Driver integrated circuit of touch panel and associated driving method

• US 10,437,365 B2
• Filed: 10/11/2017
• Issued: 10/08/2019
• Est. Priority Date: 10/11/2017
• Status: Active Grant

• Current Assignee: PixArt Imaging Incorporated
• Original Assignee: PixArt Imaging Incorporated
• Inventors: Liao, Chi-Chieh, Hsu, Che-Chia, Chen, Yu-Han
• Primary Examiner(s): Rayan, Mihir K
• Application Number:
  US15/730,698
• Publication Number:
  US 20190107907A1
• Time in Patent Office: 727 Days
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• 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: H03M 1/12 Analogue/digital converters H03M1/001 – H03M1/10 take precedence

Abstract

A driver integrated circuit (IC) includes: a built-in capacitor, a reading circuit, an analog-to-digital converter (ADC) and a coupling circuit, wherein the reading circuit receives a sensing signal from a touch panel and outputs an analog sensing data; the ADC is coupled to the reading circuit, and is used to receive and convert the analog sensing data to a digital sensing data; and the coupling circuit is coupled to the reading circuit, and is used to selectively couple the built-in capacitor to the touch panel when the driver IC operates in a touch sensing mode.

Claims

1. A driver integrated circuit (IC), comprising:

a built-in capacitor installed within the driver IC to be externally connected to a touch panel;

a reading circuit, arranged to receive a sensing signal from the touch panel and output an analog sensing data;

an Analog-to-Digital converter (ADC), coupled to the reading circuit, wherein the ADC is arranged to receive and convert the analog sensing data to a digital sensing data; and

a coupling circuit, coupled to the reading circuit, wherein the coupling circuit is arranged to selectively couple the built-in capacitor to a plurality of sensing electrodes of the touch panel via a plurality of sensing pins outside the driver IC when the driver IC operates in a touch sensing mode;

wherein the coupling circuit comprises;

a control circuit, arranged to receive the sensing signal from at least one of a plurality of sensing electrodes of the touch panel to detect occurrence of a touch event, and is further arranged to compare a number of sensing electrodes sensing the touch event with a predetermined value when the touch event is detected, and generate a control signal; and

a switch, coupled between the reading circuit and the built-in capacitor, wherein the switch couples the built-in capacitor to the touch panel according to the control signal.

2. The driver IC of claim 1, wherein when the built-in capacitor is coupled to the touch panel via the switch of the coupling circuit, and the built-in capacitor and the touch panel are connected in parallel.

3. The driver IC of claim 2, wherein when the number of sensing electrodes sensing the touch event is not greater than the predetermined value, the built-in capacitor is coupled to the touch panel via the coupling circuit;

and when the number of sensing electrodes sensing the touch event is greater than the predetermined value, the built-in capacitor is not coupled to the touch panel via the coupling circuit.

4. The driver IC of claim 1, wherein when the built-in capacitor is coupled to the touch panel via the coupling circuit, the built-in capacitor and the touch panel are connected in series.

5. The driver IC of claim 4, wherein when the number of sensing electrodes sensing the touch event is not greater than the predetermined value, the built-in capacitor is not coupled to the touch panel via the coupling circuit;

and when the number of sensing electrodes sensing the touch event is greater than the predetermined value, the built-in capacitor is coupled to the touch panel via the coupling circuit.

6. The driver IC of claim 1, wherein the reading circuit receives the sensing signal via a sensing pin outside the driver IC.

7. The driver IC of claim 1, wherein the sensing signal is outputted from one of a plurality of sensing electrodes of the touch panel.

8. The driver IC of claim 1, further comprising:

a clock generating circuit, arranged to generate a clock signal; and

a frequency divider, coupled to the clock generating circuit, wherein the frequency divider is arranged to perform a frequency division upon the clock signal to generate a driving signal, and the driving signal is sent to each of a plurality of sensing electrodes of the touch panel, sequentially and repeatedly.

9. The driver IC of claim 1, wherein the touch panel is a touch display panel, the driver IC selectively operates in a display mode and the touch sensing mode, and when the driver IC operates in the display mode, the driver IC outputs display data to a plurality of sensing electrodes of the touch panel.

10. A driving method of a touch panel, comprising:

receiving a sensing signal from the touch panel;

outputting an analog sensing data;

performing an analog-to-digital conversion upon the analog sensing data to convert the analog sensing data to a digital sensing data; and

selectively coupling a built-in capacitor to a plurality of sensing electrodes of the touch panel via a plurality of sensing pins outside a driver IC when operating in a touch sensing mode, the built-in capacitor being installed within the driver IC to be externally connected to the touch panel;

wherein selectively coupling the built-in capacitor to the touch panel when operating in the touch sensing mode comprises;

receiving the sensing signal from at least one of a plurality of sensing electrodes of the touch panel to detect occurrence of a touch event;

when the touch event is detected, comparing a number of sensing electrodes sensing the touch event with a predetermined value, and generating a control signal; and

coupling the built-in capacitor to the touch panel according to the control signal.

11. The driving method of claim 10, further comprising:

coupling the built-in capacitor to the touch panel in parallel.

12. The driving method of claim 11, wherein when the number of sensing electrodes sensing the touch event is not greater than the predetermined value, the built-in capacitor is coupled to the touch panel according to the control signal;

and when the number of sensing electrodes sensing the touch event is greater than the predetermined value, the built-in capacitor is not coupled to the touch panel according to the control signal.

13. The driving method of claim 10, further comprising:

coupling the built-in capacitor to the touch panel in series.

14. The driving method of claim 13, wherein when the number of sensing electrodes sensing the touch event is not greater than the predetermined value, the built-in capacitor is not coupled to the touch panel according to the control signal;

and when the number of sensing electrodes sensing the touch event is greater than the predetermined value, the built-in capacitor is coupled to the touch panel according to the control signal.

15. The driving method of claim 10, further comprising:

generating a clock signal;

performing a frequency division upon the clock signal to generate a driving signal; and

sending the driving signal to each of a plurality of sensing electrodes of the touch panel, sequentially and repeatedly.

16. The driving method of claim 10, wherein the sensing signal is outputted from each of the plurality of sensing electrodes of the touch panel.

17. The driving method of claim 10, wherein the touch panel is a touch display panel, and the driving method further comprises:

selectively operating in a display mode and the touch sensing mode; and

when operating in the display mode, outputting a display data to the plurality of sensing electrodes.

18. A touch-controlled system, comprising:

a touch panel; and

a driver integrated circuit (IC), coupled to the touch panel, comprising;

a built-in capacitor installed within the driver IC externally connected to the touch panel;

a reading circuit, arranged to receive a sensing signal from the touch panel and output an analog sensing data;

an Analog-to-Digital converter (ADC), coupled to the reading circuit, wherein the ADC is arranged to receive and convert the analog sensing data to a digital sensing data; and

a coupling circuit, coupled to the reading circuit, wherein the coupling circuit is arranged to selectively couple the built-in capacitor to a plurality of sensing electrodes of the touch panel via a plurality of sensing pins outside the driver IC when the driver IC operates in a touch sensing mode;

wherein the coupling circuit comprises;

a control circuit, arranged to receive the sensing signal from at least one of a plurality of sensing electrodes of the touch panel to detect occurrence of a touch event, and is further arranged to compare a number of sensing electrodes sensing the touch event with a predetermined value when the touch event is detected, and generate a control signal; and

a switch, coupled between the reading circuit and the built-in capacitor, wherein the switch couples the built-in capacitor to the touch panel according to the control signal.