Display device with touch sensor, potential control method, and program

• US 9,639,191 B2
• Filed: 10/26/2012
• Issued: 05/02/2017
• Est. Priority Date: 11/07/2011
• Status: Active Grant

• Current Assignee: Japan Display Incorporated
• Original Assignee: Japan Display Incorporated
• Inventors: Takeuchi, Takeya, Mizuhashi, Hiroshi, Katsuta, Tadayoshi, Shima, Takehiro
• Primary Examiner(s): Nguyen, Chanh
• Assistant Examiner(s): Shen, Yuzhen
• Application Number:
  US13/661,580
• Publication Number:
  US 20130113735A1
• Time in Patent Office: 1,649 Days
• Field of Search: 345173
• CPC Class Codes: G02F 1/133302 Rigid substrates, e.g. inorganic substrates
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/133528 Polarisers
• CPC Class Codes: G02F 1/136286 Wiring, e.g. gate line, drain line
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G02F 2201/121 common or background
• CPC Class Codes: G02F 2201/123 pixel
• CPC Class Codes: G06F 2203/04101 2.5D-digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface and also measures the distance of the input means within a short range in the Z direction, possibly with a separate measurement setup
• 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 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 3/04184 Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally
• 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

Abstract

Disclosed herein is a display device with a touch sensor, including: a plurality of display pixel electrodes; a common electrode configured to be provided opposed to the display pixel electrodes; a display function layer configured to have an image display function; a display control circuit configured to apply a display voltage between the display pixel electrodes and the common electrode based on an image signal and carry out image display control so that the display function of the display function layer be exerted; and a touch detection electrode configured to be provided opposed to the common electrode and form capacitance between the touch detection electrode and the common electrode.

Claims

1. A display device with a touch sensor, comprising:

a plurality of display pixel electrodes;

a common electrode configured to be provided opposed to the display pixel electrodes;

a display function layer configured to have an image display function;

a display control circuit configured to apply a display voltage between the display pixel electrodes and the common electrode based on an image signal and carry out image display control so that the display function of the display function layer be exerted; and

a touch detection electrode configured to be provided opposed to the common electrode and form capacitance between the touch detection electrode and the common electrode,

wherein a display drive voltage having a fixed voltage amplitude, applied to the common electrode by the display control circuit is utilized as a touch sensor drive signal,

wherein a predetermined voltage is applied through a gate buffer to a gate of a thin-film transistor circuit connected to the display pixel electrode,

wherein during application of the touch sensor drive signal, a potential of the gate is set to a floating state in which the gate and the gate buffer are in an electrically open state,

wherein the gate buffer includes a switch that is configured to set the potential of the gate in the floating state,

wherein the gate is set to an ON state when a first gate voltage is applied to the gate through the gate buffer,

wherein the gate is set to an OFF state when a second gate voltage is applied to the gate through the gate buffer,

during the application of the touch sensor drive signal the gate is set to the floating state, when the switch is opened and the gate is electrically disconnected from the gate buffer,

wherein the switch is arranged between the gate buffer and a second wiring which supplies the second voltage to the gate buffer, and

wherein the gate buffer is connected to a first wiring which supplies the first voltage to the gate buffer.

2. The display device with a touch sensor according to claim 1, wherein the potential of the gate is set to the floating state during a vertical blanking period and a horizontal blanking period.

3. The display device with a touch sensor according to claim 1, wherein the potential of the gate is set to the floating state so as to become a potential subjected to coupling by the touch sensor drive signal.

4. A potential control method of a display device with a touch sensor, the display device including

a plurality of display pixel electrodes,

a common electrode provided opposed to the display pixel electrodes,

a display function layer having an image display function,

a display control circuit that applies a display voltage between the display pixel electrodes and the common electrode based on an image signal and carries out image display control so that the display function of the display function layer be exerted, and

a touch detection electrode that is provided opposed to or in juxtaposition with the common electrode and forms capacitance between the touch detection electrode and the common electrode,

the potential control method comprising:

utilizing a display drive voltage having a fixed voltage amplitude, applied to the common electrode by the display control circuit as a touch sensor drive signal; and

applying a predetermined voltage through a gate buffer to a gate of a thin-film transistor circuit connected to the display pixel electrode, and

during application of the touch sensor drive signal, setting a potential of the gate to a floating state in which the gate and the gate buffer are in an electrically open state,

wherein the gate buffer includes a switch that is configured to set the potential of the gate in the floating state,

wherein the gate is set to an ON state when a first gate voltage is applied to the gate through the gate buffer,

wherein the gate is set to an OFF state when a second gate voltage is applied to the gate through the gate buffer,

during the application of the touch sensor drive signal the gate is set to the floating state, when the switch is opened and the gate is electrically disconnected from the gate buffer,

wherein the switch is arranged between the gate buffer and a second wiring which supplies the second voltage to the gate buffer, and

wherein the gate buffer is connected to a first wiring which supplies the first voltage to the gate buffer.

5. A non-transitory computer readable storage medium comprising instructions for causing a computer that controls a display device with a touch sensor to execute processing, the display device including

a plurality of display pixel electrodes,

a common electrode provided opposed to the display pixel electrodes,

a display function layer having an image display function,

a display control circuit that applies a display voltage between the display pixel electrodes and the common electrode based on an image signal and carries out image display control so that the display function of the display function layer be exerted, and

a touch detection electrode that is provided opposed to the common electrode and forms capacitance between the touch detection electrode and the common electrode,

the processing being executed for carrying out a process comprising:

utilizing a display drive voltage having a fixed voltage amplitude, applied to the common electrode by the display control circuit as a touch sensor drive signal;

applying a predetermined voltage through a gate buffer to a gate of a thin-film transistor circuit connected to the display pixel electrode; and

during application of the touch sensor drive signal, setting a potential of the gate to a floating state in which the gate and the gate buffer are in an electrically open state,

wherein the gate buffer includes a switch that is configured to set the potential of the gate in the floating state,

wherein the gate is set to an ON state when a first gate voltage is applied to the gate through the gate buffer,

wherein the gate is set to an OFF state when a second gate voltage is applied to the gate through the gate buffer,

during the application of the touch sensor drive signal the gate is set to the floating state, when the switch is opened and the gate is electrically disconnected from the gate buffer,

wherein the switch is arranged between the gate buffer and a second wiring which supplies the second voltage to the gate buffer, and

wherein the gate buffer is connected to a first wiring which supplies the first voltage to the gate buffer.