Touch sensing system and method of driving the same

• US 10,496,205 B2
• Filed: 11/28/2017
• Issued: 12/03/2019
• Est. Priority Date: 12/28/2016
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Jung, Doyoung, Jang, Hyunwoo, Jang, Hyunguk, Bae, Sanghyuck, Ju, Suyun
• Primary Examiner(s): Eurice, Michael J
• Application Number:
  US15/824,928
• Publication Number:
  US 20180181241A1
• Time in Patent Office: 735 Days
• CPC Class Codes: G06F 2203/04104 Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger
• CPC Class Codes: G06F 2203/04808 Several contacts: gestures triggering a specific function, e.g. scrolling, zooming, right-click, when the user establishes several contacts with the surface simultaneously; e.g. using several fingers or a combination of fingers and pen
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04162 for exchanging data with external devices, e.g. smart pens, via the digitiser sensing hardware
• CPC Class Codes: G06F 3/04164 Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads
• CPC Class Codes: G06F 3/041661 using detection at multiple resolutions, e.g. coarse and fine scanning; using detection within a limited area, e.g. object tracking window
• CPC Class Codes: G06F 3/04184 Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally
• CPC Class Codes: G06F 3/0441 using active external devices, e.g. active pens, for receiving changes in electrical potential transmitted by the digitiser, e.g. tablet driving signals
• CPC Class Codes: G06F 3/0442 using active external devices, e.g. active pens, for transmitting changes in electrical potential to be received by the digitiser
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G06F 3/0488 using a touch-screen or digitiser, e.g. input of commands through traced gestures
• CPC Class Codes: G09G 3/2022 using sub-frames

Abstract

A touch sensing system and a method of driving the same are disclosed. The touch sensing system includes a touch screen integrated display panel provided with a plurality of touch sensors and a plurality of pixels, a timing controller time-dividing one display frame into a plurality of touch periods and a plurality of display periods, a microcontroller unit dividing a sensing mode of the plurality of touch sensors into a full scan mode and a local scan mode, and a touch integrated circuit (IC) sensing a finger touch input of the touch sensors through the touch periods in the full scan mode and time-division sensing a finger touch input and a pen touch input of the touch sensors through the touch periods in the local scan mode.

Claims

1. A touch sensing system comprising:

a touch screen integrated display panel provided with a plurality of touch sensors and a plurality of pixels;

a timing controller configured to time-divide one display frame into a plurality of touch periods and a plurality of display periods;

a microcontroller unit configured to divide a sensing mode of the plurality of touch sensors into a full scan mode and a local scan mode; and

a touch integrated circuit (IC) configured to sense a finger touch input of the touch sensors through the touch periods in the full scan mode and time-division sense a finger touch input and a pen touch input of the touch sensors through the touch periods in the local scan mode,

wherein the microcontroller unit generates pulse width modulation (PWM) signals respectively corresponding to a first sync signal, a second sync signal, and a touch driving signal,

wherein the first sync signal is allocated to a first touch period of the plurality of touch periods,

wherein the second sync signal is allocated to a first portion of a second touch period of the plurality of touch periods, and

wherein the touch drive signal is allocated to a second portion of the second touch period of the plurality of touch periods.

2. The touch sensing system of claim 1, wherein a magnitude of a finger touch sensing signal resulting from the finger touch input and a magnitude of a pen touch sensing signal resulting from the pen touch input appear in opposite directions based on a predetermined reference value.

3. The touch sensing system of claim 2, wherein the microcontroller unit:

switches the sensing mode of the touch sensors from the full scan mode to the local scan mode when the pen touch sensing signal is sensed during the full scan mode; and

switches the sensing mode of the touch sensors from the local scan mode to the full scan mode when the pen touch sensing signal is not sensed during the local scan mode.

4. The touch sensing system of claim 3, wherein in the full scan mode, the touch IC divides the finger touch input of the touch sensors into a plurality of areas and senses the finger touch input,

wherein the plurality of areas corresponds to the touch periods.

5. The touch sensing system of claim 3, wherein in the local scan mode, the touch IC senses only the pen touch input of some of the plurality of touch sensors including a position of the pen touch input.

6. The touch sensing system of claim 5, wherein the pen touch sensing signal includes:

pen position information indicating a contact position of the touch sensors contacting a pen; and

pen additional information indicating an additional function of the pen,

wherein the pen additional information includes pen pressure information when the pen contacts the touch sensors, button status information indicating whether or not at least one functional button that is included in the pen and performs a specific function is activated, and pen identification information for distinguishing from other pens.

7. The touch sensing system of claim 6, wherein in the local scan mode, the touch IC senses the pen touch input through touch periods for the pen position information and touch periods for the pen additional information among the plurality of touch periods.

8. The touch sensing system of claim 7, wherein in the local scan mode, the touch IC divides the finger touch input of the touch sensors into a plurality of areas and senses the finger touch input through touch periods for finger position information among the plurality of touch periods,

wherein the plurality of areas corresponds to the touch periods for the finger position information.

9. A method of driving a touch sensing system including a touch screen integrated display panel provided with a plurality of touch sensors and a plurality of pixels, the method comprising:

time-dividing one display frame into a plurality of touch periods and a plurality of display periods;

dividing a sensing mode of the plurality of touch sensors into a full scan mode and a local scan mode;

sensing a finger touch input of the touch sensors through the touch periods in the full scan mode and time-division sensing a finger touch input and a pen touch input of the touch sensors through the touch periods in the local scan mode, and

generating pulse width modulation (PWM) signals respectively corresponding to a first sync signal, a second sync signal, and a touch driving signal,

wherein the first sync signal is allocated to a first touch period of the plurality of touch periods,

wherein the second sync signal is allocated to a first portion of a second touch period of the plurality of touch periods, and

wherein the touch driving signal is allocated to a second portion of the second touch period of the plurality of touch periods.

10. The method of claim 9, wherein a magnitude of a finger touch sensing signal resulting from the finger touch input and a magnitude of a pen touch sensing signal resulting from the pen touch input appear in opposite directions based on a predetermined reference value.

11. The method of claim 10, further comprising:

switching the sensing mode of the touch sensors from the full scan mode to the local scan mode when the pen touch sensing signal is sensed during the full scan mode; and

switching the sensing mode of the touch sensors from the local scan mode to the full scan mode when the pen touch sensing signal is not sensed during the local scan mode.

12. The method of claim 11, wherein in the full scan mode, the finger touch input of the touch sensors is divided into a plurality of areas and is sensed,

wherein the plurality of areas corresponds to the touch periods.

13. The method of claim 11, wherein in the local scan mode, only the pen touch input of some of the plurality of touch sensors including a position of the pen touch input is sensed.

14. The method of claim 13, wherein the pen touch sensing signal includes:

pen position information indicating a contact position of the touch sensors contacting a pen; and

pen additional information indicating an additional function of the pen,

wherein the pen additional information includes pen pressure information when the pen contacts the touch sensors, button status information indicating whether or not at least one functional button that is included in the pen and performs a specific function is activated, and pen identification information for distinguishing from other pens.

15. The method of claim 11, wherein in the local scan mode, the pen touch input is sensed through touch periods for the pen position information and touch periods for the pen additional information among the plurality of touch periods.

16. The method of claim 15, wherein in the local scan mode, the finger touch input of the touch sensors is divided into a plurality of areas, and the finger touch input is sensed through touch periods for finger position information among the plurality of touch periods,

wherein the plurality of areas corresponds to the touch periods for the finger position information.