Patent ID: 7499065

Claim:
A method of operating an array of pixels to generate an image using a pulse-width-modulation (PWM) technique, wherein each pixel has an asymmetric switching delay between an ON and OFF state, the method comprising: assigning a set of nominal weights to a set of bits corresponding to the PWM pattern of a pixel; providing a desired intensity value to be reproduced by the pixel; determining the values of a first subset of bits according to the desired intensity such that the bits in the first set collectively present an intensity that approximates the desired intensity value; determining a residual intensity value based on the desired intensity value, the determined values of the first subset of bits and their corresponding nominal weights, and a parameter that characterizes the asymmetry of the pixel switching delay; determining the values of a second subset of bits depending on the residual intensity value, the parameter characterizing the asymmetry of the switching delay, the values and weights of the first subset of bits, and a dither threshold value; and operating the pixels with the PWM technique according to the determined bit values of the first and second subsets.