Transmitter, touch sensitive system and transmitting method thereof

• US 9,823,791 B2
• Filed: 11/10/2014
• Issued: 11/21/2017
• Est. Priority Date: 11/08/2013
• Status: Active Grant

• Current Assignee: eGalax_eMPIA Technology Inc.
• Original Assignee: eGalax_eMPIA Technology Inc.
• Inventors: Chang, Chin-Fu
• Primary Examiner(s): EARLES, BRYAN E
• Application Number:
  US14/537,286
• Publication Number:
  US 20150130757A1
• Time in Patent Office: 1,107 Days
• 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 3/044 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

Abstract

The present invention provides a transmitter, which includes a transmitting module configured to transmit an electrical signal to a touch sensitive device according to at least one transmitter operating status such that the touch sensitive device acknowledges the transmitter operating status by analyzing the electrical signal including one or more first frequencies; a detecting module configured to detect an interference signal coherent to the electrical signal from a received signal external to the transmitter when the transmitting module is not transmitting the electrical signal; and a processing module configured to replace the detected one or more first frequencies with one or more second frequencies in response to the interference signal being detected by the detecting module.

Claims

1. A transmitter comprising:

a transmitting module configured to transmit an electrical signal to a touch sensitive device according to at least one transmitter operating status such that the touch sensitive device acknowledges the transmitter operating status by analyzing the electrical signal including one or more first frequencies;

a detecting module configured to detect an interference signal coherent to the electrical signal from a received signal external to the transmitter when the transmitting module is not transmitting the electrical signal; and

a processing module configured to replace the detected one or more first frequencies with one or more second frequencies in response to the interference signal being detected by the detecting module, wherein the step of replacing the one or more first frequencies with the one or more second frequency includes one of the following;

when the electrical signal includes one first frequency and when the received signal includes an interference signal of the first frequency, the electrical signal after frequency substitution includes a plurality of the second frequencies;

when the electrical signal includes a plurality of the first frequencies and when the received signal includes an interference signal of a plurality of the first frequencies, the electrical signal after frequency substitution includes one second frequency; and

when the electrical signal includes a plurality of the first frequencies and when the received signal includes an interference signal of a plurality of the first frequencies, the electrical signal after frequency substitution includes a plurality of the second frequencies.

2. The transmitter of claim 1, wherein the detecting module further includes at least one demodulator for determining if the first frequency is included in the received signal, the demodulator includes:

a signal generator for generating an in-phase signal and an orthogonal signal, wherein the frequency of the in-phase signal and the orthogonal signal is the first frequency;

at least a mixer for mixing the in-phase signal with the received signal to generate an in-phase analog signal, and mixing the orthogonal signal with the received signal to generate an orthogonal analog signal;

at least an integrator for performing integration on the in-phase analog signal to generate an in-phase integration signal, and performing integration on the orthogonal analog signal to generate an orthogonal integration signal;

at least a squarer for calculating the square of the in-phase integration signal and the square of the orthogonal integration signal; and

at least a Root Mean Square (RMS) of Sum element for calculating the root mean square of the sum of the square of the in-phase integration signal and the square of the orthogonal integration signal to obtain the signal strength corresponding to the first frequency.

3. The transmitter of claim 1, wherein the detecting module further includes at least one demodulator for determining if the first frequency is included in the received signal, the demodulator includes:

an analog-to-digital converter (ADC) for performing analog-to-digital conversion on the received signal to produce a digital received signal;

a signal generator for generating an in-phase signal and an orthogonal signal, wherein the frequency of the in-phase signal and the orthogonal signal is the first frequency;

at least a mixer for mixing the in-phase signal with the digital received signal to generate an in-phase digital signal, and mixing the orthogonal signal with the digital received signal to generate an orthogonal digital signal;

at least an addition integrator for performing addition integration on the in-phase digital signal to generate an in-phase integration signal, and performing integration on the orthogonal digital signal to generate an orthogonal integration signal;

at least a squarer for calculating the square of the in-phase integration signal and the square of the orthogonal integration signal; and

at least a Root Mean Square (RMS) of Sum element for calculating the root mean square of the sum of the square of the in-phase integration signal and the square of the orthogonal integration signal to obtain the signal strength corresponding to the first frequency.

