Liquid crystal display device having drive circuits with master/slave control
View Patent ↗A liquid crystal display device used in miniaturized portable equipment includes a distribution circuit to cope with a high-definition multi-grayscale display. A distribution circuit distributes an output of a drive circuit to a plurality of video signal lines within one scanning period, the distribution circuit being divided into a plurality of distribution circuits, and control signals being supplied to each distribution circuit from both end portions of each distribution circuit. When an output part of the drive circuit is configured such that a high withstand-voltage output amplifier and a low withstand-voltage output amplifier are alternately connected with the distribution circuit, a master function and a slave function are imparted to the drive circuit so as to allow the drive circuit to cope with odd-numbered outputs.
1. A liquid crystal display device comprising:
a liquid crystal display panel; and
first and second drive circuits which are configured to drive the liquid crystal display panel, wherein
a first distribution circuit is configured to distribute video signals outputted from the first drive circuit to a plurality of video signal lines arranged on the liquid crystal display panel and formed on the liquid crystal display panel,
a second distribution circuit is configured to distribute video signals outputted from the second drive circuit to a plurality of video signal lines arranged on the liquid crystal display panel and formed on the liquid crystal display panel,
the first distribution circuit is configured to be controlled in response to a first control signal outputted from the first drive circuit,
the second distribution circuit is configured to be controlled in response to a second control signal outputted from the second drive circuit,
the first drive circuit includes a plurality of video signal output terminals which are configured to output the video signals, first and second control signal output terminals which are formed with the plurality of video signal output terminals sandwiched therebetween and are configured to output the control signals,
the second drive circuit includes a plurality of video signal output terminals which are configured to output the video signals, third and fourth control signal output terminals which are formed with the plurality of video signal output terminals sandwiched therebetween and are configured to output the control signals,
a master/slave control signal line is connected between the first drive circuit and the second drive circuit for imparting a slave function of the second drive circuit,
the first drive circuit starts outputting the grayscale voltage of positive polarity,
the second drive circuit starts outputting the grayscale voltage of negative polarity, and
the first distribution circuit has an input terminal which connects to two video signal output terminals of the first drive circuit.
2. A liquid crystal display device according to claim 1 , wherein a scanning signal line drive circuit is formed on the liquid crystal display panel, and the drive circuit includes scanning signal output terminals which are connected to the scanning signal line drive circuit outside the control signal output terminals.
3. A liquid crystal display device according to claim 1 , wherein the number of the video signal output terminals sandwiched between the first control signal output terminal and the third control signal output terminal is an even number.
4. A liquid crystal display device according to claim 1 , wherein said plurality of video signal output terminals which are arranged adjacent to each other are configured to output video signals having polarities opposite to each other therefrom.
5. A liquid crystal display device comprising:
a first substrate;
a second substrate;
liquid crystal composition which is sandwiched between the first substrate and the second substrate;
a plurality of pixel electrodes which are formed on the first substrate;
a plurality of video signal lines which are configured to supply video signals to the pixel electrodes;
first and second drive circuits which are mounted on the first substrate and is configured to output the video signals from video signal output terminals; and
first and second distribution circuits which are formed on the first substrate and is configured to distribute the video signals outputted from the drive circuit to the plurality of video signal lines arranged on a liquid crystal display panel, wherein
the first distribution circuit is configured to be controlled in response to a first control signal outputted from the first drive circuit,
the second distribution circuit is configured to be controlled in response to a second control signal outputted from the second drive circuit,
the first drive circuit and the first distribution circuit are connected to each other by a plurality of relay signal lines which relay the video signals,
the second drive circuit and the second distribution circuit are connected to each other by a plurality of relay signal lines which relay the video signals,
the relay signal lines are connected to the drive circuit via the video signal output terminals,
the number of the relay signal lines which are connected to the video signal output terminals is an even number,
the number of the relay signal lines which are connected to the distribution circuit is an odd number,
a master/slave control signal line is connected between the first drive circuit and the second drive circuit for imparting a slave function of the second drive circuit, and
the first distribution circuit has an input terminal which connects to two video signal output terminals of the first drive circuit.
6. A liquid crystal display device according to claim 5 , wherein control signal output terminals from which the control signals are outputted are arranged outside the video signal output terminals.
7. A liquid crystal display device according to claim 5 , wherein control signal output terminals from which the control signals are outputted are arranged outside the video signal output terminals, and
a scanning signal line drive circuit is formed on the liquid crystal display panel, and the first drive circuit includes scanning signal output terminals which are connected to the scanning signal line drive circuit outside the control signal output terminals.
8. A liquid crystal display device according to claim 5 , wherein video signals having polarities opposite to each other are outputted to said two relay signal lines which are arranged adjacent to each other.
9. A liquid crystal display device comprising:
a first substrate;
a second substrate;
liquid crystal composition which is sandwiched between the first substrate and the second substrate;
a plurality of pixel electrodes which are formed on the first substrate;
a plurality of video signal lines which are configured to supply video signals to the pixel electrodes;
a first drive circuit and a second drive circuit which are mounted on the first substrate and are configured to output the video signal from video signal output terminals;
a first distribution circuit which is formed on the first substrate and is configured to distribute the video signals outputted from the first drive circuit to the plurality of video signal lines arranged on a liquid crystal display panel; and
a second distribution circuit which is formed on the first substrate and is configured to distribute the video signals outputted from the second drive circuit to the plurality of video signal lines arranged on the liquid crystal display panel, wherein
the first distribution circuit is configured to be controlled in response to a first control signal outputted from the first drive circuit,
the second distribution circuit is configured to be controlled in response to a second control signal outputted from the second drive circuit,
the first drive circuit and the first distribution circuit are connected to each other by a plurality of relay signal lines and the second drive circuit and the second distribution circuit are connected to each other by a plurality of relay signal lines, the plurality of relay signal lines relay the video signals,
the relay signal lines are connected to the first and second drive circuits via the video signal output terminals,
the number of the relay signal lines which are connected to the video signal output terminals provided to the first drive circuit is an even number,
the number of the relay signal lines which are connected to the first distribution circuit is an odd number,
polarity of the n th relay signal line, n being an odd number, which is connected to the first distribution circuit and polarity of the m th relay signal line, m being an odd number, which is connected to the second distribution circuit are set opposite to each other,
a master/slave control signal line is connected between the first drive circuit and the second drive circuit for imparting a slave function of the second drive circuit, and
the first distribution circuit has an input terminal which connects to two video signal output terminals of the first drive circuit.
10. A liquid crystal display device according to claim 9 , wherein the control signal output terminals from which the control signals are outputted are arranged outside the video signal output terminals.
11. A liquid crystal display device according to claim 9 , wherein the control signal output terminals from which the control signals are outputted are arranged outside the video signal output terminals, and
a scanning signal line drive circuit is formed on the liquid crystal display panel, and the first drive circuit includes scanning signal output terminals which are connected to the scanning signal line drive circuit outside the control signal output terminals.