Touch panel for display device

• US 20040105040A1
• Filed: 11/07/2003
• Published: 06/03/2004
• Est. Priority Date: 11/14/2002
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Philips LCD Company Limited (LG Display Co., Ltd.)
• Inventors: Hong, Hee Jung, Oh, Eui Yeol
• Granted Patent: US 7,084,933 B2
• Time in Patent Office: Days
• US Class Current: 349/12
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• 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 2203/04106 Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection
• 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 3/046 by electromagnetic means

Abstract

A touch panel for a display device integrates functionality provided by capacitive-type and EM-type touch panels. The touch panel is integrated with the display device and includes a capacitive-type touch panel arranged above the display device and an EM-type touch panel arranged below the display device.

Claims

1. A touch panel for a display device, comprising:

a capacitive-type touch panel arranged above the display device; and

an electromagnetic (EM)-type touch panel arranged below the display device.

2. The touch panel of claim 1, wherein the display device comprises an liquid crystal display (LCD).

3. The touch panel of claim 1, wherein the display device comprises a plasma display panel (PDP).

4. The touch panel of claim 1, wherein the display device comprises an electro-luminescent display (ELD).

5. The touch panel of claim 1, wherein the display device comprises a vacuum-fluorescent display (VFD).

6. The touch panel of claim 1, wherein the display device comprises a cathode ray tube (CRT).

7. The touch panel of claim 1, wherein the capacitive-type touch panel is spaced apart from the display device by a predetermined distance.

8. The touch panel of claim 1, wherein the capacitive-type touch panel includes:

a transparent electrode;

a plurality of metal electrodes arranged at corners of the transparent electrode; and

a passivation layer arranged over an entire surface of the transparent electrode and on the metal electrodes.

9. The touch panel of claim 8, wherein the transparent electrode comprises indium-tin-oxide (ITO).

10. The touch panel of claim 8, wherein the transparent electrode comprises tin-antimony-oxide (TAO).

11. The touch panel of claim 8, wherein the metal electrodes comprise silver.

12. The touch panel of claim 8, wherein the metal electrodes comprise a mixture of silver and glass.

13. The touch panel of claim 1, wherein the EM-type touch panel includes:

a sensor board arranged below the display device, wherein electromagnetic fields are generatable by the sensor board; and

a control board arranged below and in electrical communication with the sensor board, wherein a location of a contact point generated by a contact object is determinable by the control board.

14. The touch panel of claim 13, wherein the control board includes:

a first driving part for driving the capacitive-type touch panel, wherein a capacitance value is detectable by the first driving part;

a second driving part for driving the EM-type touch panel, wherein an electromagnetic field is detectable by the second driving part; and

a third driving part for selectively switching between the first and second driving parts.

15. The touch panel of claim 13, wherein the sensor board includes:

a sensor PCB;

a shield plate; and

a connector connecting the sensor PCB to the control board.

16. The touch panel of claim 15, wherein the sensor PCB is connected to the shield plate by an adhesive.

17. The touch panel of claim 1, further comprising a passivation layer arranged over the display device.

18. The touch panel of claim 17, wherein the passivation layer is formed of an insulating material.

19. The touch panel of claim 18, wherein the passivation layer includes silicon nitride.

20. The touch panel of claim 18, wherein the passivation layer includes silicon oxide.

21. The touch panel of claim 18, wherein the passivation layer includes Benzocyclobutene (BCB).

22. The touch panel of claim 18, wherein the passivation layer includes acrylic resin.

23. The touch panel of claim 1, further comprising a case top securing the display device, the capacitive-type touch panel, and the EM-type touch panel together as a single body.

24. The touch panel display device of claim 23, wherein the case top is metal.

25. A touch panel display device, comprising:

a display device;

a capacitive-type touch panel arranged above the display device;

an electromagnetic (EM)-type touch panel arranged below display device; and

a case top securing the display device, the capacitive-type touch panel, and the EM-type touch panel together as a single body.

26. The touch panel display device of claim 25, wherein the case top is metal.

27. The touch panel of claim 25, wherein the display device comprises an liquid crystal display (LCD).

28. The touch panel of claim 27, wherein the LCD comprises:

an upper substrate;

a lower substrate bonded to the upper substrate;

liquid crystal material arranged between the bonded upper and lower substrates;

an upper polarizing plate adhered to an upper surface of the upper substrate;

a lower polarizing plate adhered to a lower surface of the lower substrate;

a backlight arranged between the lower polarizing plate and the EM-type touch panel; and

a passivation layer arranged between the upper polarizing plate and the capacitive-type touch panel.

29. The touch panel of claim 28, wherein the passivation layer is spaced apart from the upper polarizing plate by a predetermined distance.

30. The touch panel of claim 25, wherein the display device comprises a plasma display panel (PDP).

31. The touch panel of claim 25, wherein the display device comprises an electro-luminescent display (ELD).

32. The touch panel of claim 25, wherein the display device comprises a vacuum-fluorescent display (VFD).

33. The touch panel of claim 25, wherein the display device comprises a cathode ray tube (CRT).