Organic Light Emitting Display Device

• US 20180095582A1
• Filed: 12/02/2016
• Published: 04/05/2018
• Est. Priority Date: 09/30/2016
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: HWANG, JongHee, KIM, KiDuk, KIM, EunJung
• Granted Patent: US 10,275,075 B2
• Time in Patent Office: Days
• 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 2203/04105 Pressure sensors for measuring the pressure or force exerted on the touch surface without providing the touch position
• CPC Class Codes: G06F 2203/04111 Cross over in capacitive digitiser, i.e. details of structures for connecting electrodes of the sensing pattern where the connections cross each other, e.g. bridge structures comprising an insulating layer, or vias through substrate
• 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 3/0412 Digitisers structurally integrated in a display
• 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: G06F 3/0447 Position sensing using the local deformation of sensor cells
• CPC Class Codes: H10K 59/131 Interconnections, e.g. wiring lines or terminals
• CPC Class Codes: H10K 59/38 comprising colour filters or colour changing media [CCM]
• CPC Class Codes: H10K 59/40 OLEDs integrated with touch screens

Abstract

Disclosed is an organic light emitting display device including an encapsulation layer covering a pixel array layer provided on a substrate and a cover window coupled to a touch sensing layer. The touch sensing layer may include a first touch electrode layer provided on the encapsulation layer, a second touch electrode layer provided on the first touch electrode layer, and a pressure reaction member provided between the first touch electrode layer and the second touch electrode layer. Electrical characteristic of the pressure reaction member may be changed according to force applied to the pressure reaction member.

Claims

1. An organic light emitting display device comprising:

a display layer comprising;

a substrate,

a pixel array layer on the substrate, the pixel array layer including a plurality of pixels, each of the plurality of pixels including a thin film transistor (TFT) and an organic light emitting diode, and

an encapsulation layer covering the pixel array layer;

a cover window; and

a touch sensing layer directly disposed on the display layer, the touch sensing layer disposed between the display layer and the cover window, the touch sensing layer comprising;

a first touch electrode layer directly on the display layer,

a second touch electrode layer between the first touch electrode layer and the cover window, and

a pressure reaction member between the first touch electrode layer and the second touch electrode layer, electrical characteristic of the pressure reaction member changed according to force applied to the pressure reaction member.

2. The organic light emitting display device of claim 1, further comprising:

a touch driving circuit configured to determine force of a touch on the cover window according to a change in the electrical characteristic of the pressure reaction member associated with the touch, wherein the change in the electrical characteristic of the pressure reaction member is a change in a capacitance of the pressure reaction member or a change in a resistance of the pressure reaction member.

3. The organic light emitting display device of claim 1, wherein the pressure reaction member comprises a piezoelectric material or a piezoresistive material.

4. The organic light emitting display device of claim 3, wherein the piezoelectric material comprises at least one of lead zirconate titanate (PZT), BaTiO₃, polyvinylidene difluoride (PVDF), and parylene-C.

5. The organic light emitting display device of claim 3, wherein the piezoresistive material comprises a polymer and a conductive filler.

6. The organic light emitting display device of claim 5, wherein the conductive filler comprises at least one of nickel (Ni), copper (Cu), silver (Ag), aluminum (Al), iron (Fe), vanadium oxide (V₂O₃), titanium oxide (TiO), carbon black, graphite, graphene, and carbon nano tube (CNT).

7. The organic light emitting display device of claim 1,

wherein the display layer further comprises a barrier film disposed between the encapsulation layer and the first touch electrode layer,

wherein the first touch electrode layer comprises a plurality of first touch electrodes and a plurality of second touch electrodes directly on the barrier film, and

wherein the second touch electrode layer comprises a plurality of third touch electrodes disposed on the pressure reaction member.

8. The organic light emitting display device of claim 1,

wherein the display layer further comprises:

a light control film disposed between the encapsulation layer and the first touch electrode layer,

wherein the first touch electrode layer comprises a plurality of first touch electrodes and a plurality of second touch electrodes directly on the light control film, and

wherein the second touch electrode layer comprises a plurality of third touch electrodes disposed on the pressure reaction member.

9. The organic light emitting display device of claim 1,

wherein the display layer further comprises:

a black matrix directly on the encapsulation layer, the black matrix defining an opening area of each of the plurality of pixels;

a color filter layer disposed in the opening area of each of the plurality of pixels; and

a buffer layer covering the black matrix and the color filter layer,

wherein the first touch electrode layer comprises a plurality of first touch electrodes and a plurality of second touch electrodes directly on the buffer layer, and

wherein the second touch electrode layer comprises a plurality of third touch electrodes directly on the pressure reaction member.

10. The organic light emitting display device of claim 1,

wherein the first touch electrode layer comprises a plurality of first touch electrodes and a plurality of second touch electrodes directly on the display layer, and

wherein the second touch electrode layer comprises a plurality of third touch electrodes disposed on the pressure reaction member.

