ⁢ ⁢ g - V r_dark ) ⁢ PWM ⁡ ( G ) , ( V r ⁢ ⁢ b - V r_dark ) ⁢ PWM ⁡ ( B ) , ( V g ⁢ ⁢ r - V g_dark ) ⁢ PWM ⁡ ( R ) , ( V g ⁢ ⁢ g - V g_dark ) ⁢ PWM ⁡ ( G ) , ( V g ⁢ ⁢ b - V g_dark ) ⁢ PWM ⁡ ( B ) , ( V b ⁢ ⁢ r - V b_dark ) ⁢ PWM ⁡ ( R ) , ( V b ⁢ ⁢ g - V b_dark ) ⁢ PWM ⁡ ( G ) , ( V b ⁢ ⁢ b - V b_dark ) ⁢ PWM ⁡ ( B ) , ⁢ ] - 1 × ⁢ [ ⁢ V m ⁡ ( R ) - V r_dark V m ⁡ ( G ) - V g_dark V m ⁡ ( B ) - V b_dark ⁢ ] ⁢ = [ ⁢ S 1 , S 2 , S 3 ⁢ ] .