Display device and method of driving the same

• US 10,488,927 B2
• Filed: 12/27/2016
• Issued: 11/26/2019
• Est. Priority Date: 12/30/2015
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Lim, MyungJin, Kim, CheolSe, Ham, Yong-Su, Kim, Taeheon, Lee, YongWoo, Kho, YuSeon, Choi, Seulgi
• Primary Examiner(s): Khan, Ibrahim A
• Application Number:
  US15/391,077
• Publication Number:
  US 20170192508A1
• Time in Patent Office: 1,064 Days
• 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 3/016 Input arrangements with force or tactile feedback as computer generated output to the user
• 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

Abstract

Provided are a display device and a method of driving the same. The display device includes: a touch sensitive element having an electroactive layer and a plurality of electrodes disposed on at least one of a top surface and a bottom surface of the electroactive layer; a display panel disposed under the touch sensitive element; and a touch sensor disposed under the touch sensitive element and having a plurality of touch electrodes, and each of the plurality of electrodes of the touch sensitive element overlaps with one touch electrode from among the plurality of touch electrodes in a one to one correspondence.

Claims

1. A display device comprising:

a touch sensitive element comprising a plurality of cells, each of the plurality of cells having an electroactive layer, a plurality of first electrodes disposed on a first surface of the electroactive layer and spaced apart from each other, and a plurality of second electrodes disposed on a second surface of the electroactive layer opposite to the first surface and spaced apart from each other;

a display panel disposed under the touch sensitive element; and

a touch sensor integrated in the display panel and having a plurality of touch electrodes spaced apart from each other,

wherein a pair of the first and second electrodes of the touch sensitive element in each of the plurality of cells overlaps with only one touch electrode of the plurality of touch electrodes, and

wherein the pair of the first and second electrodes of the touch sensitive element have a comb shape with the combs disposed alternately, and overlap the corresponding touch electrode of the plurality of the touch electrodes having a same shape.

2. The display device according to claim 1, wherein an area of each of the plurality of electrodes of the touch sensitive element is equal to or smaller than an area of the corresponding one touch electrode of the plurality of touch electrodes.

3. The display device according to claim 1, wherein each of the plurality of cells include a driving circuit implemented by an active matrix method.

4. The display device according to claim 1, wherein

the plurality of touch electrodes are a plurality of common electrodes driving the display panel.

5. The display device according to claim 4, wherein the display device is time-division driven into an image display period and a touch sensing period, and

during the image display period, a common voltage is applied to the plurality of touch electrodes and a driving voltage is applied to the plurality of electrodes of the touch sensitive element, and

during the touch sensing period, the plurality of electrodes of the touch sensitive element are floating.

6. The display device according to claim 1, wherein the touch sensor is an on-cell type touch sensor in which the plurality of touch electrodes is disposed on a top surface of the display panel.

7. The display device according to claim 6, wherein the display device is time-division driven into a touch sensing period and a touch sensitive element driving period, and

the plurality of electrodes of the touch sensitive element are floating during the touch sensing period.

8. The display device according to claim 1, wherein the electroactive layer comprises an electroactive polymer, and

the plurality of electrodes of the touch sensitive element comprises a transparent conductive material.

9. A display device comprising:

a display panel;

a touch sensor having a plurality of touch electrodes disposed in the display panel, and wherein the plurality of touch electrodes are spaced apart from each other; and

a touch sensitive element comprising a plurality of cells disposed on the display panel and the touch sensor,

wherein each of the plurality of cells of the touch sensitive element includes;

an electroactive layer, and

a plurality of first electrodes disposed on a first surface of the electroactive layer and spaced apart from each other, and a plurality of second electrodes disposed on a second surface of the electroactive layer opposite to the first surface and spaced apart from each other, and

wherein a pair of the first and second electrodes in each of the plurality of cells corresponds with one touch electrode among the plurality of touch electrodes, and

wherein the pair of the first and second electrodes of the touch sensitive element have a comb shape with the combs disposed alternately, and overlap the corresponding touch electrode of the plurality of the touch electrodes having a same shape.

10. The display device according to claim 9, wherein the display panel is a liquid crystal display panel, and

the plurality of touch electrodes are common electrodes of the liquid crystal display panel.

11. The display device according to claim 9, wherein the display panel is an organic light emitting display panel, and

the plurality of touch electrodes is disposed on a top surface of an upper substrate of the organic light emitting display panel.

12. The display device according to claim 9, wherein an area of each of the plurality of electrodes of the touch sensitive element is equal to or smaller than an area of the corresponding one touch electrode of the plurality of touch electrodes.

13. A method of driving a display device, the method comprising:

applying a common voltage to a plurality of common electrodes of a display panel spaced apart from each other in which a touch panel is integrated and applying a driving voltage to a touch sensing element comprising a plurality of cells, each of the plurality of cells having a plurality of first electrodes disposed on a first surface of an electroactive layer of a touch sensitive element positioned on the display panel and spaced apart from each other, and a plurality of second electrodes disposed on a second surface of the electroactive layer and spaced apart from each other, during an image display period; and

applying a touch signal to the plurality of common electrodes and floating the plurality of first and second electrodes of the touch sensitive element, during a touch sensing period,

wherein a pair of the first and second electrodes of the touch sensitive element in each of the plurality of cells overlaps with only one common electrode of the plurality of common electrodes, and

wherein the pair of the first and second electrodes of the touch sensitive element have a comb shape with the combs disposed alternately, and overlap the corresponding touch electrode of the plurality of the touch electrodes having a same shape.