Display apparatus, data line driver, and display panel driving method
View Patent ↗A display apparatus includes a display panel containing data lines; a driving circuit configured to generate a data signal in response to a first pixel data of k (k is an natural number) bits and to supply the data signal to one of the data lines; and a capacitor. A switch circuit connects or disconnects the data line to or from the capacitor in response to upper m bits (m is a natural number smaller than k) of the first pixel data.
1. A data line driver which drives a data line of a display panel, comprising:
a positive polarity driving circuit configured to operate in a first voltage range between a reference voltage and a first voltage greater than said reference voltage to output to a first node, a positive polarity data signal with respect to said reference voltage;
a negative polarity driving circuit configured to operate in a second voltage range between said reference voltage and a second voltage less than said reference voltage to output to a second node, a negative polarity data signal with respect to said reference voltage;
a first collection switch provided between said first node and a first collection line;
a second collection switch provided between said second node and a second collection line; and
a changeover switch provided between said first and second nodes and between first and second output terminals, to operate in a third voltage range which is from said second voltage to said first voltage,
wherein electric charges accumulated on said data line are transferred by controlling said first and second collection switches,
wherein said changeover switch comprises:
a first changeover switch provided between said first node and said first output terminal;
a second changeover switch provided between said second node and said second output terminal;
a third changeover switch provided between said first node and said second output terminal; and
a fourth changeover switch provided between said second node and said first output terminal.
2. The data line driver according to claim 1 , further comprising:
first and second precharge switches provided between said reference voltage line and said first and second nodes, respectively.
3. The data line driver according to claim 1 , further comprising:
diode elements provided between said reference voltage line and said first and second nodes, respectively.
4. The data line driver according to claim 1 , wherein said reference voltage is a system ground of the display apparatus.
5. The data line driver according to claim 1 , wherein said first collection switch operates in said first voltage range, and said second collection switch operates in said second voltage range.
6. The data line driver according to claim 1 , wherein said first and second collection switches connect or disconnect said data line to or from said first and second collection lines electrically in response to upper m bits (m<k) of an image data of k bits.
7. The data line driver according to claim 2 , wherein said first precharge switch operates in said first voltage range, and said second precharge switch operates in said second voltage range.
8. The data line driver according to claim 1 , wherein after said first and second collection switches are turned on to move electric charges accumulated on said data line to said first and second collection lines, said first and second collection switches are turned off and said first to fourth changeover switches are turned on at a same time to neutralize charges on the data line.
9. The data line driver according to claim 1 , wherein breakdown voltages of elements of said positive and negative polarity driving circuits are less than those of elements of said changeover switch.
10. The data line driver according to claim 1 , wherein thicknesses of gate insulating films of transistors in said positive and negative polarity driving circuits are less than thicknesses of transistors in said changeover switch.
11. The data line driver according to claim 1 , wherein gate lengths of transistors in said positive and negative polarity driving circuits are less than those of transistors in said changeover switch.
12. The data line driver according to claim 1 , wherein breakdown voltages of elements of said first and second collection switches are less than breakdown voltages of elements of said changeover switch.
13. The data line driver according to claim 1 , wherein thicknesses of gate insulating films of transistors in said first and second collection switches are less than those of transistors in said changeover switch.
14. The data line driver according to claim 1 , wherein gate lengths of transistors in said first and second collection switches are less than those of transistors in said changeover switch.