Double-sided touch-sensitive panel with shield and drive combined layer

• US 7,920,129 B2
• Filed: 01/03/2007
• Issued: 04/05/2011
• Est. Priority Date: 01/03/2007
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Land, Brian Richards, Hotelling, Steve Porter
• Primary Examiner(s): Wang; Quan-Zhen
• Assistant Examiner(s): Nguyen; Jennifer T
• Application Number:
  US11/650,182
• Publication Number:
  US 20080158183A1
• Time in Patent Office: 1,553 Days
• Field of Search: 345173-179, 345156-162, 178 1801- 1807, 178 1901- 1906, 178 2001- 2004
• US Class Current: 345/173
• CPC Class Codes: G02F 1/133342 for double-sided displays
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G06F 1/1692 the I/O peripheral being a secondary touch screen used as control interface, e.g. virtual buttons or sliders
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 2203/04104 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 2203/04107 Shielding in digitiser, i.e. guard or shielding arrangements, mostly for capacitive touchscreens, e.g. driven shields, driven grounds
• 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 3/0445 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
• CPC Class Codes: G06F 3/047 using sets of wires, e.g. crossed wires
• CPC Class Codes: G09G 2300/04 Structural and physical details of display devices
• CPC Class Codes: G09G 5/003 Details of a display terminal, the details relating to the control arrangement of the display terminal and to the interfaces thereto specific for a CRT G09G1/165; for a flat panel G09G3/2092

Abstract

A multi-touch capacitive touch sensor panel can be created using a substrate with column and row traces formed on either side of the substrate. To shield the column (sense) traces from the effects of capacitive coupling from a modulated Vcom layer in an adjacent liquid crystal display (LCD) or any source of capacitive coupling, the row traces can be widened to shield the column traces, and the row traces can be placed closer to the LCD. In particular, the rows can be widened so that there is spacing of about 30 microns between adjacent row traces. In this manner, the row traces can serve the dual functions of driving the touch sensor panel, and also the function of shielding the more sensitive column (sense) traces from the effects of capacitive coupling.

Claims

1. A capacitive touch sensor panel, comprising:

a first set of traces of conductive material arranged along a first dimension of a two-dimensional coordinate system, the first set of traces having one or more widths including a maximum width; and

a second set of traces of the conductive material spatially separated from the first set of traces by a dielectric and arranged along a second dimension of the two-dimensional coordinate system, the second set of traces having one or more widths including a minimum width;

wherein the minimum width of the second set of traces is substantially greater than the maximum width of the first set of traces at least at an intersection of the first and second sets of traces to provide shielding for the first set of traces; and

wherein sensors are formed at locations at which the first set of traces intersects with the second set of traces while separated by the dielectric.

2. The capacitive touch sensor panel of claim 1, further comprising a liquid crystal display (LCD) adjacent to the touch sensor panel, the LCD emitting a modulated Vcom signal, and the second set of traces configured for shielding the first set of traces from the modulated Vcom signal.

3. The capacitive touch sensor panel of claim 1, wherein the second set of traces are widened to substantially electrically isolate the first set of traces from a liquid crystal display (LCD).

4. The capacitive touch sensor panel of claim 3, wherein the second set of traces includes a gap of about 30 microns between adjacent traces.

5. The capacitive touch sensor panel of claim 1, further comprising a computing system that incorporates the sensor panel.

6. The capacitive touch sensor panel of claim 5, further comprising a mobile telephone that incorporates the computing system.

7. The capacitive touch sensor panel of claim 5, further comprising a digital audio player that incorporates the computing system.

8. A mobile telephone having a capacitive touch sensor panel, the touch sensor panel comprising:

a first set of traces of conductive material arranged along a first dimension of a two-dimensional coordinate system, the first set of traces having one or more widths including a maximum width; and

a second set of traces of the conductive material spatially separated from the first set of traces by a dielectric and arranged along a second dimension of the two-dimensional coordinate system, the second set of traces having one or more widths including a minimum width;

wherein the minimum width of the second set of traces is substantially greater than the maximum width of the first set of traces at least at an intersection of the first and second sets of traces to provide shielding for the first set of traces; and

wherein sensors are formed at locations at which the first set of traces intersects with the second set of traces while separated by the dielectric.

9. A digital audio player having a capacitive touch sensor panel, the touch sensor panel comprising:

a first set of traces of conductive material arranged along a first dimension of a two-dimensional coordinate system, the first set of traces having one or more widths including a maximum width; and

a second set of traces of the conductive material spatially separated from the first set of traces by a dielectric and arranged along a second dimension of the two-dimensional coordinate system, the second set of traces having one or more widths including a minimum width;

wherein the minimum width of the second set of traces is substantially greater than the maximum width of the first set of traces at least at an intersection of the first and second sets of traces to provide shielding for the first set of traces; and

wherein sensors are formed at locations at which the first set of traces intersects with the second set of traces while separated by the dielectric.

10. A capacitive touch sensor panel, comprising:

sense traces having one or more widths including a maximum width; and

drive traces spatially separated from the sense traces by a dielectric, the drive traces having one or more widths including a minimum width, the minimum width of the drive traces being substantially greater than the maximum width of the sense traces at least at an intersection of the sense and drive traces to provide shielding for the sense traces;

wherein sensors are formed at locations at which the sense traces intersect with the drive traces while separated by the dielectric.

