Using spectral control in detecting touch input

• US 9,459,715 B1
• Filed: 09/20/2013
• Issued: 10/04/2016
• Est. Priority Date: 09/20/2013
• Status: Active Grant

• Current Assignee: Sentons, Inc.
• Original Assignee: Sentons, Inc.
• Inventors: Sheng, Samuel W., Shih, Shih-Ming, Altekar, Shirish A.
• Primary Examiner(s): Li, Lin
• Application Number:
  US14/033,325
• Time in Patent Office: 1,110 Days
• US Class Current: 1/1
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: G06F 3/043 using propagating acoustic waves
• CPC Class Codes: G06F 3/0436 in which generating transducers and detecting transducers are attached to a single acoustic waves transmission substrate

Abstract

Detecting a location of a touch input on a surface of a propagating medium is disclosed. A transmitter coupled to the propagating medium emits a signal. The signal is received using a receiver coupled to the propagating medium. The receiver is configured to receive the signal from the transmitter to at least in part detect the location of the touch input as indicated by an effect of the touch input on the signal. Spectral control of the signal is performed.

Claims

1. A system for detecting a location of a touch input on a surface of a propagating medium, including:

a transmitter coupled to the propagating medium and configured to emit a signal, wherein the signal has been allowed to freely propagate through the propagating medium in multiple directions to a plurality of receivers on a plurality axes of the propagating medium, wherein the propagating medium is a touch input medium made of at least one of the following;

glass, plastic, metal, or semiconductor;

a receiver coupled to the propagating medium, wherein the receiver is one of the plurality of receivers on the plurality axes of the propagating medium and the receiver is configured to receive a touch input affected version of the signal to at least in part detect the location of the touch input as indicated by an effect of the touch input on the signal;

a signal generator configured to perform spectral control including by using a windowing function or an amplitude modulation to generate an intermediary signal that is modulated to a carrier frequency to generate the emitted signal and selecting the carrier frequency such that the emitted signal is an ultrasonic signal.

2. The system of claim 1, wherein performing spectral control includes controlling a frequency range of the signal.

3. The system of claim 1, wherein performing spectral control includes utilizing the windowing function.

4. The system of claim 1, wherein performing spectral control includes utilizing the amplitude modulation.

5. The system of claim 1, wherein performing spectral control includes utilizing a Hanning window function.

6. The system of claim 1, wherein performing spectral control includes utilizing a raised cosine window function.

7. The system of claim 1, wherein performing spectral control includes attempting to only excite a select propagation mode of the propagating medium.

8. The system of claim 1, wherein performing spectral control includes attempting to avoid exciting a select propagation mode of the propagating medium.

9. The system of claim 1, wherein performing spectral control includes attempting to only excite A0 propagation mode of the propagating medium.

10. The system of claim 1, wherein performing spectral control includes performing signal-sideband modulation.

11. The system of claim 1, wherein performing spectral control includes performing vestigial sideband modulation.

12. The system of claim 1, wherein the signal utilizes double-sideband modulation.

13. The system of claim 1, wherein performing spectral control includes utilizing the windowing function and utilizing the amplitude modulation.

14. The system of claim 1, wherein performing spectral control includes utilizing a Hanning window function and performing vestigial sideband modulation.

15. The system of claim 1, wherein performing spectral control includes utilizing the windowing function and the type of windowing function to be utilized is determined based at least in part on a property of the propagation medium.

16. The system of claim 1, wherein performing spectral control includes utilizing the windowing function and a parameter of windowing function to be utilized is determined based at least in part on a property of the propagation medium.

17. The system of claim 1, wherein performing spectral control includes utilizing the windowing function and a parameter of windowing function to be utilized is determined based at least in part on a property of the transmitter.

18. The system of claim 1, wherein the transmitter and the receiver are the same transducer.

19. A method for detecting a location of a touch input on a surface of a propagating medium including:

emitting from a transmitter coupled to the propagating medium a signal, wherein the signal has been allowed to freely propagate through the propagating medium in multiple directions to a plurality of receivers on a plurality axes of the propagating medium, wherein the propagating medium is a touch input medium made of at least one of the following;

glass, plastic, metal, or semiconductor;

receiving the signal using a receiver coupled to the propagating medium, wherein the receiver is one of the plurality of receivers on the plurality axes of the propagating medium and the receiver is configured to receive a touch input affected version of the signal to at least in part detect the location of the touch input as indicated by an effect of the touch input on the signal; and

performing spectral control by a signal generator using a windowing function or an amplitude modulation to generate an intermediary signal that is modulated to a carrier frequency to generate the emitted signal and selecting the carrier frequency such that the emitted signal is an ultrasonic signal.

20. A computer program product for detecting a location of a touch input on a surface of a propagating medium, the computer program product being embodied in a non-transitory computer readable storage medium and comprising computer instructions for:

emitting from a transmitter coupled to the propagating medium a signal, wherein the signal has been allowed to freely propagate through the propagating medium in multiple directions to a plurality of receivers on a plurality axes of the propagating medium, wherein the propagating medium is a touch input medium made of at least one of the following;

glass, plastic, metal, or semiconductor;

receiving the signal using a receiver coupled to the propagating medium, wherein the receiver is one of the plurality of receivers on the plurality axes of the propagating medium and the receiver is configured to receive a touch input affected version of the signal to at least in part detect the location of the touch input as indicated by an effect of the touch input on the signal; and

performing spectral control by a signal generator using a windowing function or an amplitude modulation to generate an intermediary signal that is modulated to a carrier frequency to generate the emitted signal and selecting the carrier frequency such that the emitted signal is an ultrasonic signal.