Touch screen liquid crystal display

• US 8,259,078 B2
• Filed: 06/08/2007
• Issued: 09/04/2012
• Est. Priority Date: 06/09/2006
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Hotelling, Steve Porter, Chen, Wei, Krah, Christoph Horst, Elias, John Greer, Yao, Wei Hsin, Zhong, John Z., Hodge, Andrew Bert, Land, Brian Richards, den Boer, Willem
• Primary Examiner(s): Eisen, Alexander
• Assistant Examiner(s): MARINELLI, PATRICK
• Application Number:
  US11/760,036
• Publication Number:
  US 20080062147A1
• Time in Patent Office: 1,915 Days
• Field of Search: 345156-184, 345 87-104, 345204-215, 345690-699, 178 1801- 2004
• US Class Current: 345/173
• 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. An integrated liquid crystal display touch screen comprising:

a first polarizer;

a second polarizer;

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;

a liquid crystal layer disposed between the first and second substrates;

a plurality of touch sensing elements disposed between the first and second polarizers and not between the first and second substrates, the plurality of touch sensing elements comprising a plurality of touch drive electrodes and a plurality of touch sense electrodes, the plurality of touch drive electrodes and the plurality of touch sense electrodes being operative at least during a touch sensing mode of operation;

the plurality of touch drive electrodes and the plurality of touch sense electrodes spaced apart from one another to form capacitive coupling nodes therebetween;

a counter electrode used during a liquid crystal display operation and disposed between the liquid crystal layer and the second substrate, the counter electrode separate and distinct from the plurality of touch drive electrodes and separate and distinct from the plurality of touch sense electrodes;

the counter electrode being grounded during the touch sensing mode of operation to shield the plurality of touch drive electrodes and the plurality of touch sense electrodes disposed above the counter electrode, from the liquid crystal layer disposed below the counter electrode;

the plurality of touch drive electrodes operative to receive a periodic voltage;

the plurality of touch drive electrodes driven by the periodic voltage one at a time or in groups; and

at least one capacitance sensing circuit operatively coupled to the plurality of touch sense electrodes during the touch sensing mode of operation for measuring a change in current and/or voltage resulting from a change in capacitance at the capacitive coupling nodes.

2. The touch screen of claim 1 wherein the second substrate has a color filter disposed thereon.

3. The touch screen of claim 2 wherein the color filter is formed on a side of the second substrate facing the liquid crystal layer, and wherein the plurality of touch sensing elements are formed on the second substrate on a side opposite that of the color filter.

4. The touch screen of claim 3 wherein the plurality of touch sensing elements further comprise:

a first plurality of touch electrodes formed on the second substrate, the first plurality of touch electrodes being one of the plurality of touch drive or the plurality of touch sense electrodes;

a dielectric deposited over the first plurality of electrodes; and

a second plurality of touch electrodes formed on top of the dielectric, the second plurality of touch electrodes being the other of the plurality of touch drive or the plurality of touch sense electrodes.

5. The touch screen of claim 4 wherein the first plurality of touch electrodes formed on the second substrate comprises ITO patterned to form the plurality of touch drive electrodes or the plurality of touch sense electrodes.

6. The touch screen of claim 4 wherein the plurality of touch drive electrodes are driven by the periodic voltage one at a time or in groups while the non-driven touch drive electrodes are grounded.

7. The touch screen of claim 1 wherein the plurality of touch drive electrodes are driven by the periodic voltage one at a time or in groups while the non-driven touch drive electrodes are grounded.

8. The touch screen of claim 1 wherein the second substrate is glass.

9. The touch screen of claim 1 wherein the second substrate is plastic.

10. The touch screen of claim 1 wherein the plurality of touch sensing elements comprises a mutual capacitance touch-sensing arrangement.

11. The electronic device of claim 10,

wherein the first substrate further comprises touch control circuitry;

and the touch screen further comprises an electrical connect r electrically connecting the touch control circuitry on the first substrate to the top surface of the second substrate.

