TOUCH SCREEN LIQUID CRYSTAL DISPLAY

• US 20080062148A1
• Filed: 06/08/2007
• Published: 03/13/2008
• Est. Priority Date: 06/09/2006
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Hotelling, Steve, Yao, Wei, Chen, Wei, Krah, Christoph, Hodge, Andrew, Boer, Willem, Zhong, John, Elias, John, Land, Brian
• Granted Patent: US 8,243,027 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• 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 3/04164 Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads
• 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 3/04184 Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G06F 3/0444 using a single conductive element covering the whole sensing surface, e.g. by sensing the electrical current flowing at the corners
• 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

Abstract

Disclosed herein are liquid-crystal display (LCD) touch screens that integrate the touch sensing elements with the display circuitry. The integration may take a variety of forms. Touch sensing elements can be completely implemented within the LCD stackup but outside the not between the color filter plate and the array plate. Alternatively, some touch sensing elements can be between the color filter and array plates with other touch sensing elements not between the plates. In another alternative, all touch sensing elements can be between the color filter and array plates. The latter alternative can include both conventional and in-plane-switching (IPS) LCDs. In some forms, one or more display structures can also have a touch sensing function. Techniques for manufacturing and operating such displays, as well as various devices embodying such displays are also disclosed.

Claims

1. A touch screen comprising a liquid crystal display with integral touch sensing, the touch screen comprising:

a first substrate having display control circuitry formed thereon, the first substrate being disposed between the first polarizer and the second polarizer;

a second substrate disposed between the first polarizer and the second polarizer and adjacent the first substrate;

at least one touch sensing element disposed between the first and second substrates, wherein all touch sensing elements are disposed between the first and second substrates.

2. The touch screen of claim 1 wherein the at least one touch sensing element between the first and second substrates comprises:

a plurality of touch drive electrodes deposited on the second substrate; and

a conductive black matrix segmented into a plurality of touch sense electrodes.

3. The touch screen of claim 2 wherein the plurality of touch drive electrodes are configured to be used for display V_COM.

4. The touch screen of claim 1 wherein the at least one touch sensing element between the first and second substrates comprises:

a plurality of touch drive electrodes deposited on the second substrate; and

a plurality of metal touch sense electrodes disposed behind a black matrix.

5. The touch screen of claim 2 wherein the plurality of touch drive electrodes are configured to be used for display V_COM.

6. The touch screen of claim 1 wherein the at least one touch sensing element between the first and second substrates comprises:

an unpatterned ITO touch-sensing layer deposited on a substrate;

a plurality of switches arranged about a periphery of the unpatterned ITO layer;

a first bus having a first subset of the plurality of switches connected thereto; and

a second bus having a second subset of the plurality of switches connected thereto.

7. The touch screen of claim 6 wherein the unpatterned ITO layer is deposited on the second substrate.

8. The touch screen of claim 7 wherein the unpatterned ITO layer is used for display V_COM.

9. The touch screen of claim 6 wherein the plurality of switches comprise TFTs.

10. The touch screen of claim 1 wherein the at least one touch sensing element between the first and second substrates comprises:

an ITO touch-sensing layer patterned into a plurality of rows and deposited on a substrate;

a plurality of switches arranged at a first end of the plurality of rows and connected to a first bus; and

a plurality of switches arranged at a second end of the plurality of rows and connected to a second bus.

11. The touch screen of claim 10 wherein the ITO touch-sensing layer patterned into a plurality of rows is deposited on the second substrate.

12. The touch screen of claim 11 wherein the ITO touch-sensing layer patterned into a plurality of rows is used for display V_COM.

13. The touch screen of claim 10 wherein the plurality of switches comprise TFTs.

14. The touch screen of claim 1 wherein the at least one touch sensing element disposed between the first and second substrates comprises:

a segmented ITO layer deposited on the second substrate; and

a plurality of switches deposited on the second substrate and connected such that each ITO segment can be configured to function as one of display V_COM, touch drive, or touch sense at a given time.

15. The touch screen of claim 14 wherein the plurality of switches comprise thin film transistors.

16. The touch screen of claim 1 wherein the at least one touch sensing element between the first and second substrates comprises:

a first ITO layer deposited on the second substrate patterned into a plurality of touch sense electrodes;

a second ITO layer deposited on the second substrate patterned into a plurality of touch drive electrodes.