11. The capacitive touch sensor panel of claim 10, further comprising a liquid crystal display (LCD) adjacent to the touch sensor panel, the LCD emitting a modulated Vcom signal, and the drive traces configured for shielding the sense traces from the modulated Vcom signal.

12. The capacitive touch sensor panel of claim 10, wherein the drive traces are widened to substantially electrically isolate the sense traces from a liquid crystal display (LCD).

13. The capacitive touch sensor panel of claim 12, wherein the drive traces include a gap of about 30 microns between adjacent traces.

14. The capacitive touch sensor panel of claim 10, further comprising a computing system that incorporates the sensor panel.

15. The capacitive touch sensor panel of claim 14, further comprising a mobile telephone that incorporates the computing system.

16. The capacitive touch sensor panel of claim 14, further comprising a digital audio player that incorporates the computing system.

17. A method for shielding a capacitive touch sensor panel from capacitive coupling of modulated signals, comprising:

forming a first set of sense traces having one or more widths including a maximum width;

orienting the sense traces along a first dimension of a two-dimensional coordinate system;

forming a second set of drive traces spatially separated from the first set of sense traces by a dielectric, the second set of drive traces having one or more widths including a minimum width, the minimum width of the drive traces being substantially greater than the maximum width of the sense traces at least at an intersection of the first and second sets of traces to provide shielding for the sense traces; and

orienting the drive traces along a second dimension of the two-dimensional coordinate system to form sensors at locations at which the sense traces intersect with the drive traces while separated by the dielectric.

18. The method of claim 17, further comprising affixing a liquid crystal display (LCD) adjacent to a side of the touch sensor panel closest to the drive traces, the LCD capable of emitting a modulated Vcom signal.

19. The method of claim 17, further comprising widening the drive traces to substantially electrically isolate the sense traces from a liquid crystal display (LCD).

20. The method of claim 19, further comprising creating a gap of about 30 microns between adjacent drive traces.

21. A method for shielding a capacitive touch sensor panel from a source of capacitive coupling, comprising:

forming a first set of traces further from the source of capacitive coupling than a second set of traces, the first set of traces configured for sensing changes in mutual capacitance, the first set of traces having one or more widths including a maximum width;

orienting the first set of traces along a first dimension of a two-dimensional coordinate system;

forming the second set of traces closer to the source of capacitive coupling than the first set of traces and spatially separated from the first set of traces by a dielectric, the second set of traces having one or more widths including a minimum width, the minimum width of the second set of traces being substantially greater than the maximum width of the first set of traces at least at an intersection of the first and second sets of traces to provide shielding for the first set of traces, the second set of traces configured for being driven by low impedance driver outputs; and

orienting the second set of traces along a second dimension of the two-dimensional coordinate system to form sensors at locations at which the first set of traces intersects with the second set of traces while separated by the dielectric.

22. The method of claim 21, further comprising widening the drive traces to substantially electrically isolate the sense traces from a liquid crystal display (LCD).

23. The method of claim 22, further comprising creating a gap of about 30 microns between adjacent drive traces.

24. A capacitive touch sensor panel, comprising:

sense traces formed on a first layer and arranged along a first dimension of a two-dimensional coordinate system; and

drive traces formed on a second layer spatially separated from the first layer by a dielectric, the drive traces arranged along a second dimension of the two-dimensional coordinate system;

wherein the drive traces are widened as compared to the sense traces to substantially cover the second layer except for a gap between adjacent drive traces so as to substantially electrically isolate the sense traces from a liquid crystal display (LCD);

wherein sensors are formed at locations at which the sense traces intersect with the drive traces while separated by the dielectric; and

wherein each of the drive traces is of a substantially constant width.

25. A method for shielding a capacitive touch sensor panel from coupling of modulated signals, comprising:

forming a first set of sense traces on a first layer;

orienting the sense traces along a first dimension of a two-dimensional coordinate system;

forming a second set of widened drive traces on a second layer spatially separated from the first layer, the drive traces widened as compared to the sense traces to substantially cover the second layer except for a gap between adjacent drive traces so as to substantially electrically isolate the first set of sense traces from a liquid crystal display (LCD); and

orienting the drive traces along a second dimension of the two-dimensional coordinate system to form sensors at locations at which the sense traces intersect with the drive traces;

wherein each of the drive traces is of a substantially constant width.

26. A touch sensitive computing system, comprising:

a touch processor;

a display;

a touch sensor panel adjacent to the display and coupled to the touch processor, the touch sensor panel including

sense traces formed on a first layer, and

drive traces formed on a second layer spatially separated from the first layer, the drive traces widened as compared to the sense traces to substantially cover the second layer except for a gap between adjacent drive traces so as to substantially electrically isolate the sense traces from a liquid crystal display (LCD),

wherein sensors are formed at locations at which the sense traces intersect with the drive traces; and

wherein each of the drive traces is of a substantially constant width.

27. The touch sensitive computing system of claim 26, wherein the computing system is incorporated into a mobile telephone.

28. The touch sensitive computing system of claim 26, wherein the computing system is incorporated into a media player.

29. The touch sensitive computing system of claim 26, wherein the computing system is incorporated into personal computer.