12. The electronic device of claim 11, wherein the electrically connector comprises a flexible printed circuit.

13. The electronic d vice of claim 11 wherein the electrical connector comprises a first flexible printed circuit connecting the plurality of touch sense electrodes to the touch control circuitry and a second flexible printed, circuit connecting the plurality of touch drive electrodes to the touch control circuitry.

14. The touch screen of claim 1,

wherein the first substrate further comprises touch control circuitry;

and the touch screen further comprises an electrical connect r electrically connecting the touch control circuitry on the first substrate to the top surface of the second substrate.

15. The touch screen of claim 14, wherein the electrically connector comprises a flexible printed circuit.

16. The touch screen of claim 14 wherein the electrical connector comprises a first flexible printed circuit connecting the plurality of touch sense electrodes to the touch control circuitry and a second flexible printed circuit connecting the plurality of touch drive electrodes to the touch control circuitry.

17. An electronic device incorporating an integrated liquid crystal display touch screen, wherein the liquid crystal display touch screen comprises:

a first polarizer;

a second polarizer;

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;

a liquid crystal layer disposed between the first and second substrates;

a plurality of touch sensing elements disposed between the first and second polarizers and not between the first and second substrates, the plurality of touch sensing elements comprising a plurality of touch drive electrodes and a plurality of touch sense electrodes, the plurality of touch drive electrodes and the plurality of touch sense electrodes being operative at least during a touch sensing mode of operation;

the plurality of touch drive electrodes and the plurality of touch sense electrodes spaced apart from one another to form capacitive coupling nodes therebetween;

a counter electrode used during a liquid crystal display operation and disposed between the liquid crystal layer and the second substrate, the counter electrode separate and distinct from the plurality of touch drive electrodes and separate and distinct from the plurality of touch sense electrodes;

the counter electrode being grounded during the touch sensing mode of operation to shield the plurality of touch drive electrodes and the plurality of touch sense electrodes disposed above the counter electrode, from the liquid crystal layer disposed below the counter electrode;

the plurality of touch drive electrodes operative to receive a periodic voltage;

the plurality of touch drive electrodes driven by the periodic voltage one at a time or in groups; and

at least one capacitance sensing, circuit operatively coupled to the plurality of touch sense electrodes during the touch sensing mode of operation for measuring a change in current and/or voltage resulting from a change in capacitance at the capacitive coupling nodes.

18. The electronic device of claim 17 wherein a color filter is formed on a side of the second substrate facing the liquid crystal layer, and wherein the plurality of touch sensing elements are formed on the second substrate on a side opposite that of the color filter.

19. The electronic device of claim 18,

wherein the plurality of touch drive electrodes are driven by the periodic voltage one at a time or in groups while the non-driven touch drive electrodes are grounded.

20. The electronic device of claim 19 wherein the plurality of touch sensing elements further comprise:

a first plurality of touch electrodes formed on the second substrate, the first plurality of touch electrodes being one of the plurality of touch drive or the plurality of touch sense electrodes;

a dielectric deposited over the first plurality of electrodes; and

a second plurality of touch electrodes formed on top of the dielectric, the second plurality of touch electrodes being the other of the plurality of touch drive or the plurality of touch sense electrodes.

21. The electronic device of claim 20 wherein the electronic device comprises at least one of a handheld computer, a personal digital assistant, a media player, a mobile telephone, a desktop computer, a tablet computer, and a notebook computer.

22. The electronic device of claim 18 wherein the plurality of touch sensing elements further comprise:

a first plurality of touch electrodes formed on the second substrate, the first plurality of touch electrodes being one of the plurality of touch drive or the plurality of touch sense electrodes;

a dielectric deposited over the first plurality of electrodes; and

a second plurality of touch electrodes formed on top of the dielectric, the second plurality of touch electrodes being the other of the plurality of touch drive or the plurality of touch sense electrodes.

23. The electronic device of claim 17 wherein the one or more touch sensors formed on the second substrate further comprise:

a first plurality of touch electrodes formed on the second substrate, the first plurality of touch electrodes being one of the plurality of touch drive or touch sense electrodes;

a dielectric deposited over the first plurality of electrodes; and

a second plurality of touch electrodes formed on top of the dielectric, the second plurality of touch electrodes being the other of the 3.1urality of touch drive or touch sense electrodes.

