Calibration of a touch-sensor device

• US 9,292,122 B1
• Filed: 08/17/2012
• Issued: 03/22/2016
• Est. Priority Date: 09/06/2007
• Status: Expired due to Fees

• Current Assignee: Monterey Research, LLC (Vector Capital Corporation)
• Original Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Inventors: Maharyta, Andriy, Birch, Robert Michael
• Primary Examiner(s): Nguyen, Vincent Q
• Application Number:
  US13/588,477
• Time in Patent Office: 1,313 Days
• Field of Search: 324/601, 324/658
• US Class Current: 1/1
• CPC Class Codes: G06F 2203/0339 Touch strips, e.g. orthogonal touch strips to control cursor movement or scrolling; single touch strip to adjust parameter or to implement a row of soft keys
• CPC Class Codes: G06F 3/03547 Touch pads, in which fingers can move on a surface
• CPC Class Codes: G06F 3/04164 Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• 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

Abstract

An apparatus having a processing device for calibrating a touch-sensor device with calibration capacitors is described. Methods of calibrating the touch-sensor device using the same are also described. Processing device and multiple calibration capacitors are disposed on an integrated circuit (IC) die substrate. The processing device includes a measurement circuit to be coupled to a touch-sensor device and a switching circuit to selectively couple the calibration capacitors to the measurement circuit. The processing device is configured to calibrate the touch-sensor device by applying one or more capacitance touch values from one or more of the calibration capacitors using the switching circuit. The one or more capacitance touch values simulate a touch on the touch-sensor device.

Claims

1. An apparatus comprising

a processing device disposed on an integrated circuit (IC) die substrate, wherein the processing device comprises:

a plurality of calibration capacitors disposed on the IC die substrate;

a charge measurement circuit to be coupled to a capacitive touch-sensor device; and

a switching circuit to selectively couple the plurality of calibration capacitors to the charge measurement circuit, and wherein the processing device is configured to calibrate the capacitive touch-sensor device by applying one or more capacitance touch values from one or more of the plurality of calibration capacitors using the switching circuit, wherein the one or more capacitance touch values simulate a touch on the capacitive touch-sensor device.

2. The apparatus of claim 1, further comprising a plurality of electrical traces coupled to the processing device and to be coupled to the capacitive touch-sensor device, wherein the switching circuit is configured to selectively couple individual ones of the plurality of calibration capacitors to individual ones of the plurality of electrical traces to simulate the touch on the capacitive touch-sensor device.

3. The apparatus of claim 1, wherein the switching circuit comprises a plurality of connection switches, each of the plurality of connection switches coupled with one of the plurality of calibration capacitors.

4. The apparatus of claim 3, wherein the plurality of connection switches are analog switches.

5. The apparatus of claim 3, wherein the plurality of connection switches are digital switches.

6. The apparatus of claim 1, wherein the processing device is configured to calibrate the capacitive touch-sensor device without the use of a manual touch.

7. The apparatus of claim 1, further comprising the capacitive touch-sensor device, wherein the capacitive touch-sensor device is a touch panel comprising a set of edges, the panel coupled with the charge measurement circuit, wherein the plurality of calibration capacitors are configured to simulate the touch at the set of edges of the touch panel.

8. The apparatus of claim 7, wherein the processing device is configured to calculate at least one of a coordinate gain or a coordinate offset based on a signal change of the touch panel, the signal change caused by at least one of the plurality of calibration capacitors.

9. A method comprising:

coupling a processing device to a capacitive touch-sensor device, the processing device being disposed on an integrated circuit (IC) die substrate and comprising a charge measurement circuit and a switching circuit;

selectively coupling one or more of a plurality of calibration capacitors to the charge measurement circuit via the switching circuit to apply one or more capacitance touch values to simulate a touch on the capacitive touch-sensor device, wherein the plurality of calibration capacitors are disposed on the IC die substrate; and

calibrating the capacitive touch-sensor device based on the simulated touch.

10. The method of claim 9, wherein calibrating the capacitive touch-sensor device comprises calibrating without the use of a manual touch.

11. The method of claim 9, wherein the coupling the processing device to the capacitive touch-sensor device comprising coupling a plurality of electrical traces of the processing device to the capacitive touch-sensor device, and wherein the selectively coupling comprises selectively coupling individual ones of the plurality of calibration capacitors to individual ones of the plurality of electrical traces via a plurality of connection switches, each of the plurality of connection to simulate the touch on the capacitive touch-sensor device.

12. The method of claim 9, wherein the capacitive touch-sensor device comprises a touch panel comprising a set of edges, and wherein the selectively coupling comprises selectively coupling one or more of a plurality of calibration capacitors to the charge measurement circuit via the switching circuit to apply one or more capacitance touch values to simulate the touch at the set of edges of the touch panel.

13. The method of claim 9, wherein the calibrating the capacitive touch-sensor device comprises calculating at least one of a coordinate gain or a coordinate offset based on a signal change of the panel, the signal change caused by at least one of the plurality of calibration capacitors.

14. The method of claim 9, wherein the calibrating the capacitive touch-sensor device comprises repeating the selectively coupling to simulate a touch periodically to compensate for calibration drift in the capacitive touch-sensor device.

15. The method of claim 9, wherein the selectively coupling to apply one or more capacitance touch values comprises selectively coupling the one or more of the plurality of capacitors to apply the one or more capacitance touch values that are approximately in the range of 0.5-5 picofarads.

16. A method comprising:

selectively coupling, by a first pair of connection switches of a processing device, a first pair of calibration capacitors, each calibration capacitor coupled, between a capacitive touch-sensor device and a charge measurement circuit of the processing device, with one of a first pair of electrical traces, to apply a first capacitance value to the first pair of electrical traces to similar a first touch on the capacitive touch-sensor device, wherein the processing device is disposed on an integrated circuit (IC) die substrate and the first pair of calibration capacitors are disposed on the IC die substrate;

selectively coupling, by a second pair of connection switches of the processing device, a second pair of calibration capacitors, each calibration capacitor coupled, between the capacitive touch-sensor device and the charge measurement circuit, with one of a second pair of electrical traces, to apply a second capacitance value to the second pair of electrical traces to simulate a second touch on the capacitive touch-sensor device, wherein the second pair of calibration capacitors are disposed on the IC die substrate; and

calibrating the capacitive touch-sensor device based on the simulated first touch and the simulated second touch.

17. The method of claim 16, wherein the calibrating the capacitive touch-sensor device comprises calibrating without the use of a manual touch.

18. The method of claim 16, wherein the selectively coupling the first pair to simulate the first touch comprises selectively coupling the first pair to simulate the first touch at an edge of a panel of the capacitive touch-sensor device, and wherein the selectively coupling the second pair to simulate the second touch comprises selectively coupling the second pair to simulate the second touch at another edge of the panel.

19. The method of claim 16, wherein the calibrating the capacitive touch-sensor device comprises calculating at least one of a coordinate gain or a coordinate offset based on a signal change of the capacitive touch-sensor device, the signal change caused by at least one of the calibration capacitors of the first and second pairs of calibration capacitors.

20. The method of claim 16, wherein the calibrating the capacitive touch-sensor device comprises repeating the selectively coupling the first pair to simulate the first touch periodically and repeating the selectively coupling the second pair to simulate the second touch periodically to compensate for calibration drift in the capacitive touch-sensor device.