Multi-sensor touch integrated display driver configuration for capacitive sensing devices

• US 10,067,626 B2
• Filed: 09/15/2017
• Issued: 09/04/2018
• Est. Priority Date: 10/02/2013
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Synaptics Incorporated
• Inventors: Ludden, Christopher A.
• Primary Examiner(s): Danielsen, Nathan
• Application Number:
  US15/706,200
• Publication Number:
  US 20180004327A1
• Time in Patent Office: 354 Days
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• 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 2330/06 Handling electromagnetic interferences [EMI], covering emitted as well as received electromagnetic radiation
• 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 5/00 Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators image data processing or generation, in general G06T

Abstract

Embodiments of the disclosure generally provide an integrated control system having an integrated controller that is configured to provide both display updating signals to a display device and a capacitive sensing signal to a sensor electrode that is disposed within the integrated input device. The internal and/or external signal routing configurations described herein can be adapted to reduce signal routing complexity typically found in conventional devices and reduce the effect of electrical interference created by the capacitive coupling formed between the display routing, capacitive sensing routing and/or other components within the integrated control system. Embodiments can also be used to reduce electromagnetic interference (EMI) on the display and touch sensing signals received, transmitted and processed within the integrated control system.

Claims

1. A controller comprising:

display circuitry coupled to a first subset of a plurality of output pads, the first subset of output pads is configured to transfer display update signals to display electrodes of a display device during a first time period;

capacitive sensing circuitry coupled to a second subset of the plurality of output pads, the second subset of output pads is configured to transfer capacitive sensing signals to sensor electrodes of a sensing device during a second time period; and

guarding circuitry configured to operate at least a portion of the display circuitry during the second time period to reduce effects of capacitance between elements within the controller.

2. The controller of claim 1, wherein the guarding circuitry is further configured to operate at least a portion of the capacitive sensing circuitry during the second time period.

3. The controller of claim 1, wherein operating the at least a portion of the display circuitry during the second time period comprises:

driving a guarding signal onto the at least a portion of the display circuitry, and wherein the guarding signal and the capacitive sensing signals are similar in at least one of phase and amplitude.

4. The controller of claim 1, wherein operating the at least a portion of the display circuitry during the second time comprises:

driving a shield signal on the at least a portion of the display circuitry, and wherein the shield signal is a substantially constant voltage signal.

5. The controller of claim 1, wherein operating the at least a portion of the display circuit during the second time comprises:

electrically floating the at least a portion of the display circuit.

6. The controller of claim 1, wherein the guarding circuitry is further configured to drive one or more the display electrodes with a guarding signal during the second time period, and wherein the guarding signal and the capacitive sensing signals are similar in at least one of phase and amplitude.

7. The controller of claim 1, wherein the guarding circuitry is further configured to electrically float one or more of the display electrodes during the second time period.

8. The controller of claim 1, wherein the first time period and the second time period are non-overlapping.

9. The controller of claim 1, wherein the first time period and the second time period at least partially overlap.

10. The controller of claim 1, wherein the guarding circuitry is further configured to deliver a guarding signal to a diffusion region of the controller, wherein a first sensor electrode trace is disposed on the diffusion region, and wherein the guarding signal and the capacitive sensing signals are similar in at least one of phase and amplitude.

11. The controller of claim 1, wherein the first subset of output pads is source driver output pads, and wherein the second subset of output pads is capacitive sensing pads.

12. The controller of claim 1, wherein one or more of the second subset of output pads is disposed between two of the first subset of output pads.

13. The controller of claim 1, wherein the first subset of output pads is selectively coupled to the display electrodes, and wherein the second subset of output pads is selectively coupled to the sensor electrodes.

14. The controller of claim 1, wherein the guarding circuitry comprises at least one signal generator.

15. An input device comprising:

a display device having a plurality of display electrodes;

a sensing device having a plurality of sensor electrodes; and

a controller coupled to the plurality of sensor electrodes and the plurality of display electrodes, wherein the controller comprises;

a plurality of output pads;

display circuitry coupled to a first subset of the plurality of output pads, the first subset of output pads is configured to transfer display update signals to the plurality of display electrodes during a first time period;

capacitive sensing circuitry coupled to a second subset of the plurality of output pads, the second subset of output pads is configured to transfer capacitive sensing signals to the plurality of sensor electrodes during a second time period; and

guarding circuitry configured to operate at least a portion of the display circuitry during the second time period to reduce effects of capacitance between elements within the controller.

16. The input device of claim 15, wherein the guarding circuitry is further configured to operate at least a portion of the capacitive sensing circuitry during the second time period.

17. The input device of claim 15, wherein operating the at least a portion of the display circuitry during the second time period comprises:

driving a guarding signal onto the at least a portion of the display circuitry, and wherein the guarding signal and the capacitive sensing signals are similar in at least one of phase and amplitude.

18. The input device of claim 15, wherein operating the at least a portion of the display circuitry during the second time comprises:

one of driving a shield signal on the at least a portion of the display circuitry and electrically floating the at least a portion of the display circuitry, and wherein the shield signal is a substantially constant voltage signal.

19. The input device of claim 15, wherein the guarding circuitry is further configured to drive one or more of the plurality of display electrodes with a guarding signal during the second time period, and wherein the guarding signal and the capacitive sensing signals are similar in at least one of phase and amplitude.

20. The input device of claim 15, wherein the first time period and the second time period are non-overlapping.