TOUCH SCREEN APPARATUS AND DRIVING METHOD THEREOF

• US 20130057507A1
• Filed: 08/13/2012
• Published: 03/07/2013
• Est. Priority Date: 09/05/2011
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: HEO, Jonggu, SHIN, Myungho, KIM, Kyounghwan, KIM, Younggyu
• Granted Patent: US 8,730,208 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: G06F 2203/04106 Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection
• CPC Class Codes: G06F 3/04164 Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads
• 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 3/0443 using a single layer of sensing electrodes

Abstract

A touch screen apparatus and a driving method thereof are provided. The touch screen drive circuit performs a setup operation for selecting Tx lines to be supplied with the drive signal and Rx lines to receive the voltages of the touch sensors, a sensing operation for supplying a drive signal to the Tx lines and receiving and sampling touch sensor voltages through the Rx lines, an ADC operation for converting the sampled voltages into digital data, a coordinate detection operation for analyzing the digital data by a preset touch detection algorithm and estimating the coordinates of a touch input position, and a data transmission operation for transmitting touch coordinate data comprising the coordinates to an external system. At least two operations among the setup operation, the sensing operation, and the ADC operation are performed in parallel.

Claims

1. A touch screen apparatus comprising:

a touch screen comprising Tx lines, Rx lines crossing the Tx lines, and touch sensors formed between the Tx lines and the Rx lines; and

a touch screen drive circuit that supplies a drive signal to the Tx lines, and samples voltages of the touch sensors received through the Rx lines and converts the sampled voltages into digital data,

wherein the touch screen drive circuit performs

a setup operation for selecting Tx lines to be supplied with the drive signal and Rx lines to receive the voltages of the touch sensors,

a sensing operation for supplying a drive signal to the Tx lines and receiving and sampling touch sensor voltages through the Rx lines,

an ADC operation for converting the sampled voltages into digital data,

a coordinate detection operation for analyzing the digital data by a preset touch detection algorithm and estimating the coordinates of a touch input position, and

a data transmission operation for transmitting touch coordinate data comprising the coordinates to an external system, and

the touch screen drive circuit performs at least two operations among the setup operation, the sensing operation, and the ADC operation in parallel.

2. The touch screen apparatus of claim 1, wherein the touch screen drive circuit comprises:

a Tx drive circuit that selects a Tx line in response to a Tx setup signal and supplies the drive signal to the selected Tx line;

an Rx drive circuit that selects an Rx line in response to an Rx setup signal, receives and samples a voltage of a touch sensor through the selected Rx line, and converts the sampled voltage in response to an ADC clock; and

a touch controller that controls operation timings of the Tx drive circuit and the Rx drive circuit and generates one or more of the setup signals and the ADC clock during a sensing time.

3. The touch screen apparatus of claim 2, wherein the touch controller generates setup singles for selecting an (I+1)th touch sensor during the sensing time of an I-th (I is a positive integer).

4. The touch screen apparatus of claim 3, wherein the touch controller transmits an ADC clock to the Rx drive circuit,

the ADC clock being transmitted to convert a voltage of an (I−

1)th touch sensor into digital data during the sensing time of the I-th (I is a positive integer) touch sensor.

5. The touch screen apparatus of claim 1, wherein the touch controller performs the coordinate detection operation and the data transmission operation in parallel.

6. The touch screen apparatus of claim 4, wherein the touch controller performs the coordinate detection operation and the data transmission operation in parallel.

7. The touch screen apparatus of claim 1, wherein, upon receipt of group setup information comprising a plurality of Tx setup information and a plurality of Rx setup information, the touch screen drive circuit performs the sensing operation and the ADC operation in parallel,

the group setup information comprises a plurality of Tx channel information and a plurality of Rx channel information for sensing touch sensors present in 1 line.

8. The touch screen apparatus of claim 7, wherein the touch screen drive circuit receives the group setup information and stores in a buffer memory, performs a setup operation for Tx lines and Rx lines required to sense all touch sensors in a currently sensed group, based on the group setup information read from the buffer memory, until the sensing of all the touch sensors in the group is completed, stores next group setup information received from the touch controller in the buffer memory after completion of the sensing of all the touch sensors in the currently sensed group, and performs a setup operation for Tx lines and Rx lines required to sense touch sensors in the next group based on the next group setup information read from the buffer memory.

