Touch sensor configured to detect touch pressure and display device including the same

• US 10,296,149 B2
• Filed: 05/31/2017
• Issued: 05/21/2019
• Est. Priority Date: 10/17/2016
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Hong, Won Ki, Baek, Jong In, Sung, Eun Jin
• Primary Examiner(s): Chang, Kent W
• Assistant Examiner(s): Brittingham, Nathaniel P
• Application Number:
  US15/610,383
• Publication Number:
  US 20180107325A1
• Time in Patent Office: 720 Days
• CPC Class Codes: G06F 2203/04107 Shielding in digitiser, i.e. guard or shielding arrangements, mostly for capacitive touchscreens, e.g. driven shields, driven grounds
• CPC Class Codes: G06F 2203/04112 Electrode mesh in capacitive digitiser: electrode for touch sensing is formed of a mesh of very fine, normally metallic, interconnected lines that are almost invisible to see. This provides a quite large but transparent electrode surface, without need for ITO or similar transparent conductive material
• 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 3/0447 Position sensing using the local deformation of sensor cells

Abstract

A display device includes a display panel, a touch sensor, and a conductive layer. The touch sensor is disposed on the display panel, and is configured to detect a pressure of a touch and calculate a position and an intensity of the touch. The conductive layer is disposed on the touch sensor. The touch sensor includes a plurality of first electrodes, a plurality of second electrodes spaced apart from the plurality of first electrodes, and a plurality of elastic members disposed between the plurality of first electrodes and the plurality of second electrodes. The display device is configured to calculate a variation a of capacitance between the plurality of first electrodes and the plurality of second electrodes that is caused by a transformation of the elastic member in response to the pressure of the touch.

Claims

1. A display device, comprising:

a display panel;

a touch sensor disposed on the display panel, and configured to detect a pressure of a touch and calculate a position and an intensity of the touch;

a polarizing plate disposed on the touch sensor;

a window disposed on the polarizing plate;

a first conductive layer disposed between the touch sensor and the polarizing plate; and

a second conductive layer disposed between the polarizing plate and the window, wherein the touch sensor includes;

a plurality of first electrodes;

a plurality of second electrodes spaced apart from the plurality of first electrodes, the plurality of second electrodes corresponding to the plurality of first electrodes so as to form a plurality of electrode pairs including a first electrode of the plurality of first electrodes and a corresponding second electrode of the plurality of second electrodes; and

at least one elastic member disposed between the plurality of first electrodes and the plurality of second electrodes,

wherein the display device is configured to calculate a variation of a capacitance between the plurality of first electrodes and the plurality of second electrodes that is caused by a transformation of the at least one elastic member in response to the pressure of the touch, and

wherein the at least one elastic member comprises a plurality of elastic members, each of which is disposed between the first and second electrodes of each electrode pair of the plurality of electrode pairs.

2. The display device of claim 1, wherein the plurality of second electrodes is disposed between the plurality of first electrodes and the display panel.

3. The display device of claim 1, wherein the plurality of first electrodes and the plurality of second electrodes each include a transparent conductive material.

4. The display device of claim 1, wherein the at least one elastic member includes a transparent insulating material.

5. The display device of claim 1, wherein a ground voltage is applied to the first and second conductive layers.

6. The display device of claim 1, wherein the first and second conductive layers are in a floating state.

7. The display device of claim 1, wherein the first and second conductive layers include a transparent conductive material.

8. The display device of claim 1, wherein a surface resistance of the first and second conductive layers is less than or equal to 1,000Ω

/□

.

9. A touch sensor, comprising:

a plurality of first electrodes;

a plurality of second electrodes spaced apart from the plurality of first electrodes, the plurality of second electrodes corresponding to the plurality of first electrodes so as to form a plurality of electrode pairs including a first electrode of the plurality of first electrodes and a corresponding second electrode of the plurality of second electrodes;

at least one elastic member disposed between the plurality of first electrodes and the plurality of second electrodes, each of the at least one elastic member being configured to deform in response to a pressure of a touch; and

a conductive layer disposed on the plurality of first electrodes, wherein the touch sensor is configured to obtain detection signals corresponding to a variation of capacitance between the plurality of first electrodes and the plurality of second electrodes caused by a deformation of the at least one elastic member, and to calculates a position and an intensity of the touch therefrom,

wherein the conductive layer includes a pattern of openings of a predetermined shape, and

wherein the at least one elastic member comprises a plurality of elastic members, each of which is disposed between the first and second electrodes of each electrode pair of the plurality of electrode pairs.

10. The touch sensor of claim 9, wherein the plurality of first electrodes and the plurality of second electrodes each include a transparent conductive material.

11. The touch sensor of claim 9, wherein the at least one elastic member includes a transparent insulating material.

12. The touch sensor of claim 9, wherein the detection signals are output from the plurality of first electrodes.

13. The touch sensor of claim 9, wherein the conductive layer includes a transparent conductive material.

14. The touch sensor of claim 9, wherein the plurality of first electrodes are disposed between the plurality of second electrodes and the conductive layer.

15. The touch sensor of claim 9, wherein a ground voltage is applied to the conductive layer.

16. The touch sensor of claim 9, wherein the conductive layer is in a floating state.

17. The touch sensor of claim 9, wherein when the touch is applied to the touch sensor by a conductive touch tool, the conductive layer blocks charge from moving from the plurality of second electrodes to the conductive touch tool.

18. A touch-screen display, comprising:

a display panel;

a plurality of first electrodes disposed on the display panel;

at least one elastic member extending over the plurality of first electrodes;

a plurality of second electrodes, disposed over the elastic member, corresponding to the plurality of first electrodes so as to form a plurality of electrode pairs including a first electrode of the plurality of first electrodes and a corresponding second electrode of the plurality of second electrodes;

a polarizing plate disposed on the plurality of second electrodes;

a transparent conductive layer disposed over the polarizing plate; and

a touch sensor controller configured to monitor a capacitance between the first electrode and the second electrode of each electrode pair of the plurality of electrode pairs,

wherein the at least one elastic member comprises a plurality of elastic members, each of which is disposed between the first and second electrodes of each electrode pair of the plurality of electrode pairs.

19. The touch-screen display of claim 18, wherein the touch sensor controller is further configured to determine a position and pressure of a touch based on a change in the monitored capacitance.