4. The transmitter of claim 1, wherein the detecting module further includes at least one demodulator for determining if the first frequency is included in the received signal, the demodulator includes:

an analog-to-digital converter (ADC) for performing analog-to-digital conversion on the received signal to produce a digital received signal; and

a Fourier Transformer for performing Fourier Transform on the digital received signal to generate the signal strength corresponding to the first frequency.

5. The transmitter of claim 1, wherein the electrical signal including the first frequency and the electrical signal including the second frequency correspond to the same transmitter operating status.

6. The transmitter of claim 1, wherein when the received signal includes a plurality of the first frequencies and when the electrical signal after frequency substitution includes a plurality of the second frequencies, the number of the plurality of the first frequencies is different from that of the plurality of the second frequencies.

7. The transmitter of claim 1, wherein the step of replacing the one or more first frequencies with the one or more second frequency includes one of the following:

when the electrical signal includes a plurality of the first frequencies and when the received signal includes an interference signal of a plurality of the first frequencies, the frequency with the largest interference signal strength among the plurality of first frequencies is replaced first;

when the electrical signal includes a plurality of the first frequencies and when the received signal includes an interference signal of a plurality of the first frequencies, the frequency with the largest weighted value among the plurality of first frequencies is replaced first; and

when the electrical signal includes a plurality of the first frequencies and when the received signal includes an interference signal of a plurality of the first frequencies, based on a predetermined order, the most former one of the plurality of first frequencies in that order is replaced first.

8. The transmitter of claim 1, wherein the first frequency and the second frequency are not mutually resonant.

9. The transmitter of claim 1, wherein the detecting module is used to detect the received signal from a contact area between the transmitter with the touch sensitive device.

10. The transmitter of claim 1, further comprising a sensor module, wherein the transmitter operating status is produced based on a sensor status inside the sensor module.

11. The transmitter of claim 10, wherein a sensor inside the sensor module includes one of the following:

a button;

a knob;

a pressure sensor;

an accelerometer; and

a gyroscope.

12. A transmitting method applicable to a transmitter comprising the following steps of:

transmitting an electrical signal to a touch sensitive device according to at least one transmitter operating status such that the touch sensitive device acknowledges the transmitter operating status by analyzing the electrical signal including one or more first frequencies;

determining if an interference signal coherent to the electrical signal is included in a received signal external to the transmitter when the electrical signal is not being transmitted; and

replacing the detected one or more first frequencies in the electrical signal with one or more second frequencies in response to the interference signal being detected, wherein the step of replacing the one or more first frequencies with the one or more second frequency includes one of the following;

when the electrical signal includes one first frequency and when the received signal includes an interference signal of the first frequency, the electrical signal after frequency substitution includes a plurality of the second frequencies;

when the electrical signal includes a plurality of the first frequencies and when the received signal includes an interference signal of a plurality of the first frequencies, the electrical signal after frequency substitution includes one second frequency; and

when the electrical signal includes a plurality of the first frequencies and when the received signal includes an interference signal of a plurality of the first frequencies, the electrical signal after frequency substitution includes a plurality of the second frequencies.

13. The transmitting method of claim 12, further comprising the following steps for determining if the received signal includes the first frequency:

generating an in-phase signal and an orthogonal signal, wherein the frequency of the in-phase signal and the orthogonal signal is the first frequency;

mixing the in-phase signal with the received signal to generate an in-phase analog signal, and mixing the orthogonal signal with the received signal to generate an orthogonal analog signal;

performing integration on the in-phase analog signal to generate an in-phase integration signal, and performing integration on the orthogonal analog signal to generate an orthogonal integration signal;

calculating the square of the in-phase integration signal and the square of the orthogonal integration signal; and

calculating the root mean square of the sum of the square of the in-phase integration signal and the square of the orthogonal integration signal to obtain the signal strength corresponding to the first frequency.

14. The transmitting method of claim 12, further comprising the following steps for determining if the received signal includes the first frequency:

performing analog-to-digital conversion on the received signal to produce a digital received signal;

generating an in-phase signal and an orthogonal signal, wherein the frequency of the in-phase signal and the orthogonal signal is the first frequency;

mixing the in-phase signal with the digital received signal to generate an in-phase digital signal, and mixing the orthogonal signal with the digital received signal to generate an orthogonal digital signal;

performing addition integration on the in-phase digital signal to generate an in-phase integration signal, and performing integration on the orthogonal digital signal to generate an orthogonal integration signal;

calculating the square of the in-phase integration signal and the square of the orthogonal integration signal; and

calculating the root mean square of the sum of the square of the in-phase integration signal and the square of the orthogonal integration signal to obtain the signal strength corresponding to the first frequency.

