Liquid crystal display, apparatus for driving a liquid crystal display, and method of generating gray voltages
View Patent ↗A liquid crystal display, apparatus for driving a liquid crystal display and a method of driving gray voltages for the same. The liquid crystal display includes a plurality of gate lines transmitting gate signals, a plurality of data lines intersecting the plurality of gate lines and transmitting data voltages, and a plurality of pixel rows. Each pixel row includes a plurality of pixels, and each pixel includes a switching element connected to one of the plurality of gate lines and one of the plurality of data lines. The polarity of the data voltages supplied to the plurality of pixels are inverted by a pixel group including two or more pixel rows. The absolute values of the data voltages applied to one row of the pixel group with respect to a first predetermined voltage are greater than the absolute values of the data voltages applied to another row of the pixel group for the same grays.
1. An apparatus for driving a liquid crystal display, comprising:
a gray voltage producer generating a plurality of positive gray voltages and a plurality of negative gray voltages based on a plurality of reference voltages including a first reference voltage for positive grays and a second reference voltages for negative grays;
a pulse signal producer generating first and second pulse signals with inverted phases; and
a reference voltage generator adjusting a voltage level of the first and the second pulse signals from the pulse signal producer to generate the first and the second reference voltages,
wherein the reference voltage generator comprises:
a switch alternately switching the first and the second pulse signals;
a pair of first resistors connected in series between a first predetermined voltage and a second predetermined voltage;
a pair of second resistors respectively connected to the first and the second pulse signals, the switch connected to a node between the first resistors and alternately connected to the second resistors;
a first amplifier, connected to the node, for amplifying a voltage of the node to produce the first reference voltage; and
a second amplifier inverting an output of the first amplifier with respect to a predetermined voltage to produce the second reference voltage.