Touch screen driver and display device for driving a touch screen

• US 9,323,381 B2
• Filed: 04/24/2013
• Issued: 04/26/2016
• Est. Priority Date: 04/24/2012
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Lim, Kyusam, Jang, Chulsang
• Primary Examiner(s): Snyder, Adam J
• Application Number:
  US13/869,738
• Publication Number:
  US 20130278525A1
• Time in Patent Office: 1,098 Days
• Field of Search: 345/174, 178/18.06
• US Class Current: 1/1
• CPC Class Codes: G06F 2203/04803 Split screen, i.e. subdividing the display area or the window area into separate subareas
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
• CPC Class Codes: G06F 3/04886 by partitioning the display area of the touch-screen or the surface of the digitising tablet into independently controllable areas, e.g. virtual keyboards or menus

Abstract

A touch screen driver includes a plurality of integrated circuits for dividedly driving a touch screen. One of the plurality of integrated circuits, which generates a driving signal to be supplied to Tx lines of the touch screen, transmits a synchronization signal synchronized with the driving signal to other integrated circuit. The other integrated circuit receiving the synchronization signal receives charges of the touch sensors through Rx lines of the touch screen in response to the synchronization signal.

Claims

1. A touch screen driver for driving a touch screen, which includes Tx lines, Rx lines and touch sensors formed at crossings of the Tx lines and the Rx lines, the touch screen driver comprising:

a plurality of integrated circuits including a first integrated circuit and a second integrated circuit, and configured to dividedly drive the touch screen,

wherein one of the plurality of integrated circuits, which generates a driving signal to be supplied to the Tx lines, transmits a synchronization signal synchronized with a rising edge of the driving signal to other integrated circuit, wherein the other integrated circuit receiving the synchronization signal receives charges of the touch sensors through the Rx lines in response to the synchronization signal;

a first touch recognition module configured to analyze touch raw data received from the first integrated circuit estimate coordinates of touch input positions and output first touch coordinate data;

a second touch recognition module configured to analyze touch raw data received from the second integrated circuit, estimate coordinates of touch input positions, and output second touch coordinate data, wherein the first touch recognition module is embedded in the first integrated circuit and the second touch recognition module is embedded in the second integrated circuit; and

a data synchronization module configured to synchronize the first touch coordinate data and the second touch coordinate data output respectively from the first touch recognition module and the second touch recognition module, and transmit the synchronized touch coordinate data to a host system.

2. The touch screen driver of claim 1, wherein the first integrated circuit is connected to Tx lines of a first group which are divided from the Tx lines, is connected to Rx lines of a first group which are divided from the Rx lines, supplies the driving signal to the Tx lines of the first group, and at the same time, transmits the synchronization signal to the second integrated circuit, and

wherein the second integrated circuit is connected to Tx lines of a second group which are divided from the Tx lines, is connected to Rx lines of a second group which are divided from the Rx lines, supplies the driving signal to the Tx lines of the second group, and at the same time, transmits the synchronization signal to the first integrated circuit.

3. The touch screen driver of claim 2, wherein each time the driving signal is supplied to the Tx lines of the first group, the first integrated circuit receives charges of the touch sensors formed in a first area of the touch screen through the Rx lines of the first group, samples voltages of the touch sensors in the first area, converts the sampled voltages of the touch sensors in the first area into a first digital data, and generates a first touch raw data, and

wherein each time the driving signal is supplied to the Tx lines of the first group in response to the synchronization signal from the first integrated circuit, the second integrated circuit receives charges of the touch sensors formed in a second area of the touch screen through the Rx lines of the second group, samples voltages of the touch sensors in the second area, converts the sampled voltages of the touch sensors in the second area into a second digital data, and generates a second touch raw data.

4. The touch screen driver of claim 3, wherein each time the driving signal is supplied to the Tx lines of the second group in response to the synchronization signal from the second integrated circuit, the first integrated circuit receives charges of the touch sensors formed in a third area of the touch screen through the Rx lines of the first group, samples voltages of the touch sensors in the third area, converts the sampled voltages of the touch sensors in the third area into a third digital data, and generates a third touch raw data, and

wherein each time the driving signal is supplied to the Tx lines of the second group, the second integrated circuit receives charges of the touch sensors formed in a fourth area of the touch screen through the Rx lines of the second group, samples voltages of the touch sensors in the fourth area, converts the sampled voltages of the touch sensors in the fourth area into a fourth digital data, and generates a fourth touch raw data.

5. The touch screen driver of claim 4, wherein

the first touch recognition module is configured to analyze the first and third touch raw data received from the first integrated circuit, estimate coordinates of a first touch input position, and output the first touch coordinate data;

and

the second touch recognition module is configured to analyze the second and fourth touch raw data received from the second integrated circuit, estimate coordinates of a second touch input position, and output the second touch coordinate data.

6. The touch screen driver of claim 4, wherein the first integrated circuit receives the second and fourth touch raw data output from the second integrated circuit and synchronizes the received second and fourth touch raw data with the first and third touch raw data generated by the first integrated circuit.

