Patterned resistive touch panel

• US 20100277418A1
• Filed: 05/04/2009
• Published: 11/04/2010
• Est. Priority Date: 05/04/2009
• Status: Active Grant

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation
• Inventors: Lee, Seok Lyul, Li, Ming Chun, Huang, Hong Ji, Huang, Kung Chieh, Wu, Keng-Jui
• Granted Patent: US 8,432,373 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 2203/04808 Several contacts: gestures triggering a specific function, e.g. scrolling, zooming, right-click, when the user establishes several contacts with the surface simultaneously; e.g. using several fingers or a combination of fingers and pen
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact

Abstract

A touch panel having a first panel and a second panel, wherein the first panel has a voltage providing area connected to a power source and the second panel has a patterned resistive element facing the voltage providing area so that when a touch event on the touch panel occurs, the first panel is caused to make contact with and provide a voltage to the second panel at one or more contact points on the resistive element. By measuring the voltage on one or both ends of the resistive element, it is possible to determine the two-dimensional coordinates of each contact point. The touch panel can have one or more resistive elements located at different touch areas for sensing one or more touch points in a touch event.

Claims

1. A touch panel comprising:

a first substrate, and

a second substrate spaced from the first substrate leaving a gap between the first substrate and the second substrate, wherein the second substrate comprises a resistive element arranged in a meandering shape in an area, such that when a touch event occurs on the touch panel causing a contact between the first substrate and the second substrate at a contact point on the resistive element, the contact point is identifiable by two-dimensional coordinates of a location in the area.

2. A touch panel according to claim 1, wherein the resistive element has a total length defined by a first element end and a second element end, the first element end configured for electrical measurement, and wherein the first substrate is configured for connection to a power source, such that when the touch event causes the contact at the contact point on the resistive element, the first substrate is configured to provide a voltage to the resistive element at the contact point, and the electrical measurement at the first end is configured to yield a measurement value at least depending on the voltage and the two-dimensional coordinates.

3. A touch panel according to claim 2, wherein the first element end is connected to a reference resistance element for voltage measurement, and wherein the measurement value comprises a voltage value at least depending on the voltage, the two-dimensional coordinates of the contact point and resistance of the reference resistance element.

4. A touch panel according to claim 2, wherein the second element end is also configured for electrical measurement, such that when the touch event causes the contact between the first substrate and the second substrate additionally at a different contact point on the resistive element, the different contact point is identifiable by different two-dimensional coordinates of the area, and the electrical measurement at the second end is configured to yield a different measurement value.

5. A touch panel according to claim 1, wherein the two-dimensional coordinates comprise coordinate value of a first axis and coordinate value of a second axis, and wherein the resistive element comprises a plurality of first segments along the first axis and one or more second segments along the second axis, connected together to form the meandering shape.

6. A touch panel according to claim 1, wherein the second substrate further comprises a second resistive element arranged in a different area, such that when the contact between the first substrate and the second substrate additionally occurs at a further contact point at the second resistive element, the further contact point is identifiable by two-dimensional coordinates of a location in the different area.

7. A touch panel according to claim 6, wherein the resistive element has a first element end a second element end and the second resistive element has a third element end and a fourth element end, and wherein each of the first element end, the second element end, the third element end and the fourth element end is configured for electrical measurement, and the first substrate is configured for connection to a power source to provide a voltage to at least one of the contact point on the resistive element and the further contact point on the second resistive element.

8. A touch panel according to claim 1, wherein the first substrate comprises a different resistive element in meandering shape.

9. A touch panel according to claim 2, wherein the measurement value is indicative of a length of the resistive element from the contact point to the first end and the total length of the resistive element.

10. A touch panel according to claim 2, wherein the different measurement value is indicative of a length of the resistive element from the different contact point to the second end and total length of the resistive element.

14. A touch sensing system comprising:

a touch panel according to claim 1, wherein the resistive element has a first element end and a second element end,

a power source connected to the first substrate, such that when the touch event causes the contact at the contact point, the first substrate is configured to provide a voltage to the resistive element at the contact point; and

a measurement module connected to the second substrate for obtaining a measurement value at the first element end, and for determining the two-dimensional coordinates of the contact point based on the measurement value.

15. A touch sensing system according to claim 14, further comprising a look-up table so that the two-dimensional coordinates of the contact point can be determined from the look-up table based on the measurement value.

16. A touch sensing system according to claim 14, wherein the touch event causes the contact between the first substrate and the second substrate additionally at a different contact point on the resistive element, the different contact point identifiable by different two-dimensional coordinates of the area, and wherein the measurement module is configured to obtain a different measurement value at the second element end for determining the different two-dimensional coordinates of the contact point based on the different measurement value.

17. An integrated display system comprising:

a touch panel according to claim 1, and

a display panel located in relationship to the touch panel, wherein the display panel comprises displayed information visible through the touch panel so as to allow a user to select the displayed information by causing the touch event on the touch panel.

11. A method for touch sensing on a touch panel comprising a first substrate and a second substrate spaced from the first substrate leaving a gap therebetween, said method comprising:

providing a resistive element of a meandering shape in an area on the second substrate, the resistive element has a first element end and a second element end;

connecting a power source to the first substrate, such that when a touch event occurs on the touch panel causing a contact between the first substrate and the second substrate at a contact point on the resistive element, the first substrate is configured to provide a reference voltage to the resistive element at the contact point;

measuring a voltage value at the first end of the resistive element; and

obtaining two-dimensional coordinates of the contact point at least based on the voltage value.

12. A method according to claim 11, wherein the resistive element has a resistance value between the contact point and the first element end, said resistance value indicative of the two-dimensional coordinates of the contact point, said method further comprising:

connecting a reference resistance element to the first element end for said measuring, the reference resistance element having a reference resistance value; and

computing the resistance value based on the reference resistance value, the reference voltage and the voltage value at the first end, so as to determine the two-dimensional coordinates of the contact point.

13. A method according to claim 11, wherein the two-dimensional coordinates of the contact point are obtained a look-up table based on the voltage value.

18. A touch panel module comprising:

a first substrate configured for connection to a power source;

a second substrate spaced from the first substrate leaving a gap between the first substrate and the second substrate, the second substrate comprising a resistive element having a first end and a second end;

an electrical measurement device coupled to the first end and the second end, such that when a touch event occurs on the touch panel causing a contact between the first substrate and a second substrate at a contact point on the resistive element, the electrical measurement device receives at least one of a first signal from the first end and a second signal from the second end.

19. A touch panel module according to claim 18, wherein the first signal is indicative of a length of the resistive element from the contact point to the first end.

20. A touch panel module according to claim 18, wherein the second signal is indicative of a length of the resistive element from the contact point to the second end.

21. A touch panel module according to claim 18, wherein the first substrate comprises a layer of indium-tin oxide connected to the power source for providing the voltage to the resistive element in the touch event.

22. A touch panel module according to claim 18, wherein the resistive element is arranged in a meandering shape.