11. The organic light emitting display device of claim 10, wherein the plurality of first touch electrodes, the plurality of second touch electrodes, and the plurality of third touch electrodes each comprise an amorphous transparent conductive material.

12. The organic light emitting display device of claim 10,

wherein the second touch electrode layer further comprises a plurality of first secondary electrodes and a plurality of second secondary electrodes disposed along the plurality of third touch electrodes, each of the plurality of third touch electrodes disposed between an adjacent one of the first secondary electrodes and an adjacent one of the second secondary electrodes,

wherein the plurality of third touch electrodes, the plurality of first secondary electrodes, and the plurality of second secondary electrodes are electrically floated during a touch position sensing period, and

wherein a third touch electrode of the plurality of third touch electrodes is electrically connected to the adjacent one of the first secondary electrodes and the adjacent one of the second secondary electrodes during a touch force sensing period.

13. The organic light emitting display device of claim 12, further comprising:

a touch driving circuit connected to the plurality of first touch electrodes, the plurality of second touch electrodes, and the plurality of third touch electrodes,

wherein, during the touch position sensing period, the touch driving circuit applies a first touch driving pulse to at least one of the first touch electrodes, senses a first touch sensing signal responsive to the first touch driving pulse through the plurality of second touch electrodes, and determines a touch event area corresponding to a touch on the cover window according to the first touch sensing signal, and

wherein, during the touch force sensing period, the touch driving circuit applies a second touch driving pulse to at least one of the third touch electrodes disposed in the touch event area, senses a second touch sensing signal responsive to the second touch driving pulse through the plurality of second touch electrodes, and determines a touch force level and a touch position coordinate of the touch according to the second touch sensing signal.

14. The organic light emitting display device of claim 13, wherein the second touch electrode layer further comprises a plurality of connection electrodes, each of the plurality of connection electrodes facing one end of a corresponding one of the third touch electrodes and electrically connecting one end of a corresponding one of the first secondary electrodes to one end of a corresponding one of the second secondary electrodes adjacent to the one of the third touch electrodes.

15. The organic light emitting display device of claim 1,

wherein the first touch electrode layer comprises:

a plurality of first touch electrodes directly on the encapsulation layer,

an electrode insulation layer disposed on the encapsulation layer, the electrode insulation layer covering the plurality of first touch electrodes, and

a plurality of second touch electrodes directly on the electrode insulation layer, the plurality of second touch electrodes intersecting the plurality of first touch electrodes, and

wherein the second touch electrode layer comprises a plurality of third touch electrodes directly disposed on the pressure reaction member.

16. The organic light emitting display device of claim 15,

wherein the first touch electrode layer further comprises a plurality of first secondary electrodes and a plurality of second secondary electrodes disposed along the plurality of second touch electrodes, each of the plurality of second touch electrodes disposed between an adjacent one of the first secondary electrodes and an adjacent one of the second secondary electrodes,

wherein the plurality of third touch electrodes, the plurality of first secondary electrodes, and the plurality of second secondary electrodes are electrically floated during a touch position sensing period, and

wherein a second touch electrode of the plurality of second touch electrodes is electrically connected to the adjacent one of the first secondary electrodes and the adjacent one of the second secondary electrodes during a touch force sensing period.

17. The organic light emitting display device of claim 16, further comprising:

a touch driving circuit connected to the plurality of first touch electrodes, the plurality of second touch electrodes, and the plurality of third touch electrodes,

wherein, during the touch position sensing period, the touch driving circuit applies a first touch driving pulse to at least one first touch electrode, senses a first touch sensing signal responsive to the first touch driving pulse through the plurality of second touch electrodes, and determines a touch event area corresponding to a touch on the cover window according to the first touch sensing signal, and

wherein, during the touch force sensing period, the touch driving circuit applies a second touch driving pulse to at least one of the third touch electrodes disposed in the touch event area, senses a second touch sensing signal responsive to the second touch driving pulse through (i) the plurality of second touch electrodes, (ii) the first secondary electrodes, and (iii) the second secondary electrodes, and determines a touch force level and a touch position coordinate of the touch according to the second touch sensing signal.

18. The organic light emitting display device of claim 17, wherein the first touch electrode layer further comprises a plurality of connection electrodes, each of the plurality of connection electrodes facing one end of a corresponding one of the second touch electrodes and electrically connecting one end of a corresponding one of the first secondary electrodes to one end of a corresponding one of the second secondary electrodes adjacent to the corresponding one of the second touch electrodes.

19. The organic light emitting display device of claim 1,

wherein the second touch electrode layer comprises a plurality of first touch electrodes and a plurality of second touch electrodes directly on the pressure reaction member, and

wherein the first touch electrode layer comprises a third touch electrode directly on the display layer.