Ramp signal producing method, ramp signal producing apparatus, and liquid crystal drive/display apparatus

摘要

In a ramp signal producing apparatus, a ramp signal is produced under low clock signal frequency in a compact circuit arrangement. Luminance control and a white balance control are carried out by the ramp signal in a liquid crystal display. The ramp signal producing apparatus is comprised of: an up/down counter for either counting up, or counting down a clock signal supplied thereto; amplitude amount converting means for converting the amplitude of the supplied clock signal into such an amplitude value corresponding to the count value of the up/down counter and for converting the amplitude value in such a manner that a change amount per one count value is increased during the count down operation by the up/down counter; and ramp signal producing means for producing such a ramp signal with an amplitude corresponding to the converted amplitude value.