Patent ID: 7375734

Claim:
A multi-channel driver for a monitor having multiple data channels, the multi-channel driver comprising: an m-bit counter for outputting an m-bit counting signal; a GAMMA adjustment unit connecting to the m-bit counter and mapping the m-bit counting signal to a range of a GAMMA curve, so as to output an n-bit signal mapped by the m-bit counting signal, where m>n; and a plurality of pulse width modulation (PWM) driving components wherein each of the PWM driving components comprises two input terminals and an output terminal, wherein one of the input terminals is connected to an output terminal of the GAMMA adjustment unit to receive a first n-bit input signal through a first n-bit register, and the other one of the input terminals receives a second n-bit input signal through a second n-bit register, and each PWM driving component compares the first and the second n-bit input signals in order to output a PWM driver signal to a corresponding data channel of the monitor, wherein the GAMMA adjustment unit executes a GAMMA adjustment method comprising the steps of: (a) determining a located curve range of an m-bit input signal, which is an m-bit counting signal output by the m-bit counter, on an approximate GAMMA curve, wherein the approximate GAMMA curve represents a relationship of a voltage range represented by n-bit values to the m-bit input signal, and the approximate GAMMA curve is formed by a plurality of lines with different slopes and lengths, so as to determine the line on which the m-bit input signal is located and to output an adjustment value, which is a minimum voltage value corresponding to the located line, represented by an n-bit value; (b) using a calculation formula to acquire a relative n-bit voltage value corresponding to the m-bit input signal, wherein the calculation formula is G ′ = CNT - X a - 1 X a - X a - 1 2 n / ( a + 1 ) , wherein G′ is the relative n-bit voltage value; CNT is the m-bit input signal; X a is the maximum value of the located line; X a−1 is the minimum value of the located line; and a+1 is the quantity of the plurality of the lines; and (c) adding the adjustment value from step (a) to the relative n-bit voltage value G′ from step (b) to derive an n-bit signal mapped by the m-bit input signal.