17. The touch screen of claim 16 wherein the plurality of touch drive electrodes are also used for V_COM.

18. The touch screen of claim 1 wherein the at least one touch sensing element between the first and second substrates comprises:

a first ITO layer deposited on the second substrate patterned into a plurality of touch drive electrodes; and

a second ITO layer deposited on the second substrate patterned into a plurality of touch sense electrodes.

19. The touch screen of claim 18 wherein the plurality of touch sense electrodes are also used for V_COM.

20. The touch screen of claim 1 wherein the at least one touch sensing element between the first and second substrates comprises an ITO layer deposited on the second substrate and segmented into a plurality of touch drive electrodes and a plurality of touch sense electrodes.

21. The touch screen of claim 20 wherein the touch drive electrodes comprise resistance reducing metal segments.

22. The touch screen of claim 20 further comprising a plurality of guard traces configured to block a portion of an electric field between the touch drive electrodes and the touch sense electrodes.

23. The touch screen of claim 1 wherein the at least one touch sensing element between the first and second substrates comprises:

an ITO layer deposited on the second substrate and patterned into a plurality of individually addressable touch pixels, each touch pixel comprising a drive electrode and a sense electrode;

a plurality of drive lines connected to each drive electrode; and

a plurality of sense lines connected to each sense electrode.

24. The touch screen of claim 23 wherein at least one of the plurality of drive lines or at least one of the plurality of sense lines is formed from a conductive black mask.

25. The touch screen of claim 23 wherein at least one of the plurality of drive lines or at least one of the plurality of sense lines comprises a metal line disposed behind a black matrix.

26. The touch screen of claim 1 wherein the at least one touch sensing element between the first and second substrates comprises:

a first segmented ITO layer disposed on the second substrate and segmented into at least two plates corresponding to each display pixel;

a second segmented ITO layer disposed on the second substrate and segmented into an island corresponding to each display pixel; and

a switch connected between a V_COM electrode of the display and one of the at least two plates;

whereby V_COM can be used as a touch drive line and a data line of the display can be used as a touch sense line.

27. The touch screen of claim 1 wherein the at least one touch sensing element between the first and second substrates comprises:

a segmented ITO layer patterned into a plurality of touch sense electrodes disposed on the second substrate; and

display select line circuitry configured to act as a plurality of touch drive electrodes.

28. The touch screen of claim 27 wherein the segmented ITO layer is configured to be used for display V_COM.

29. The touch screen of claim 27 wherein the display select line circuitry is disposed on the first substrate.

30. An electronic device incorporating an integrated liquid crystal display touch screen, the touch screen comprising:

a first substrate having display control circuitry formed thereon, the first substrate being disposed between the first polarizer and the second polarizer;

a second substrate disposed between the first polarizer and the second polarizer and adjacent the first substrate;

at least one touch sensing element disposed between the first and second substrates, wherein all touch sensing elements are disposed between the first and second substrates.

31. The electronic device of claim 30 wherein the electronic device is selected from the group consisting of a desktop computer, a tablet computer, and a notebook computer.

32. The electronic device of claim 30 wherein the electronic device comprises at least one of a handheld computer, a personal digital assistant, a media player, and a mobile telephone.

33. The electronic device of claim 30, wherein the at least one touch sensing element between the first and second substrates comprises:

a plurality of touch drive electrodes deposited on the second substrate; and

a conductive black matrix segmented into a plurality of touch sense electrodes.

34. The electronic device of claim 33 wherein the electronic device is selected from the group consisting of a desktop computer, a tablet computer, and a notebook computer.

35. The electronic device of claim 33 wherein the electronic device comprises at least one of a handheld computer, a personal digital assistant, a media player, and a mobile telephone.

36. The electronic device of claim 30 wherein the at least one touch sensing element between the first and second substrates comprises:

a plurality of touch drive electrodes deposited on the second substrate; and

a plurality of metal touch sense electrodes disposed behind a black matrix.

37. The electronic device of claim 36 wherein the electronic device is selected from the group consisting of a desktop computer, a tablet computer, and a notebook computer.

38. The electronic device of claim 36 wherein the electronic device comprises at least one of a handheld computer, a personal digital assistant, a media player, and a mobile telephone.

39. The electronic device of claim 30 wherein the at least one touch sensing element between the first and second substrates comprises:

an unpatterned ITO touch-sensing layer deposited on a substrate;

a plurality of switches arranged about a periphery of the unpatterned ITO layer;

a first bus having a first subset of the plurality of switches connected thereto; and

a second bus having a second subset of the plurality of switches connected thereto.

