Data driving apparatus and method for liquid crystal display
View Patent ↗A data driving apparatus for a liquid crystal display includes a plurality of output buffer integrated circuits for buffering a plurality of pixel signals and outputting the plurality of pixel signals to a plurality of data lines; a plurality of digital to analog converter integrated circuits, each of which are commonly connected to input terminals of at least two of the plurality of output buffer integrated circuits, for converting input pixel data to the plurality of pixel signals and selectively outputting the plurality of pixel signals to the at least two output buffer integrated circuits; and timing control means for controlling the plurality of digital to analog converter integrated circuits and making a time division of the pixel data into at least two regions to sequentially supply the pixel data to the plurality of data lines.
1. A data driving apparatus for a liquid crystal display, comprising:
a plurality of output buffer integrated circuits, each of the output buffer integrated circuits simultaneously buffering a plurality of pixel signals and outputting the plurality of pixel signals to a plurality of data lines;
a plurality of digital to analog converter integrated circuits, each of which are connected to input terminals of at least two of the plurality of output buffer integrated circuits, converting input pixel data into the plurality of pixel signals and selectively outputting the plurality of pixel signals to one of the at least two output buffer integrated circuits; and
timing control means for controlling the plurality of digital to analog converter integrated circuits and making a time division of the input pixel data into at least two regions to sequentially supply the pixel data to the plurality of data lines.
2. The data driving apparatus according to claim 1 , wherein the plurality of digital to analog converter integrated circuits are mounted in a printed circuit board connected to the timing control means, and each of the plurality of output buffer integrated circuits is mounted in a tape carrier package electrically connected between the printed circuit board and a liquid crystal display panel at which the plurality of data lines are arranged.
3. The data driving apparatus according to claim 1 , wherein each of the plurality of digital to analog converter integrated circuits includes:
shift register means for sequentially outputting a sampling signal under control of the timing control means;
latch means for responding to the control of the timing control means and the sampling signal to sequentially latch pixel data inputted from the timing control means and to output the latched pixel data at the same time;
digital to analog converting means for converting the pixel data into positive and negative pixel signals using input gamma voltages to output the pixel signals responding to a polarity control signal from the timing control means; and
a demultiplexor for responding to a selection control signal from the timing control means to selectively output the pixel signals from the digital to analog converting means to the at least two output buffer integrated circuits.
4. The data driving apparatus according to claim 3 , wherein each of the plurality of digital to analog converter integrated circuits further includes:
a signal controller for interfacing various control signals from the timing control means and the pixel data to apply the control signals to the shift register means, the latch means, the digital to analog converting means and the demultiplexor; and
gamma voltage means for sub-dividing an input gamma reference voltage to generate gamma voltages.
5. The data driving apparatus according to claim 3 , wherein the timing control means inverts a logical state of the selection control signal every period of an output enable signal controlling an output of the latching means, thereby allowing the pixel signals to be sequentially applied to the at least two output buffer integrated circuits.
6. The data driving apparatus according to claim 1 , wherein each of the output buffer integrated circuits outputs the pixel signals to n data lines, n being a positive integer greater than one, and each of the digital to analog converter integrated circuits converts the pixel data into the pixel signals n-by-n and outputs the converted pixel signals to one of the at least two output buffer integrated circuits n-by-n.
7. A data driving apparatus for a liquid crystal display, comprising:
a plurality of output buffer integrated circuits, each output buffer integrated circuit simultaneously buffering a plurality of pixel signals and outputting the plurality of pixel signals to a plurality of data lines; and
a plurality of digital to analog converter integrated circuits, each of which are connected to input terminals of at least two of the plurality of output buffer integrated circuits, converting input pixel data into the plurality of pixel signals and outputting the plurality of pixel signals to one of the at least two output buffer integrated circuits based on a time division of the pixel signals, such that the buffered pixel signals from each of the output buffer integrated circuits are applied sequentially to the plurality of data lines.
8. The data driving apparatus according to claim 7 , further comprising timing control means for controlling the plurality of digital to analog converter integrated circuits and making the time division of the input pixel data into at least two regions to sequentially supply the pixel data to the plurality of data lines.
9. The data driving apparatus according to claim 7 , wherein each of the output buffer integrated circuits outputs the pixel signals to n data lines, n being a positive integer greater than one, and each of the digital to analog converter integrated circuits converts the pixel data into the pixel signals n-by-n and outputs the converted pixel signals to one of the at least two output buffer integrated circuits n-by-n.
10. A method of driving a data driving apparatus for driving a plurality of data lines arranged at a liquid crystal display panel wherein the driving apparatus includes a plurality of output buffer integrated circuits, each of the output buffer integrated circuits connected to more than one of the plurality of data lines, and a plurality of digital to analog converter integrated circuits commonly connected to input terminals of at least two of the plurality of output buffer integrated circuits, the method comprising:
making a time division of pixel data to be supplied to each of the plurality of digital to analog converter integrated circuits into at least two regions;
converting the pixel data into analog pixel signals;
selectively applying the converted pixel signals to one of the at least two output buffer integrated circuits based on the time division of the pixel data; and
applying the buffered pixel signals from each of the output buffer integrated circuits sequentially to the plurality of data lines.
11. The method according to claim 10 , wherein the step of converting the pixel data into the pixel signals includes:
generating a sequential sampling signal;
responding to the sampling signal to sequentially sample and latch the pixel data; converting the pixel data into a plurality of positive and negative pixel signals using gamma voltages; and
selecting any one of the plurality of positive and negative pixel signals to output the pixel signals.
12. The method according to claim 10 , wherein each of the output buffer integrated circuits connects to n data lines, n being a positive integer greater than one, the pixel data are converted into the pixel signals n-by-n, the converted pixel signals are outputted to one of the at least two output buffer integrated circuits n-by-n, and the buffered pixel signals are outputted to the data lines sequentially from one of the at least two output buffer integrated circuits n-by-n.