7. The touch screen driver of claim 6, wherein the first touch recognition module is configured to analyze the synchronized first and fourth touch raw data received from the first integrated circuit, estimate coordinates of the first touch input position, and output the first touch coordinate data.

8. The touch screen driver of claim 1,

wherein the first integrated circuit is connected to the Tx lines, is connected to Rx lines of a first group which are divided from the Rx lines, supplies the driving signal to the Tx lines, and at the same time, transmits the synchronization signal to the second integrated circuit, and

wherein the second integrated circuit is connected to Rx lines of a second group which are divided from the Rx lines.

9. The touch screen driver of claim 8, wherein each time the driving signal is supplied to the Tx lines, the first integrated circuit receives charges of the touch sensors formed in a first area of the touch screen through the Rx lines of the first group, samples voltages of the touch sensors in the first area, converts the sampled voltages of the touch sensors in the first area into a first digital data, and generates a first touch raw data, and

wherein each time the driving signal is supplied to the Tx lines in response to the synchronization signal from the first integrated circuit, the second integrated circuit receives charges of the touch sensors formed in a second area of the touch screen through the Rx lines of the second group, samples voltages of the touch sensors in the second area, converts the sampled voltages of the touch sensors in the second area into a second digital data, and generates a second touch raw data.

10. The touch screen driver of claim 9, wherein the second touch recognition module is configured to analyze the touch raw data received from the second integrated circuit, estimate coordinates of the second touch input position, and output the second touch coordinate data.

11. The touch screen driver of claim 9, wherein the first integrated circuit receives the second touch raw data output from the second integrated circuit and synchronizes the received second touch raw data with the first touch raw data generated by the first integrated circuit.

12. A display device comprising a touch screen which includes Tx lines, Rx lines and touch sensors formed at crossings of the Tx lines and the Rx lines, the display device comprising:

a plurality of integrated circuits including a first integrated circuit and a second integrated circuit configured to dividedly drive the touch screen,

wherein one of the plurality of integrated circuits, which generates a driving signal to be supplied to the Tx lines, transmits a synchronization signal synchronized with a rising edge of the driving signal to other integrated circuit, wherein the other integrated circuit receiving the synchronization signal receives charges of the touch sensors through the Rx lines in response to the synchronization signal;

a first touch recognition module configured to analyze touch raw data received from the first integrated circuit, estimate coordinates of touch input positions, and output first touch coordinate data;

a second touch recognition module configured to analyze touch raw data received from the second integrated circuit, estimate coordinates of touch input positions, and output second touch coordinate data, wherein the first touch recognition module is embedded in the first integrated circuit and the second touch recognition module is embedded in the second integrated circuit; and

a data synchronization module configured to synchronize the first and second touch coordinate data output respectively from the first and second touch recognition modules, and transmits the synchronized touch coordinate data to a host system.

13. The display device of claim 12, wherein

the first integrated circuit is connected to Tx lines of a first group which are divided from the Tx lines, is connected to Rx lines of a first group which are divided from the Rx lines, supplies the driving signal to the Tx lines of the first group, and at the same time, transmits the synchronization signal to the second integrated circuit, and

wherein the second integrated circuit is connected to Tx lines of a second group which are divided from the Tx lines, is connected to Rx lines of the a second group which are divided from the Rx lines, supplies the driving signal to the Tx lines of the second group, and at the same time, transmits the synchronization signal to the first integrated circuit.

14. The display device of claim 13, wherein each time the driving signal is supplied to the Tx lines of the first group, the first integrated circuit receives charges of the touch sensors formed in a first area of the touch screen through the Rx lines of the first group, samples voltages of the touch sensors in the first area, converts the sampled voltages of the touch sensors in the first area into a first digital data, and generates a first touch raw data, and

wherein each time the driving signal is supplied to the Tx lines of the first group in response to the synchronization signal from the first integrated circuit, the second integrated circuit receives charges of the touch sensors forming in a second area of the touch screen through the Rx lines of the second group, samples voltages of the touch sensors in the second area, converts the sampled voltages of the touch sensors in the second area into a second digital data, and generates a second touch raw data.

15. The display device of claim 14, wherein each time the driving signal is supplied to the Tx lines of the second group in response to the synchronization signal from the second integrated circuit, the first integrated circuit receives charges of the touch sensors formed in a third area of the touch screen through the Rx lines of the first group, samples voltages of the touch sensors in the third area, converts the sampled voltages of the touch sensors in the third area into a third digital data, and generates a third touch raw data, and

wherein each time the driving signal is supplied to the Tx lines of the second group, the second integrated circuit receives charges of the touch sensors formed in a fourth area of the touch screen through the Rx lines of the second group, samples voltages of the touch sensors in the fourth area, converts the sampled voltages of the touch sensors in the fourth area into a fourth digital data, and generates a fourth touch raw data.

16. The display device of claim 15, wherein the first integrated circuit receives the second and fourth touch raw data output from the second integrated circuit and synchronizes the received second and fourth touch raw data with the first and third touch raw data generated by the first integrated circuit.