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

• US 8,884,890 B2
• Filed: 04/01/2011
• Issued: 11/11/2014
• Est. Priority Date: 01/03/2007
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Hotelling, Steve Porter, Land, Brian Richards
• Primary Examiner(s): NGUYEN, JENNIFER T
• Application Number:
  US13/078,789
• Publication Number:
  US 20110181549A1
• Time in Patent Office: 1,320 Days
• Field of Search: 345173-179, 178 1801- 1806
• 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 touch sensor panel, comprising:

a first set of traces of conductive material having lengths arranged along a first dimension of a two-dimensional coordinate system, an average width of the first set of traces over an entire length of the trace defining a first average width; and

a second set of traces of the conductive material spatially separated from the first set of traces by a dielectric having lengths arranged along a second dimension of the two-dimensional coordinate system, an average width of the second set of traces over an entire length of the trace defining a second average width;

wherein the second average width is substantially greater than the first average width to provide shielding for the first set of traces.

2. The touch sensor panel of claim 1, wherein the plurality of second traces are coupled for receiving a stimulation signal.

3. The touch sensor panel of claim 1, wherein sensors are formed at locations at which the first set of traces and the second set of traces pass above and below each other but do not make direct electrical contact with each other while separated by the dielectric.

4. The touch sensor panel of claim 1, wherein the second average width is selected to provide an average spacing between the second set of traces of less than a predetermined amount to provide optical uniformity.

5. The touch sensor panel of claim 1, the touch sensor panel incorporated into a touch-sensitive computing system.

6. The touch sensor panel of claim 1, the touch sensor panel supported on a liquid crystal display (LCD) capable of emitting a modulated signal, wherein the second set of traces are configured for shielding the first set of traces from the modulated signal.

7. The touch sensor panel of claim 1, the touch sensor panel coupled to a panel subsystem controller configured for sending stimulation signals to the second set of traces and receiving sense signals from the first set of traces.

8. A touch sensor panel, comprising:

a plurality of sense traces of conductive material each having an average width defining a sense trace average width; and

a plurality of drive traces of the conductive material spatially separated from the plurality of sense traces by a dielectric, the plurality of drive traces each having an average width defining a drive trace average width;

wherein the drive trace average width is substantially greater than the sense trace average width to provide shielding for the plurality of sense traces.

9. The touch sensor panel of claim 8, wherein the plurality of drive traces are coupled for receiving a stimulation signal.

10. The touch sensor panel of claim 8, wherein sensors are formed at locations at which the plurality of sense traces and the plurality of drive traces pass above and below each other but do not make direct electrical contact with each other while separated by the dielectric.

11. The touch sensor panel of claim 8, wherein the drive trace average width of the plurality of drive traces is selected to provide an average spacing between the plurality of drive traces of less than a predetermined amount to provide optical uniformity.

12. The touch sensor panel of claim 8, the touch sensor panel incorporated into a touch-sensitive computing system.

13. The touch sensor panel of claim 8, the touch sensor panel supported on a liquid crystal display (LCD) capable of emitting a modulated signal, wherein the plurality of drive traces are configured for shielding the plurality of sense traces from the modulated signal.

14. The touch sensor panel of claim 8, the touch sensor panel coupled to a panel subsystem controller configured for sending stimulation signals to the plurality of drive traces and receiving sense signals from the plurality of sense traces.

15. A method for shielding a touch sensor panel, comprising:

interposing a second layer of conductive material including a plurality of second traces between a first layer of the conductive material including a plurality of first traces and a noise source, the plurality of second traces having an average width defining a second average width and the plurality of first traces having an average width defining a first average width; and

configuring the plurality of second traces such that the second average width is substantially greater than the first average width to provide shielding for the first plurality of traces.

16. The method of claim 15, further comprising coupling the plurality of second traces to a stimulation signal.

17. The method of claim 15, further comprising arranging the plurality of second traces and the plurality of first traces to form sensors at locations at which the plurality of second traces and the plurality of first traces pass above and below each other but do not make direct electrical contact with each other.

18. The method of claim 15, further comprising selecting the second average width of the second plurality of traces to provide an average spacing between the second plurality of traces of less than a predetermined amount to provide optical uniformity.

19. A computing device, comprising:

a circuit capable of emitting electromagnetic interference;

a touch sensor panel coupled to the circuit, the touch sensor panel including

a first set of traces of conductive material having lengths arranged along a first dimension of a two-dimensional coordinate system, an average width of the first set of traces over an entire length of the trace defining a first average width, and

a second set of traces of the conductive material spatially separated from the first set of traces by a dielectric having lengths arranged along a second dimension of the two-dimensional coordinate system, an average width of the second set of traces over an entire length of the trace defining a second average width,

wherein the second average width is substantially greater than the first average width to provide shielding for the first set of traces; and

a panel subsystem controller coupled to the touch sensor panel, the panel subsystem controller configured for sending stimulation signals to the second set of traces and receiving sense signals from the first set of traces.

20. The computing device of claim 19, wherein sensors are formed at locations on the touch sensor panel at which the first set of traces and the second set of traces pass above and below each other but do not make direct electrical contact with each other while separated by a dielectric.

21. The computing device of claim 19, wherein the second average width of the second set of traces is selected to provide an average spacing between the second set of traces of less than a predetermined amount to provide optical uniformity.

22. The computing device of claim 19, wherein the second set of traces are coupled for receiving a stimulation signal.