TOUCH DISPLAY DEVICE

• US 20160170522A1
• Filed: 06/01/2015
• Published: 06/16/2016
• Est. Priority Date: 12/16/2014
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Slobodin, David Elliott, Westhues, Jonathan
• Granted Patent: US 9,851,854 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• 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 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: G09G 3/3291 in which the data driver supplies a variable data voltage for setting the current through, or the voltage across, the light-emitting elements
• CPC Class Codes: H10K 59/40 OLEDs integrated with touch screens

Abstract

A touch display device includes a display panel, a plurality of receive electrodes, an enable electrode driver, and a touch sense circuit. The display panel includes a plurality of data electrodes and a plurality of enable electrodes connected to a plurality of display cells. Each display cell is connected to a pair of an enable electrode and a data electrode. The enable electrode driver drives a first enable electrode with a display voltage to activate display cells coupled to the first enable electrode, and drives a second enable electrode different than the first enable electrode with a transmit voltage to produce a capacitive coupling between the second enable electrode and a receive electrode. The touch sense circuit is configured to recognize a touch input to the touch display device based on a change in capacitance between the second enable electrode and the receive electrode.

Claims

1. A device comprising:

a display panel including (1) a plurality of display cells each including a display element, (2) a plurality of data electrodes connected to the plurality of display cells, and (3) a plurality of enable electrodes connected to the plurality of display cells, where each display cell is connected to a different pair of an enable electrode of the plurality of enable electrodes and a data electrode of the plurality of data electrodes;

a plurality of receive electrodes coupled to the display panel;

an enable electrode driver configured to (1) drive a first enable electrode with a display voltage to activate display cells coupled to the first enable electrode, and (2) drive a second enable electrode different than the first enable electrode with a transmit voltage that does not activate the display cells coupled to the second enable electrode and produces a capacitive coupling between the second enable electrode and one or more of the plurality of receive electrodes; and

a touch sense circuit configured to recognize a touch input to the touch display device based on a change in capacitance between the second enable electrode and one or more of the plurality of receive electrodes.

2. The device of claim 1, where the second enable electrode is being driven with the transmit voltage while the first enable electrode is being driven with the display voltage.

3. The device of claim 1, where the display voltage is biased in a first polarity and the transmit voltage is biased in a second polarity that opposes the first polarity.

4. The device of claim 1, where the enable electrode driver is configured to, while the first enable electrode is being driven with the display voltage, drive a subset of two or more enable electrodes of the plurality of enable electrodes with the transmit voltage to produce a capacitive coupling between the subset of two or more enable electrodes and the one or more of the plurality of receive electrodes;

and

where the touch sense circuit is configured to recognize a touch input to the touch display device based on a change in capacitance between the subset of two or more enable electrodes and the one or more of the plurality of receive electrodes.

5. The device of claim 4, where the subset of two or more enable electrodes is a first subset, and where the enable electrode driver is configured to, while the first subset of two or more enable electrodes is being driven with the transmit voltage and while the first enable electrode is being driven with the display voltage, hold a second subset of enable electrodes that does not include the first enable electrode at a relative ground.

6. The device of claim 4, where the plurality of enable electrodes include enable electrodes that are overlapped by the plurality of receive electrodes to a first degree and enable electrodes that are overlapped by the plurality of receive electrodes to less than the first degree, and where one or more of the enable electrodes that are overlapped by the plurality of receive electrodes to less than the first degree are included in the subset and the enable electrodes that are overlapped by the plurality of receive electrodes to the first degree are not included in the subset.

7. The device of claim 4, where the two or more enable electrodes of the subset neighbor each other and/or neighbor the first enable electrode.

8. The device of claim 1, where the display elements in each of the plurality of display cells are organic light emitting diodes (OLEDs).

9. The device of claim 1, further comprising:

a data driver configured, to while the first enable electrode is being driven with the display voltage, drive each of the plurality of data electrodes with an individual brightness voltage to adjust an individual brightness level of the display element of the display cell connected to the first enable electrode and the corresponding data electrode.

10. The device of claim 1, where the transmit voltage is at least four times an unsigned magnitude of the display voltage.