9. The touch screen apparatus of claim 1, wherein, upon receipt of group setup information comprising a plurality of Tx setup information and a plurality of Rx setup information, the touch screen drive circuit performs the sensing operation and the ADC operation in parallel,

the group setup information comprising a plurality of Tx channel information and a plurality of Rx channel information for sensing all touch sensors of the touch screen.

10. The touch screen apparatus of claim 9, wherein the touch screen drive circuit receives the group setup information and stores in a buffer memory, performs a setup operation for Tx lines and Rx lines required to sense all touch sensors in a currently sensed group, based on the group setup information read from the buffer memory, until the sensing of all touch sensors of the touch screen is completed, stores next group setup information received from the touch controller in the buffer memory after completion of the sensing of all the touch sensors of the touch screen, and performs a setup operation for Tx lines and Rx lines required to sense all the touch sensors again based on the next group setup information read from the buffer memory.

11. The touch screen apparatus of claim 7, wherein the touch controller performs the coordinate detection operation and the data transmission operation in parallel.

12. The touch screen apparatus of claim 9, wherein the touch controller performs the coordinate detection operation and the data transmission operation in parallel.

13. The touch screen apparatus of claim 1, wherein the touch screen drive circuit virtually divides the touch screen into a plurality of blocks, simultaneously supplies a drive signal to the Tx lines in units of blocks to detect the presence or absence of a touch input in a block sensing process, and sequentially supplies the drive signal to the Tx lines of a block from which the touch input is detected to precisely sense the touch input position in a partial sensing process,

wherein the touch screen drive circuit performs at least two operations among the setup operation, the sensing operation, and the ADC operation in parallel for the block sensing process and the partial sensing process, respectively.

14. The touch screen apparatus of claim 7, wherein the touch screen drive circuit virtually divides the touch screen into a plurality of blocks, simultaneously supplies a drive signal to the Tx lines in units of blocks to detect the presence or absence of a touch input in a block sensing process, and sequentially supplies the drive signal to the Tx lines of a block from which the touch input is detected to precisely sense the touch input position in a partial sensing process.

15. The touch screen apparatus of claim 14, wherein the touch screen drive circuit performs the sensing operation and the ADC operation in parallel for the block sensing process and the partial sensing process, respectively.

16. The touch screen apparatus of claim 9, wherein the touch screen drive circuit virtually divides the touch screen into a plurality of blocks, simultaneously supplies a drive signal to the Tx lines in units of blocks to detect the presence or absence of a touch input in a block sensing process, and sequentially supplies the drive signal to the Tx lines of a block from which the touch input is detected to precisely sense the touch input position in a partial sensing process.

17. The touch screen apparatus of claim 14, wherein the touch screen drive circuit performs the sensing operation and the ADC operation in parallel for the block sensing process and the partial sensing process, respectively.

18. A driving method of a touch screen apparatus, which drives a touch screen comprising Tx lines, Rx lines crossing the Tx lines, and touch sensors formed between the Tx lines and the Rx lines, the method comprising:

executing a setup operation for selecting Tx lines to be supplied with the drive signal and Rx lines to receive the voltages of the touch sensors;

executing a sensing operation for supplying a drive signal to the Tx lines and receiving and sampling touch sensor voltages through the Rx lines;

executing an ADC operation for converting the sampled voltages into digital data;

executing a coordinate detection operation for analyzing the digital data by a preset touch detection algorithm and estimating the coordinates of a touch input position; and

executing a data transmission operation for transmitting touch coordinate data comprising the coordinates to an external system,

wherein at least two operations among the setup operation, the sensing operation, and the ADC operation are performed in parallel.

19. The method of claim 18, further comprising:

generating setup signals for selecting an (I+1)th touch sensor during the sensing time of an I-th (I is a positive integer); and

generating an ADC clock for converting a voltage of an (I−

1)th touch sensor into digital data during the sensing time of the I-th touch sensor.

20. The method of claim 18, wherein the coordinate detection operation and the data transmission operation are performed in parallel.