15. The transmitting method of claim 12, further comprising the following steps for determining if the received signal includes the first frequency:

performing analog-to-digital conversion on the received signal to produce a digital received signal; and

performing Fourier Transform on the digital received signal to generate the signal strength corresponding to the first frequency.

16. The transmitting method of claim 12, wherein the electrical signal including the first frequency and the electrical signal including the second frequency correspond to the same transmitter operating status.

17. The transmitting method of claim 12, wherein when the received signal includes a plurality of the first frequencies and when the electrical signal after frequency substitution includes a plurality of the second frequencies, the number of the plurality of the first frequencies is different from that of the plurality of the second frequencies.

18. The transmitting method of claim 12, wherein the step of replacing the one or more first frequencies with the one or more second frequency includes one of the following:

when the electrical signal includes a plurality of the first frequencies and when the received signal includes an interference signal of a plurality of the first frequencies, the frequency with the largest interference signal strength among the plurality of first frequencies is replaced first;

when the electrical signal includes a plurality of the first frequencies and when the received signal includes an interference signal of a plurality of the first frequencies, the frequency with the largest weighted value among the plurality of first frequencies is replaced first; and

when the electrical signal includes a plurality of the first frequencies and when the received signal includes an interference signal of a plurality of the first frequencies, based on a predetermined order, the most former one of the plurality of first frequencies in that order is replaced first.

19. The transmitting method of claim 12, wherein the first frequency and the second frequency are not mutually resonant.

20. The transmitting method of claim 12, wherein the received signal is from a contact area between the transmitter and the touch sensitive device.

21. The transmitting method of claim 12, further comprising a sensor module, wherein the transmitter operating status is produced based on a sensor status inside the sensor module.

22. The transmitting method of claim 21, wherein a sensor inside the sensor module includes one of the following:

a button;

a knob;

a pressure sensor;

an accelerometer; and

a gyroscope.

23. A touch sensitive system comprising:

a touch sensitive device; and

a transmitter including;

a transmitting module configured to transmit an electrical signal to the touch sensitive device according to at least one transmitter operating status such that the touch sensitive device acknowledges the transmitter operating status by analyzing the electrical signal including one or more first frequencies;

a detecting module configured to detect an interference signal coherent to the electrical signal from a received signal external to the transmitter when the transmitting module is not transmitting the electrical signal; and

a processing module configured to replace the detected one or more first frequencies with one or more second frequencies in response to the interference signal being detected by the detecting module, wherein the step of replacing the one or more first frequencies with the one or more second frequency includes one of the following;

when the electrical signal includes one first frequency and when the received signal includes an interference signal of the first frequency, the electrical signal after frequency substitution includes a plurality of the second frequencies;

when the electrical signal includes a plurality of the first frequencies and when the received signal includes an interference signal of a plurality of the first frequencies, the electrical signal after frequency substitution includes one second frequency; and

when the electrical signal includes a plurality of the first frequencies and when the received signal includes an interference signal of a plurality of the first frequencies, the electrical signal after frequency substitution includes a plurality of the second frequencies.

24. The touch sensitive system of claim 23, wherein the touch sensitive device obtains a relative position of the transmitter with respect to the touch sensitive device based on the electrical signal.

25. The touch sensitive system of claim 23, wherein the method for analyzing the electrical signal used by the touch sensitive device is the same as the detection method used by the detecting module.

26. The touch sensitive system of claim 23, wherein the touch sensitive device detects the electrical signal when the transmitting module is transmitting the electrical signal.

27. The touch sensitive system of claim 23, wherein the transmitter further includes a sensor module, wherein the transmitter operating status is produced based on a sensor status inside the sensor module.

28. The touch sensitive system of claim 27, wherein a sensor inside the sensor module includes one of the following:

a button;

a knob;

a pressure sensor;

an accelerometer; and

a gyroscope.