11. A method for controlling a touch display device including a display panel including (1) a plurality of display cells each including a display element, (2) a plurality of data electrodes connected to the plurality of display cells, and (3) a plurality of enable electrodes connected to the plurality of display cells, where each display cell is connected to a different pair of an enable electrode and a data electrode, and a plurality of receive electrodes coupled to the display panel, the method comprising:

driving a first enable electrode with a display voltage biased in a first polarity to activate display cells coupled to the first enable electrode;

while the first enable electrode is being driven with the display voltage, driving a second enable electrode different than the first enable electrode with a transmit voltage biased in a second polarity opposing the first polarity to produce a capacitive coupling between the second enable electrode and one or more of the plurality of receive electrodes; and

recognizing a touch input to the touch display device based on a change in capacitance between the second enable electrode and the one or more of the plurality of receive electrodes.

12. The method of claim 11, further comprising:

while the first enable electrode is being driven with the display voltage, driving a subset of two or more enable electrodes of the plurality of enable electrodes with the transmit voltage to produce a capacitive coupling between the subset of two or more enable electrodes and the one or more of the plurality of receive electrodes; and

recognizing a touch input to the touch display device based on a change in capacitance between the subset of two or more enable electrodes and the one or more of the plurality of receive electrodes.

13. The method of claim 12, where the subset of two or more enable electrodes is a first subset, and where the method further comprises, while the first subset of two or more enable electrodes is being driven with the transmit voltage and while the first enable electrode is being driven with the display voltage, holding a second subset of enable electrodes that does not include the first enable electrode at a relative ground.

14. The method of claim 12, where the plurality of enable electrodes include enable electrodes that are overlapped by the plurality of receive electrodes to a first degree and enable electrodes that are overlapped by the plurality of receive electrodes to less than the first degree, and where one or more of the enable electrodes that are overlapped by the plurality of receive electrodes to less than the first degree are included in the subset and the enable electrodes that are overlapped by the plurality of receive electrodes to the first degree are not included in the subset.

15. The method of claim 11, further comprising:

while the first enable electrode is being driven with the display voltage, driving each of the plurality of data electrodes with an individual brightness voltage to adjust an individual brightness level of the display element of the display cell connected to the first enable electrode and the corresponding data electrode.

16. The method of claim 11, where the display element in each of the plurality of display cells is an organic light emitting diode (OLED).

17. The method of claim 11, where the capacitive coupling produces a baseline current induced by the one or more receive electrodes and the change in capacitive coupling includes a change in currant induced by the one or more receive electrodes that is greater than a current threshold from the baseline current.

18. The method of claim 11, where the transmit voltage is at least four times an unsigned magnitude of the display voltage.

19. A touch display device comprising:

an organic light emitting diode (OLED) display panel including (1) a plurality of display cells each including an OLED, (2) a plurality of data electrodes connected to the plurality of display cells, and (3) a plurality of enable electrodes connected to the plurality of display cells, where each display cell is connected to a different pair of an enable electrode of the plurality of enable electrodes and a data electrode of the plurality of data electrodes;

a plurality of receive electrodes coupled to the OLED display panel;

an enable driver configured to (1) drive a first enable electrode with a display voltage biased in a first polarity to activate display cells coupled to the first enable electrode, and (2) while the first enable electrode is being driven with the display voltage, drive a subset of two or more enable electrodes of the plurality of enable electrodes with a transmit voltage biased in a second polarity opposing the first polarity to produce a capacitive coupling between the subset of two or more enable electrodes and one or more of the plurality of receive electrodes;

a display driver configured to, while the first enable electrode is being driven with the display voltage, drive each of the plurality of data electrodes with an individual brightness voltage to adjust an individual brightness level of the OLED of the display cell connected to the first enable electrode and the corresponding data electrode; and

a touch sense circuit configured to recognize a touch input to the touch display device based on a change in capacitance between the subset of two or more enable electrodes and the one or more of the plurality of receive electrodes.

20. The touch display device of claim 19, where the plurality of enable electrodes include enable electrodes that are overlapped by the plurality of receive electrodes to a first degree and enable electrodes that are overlapped by the plurality of receive electrodes to less than the first degree, and where one or more of the enable electrodes that are overlapped by receive electrodes to less than the first degree are included in the subset and the enable electrodes that are overlapped by the plurality of receive electrodes to the first degree are not included in the subset.