Patent ID: 7286110

Claim:
A liquid crystal display control driver controlling a driving of a plurality of common electrodes and a plurality of segment electrodes which are included in a liquid crystal panel capable of displaying a plurality of rows, the liquid crystal display control driver being capable of setting a display of a part of an area in the liquid crystal panel, the liquid crystal display control driver comprising: an interface circuit receiving a signal to be supplied from an output side of the liquid crystal display control driver; a display data RAM; an address counter; a common driver; a segment driver; a latch circuit holding a signal supplied to the segment driver; a shift register supplying a selection signal to the common driver; a voltage converter circuit converting a boost voltage to drive a bias voltage to be supplied to the plurality of common electrodes, and supplying the bias voltage to the common driver; a drive duty setting register setting a drive duty of the liquid crystal panel; a bias register setting a drive bias ratio; a boost power setting circuit setting a boost power of the boost voltage; a display row setting register setting a position of the part of the area; and a timing generation circuit capable of adjusting a period of a clock signal to be supplied to the shift register in accordance with the drive duty, wherein the shift register generates the selection signal to select common electrodes corresponding to the position set by the display row setting register in accordance with the clock signal.