40. The electronic device of claim 39 wherein the electronic device is selected from the group consisting of a desktop computer, a tablet computer, and a notebook computer.

41. The electronic device of claim 39 wherein the electronic device comprises at least one of a handheld computer, a personal digital assistant, a media player, and a mobile telephone.

42. The electronic device of claim 30 wherein the at least one touch sensing element between the first and second substrates comprises:

an ITO touch-sensing layer patterned into a plurality of rows and deposited on a substrate;

a plurality of switches arranged at a first end of the plurality of rows and connected to a first bus; and

a plurality of switches arranged at a second end of the plurality of rows and connected to a second bus.

43. The electronic device of claim 42 wherein the electronic device is selected from the group consisting of a desktop computer, a tablet computer, and a notebook computer.

44. The electronic device of claim 42 wherein the electronic device comprises at least one of a handheld computer, a personal digital assistant, a media player, and a mobile telephone.

45. The electronic device of claim 30 wherein the at least one touch sensing element disposed between the first and second substrates comprises:

a segmented ITO layer deposited on the second substrate; and

a plurality of switches deposited on the second substrate and connected such that each ITO segment can be configured to function as one of display V_COM, touch drive, or touch sense at a given time.

46. The electronic device of claim 45 wherein the electronic device is selected from the group consisting of a desktop computer, a tablet computer, and a notebook computer.

47. The electronic device of claim 45 wherein the electronic device comprises at least one of a handheld computer, a personal digital assistant, a media player, and a mobile telephone.

48. The electronic device of claim 30 wherein the at least one touch sensing element between the first and second substrates comprises:

a first ITO layer deposited on the second substrate patterned into a plurality of touch sense electrodes;

a second ITO layer deposited on the second substrate patterned into a plurality of touch drive electrodes.

49. The electronic device of claim 48 wherein the electronic device is selected from the group consisting of a desktop computer, a tablet computer, and a notebook computer.

50. The electronic device of claim 48 wherein the electronic device comprises at least one of a handheld computer, a personal digital assistant, a media player, and a mobile telephone.

51. The electronic device of claim 30 wherein the at least one touch sensing element between the first and second substrates comprises:

a first ITO layer deposited on the second substrate patterned into a plurality of touch drive electrodes; and

a second ITO layer deposited on the second substrate patterned into a plurality of touch sense electrodes.

52. The electronic device of claim 51 wherein the electronic device is selected from the group consisting of a desktop computer, a tablet computer, and a notebook computer.

53. The electronic device of claim 51 wherein the electronic device comprises at least one of a handheld computer, a personal digital assistant, a media player, and a mobile telephone.

54. The electronic device of claim 30 wherein the at least one touch sensing element between the first and second substrates comprises an ITO layer deposited on the second substrate and segmented into a plurality of touch drive electrodes and a plurality of touch sense electrodes.

55. The electronic device of claim 54 wherein the electronic device is selected from the group consisting of a desktop computer, a tablet computer, and a notebook computer.

56. The electronic device of claim 54 wherein the electronic device comprises at least one of a handheld computer, a personal digital assistant, a media player, and a mobile telephone.

57. The electronic device of claim 30 wherein the at least one touch sensing element between the first and second substrates comprises:

an ITO layer deposited on the second substrate and patterned into a plurality of individually addressable touch pixels, each touch pixel comprising a drive electrode and a sense electrode;

a plurality of drive lines connected to each drive electrode; and

a plurality of sense lines connected to each sense electrode.

58. The electronic device of claim 57 wherein the electronic device is selected from the group consisting of a desktop computer, a tablet computer, and a notebook computer.

59. The electronic device of claim 57 wherein the electronic device comprises at least one of a handheld computer, a personal digital assistant, a media player, and a mobile telephone.

60. The electronic device of claim 30 wherein the at least one touch sensing element between the first and second substrates comprises:

a first segmented ITO layer disposed on the second substrate and segmented into at least two plates corresponding to each display pixel;

a second segmented ITO layer disposed on the second substrate and segmented into an island corresponding to each display pixel; and

a switch connected between a V_COM electrode of the display and one of the at least two plates;

whereby V_COM can be used as a touch drive line and a data line of the display can be used as a touch sense line.

61. The electronic device of claim 60 wherein the electronic device is selected from the group consisting of a desktop computer, a tablet computer, and a notebook computer.

