Display apparatus, method of driving the same, and sensing driver of display apparatus

• US 8,253,699 B2
• Filed: 02/12/2008
• Issued: 08/28/2012
• Est. Priority Date: 06/28/2007
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Son, Sun-Kyu
• Primary Examiner(s): Lao, Lun-Yi
• Assistant Examiner(s): Suteerawongsa, Jarurat
• Application Number:
  US12/029,703
• Publication Number:
  US 20090002312A1
• Time in Patent Office: 1,659 Days
• Field of Search: 345 50- 52, 345/55, 345/87, 345/104, 345/173, 345/179, 345/100, 345/174, 178/18.01, 178/19.01, 178/19.04, 178/18.03, 178 1805- 1807, 349/160
• US Class Current: 345/173
• CPC Class Codes: G02F 1/13394 spacers regularly patterned on the cell subtrate, e.g. walls, pillars G02F1/133377 takes precedence
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/047 using sets of wires, e.g. crossed wires

Abstract

In a display apparatus, a display panel includes touch sensors that make contact with a common electrode by an external pressure to output a common voltage, and a sensing driver receives the common voltage from the touch sensors to generate a sensing signal. A controller receives the sensing signal from the sensing driver and calculates position information to which the external pressure is applied based on the sensing signal. The sensing driver includes a switching circuit that receives a switching signal from the controller to switch the common voltage. Thus, the display apparatus prevents the common voltage from being input during a period where a voltage level of the common voltage is abnormally high, thereby preventing a logic circuit of the sensing driver from being damaged.

Claims

1. A display apparatus comprising:

a display panel including a common electrode receiving a common voltage, pixels facing the common electrode and displaying an image in response to driving signals, and touch sensors arranged adjacent to the pixels and making contact with the common electrode by an external pressure to output the common voltage;

a pixel driver electrically connected to the pixels to provide the driving signals to the pixels;

a sensing driver electrically connected to the touch sensors to receive the common voltage from the touch sensors and generate a sensing signal based on the common voltage; and

a controller which controls a drive of the pixel driver, receives the sensing signal from the sensing driver, and outputs a position information to which the external pressure is applied based on the sensing signal, and

the sensing driver comprising;

a switching circuit which receives a switching signal from the controller, outputs the common voltage during a first period where the common voltage is in a normal operation range and blocks the common voltage during a second period where the common voltage is out of the normal operation range, so that the common voltage is selectively output to prevent a damage of the sensing driver; and

a sensing signal generating circuit which generates the sensing signal based on the common voltage output from the switching circuit.

2. The display apparatus of claim 1, wherein each touch sensor comprises:

a sensing electrode making contact with the common electrode by the external pressure to receive the common voltage from the common electrode; and

a sensing line receiving the common voltage from the sensing electrode to provide the common voltage to the sensing driver.

3. The display apparatus of claim 2, wherein the switching signal is maintained at a high state during the first period, and the switching signal is maintained at a low state during the second period.

4. The display apparatus of claim 3, wherein the switching circuit comprises a transistor including an input terminal connected to the sensing line to receive the common voltage, a control terminal receiving the switching signal, and an output terminal outputting the common voltage to the sensing signal generating circuit.

5. The display apparatus of claim 2, wherein the sensing driver further comprises a level shifter that boosts the switching signal from the controller and provides the switching signal that has been boosted to the switching circuit.

6. The display apparatus of claim 1, wherein each pixel comprises:

a gate line that receives a gate signal among the driving signals;

a data line that intersects with the gate line and receives a data signal among the driving signals;

a thin film transistor electrically connected to the gate line and the data line to output the data signal in response to the gate signal; and

a pixel electrode connected to an output electrode of the thin film transistor to receive the data signal and facing the common electrode.

7. The display apparatus of claim 6, wherein each touch sensor comprises:

a sensing electrode making contact with the common electrode by the external pressure to receive the common voltage from the common electrode;

a first sensing line arranged in parallel with the data line and which receives the common voltage from the sensing electrode; and

a second sensing line arranged in parallel with the gate line and which receives the common voltage from the sensing electrode.

8. The display apparatus of claim 7, wherein the sensing driver comprises:

a first sensing driver receiving the common voltage from the first sensing line to output a first sensing signal; and

a second sensing driver receiving the common voltage from the second sensing line to output a second sensing signal.

9. The display apparatus of claim 8, wherein the pixel driver comprises:

a gate driver providing the gate signal to the gate line; and

a data driver providing the data signal to the data line.

10. The display apparatus of claim 9, wherein the gate driver and the second sensing driver are installed inside a gate driver integrated circuit, and the data driver and the first sensing driver are installed inside a data driver integrated circuit.

11. The display apparatus of claim 10, wherein the gate driver integrated circuit is mounted on the display panel and electrically connected to the gate line and the second sensing line, and the data driver integrated circuit is mounted on the display panel and electrically connected to the data line and the first sensing line.

12. The display apparatus of claim 1, wherein each touch sensor is arranged at every N pixels, where N is a natural number.

13. The display apparatus of claim 1, wherein the display panel comprises:

an array substrate;

an opposite substrate facing the array substrate; and

a liquid crystal layer interposed between the array substrate and the opposite substrate.

14. The display apparatus of claim 13, wherein the array substrate comprises a first base substrate, the pixels arranged on the first base substrate, and the touch sensors arranged on the first base substrate, and the opposite substrate comprises a second base substrate which faces the first base substrate, a protruding portion arranged on the second base substrate corresponding to the touch sensors, and the common electrode covers the protruding portion and the second base substrate.

15. The display apparatus of claim 1, wherein transistors within the switching circuit are enabled to endure a greater voltage level than transistors within the sensing signal generating circuit.

16. A method of driving a display apparatus, the method comprising:

displaying an image in response to a gate signal and a data signal;

outputting a common voltage by a pressure provided from an exterior;

switching the common voltage in response to a switching signal;

calculating a position information to which the pressure is applied based on the common voltage in response to the switching signal; and

controlling the gate signal and the data signal to perform an operation corresponding to the position information,

wherein switching the common voltage includes outputting the common voltage during a first period where the common voltage is in a normal operation range and blocking the common voltage during a second period where the common voltage is out of the normal operation range to prevent a damage of the sensing driver.

17. A sensing driver of a display apparatus, the sensing driver arranged to be electrically connected to touch sensors of the display apparatus and to receive a common voltage from the touch sensors, the sensing driver comprising:

a switching circuit including transistors which receive a switching signal to selectively output the common voltage; and

a sensing signal generating circuit including transistors which generate a sensing signal based on the common voltage output from the switching circuit;

wherein the transistors within the switching circuit are enabled to endure a greater voltage level than the transistors within the sensing signal generating circuit, and the transistor output the common voltage during a first period where the common voltage is in a normal operation range and blocks the common voltage during a second period where the common voltage is out of the normal operation range to prevent the transistors of the sensing signal generator from damage.