DRIVING CIRCUIT AND A METHOD FOR DRIVING A DISPLAY PANEL HAVING A TOUCH PANEL

• US 20170052614A1
• Filed: 03/31/2016
• Published: 02/23/2017
• Est. Priority Date: 08/19/2015
• Status: Active Grant

• Current Assignee: Novatek Microelectronics Corporation (Novatek Microelectronics Corp Limited)
• Original Assignee: Novatek Microelectronics Corporation (Novatek Microelectronics Corp Limited)
• Inventors: Cheng, Liang-Chi, Hsiao, Sheng-Wen
• Granted Patent: US 10,809,855 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• 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 3/04186 Touch location disambiguation
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• 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: G09G 2310/0275 Details of drivers for data electrodes, other than drivers for liquid crystal, plasma or OLED displays, not related to handling digital grey scale data or to communication of data to the pixels by means of a current
• CPC Class Codes: G09G 2354/00 Aspects of interface with display user
• CPC Class Codes: G09G 3/20 for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
• CPC Class Codes: G09G 3/3688 suitable for active matrices only

Abstract

A driving circuit configured to drive a display panel having a touch panel is provided. The driving circuit includes a signal generating circuit, a sensor driving circuit, and a source driving circuit. The signal generating circuit modulates a plurality of voltage signals on a first driving signal and a second driving signal, and drives the gate lines with the modulated first driving signal and the modulated second driving signal during a sensing period. The sensor driving circuit modulates the voltage signals on a third driving signal, and drives the sensor pads with the modulated third driving signal during the sensing period. The data lines are controlled to be electrically floating during the sensing period. In addition, a method for driving a display panel having a touch panel is also provided.

Claims

1. A driving circuit configured to drive a display panel having a touch panel, and the driving circuit comprising:

a signal generating circuit, coupled to gate lines of the display panel, modulating a plurality of voltage signals on a first driving signal and a second driving signal, and driving the gate lines with the modulated first driving signal and the modulated second driving signal during a sensing period;

a sensor driving circuit, coupled to sensor pads of the touch panel, modulating the voltage signals on a third driving signal, and driving the sensor pads with the modulated third driving signal during the sensing period; and

a source driving circuit, coupled to data lines of the display panel, wherein the data lines are controlled to be electrically floating during the sensing period.

2. The driving circuit according to claim 1, wherein waveforms of the modulated first driving signal, the modulated second driving signal, and the modulated third driving signal are substantially identical.

3. The driving circuit according to claim 1, wherein the signal generating circuit comprises:

a gate driver circuit, coupled to the gate lines, operating between the modulated first driving signal and the modulated second driving signal during the sensing period, and outputting the modulated first driving signal and the modulated second driving signal to the gate lines; and

a first signal modulation circuit, coupled to the gate driver circuit, receiving the voltage signals, and modulating the voltage signals on the first driving signal and the second driving signal.

4. The driving circuit according to claim 3, wherein the first signal modulation circuit comprises:

a first modulation channel, coupled to the gate driver circuit, receiving the voltage signals, and modulating the voltage signals on the first driving signal; and

a second modulation channel, coupled to the gate driver circuit, receiving the voltage signals, and modulating the voltage signals on the second driving signal.

5. The driving circuit according to claim 4, wherein each of the first modulation channel and the second modulation channel comprises:

a capacitor, coupled to the gate driver circuit, and modulating the voltage signals on the first driving signal or the second driving signal; and

a multiplexer circuit, coupled to the gate driver circuit via the capacitor, and controlled to sequentially transmit the voltage signals to the capacitor by a plurality of first control signals.

6. The driving circuit according to claim 1, wherein the sensor driving circuit comprises:

a second signal modulation circuit, coupled to the sensor pads, receiving the voltage signals, and modulating the voltage signals on the third driving signal.

7. The driving circuit according to claim 6, wherein the second signal modulation circuit comprises:

a plurality of third modulation channels, coupled to the sensor pads, receiving the voltage signals, and modulating the voltage signals on the third driving signal.

8. The driving circuit according to claim 7, wherein the sensor pads are grouped into active sensor pads and non-active sensor pads during the sensing period, and the third modulation channels coupled to the non-active sensor pads are controlled to sequentially transmit the voltage signals to the touch panel by a plurality of first control signals.

9. The driving circuit according to claim 7, wherein the third modulation channels coupled to the active sensor pads are controlled to transmit sensing signals to a determination circuit by the first control signals.

10. The driving circuit according to claim 7, wherein each of the third modulation channels comprises:

a multiplexer circuit, coupled to the display panel, and controlled to sequentially transmit the voltage signals to the display panel or transmit sensing signals to a determination circuit by the first control signals.

11. The driving circuit according to claim 1, wherein the source driving circuit is coupled to the data lines of the display panel via a switch circuit, and the switch circuit is controlled to electrically float the data lines by a second control signal during the sensing period.

12. The driving circuit according to claim 1, wherein the source driving circuit is coupled to the data lines of the display panel via a plurality of multiplexer circuits, and outputs of the multiplexer circuits are controlled to be turned off to electrically float the data lines by the signal generating circuit during the sensing period.

13. A method for driving a display panel having a touch panel, wherein the display panel comprises a plurality of gate lines and a plurality of data lines, the touch panel comprises a plurality of sensor pads, and the method comprising:

modulating a plurality of voltage signals on a first driving signal, a second driving signal, and a third driving signal during a sensing period;

driving the gate lines with the modulated first driving signal and the modulated second driving signal during the sensing period, and driving the sensor pads with the modulated third driving signal during the sensing period; and

controlling the data lines to be electrically floating during the sensing period.

14. The method according to claim 13, wherein waveforms of the modulated first driving signal, the modulated second driving signal, and the modulated third driving signal are substantially identical.

15. The method circuit according to claim 13, wherein the step of modulating the voltage signals on the first driving signal, the second driving signal, and the third driving signal comprises:

sequentially transmitting the voltage signals to a gate driver circuit to modulate the voltage signals on the first driving signal and the second driving signal according to a plurality of first control signals.

16. The method circuit according to claim 13, wherein the sensor pads are grouped into active sensor pads and non-active sensor pads during the sensing period, and the step of modulating the voltage signals on the first driving signal, the second driving signal, and the third driving signal comprises:

sequentially transmitting the voltage signals to the non-active sensor pads to modulate the voltage signals on the third driving signal according to a plurality of first control signals.

17. The method according to claim 16, wherein the step of driving the gate lines of the display panel with the modulated first driving signal and the modulated second driving signal during the sensing period, and driving the sensor pads of the touch panel with the modulated third driving signal during the sensing period comprises:

transmitting sensing signals of the active sensor pads to a determination circuit by the first control signals.

18. The method according to claim 13, wherein the data lines are coupled to a switch circuit, and the step of controlling the data lines to be electrically floating during the sensing period comprises:

controlling the switch circuit to electrically float the data lines according to a second control signal during the sensing period.

19. The method according to claim 13, wherein the data lines are coupled to a plurality of multiplexer circuits, and the step of controlling the data lines to be electrically floating during the sensing period comprises:

controlling outputs of the multiplexer circuits to be turned off to electrically float the data lines during the sensing period.