62. The electronic device of claim 60 wherein the electronic device comprises at least one of a handheld computer, a personal digital assistant, a media player, and a mobile telephone.

63. The electronic device of claim 30 wherein the at least one touch sensing element between the first and second substrates comprises:

a segmented ITO layer patterned into a plurality of touch sense electrodes disposed on the second substrate; and

display select line circuitry configured to act as a plurality of touch drive electrodes.

64. The electronic device of claim 63 wherein the electronic device is selected from the group consisting of a desktop computer, a tablet computer, and a notebook computer.

65. The electronic device of claim 63 wherein the electronic device comprises at least one of a handheld computer, a personal digital assistant, a media player, and a mobile telephone.

66. A mobile telephone incorporating an integrated liquid crystal display touch screen, the touch screen comprising:

a first substrate having display control circuitry formed thereon, the first substrate being disposed between the first polarizer and the second polarizer;

a second substrate disposed between the first polarizer and the second polarizer and adjacent the first substrate;

at least one touch sensing element disposed between the first and second substrates, wherein all touch sensing elements are disposed between the first and second substrates.

67. The mobile telephone of claim 66, wherein the at least one touch sensing element between the first and second substrates comprises:

a plurality of touch drive electrodes deposited on the second substrate; and

a conductive black matrix segmented into a plurality of touch sense electrodes.

68. The mobile telephone of claim 66 wherein the at least one touch sensing element between the first and second substrates comprises:

a plurality of touch drive electrodes deposited on the second substrate; and

a plurality of metal touch sense electrodes disposed behind a black matrix.

69. The mobile telephone of claim 66 wherein the at least one touch sensing element between the first and second substrates comprises:

an unpatterned ITO touch-sensing layer deposited on a substrate;

a plurality of switches arranged about a periphery of the unpatterned ITO layer;

a first bus having a first subset of the plurality of switches connected thereto; and

a second bus having a second subset of the plurality of switches connected thereto.

70. The mobile telephone of claim 66 wherein the at least one touch sensing element between the first and second substrates comprises:

an ITO touch-sensing layer patterned into a plurality of rows and deposited on a substrate;

a plurality of switches arranged at a first end of the plurality of rows and connected to a first bus; and

a plurality of switches arranged at a second end of the plurality of rows and connected to a second bus.

71. The mobile telephone of claim 66 wherein the at least one touch sensing element disposed between the first and second substrates comprises:

a segmented ITO layer deposited on the second substrate; and

a plurality of switches deposited on the second substrate and connected such that each ITO segment can be configured to function as one of display V_COM, touch drive, or touch sense at a given time.

72. The mobile telephone of claim 66 wherein the at least one touch sensing element between the first and second substrates comprises:

a first ITO layer deposited on the second substrate patterned into a plurality of touch sense electrodes;

a second ITO layer deposited on the second substrate patterned into a plurality of touch drive electrodes.

73. The mobile telephone of claim 66 wherein the at least one touch sensing element between the first and second substrates comprises:

a first ITO layer deposited on the second substrate patterned into a plurality of touch drive electrodes; and

a second ITO layer deposited on the second substrate patterned into a plurality of touch sense electrodes.

74. The mobile telephone of claim 66 wherein the at least one touch sensing element between the first and second substrates comprises an ITO layer deposited on the second substrate and segmented into a plurality of touch drive electrodes and a plurality of touch sense electrodes.

75. The mobile telephone of claim 66 wherein the at least one touch sensing element between the first and second substrates comprises:

an ITO layer deposited on the second substrate and patterned into a plurality of individually addressable touch pixels, each touch pixel comprising a drive electrode and a sense electrode;

a plurality of drive lines connected to each drive electrode; and

a plurality of sense lines connected to each sense electrode.

76. The mobile telephone of claim 66 wherein the at least one touch sensing element between the first and second substrates comprises:

a first segmented ITO layer disposed on the second substrate and segmented into at least two plates corresponding to each display pixel;

a second segmented ITO layer disposed on the second substrate and segmented into an island corresponding to each display pixel; and

a switch connected between a V_COM electrode of the display and one of the at least two plates;

whereby V_COM can be used as a touch drive line and a data line of the display can be used as a touch sense line.

77. The mobile telephone of claim 66 wherein the at least one touch sensing element between the first and second substrates comprises:

a segmented ITO layer patterned into a plurality of touch sense electrodes disposed on the second substrate; and

display select line circuitry configured to act as a plurality of touch drive electrodes.