24. The electronic device of claim 23 wherein the electronic device is selected from the group consisting of a desktop Computer, a tablet computer, and a notebook computer.

25. The electronic device of claim 23 wherein the electronic device comprises at least one of a handheld computer, a personal digital assistant, a media player, and a mobile telephone.

26. The electronic device of claim 23 wherein the first plurality of touch electrodes formed on the second substrate comprises ITO patterned to form the plurality of touch drive electrodes.

27. The electronic device of claim 26 wherein the electronic device is selected from the group consisting of a desktop computer, a tablet computer, and a notebook computer.

28. The electronic device of claim 26 wherein the electronic device comprises at least one of a handheld computer, a personal digital assistant, a media player, and a mobile telephone.

29. The electronic device of claim 23 wherein the first plurality of touch electrodes formed on the second substrate comprises ITO patterned to form the plurality of touch sense electrodes.

30. The electronic device of claim 29 wherein the electronic device is selected from the group consisting of a desktop computer, a tablet computer, and a notebook computer.

31. The electronic device of claim 29 wherein the electronic device comprises at least one of a handheld computer, a personal digital assistant, a media player, and a mobile telephone.

32. The electronic device of claim 17 wherein the plurality of touch drive electrodes are driven by the periodic, voltage one at a time or in groups while the non-driven touch drive electrodes are grounded.

33. The electronic device of claim 32 wherein the electronic device is selected from the group consisting of a desktop computer, a tablet computer, a notebook computer, a handheld computer, a personal digital assistant, a media player, and a mobile telephone.

34. A mobile telephone incorporating an integrated liquid crystal display touch screen, wherein the liquid crystal display touch screen comprises:

a first polarizer;

a second polarizer;

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

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

a liquid crystal layer disposed between the first and second substrates;

a plurality of touch sensing elements disposed between the first and second polarizers and not between the first and second substrates, the plurality of touch sensing elements comprising a plurality of touch drive electrodes and plurality of touch sense electrodes, the plurality of touch drive electrodes and the plurality of touch sense electrodes being operative at least during a touch sensing mode of operation;

the plurality of touch drive electrodes and the plurality of touch sense electrodes spaced apart from one another to form capacitive coupling nodes therebetween;

a counter electrode used during a liquid crystal display operation and disposed between the liquid crystal layer and the second substrate, the counter electrode separate and distinct from the plurality of touch drive electrodes and separate and distinct from the plurality of touch sense electrodes;

the counter electrode being grounded during the touch sensing mode of operation to shield the plurality of touch drive electrodes and the plurality of touch sense electrodes disposed above the counter electrode, from the liquid crystal layer disposed below the counter electrode;

the plurality of touch drive electrodes operative to receive a periodic voltage;

the plurality of touch drive electrodes driven by the periodic voltage one at a time or in groups; and

at least one capacitance sensing circuit operatively coupled to the plurality of touch sense electrodes during the touch sensing m de of operation for measuring a change in current and/or voltage resulting from a change in capacitance at the capacitive coupling nodes.

35. The mobile telephone of claim 34 wherein the color filter is formed on a side of the second substrate facing the liquid crystal layer, and wherein the plurality of touch sensing elements are formed on he second substrate on a side opposite that of the color filter.

36. The mobile telephone of claim 34 wherein the plurality of touch sensing elements further comprise:

a first st plurality of touch electrodes formed on the second substrate, the first plurality of touch el ctrodes being one of the plurality of touch drive or the plurality of touch sense electrodes;

a dielectric deposited over the first plurality of electrodes; and

a second plurality of touch electrodes formed on top of the dielectric, the second plurality of touch electrodes being the other of the plurality of touch drive or the plurality of touch sense electrodes.

37. The mobile telephone of claim 34 wherein the plurality of touch drive electrodes are driven by the periodic voltage one at a time or in groups while the non-driven touch drive electrodes are grounded.