TOUCH SENSOR WITH FORCE-ACTUATED SWITCHED CAPACITOR

• US 20120092279A1
• Filed: 10/11/2011
• Published: 04/19/2012
• Est. Priority Date: 10/18/2010
• Status: Abandoned Application

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Martin, Russel Allyn
• Application Number:
  US13/271,063
• Publication Number:
  US 20120092279A1
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B
• CPC Class Codes: G06F 21/32 using biometric data, e.g. fingerprints, iris scans or voiceprints
• CPC Class Codes: G06F 21/83 input devices, e.g. keyboards, mice or controllers thereof
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 2203/04106 Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection
• CPC Class Codes: G06F 3/03547 Touch pads, in which fingers can move on a surface
• CPC Class Codes: G06F 3/04144 using an array of force sensing means position sensing using the local deformation of sensor cells G06F3/0447
• CPC Class Codes: G06F 3/04146 using pressure sensitive conductive elements delivering a boolean signal and located between crossing sensing lines, e.g. located between X and Y sensing line layers
• 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 3/044 by capacitive means
• 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 3/0447 Position sensing using the local deformation of sensor cells
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact
• CPC Class Codes: G06V 40/1306 non-optical, e.g. ultrasonic or capacitive sensing
• CPC Class Codes: Y10T 156/10 Methods of surface bonding and/or assembly therefor
• CPC Class Codes: Y10T 29/49124 On flat or curved insulated base, e.g., printed circuit, etc.

Abstract

This disclosure provides apparatus, systems and methods of fabricating force-sensitive switches. In some implementations, an array of force-sensitive switches and local capacitors of a combined sensor device may be used to connect the local capacitor into associated projected capacitive touch (PCT) detection circuitry. In some implementations, each capacitor may be formed with a thin dielectric layer to achieve a high capacitance increase when the force-sensitive switch is closed, e.g., by the pressing of a stylus or finger. In some implementations, the same PCT detection circuitry can be used to detect changes in mutual capacitance when touched with a finger (touch mode) and changes in sensel capacitance when the force-sensitive switch is depressed (stylus or fingerprint mode).

Claims

1. An apparatus, comprising:

a first substantially transparent substrate;

first rows of substantially transparent conductor formed on the first substrate;

a first substantially transparent insulator formed on the first rows of conductor;

a second substantially transparent conductor formed in discontinuous areas of second rows on the first insulator;

a second substantially transparent and flexible substrate;

a third substantially transparent conductor formed in columns on the second substrate, the columns being substantially orthogonal to the rows; and

substantially transparent elastomeric material formed in second portions of the discontinuous areas of the second conductor, the elastomeric material extending from the discontinuous areas to the second substrate between the columns on the second substrate.

2. The apparatus of claim 1, further including substantially transparent resistors formed in first portions of the discontinuous areas, wherein the columns overlap the resistors.

3. The apparatus of claim 2, wherein the second conductor, the resistors and the third conductor form switches that may be closed when force is applied to the second substrate.

4. The apparatus of claim 1, wherein the first conductor, the first insulator and the second conductor form a first capacitor.

5. The apparatus of claim 4, further including a second capacitor configured in parallel with the first capacitor.

6. The apparatus of claim 4, wherein a capacitance of the first capacitor is modulated when a conducting object is near the second substrate.

7. The apparatus of claim 5, wherein the second conductor, a resistor and the third conductor form a switch that may be closed when force is applied to the second substrate, and wherein the switch is configured in series with the second capacitor.

8. The apparatus of claim 1, further including a sensor controller that is configured for communication with the first conductor, the second conductor and the third conductor.

9. The apparatus of claim 1, further including an analog-to-digital converter.

10. The apparatus of claim 1, further including a leakage resistor.

11. The apparatus of claim 1, further including force-sensitive resistor material disposed between the rows and the columns.

12. The apparatus of claim 8, wherein the sensor controller includes a touch sensor controller.

13. The apparatus of claim 8, wherein the sensor controller includes a handwriting sensor controller.

14. The apparatus of claim 8, wherein the sensor controller includes a fingerprint sensor controller.

15. The apparatus of claim 8, further comprising:

a display;

a processor that is configured to communicate with the display and with the sensor controller, the processor being configured to process image data; and

a memory device that is configured to communicate with the processor.

16. The apparatus of claim 15, further comprising:

a driver circuit configured to send at least one signal to the display; and

a controller configured to send at least a portion of the image data to the driver circuit.

17. The apparatus of claim 15, further comprising:

an image source module configured to send the image data to the processor, wherein the image source module includes at least one of a receiver, transceiver, and transmitter.

18. The apparatus of claim 15, further comprising:

an input device configured to receive input data and to communicate the input data to the processor.

19. A multi-touch sensing apparatus, comprising:

first substantially transparent substrate means;

first rows of substantially transparent conductor means formed on the first substrate means;

first substantially transparent insulator means formed on the first rows of conductor means;

second substantially transparent conductor means formed in discontinuous areas of second rows on the first insulator means;

second substantially transparent and flexible substrate means;

third substantially transparent conductor means formed in columns on the second substrate means, the columns being substantially orthogonal to the rows; and

substantially transparent elastomeric means formed in second portions of the discontinuous areas of the second conductor means, the elastomeric means extending from the discontinuous areas to the second substrate means between the columns on the second substrate means.

20. The apparatus of claim 19, further comprising:

substantially transparent resistor means formed in first portions of the discontinuous areas, wherein the columns overlap the resistor means.

21. The apparatus of claim 20, wherein the second conductor means, the resistor means and the third conductor means form switches that may be closed when force is applied to the second substrate means.

22. The apparatus of claim 19, wherein the first conductor means, the first insulator means and the second conductor means form a first capacitor.

23. The apparatus of claim 22, wherein the second conductor means and the third conductor means form a second capacitor configured in parallel with the first capacitor.

24. A method of forming a multi-touch sensing apparatus, comprising:

forming first rows of substantially transparent conductor material on a first substantially transparent substrate;

forming a first substantially transparent insulator on the first rows of conductor material;

forming second substantially transparent conductor material in discontinuous areas of second rows on the first insulator;

forming third substantially transparent conductor material in columns on a second substantially transparent and flexible substrate, the columns being substantially orthogonal to the rows; and

forming substantially transparent elastomeric material in second portions of the discontinuous areas of the second conductor, the elastomeric material extending from the discontinuous areas to the second substrate between the columns on the second substrate.

25. The method of claim 24, further including:

forming substantially transparent resistors in first portions of the discontinuous areas.

26. The method of claim 25, wherein the second conductor material, the resistors and the third conductor material form a switch that may be closed when force is applied to the second substrate.

27. The method of claim 26, wherein the switch is configured in series with the second capacitor.

28. The method of claim 24, wherein the first conductor material, the first insulator and the second conductor material form a first capacitor.

29. The method of claim 24, further including:

forming force-sensitive resistor material between the rows and the columns.

30. The method of claim 24, further including configuring a sensor controller for communication with the first conductor, the second conductor and the third conductor.

31. The method of claim 30, further including configuring the sensor controller to function as a touch sensor controller.

32. The method of claim 30, further including configuring the sensor controller to function as a handwriting sensor controller.

33. The method of claim 30, further comprising:

attaching the apparatus to a display; and

configuring the sensor controller for communication with a processor that is configured for controlling the display.