Display device and method of manufacturing the same

Patent metadata

Field	Value
Publication number	US-11048370-B2
Application number	US-201715816066-A
Country	US
Kind code	B2
Filing date	Nov 17, 2017
Priority date	Dec 29, 2016
Publication date	Jun 29, 2021
Grant date	Jun 29, 2021

Abstract

There is provided a display device. The display device includes a display panel for displaying an image on a front surface thereof and a pressure sensor disposed on a rear surface of the display panel to sense touch pressure of a user. The pressure sensor includes a first sensing electrode and a second sensing electrode insulated from each other to form capacitance. The first sensing electrode is printed onto the rear surface of the display panel.

First claim

What is claimed is:

1. A display device comprising:
a display panel for displaying an image on a front surface thereof;
a pressure sensor disposed on a rear surface of the display panel to sense touch pressure of a user;
a position sensor disposed on the front surface of the display panel to sense a touch position; and
a flexible printed circuit board (FPCB) having one end connected to the pressure sensor and the other end connected to the position sensor,
wherein the pressure sensor comprises a first sensing electrode and a second sensing electrode insulated from each other to form capacitance,
wherein the first sensing electrode is directly printed onto the rear surface of the display panel using conductive paste,
wherein the pressure sensor further comprises a pad disposed on the rear surface of the display panel and connected to the sensing electrode, and
wherein the pad is connected to the other end of the FPCB through a conductive adhesive member.

2. The display device of claim 1 , wherein the pressure sensor further comprises a protective layer printed onto the first sensing electrode.

3. The display device of claim 2 , wherein a thickness of the protective layer on the first sensing electrode is equal to or less than a thickness of the first sensing electrode.

4. The display device of claim 3 , further comprising:
a window disposed on a front surface of the display panel; and
an adhesive layer disposed between the display panel and the window.

5. The display device of claim 4 , wherein the adhesive layer is convex in a first direction to correspond to a second area.

6. The display device of claim 5 , wherein the display panel comprises a first area in which the first sensing electrode is disposed and the second area in which the first sensing electrode is not disposed, and
wherein the adhesive layer has different thicknesses in the first area and the second area.

7. The display device of claim 6 , wherein the thickness of the adhesive layer in the second area is larger than the thickness of the adhesive layer in the first area.

8. The display device of claim 1 , wherein the second sensing electrode is a lower cover that accommodates the display panel.

9. The display device of claim 8 , further comprising a buffer member disposed between the first sensing electrode and the lower cover.

10. The display device of claim 1 , wherein the position sensor comprises sensing electrodes disposed on the front surface of the display panel and a wiring line connected to the sensing electrodes.

11. The display device of claim 10 ,
wherein the display panel comprises a display area in which an image is displayed and a non-display area provided at least at one side of the display area, and
wherein, in a plan view, at least a portion of the pad overlaps the display area.

12. The display device of claim 10 , further comprising a main FPCB connected to the display panel,
wherein the main FPCB and the FPCB are connected to each other.

13. The display device of claim 1 ,
wherein the display panel comprises a substrate and pixels arranged on the substrate.

14. The display device of claim 13 , further comprising a light blocking layer disposed between the substrate and the first sensing electrode to prevent external light from being reflected.

15. The display device of claim 14 , wherein the light blocking layer is disposed on an entire surface of the rear surface of the display panel.

16. The display device of claim 14 , wherein the light blocking layer is disposed in a position in which the first sensing electrode is provided.

17. The display device of claim 13 , further comprising a filling layer disposed in a position in which the first sensing electrode is not provided.

18. The display device of claim 13 , further comprising a dummy pattern that is disposed in a position in which the first sensing electrode is not provided, that is formed of the same material as the first sensing electrode, and that electrically floats.

19. The display device of claim 1 , wherein the first sensing electrode comprises at least one among metal paste, metal oxide paste, conductive carbon paste, and conductive polymeric paste.

20. The display device of claim 19 , wherein the metal paste comprises at least one among silver (Ag), copper (Cu), and nickel (Ni), and
wherein the metal oxide paste comprises at least one among zinc oxide (ZnO), tin oxide (SnO), and indium oxide (InO), the conductive carbon paste comprises at least one among graphite, carbon fiber, carbon nano-fiber, carbon nano-tube, and graphene, and the conductive polymer is polythiophene-based polymer or polypyrole-based polymer.

21. The display device of claim 1 , wherein the first sensing electrode is mesh-shaped in a plan view.

22. The display device of claim 1 , wherein the first sensing electrode comprises a first sub-electrode and a second sub-electrode provided in different areas.

23. A method of manufacturing a display device, the method comprising:
providing a display panel;
directly printing a first sensing electrode onto a rear surface of the display panel using conductive paste;
printing a protective layer onto the first sensing electrode; and
accommodating the display panel in a lower cover,
wherein the display device comprises:
the display panel for displaying an image on a front surface thereof;
a pressure sensor disposed on a rear surface of the display panel to sense touch pressure of a user;
a position sensor disposed on the front surface of the display panel to sense a touch position; and
a flexible printed circuit board (FPCB) having one end connected to the pressure sensor and the other end connected to the position sensor,
wherein the pressure sensor comprises a first sensing electrode and a second sensing electrode insulated from each other to form capacitance,
wherein the first sensing electrode is directly printed onto the rear surface of the display panel using conductive paste,
wherein the pressure sensor further comprises a pad disposed on the rear surface of the display panel and connected to the sensing electrode, and
wherein the pad is connected to the other end of the FPCB through a conductive adhesive member.

24. The method of claim 23 , further comprising, after printing the protective layer, attaching a window onto the front surface of the display panel with an adhesive layer interposed between the display panel and the window.

25. The method of claim 24 , further comprising:
cutting of the display panel to which the window is attached by a unit substrate; and
assembling a lower cover with the cut display panel.

26. The method of claim 23 , further comprising printing a light blocking layer between the rear surface of the display panel and the sensing electrode.

27. The method of claim 26 , further comprising pressing and printing the sensing electrode onto the light blocking layer.

28. The method of claim 26 , further comprising forming a filling layer in an area in which the sensing electrode is not formed.

29. The method of claim 23 , further comprising polishing the protective layer.

Assignees

• Samsung Display Co Ltd

Inventors

• Ko Gun Woo
• Park Won Mo
• Park Hye Kyung

Classifications

• G06F3/0447 Primary

  Position sensing using the local deformation of sensor cells · CPC title

• G06F3/0412 Primary

  Digitisers structurally integrated in a display · CPC title

• G06F3/0446

  using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes · CPC title

• G06F3/0443

  using a single layer of sensing electrodes · CPC title

• G06F2203/04105

  Pressure sensors for measuring the pressure or force exerted on the touch surface without providing the touch position · CPC title