Liquid crystal display driver device and liquid crystal display system
View Patent ↗There is provided a display driver device (liquid crystal driver) causing no degradation in display image quality even when a plurality of signal lines (source lines) of a display panel are divided into a plurality of groups as a countermeasure against EMI. With a liquid crystal display driver device (the liquid crystal driver) for generating image signals to be impressed to respective signal lines of a display panel upon receiving display image data, and outputting the image signals in a lump, corresponding to every one line, according to an output timing signal inputted from outside, output amplifiers, in the last stage of the liquid crystal driver, for outputting the image signals, respectively, are divided into a plurality of groups, and the output amplifiers of respective groups are caused to undergo a periodical change in output sequence while the respective image signals are slightly staggered in output timing by the group.
1. A source driver on a semiconductor substrate for use with a display panel including source lines to be coupled to the source driver, gate lines to be coupled to a gate driver, and pixels arranged at crossings between the source lines and the gate lines, the source driver comprising:
a plurality of output circuits to be coupled to the source lines of the display panel and including first output circuits and second output circuits outputting voltages corresponding to a plurality of gradations to be applied to respective source lines of the display panel;
a timing controller coupled to the first and the second output circuits for controlling an output timing of the first and second output circuits;
wherein,
in a first output timing, the second output circuits output voltages after the first output circuits output voltages in a period for outputting voltages to respective source lines of the display panel; and
in a second output timing, the first output circuits output voltages after the second output circuits output voltages in a period for outputting voltages to respective source lines of the display panel.
2. A source driver according to claim 1 ,
wherein the first output circuits include odd-number-position output circuits among the plurality of output circuits and the second output circuits include even-number-position output circuits among the plurality of output circuits.
3. A source driver according to claim 1 ,
wherein the display panel is a liquid crystal display panel, and
wherein the timing controller controls the first output timing and the second output timing according to an AC conversion signal.
4. A source driver according to claim 1 ,
wherein the timing contoller controls the first output timing and the second output timing according to a signal indicating display time for one frame of the display panel.
5. A source driver on a semiconductor substrate for providing source signals to source lines of a display panel having source lines, gate lines to be driven by a gate driver, and pixels arranged at crossings between the source lines and the gate lines, the source driver comprising:
a timing controller coupled to receive a horizontal synchronizing signal and providing a first line output clock signal based on the horizontal synchronizing signal and a second line output clock signal which is delayed with respect to the first line output clock signal;
a switching circuit coupled to receive a timing signal which is periodically changed between a first level and a second level and having:
a first input coupled to receive said first line output clock signal,
a second input coupled to receive said second line output clock signal,
a first output which is coupled to the first input when the timing signal is in the first level and which is coupled to the second input when the timing signal is in the second level, and
a second output which is coupled to the first input when the timing signal is in the second level and which is coupled to the second input when the timing signal is in the first level,
first output circuits which are coupled to the first output of the switching circuit and which are to be coupled to first source lines in the source lines of the display panel to provide source signals to the first source lines in the source lines of the display panel according to the first line output clock signal or the second line output clock signal; and
second output circuits which are coupled to the second output of the switching circuit and which are to be coupled to second source lines of the display panel, which are different from the first source lines, to provide source signals to the second source lines according to the first line output clock signal or the second line output clock signal.
6. A source driver according to claim 5 ,
wherein the timing signal is based on an AC conversion signal.
7. A source driver according to claim 5 ,
wherein the timing signal is based on a frame signal.