Touch sensor, display device, and electronic apparatus

• US 9,874,976 B2
• Filed: 05/09/2017
• Issued: 01/23/2018
• Est. Priority Date: 05/26/2009
• Status: Active Grant

• Current Assignee: Japan Display Incorporated
• Original Assignee: Japan Display Incorporated
• Inventors: Takeuchi, Takeya, Noguchi, Koji, Ishizaki, Koji, Nakanishi, Takayuki, Teranishi, Yasuyuki
• Primary Examiner(s): Awad, Amr
• Assistant Examiner(s): Midkiff, Aaron
• Application Number:
  US15/590,384
• Publication Number:
  US 20170242546A1
• Time in Patent Office: 259 Days
• Field of Search: 178 1806, 345173, 345174
• CPC Class Codes: G06F 1/1643 the display being associated to a digitizer, e.g. laptops that can be used as penpads details related to the relative motion of the display enclosure with respect to the body enclosure, e.g. to move between laptop and tablet PC configuration G06F1/1615
• 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 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• 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

A touch sensor includes a sensor electrode having an electrostatic capacitance for touch detection, and a touch detection circuit detecting a contact or proximity position of an object on the basis of a detection signal obtained from the sensor electrode by applying a touch sensor drive signal to the sensor electrode. The sensor electrode is split into plural stripe-like electrode patterns. Applying the touch sensor drive signal to part of the electrode patterns forms a drive line at that time. The touch detection circuit performs a detection on the basis of a first detection signal obtained from a first drive line formed in a first period, and a second detection signal obtained from a second drive line formed in a second period.

Claims

1. A touch sensor comprising:

a sensor electrode having an electrostatic capacitance for touch detection;

a touch detection circuit that performs a detection of a contact or proximity position of an object, on the basis of a detection signal obtained from the sensor electrode by applying a touch sensor drive signal to the sensor electrode,

wherein the sensor electrode is split into a plurality of electrode patterns,

the touch sensor drive signal is applied to part of the plurality of electrode patterns,

the touch detection circuit performs the detection on the basis of

a first detection signal obtained from the sensor electrode that is coupled with the touch sensor drive signal in a first period, and

a second detection signal obtained from the sensor electrode that is coupled with a display drive signal in a second period different from the first period, and

the touch detection circuit performs the detection on the basis of a differential signal between the first detection signal and the second detection signal.

2. The touch sensor according to claim 1, wherein the first period and the second period are set alternately at a time ratio of 1 to 1.

3. The touch sensor according to claim 1, wherein:

the first period and the second period are set alternately at a time ratio of n (n;

an integer not smaller than

     2) to 1.

4. The touch sensor according to claim 1, wherein:

detection modes can be switched between a first detection mode and a second detection mode;

the first detection mode is a mode in which the first period and the second period are set alternately at a time ratio of 1 to 1; and

the second detection mode is a mode in which the first period and the second period are set alternately at a time ratio of n (n;

an integer not smaller than

     2) to 1.

5. The touch sensor according to claim 1, wherein:

the first period and the second period are set alternately in a time division manner.

6. A display device comprising:

a plurality of display pixel electrodes;

a display function layer having an image display function;

a display control circuit that controls image display on the basis of an image signal so as to apply a display drive voltage to the display pixel electrodes and to cause the display function layer to perform the image display function, on the basis of the image signal;

a sensor electrode having an electrostatic capacitance for touch detection; and

a touch detection circuit that performs a detection of a contact or proximity position of an object, on the basis of a detection signal obtained from the sensor electrode, by using the display drive voltage applied by the display control circuit as a touch sensor drive signal applied to the sensor electrode,

wherein the sensor electrode is split into a plurality of electrode patterns,

the touch sensor drive signal is applied to part of the plurality of electrode patterns,

the touch detection circuit performs the detection on the basis of

a first detection signal obtained from the sensor electrode that is coupled with the touch sensor drive signal in a first period, and

a second detection signal obtained from the sensor electrode that is coupled with the display drive voltage in a second period different from the first period, and

the touch detection circuit performs the detection on the basis of a differential signal between the first detection signal and the second detection signal.

7. The display device according to claim 6, further comprising:

a circuit board on which the display control circuit is formed; and

a counter substrate disposed in opposition to the circuit board,

wherein the display pixel electrodes are disposed on a side of the circuit board close to the counter substrate, and

the display function layer is inserted between the display pixel electrodes on the circuit board.

8. The display device according to claim 7, wherein the display function layer is a liquid crystal layer.

9. The display device according to claim 6, further comprising:

a circuit board on which the display control circuit is formed; and

a counter substrate disposed in opposition to the circuit board,

wherein the display pixel electrodes are laminated on the circuit board via an insulating layer, and

the display function layer is inserted between the display pixel electrodes on the circuit board, and the counter substrate.

10. The display device according to claim 9, wherein the display function layer is a liquid crystal layer, and performs liquid crystal display in a transverse electric field mode.

11. An electronic apparatus comprising a display device with a touch sensor, the display device including:

a plurality of display pixel electrodes;

a display function layer having an image display function;

a display control circuit that controls image display on the basis of an image signal so as to apply a display drive voltage to the display pixel electrodes to cause the display function layer to exert the image display function, on the basis of the image signal;

a sensor electrode having an electrostatic capacitance for touch detection; and

a touch detection circuit that performs a detection of a contact or proximity position of an object, on the basis of a detection signal obtained from the sensor electrode, by using the display drive voltage applied by the display control circuit as a touch sensor drive signal applied to the sensor electrode,

wherein the sensor electrode is split into a plurality of electrode patterns,

the touch sensor drive signal is applied to part of the plurality of electrode patterns,

the touch detection circuit performs the detection on the basis of

a first detection signal obtained from the sensor electrode that is coupled with the touch sensor drive signal in a first period, and

a second detection signal obtained from the sensor electrode that is coupled with the display drive voltage in a second period different from the first period, and

the touch detection circuit performs the detection on the basis of a differential signal between the first detection signal and the second detection signal.

12. The electronic apparatus according to claim 11, wherein:

the first period and the second period are set alternately in a time division manner.