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

• US 20080158183A1
• Filed: 01/03/2007
• Published: 07/03/2008
• Est. Priority Date: 01/03/2007
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Computer Incorporated (Apple Inc.)
• Inventors: Hotelling, Steve Porter, Land, Brian Richards
• Granted Patent: US 7,920,129 B2
• Time in Patent Office: Days
• 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 substrate formed from a dielectric material;

a first set of non-overlapping traces of conductive material located on a first side of the substrate and arranged along a first dimension of a two-dimensional coordinate system; and

a second set of non-overlapping traces of the conductive material located on a second side of the substrate and arranged along a second dimension of the two-dimensional coordinate system;

wherein the second set of traces are widened as compared to the first set 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 pass over the second set of traces while separated by the dielectric material of the substrate.

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 widened 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 cover the second side of the substrate except for a gap of about 30 microns between adjacent traces.

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

5. The capacitive touch sensor panel of claim 4, further comprising a mobile telephone that incorporates the computing system.

6. The capacitive touch sensor panel of claim 4, further comprising a digital audio player that incorporates the computing system.

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

a substrate formed from a dielectric material;

a first set of non-overlapping traces of conductive material located on a first side of the substrate and arranged along a first dimension of a two-dimensional coordinate system; and

a second set of non-overlapping traces of the conductive material located on a second side of the substrate and arranged along a second dimension of the two-dimensional coordinate system;

wherein the second set of traces are widened as compared to the first set 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 pass over the second set of traces while separated by the dielectric material of the substrate.

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

a substrate formed from a dielectric material;

a first set of non-overlapping traces of conductive material located on a first side of the substrate and arranged along a first dimension of a two-dimensional coordinate system; and

a second set of non-overlapping traces of the conductive material located on a second side of the substrate and arranged along a second dimension of the two-dimensional coordinate system;

wherein the second set of traces are widened as compared to the first set 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 pass over the second set of traces while separated by the dielectric material of the substrate.

9. A capacitive touch sensor panel, comprising:

sense traces formed on a first side of a dielectric substrate; and

drive traces formed on a second side of the substrate, the drive traces widened as compared to the sense traces to provide shielding for the sense traces;

wherein sensors are formed at locations at which the sense traces cross over the drive traces while separated by the dielectric substrate.

10. The capacitive touch sensor panel of claim 9, further comprising a liquid crystal display (LCD) adjacent to the touch sensor panel, the LCD emitting a modulated Vcom signal, and the widened second set drive traces configured for shielding the first set of traces from the modulated Vcom signal.

11. The capacitive touch sensor panel of claim 9, wherein the drive traces are widened to substantially cover the second side of the substrate except for a gap of about 30 microns between adjacent drive traces.

12. The capacitive touch sensor panel of claim 9, further comprising a computing system that incorporates the sensor panel.

13. The capacitive touch sensor panel of claim 12, further comprising a mobile telephone that incorporates the computing system.

14. The capacitive touch sensor panel of claim 12, further comprising a digital audio player that incorporates the computing system.

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

forming a first set of non-overlapping sense traces on a first side of a dielectric substrate;

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

forming a second set of widened non-overlapping drive traces on a second side of the substrate, the drive traces widened as compared to the sense 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 cross over the drive traces while separated by the dielectric substrate.

16. The method of claim 15, 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.

17. The method of claim 15, further comprising widening the drive traces to substantially cover the second side of the substrate except for a gap of about 30 microns between adjacent drive traces.

18. The method of claim 17, further comprising widening the drive traces until a gap of about 30 microns is formed between adjacent drive traces.

20. The method of claim 18, further comprising widening the drive traces until a gap of about 30 microns is formed between adjacent drive traces.

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

forming a first set of non-overlapping traces on a first side of a dielectric substrate furthest from the source of capacitive coupling, the first set of traces configured for sensing changes in mutual capacitance;

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

forming a second set of widened non-overlapping traces on a second side of the substrate closest to the source of capacitive coupling 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 cross over the second set of traces while separated by the dielectric substrate.