Method and device for measuring signals

• US 9,791,487 B2
• Filed: 03/27/2013
• Issued: 10/17/2017
• Est. Priority Date: 03/29/2012
• Status: Active Grant

• Current Assignee: eGalax_eMPIA Technology Inc.
• Original Assignee: eGalax_eMPIA Technology Inc.
• Inventors: Chang, Chin-Fu
• Primary Examiner(s): Assouad, Patrick
• Assistant Examiner(s): Yodichkas, Khristopher
• Application Number:
  US13/851,497
• Publication Number:
  US 20130257458A1
• Time in Patent Office: 1,665 Days
• Field of Search: 324658-690, 345156-184, 178 1801- 1806, 178 2001- 2004, 178FOR 1, 178FOR 103, 257203, 257235-236, 257239, 438144, 438 60, 438 73- 77
• CPC Class Codes: G01R 27/2605 Measuring capacitance capacitive sensors G01D5/24
• 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 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/04182 Filtering of noise external to the device and not generated by digitiser components
• 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

Abstract

Sinusoidal drive is used, and a coefficient table for a plurality of predetermined phases is established, wherein each predetermined phase is designated with a coefficient. A sinusoidal wave is measured at the plurality of predetermined phases of each half cycle to produce measured signals, and each of the measured signals is multiplied with the coefficient corresponding to the phase at which the signal is measured to produce a weighted measured signal. Then, the weighted measured signals are summed to produce a complete measured signal.

Claims

1. A method for measuring signals in a touch sensor, comprising:

receiving a sinusoidal wave by a sensing conductive strip in the touch sensor, wherein the sinusoidal wave is provided by a driving conductive strip intersecting the sensing conductive strip;

measuring signals from the sinusoidal wave at a plurality of predetermined phases of at least a cycle of the sinusoidal wave, wherein the plurality of phases are separated 60 degrees;

producing a weighted measured signal of the at least one cycle based on a product generated by multiplying each measured signal of the at least one cycle with an integer coefficient which is a multiple of the sine value of the predetermined phase at which the particular signal was measured; and

summing all of the weighted measured signals of the at least one cycle to produce a complete measured signal.

2. The method of claim 1, further comprising:

providing the sinusoidal wave at one or a set of driving conductive strips of a touch sensor; and

receiving the sinusoidal wave by one of a plurality of sensing conductive strips in the touch sensor intersecting with the one or the set of driving conductive strips provided with the sinusoidal wave, the one of the plurality of sensing conductive strips receiving the sinusoidal wave through capacitive coupling with the one or the set of driving conductive strips provided with the sinusoidal wave.

3. The method of claim 1, further comprising:

converting each measured signal from an analog measured signal to a digital measured signal, wherein the signals measured from the sinusoidal wave are in an analog form, and each weighted measured signal is a digital product of a digital measured signal multiplied by a digital sine value.

4. The method of claim 1, wherein the weighted measured signals are digital products of digital measured signals multiplied by respective integers, wherein the integers are obtained by multiplying the respective sine value with the same multiple.

5. The method of claim 1, further comprising:

converting each weighted measured signal from an analog weighted measured signal to a digital weighted measured signal, wherein the measured signals are in an analog form, and each analog weighted measured signal is obtained by amplifying the analog measured signal with a multiple of the sine value of the predetermined phase at which the signal was measured.

6. The method of claim 1, wherein the summing of all the weighted measured signals of the at least one cycle is carried out by integration, and the measured signals and the weighted measured signals are in the analog form.

7. The method of claim 1, wherein the predetermined phases are continuously arranged, and wherein adjacent phases have the same phase difference.

8. The method of claim 1, wherein the phases are at 30, 90, 150, 210, 270, and 330 degrees.

9. A device for measuring signals in a touch sensor, comprising:

an analog measuring circuit for receiving a sinusoidal wave by a sensing conductive strip in the touch sensor, wherein the sinusoidal wave is provided by a driving conductive strip intersecting the sensing conductive strip, and the analog measuring circuit is further for measuring analog signals from the sinusoidal wave at a plurality of predetermined phases of at least a cycle of the sinusoidal wave, wherein the plurality of phases are separated 60 degrees;

an analog-to-digital converter for converting each analog measured signal into a digital measured signal; and

a processor for producing a digital weighted measured signal of the at least one cycle based on a product generated by multiplying each digital measured signal of the at least one cycle with an integer coefficient which is a multiple of the sine value of the predetermined phase at which the particular signal was measured, and summing all of the digital weighted measured signals of the at least one cycle to produce a complete measured signal.

10. The device of claim 9, wherein the digital weighted measured signals are digital products of the digital measured signals multiplied by respective integers, wherein the integers are obtained by multiplying the respective sine value with the same multiple.

11. The device of claim 9, wherein the predetermined phases are continuously arranged, and wherein adjacent phases have the same phase difference.

12. The device of claim 9, wherein the phases are at 30, 90, 150, 210, 270, and 330 degrees.

13. A device for measuring signals in a touch sensor, comprising:

an analog measuring circuit for receiving a sinusoidal wave by a sensing conductive strip in the touch sensor, wherein the sinusoidal wave is provided by a driving conductive strip intersecting the sensing conductive strip, and the analog measuring circuit is further for measuring analog signals from the sinusoidal wave at a plurality of predetermined phases of at least a cycle of the sinusoidal wave, wherein the plurality of phases are separated 60 degrees;

an amplifying circuit for amplifying each analog measured signal with an integer coefficient which is a multiple of the sine value of the predetermined phase at which the particular signal was measured to produce an analog weighted measured signal;

an analog-to-digital converter for converting each analog weighted measured signal into a digital weighted measured signal; and

a processor for summing all of the digital weighted measured signals of the at least one cycle to produce a complete measured signal.

14. The device of claim 13, wherein the predetermined phases are continuously arranged, and wherein adjacent phases have the same phase difference.

15. The device of claim 13, wherein the phases are at 30, 90, 150, 210, 270, and 330 degrees.

16. A device for measuring signals in a touch sensor, comprising:

an analog measuring circuit for receiving a sinusoidal wave by a sensing conductive strip in the touch sensor, wherein the sinusoidal wave is provided by a driving conductive strip intersecting the sensing conductive strip, and the analog measuring circuit is further for measuring analog signals from the sinusoidal wave at a plurality of predetermined phases of at least a cycle of the sinusoidal wave, wherein the plurality of phases are separated 60 degrees;

an amplifying circuit for amplifying each analog measured signal with an integer coefficient which is a multiple of the sine value of the predetermined phase at which the particular signal was measured to produce an analog weighted measured signal;

an integrator circuit for performing integration on all of the analog measured signals of the at least one cycle to produce an analog complete measured signal; and

an analog-to-digital converter for converting each analog complete measured signal into a digital complete measured signal.

17. The device of claim 16, wherein the predetermined phases are continuously arranged, and wherein adjacent phases have the same phase difference.

18. The device of claim 16, wherein the phases are at 60, 90, 150, 210, 270, and 330 degrees.