Touch input detection along device sidewall

1. A system for detecting a touch input, comprising:

a plurality of transmitters coupled to a propagating medium, wherein each of the plurality of transmitters is configured to emit a propagating signal that propagates through the propagating medium;

a plurality of receivers coupled to the propagating medium, wherein each of the plurality of receivers is configured to detect one or more of the propagating signals that have been disturbed by the touch input, and the plurality of transmitters and the plurality of receivers are coupled to the propagating medium on an internal side of a device sidewall; and

a processor configured to analyze one or more detected propagating signals that have been disturbed by the touch input to identify the touch input on an external surface of the device sidewall, wherein the processor is configured to analyze the one or more detected propagating signals including by being configured to identify a portion of the one or more detected propagating signals that has been disturbed by the touch input and propagated through the device sidewall and determine an amount of a force magnitude of the touch input including by comparing to a reference value a magnitude of a signal amplitude associated with the identified portion of the one or more detected propagating signals emitted prior to the touch input and disturbed by the touch input, and the magnitude of the signal amplitude associated with the identified portion indicates an amount of disturbance to one or more of the propagating signals emitted prior to the touch input and propagated through the device sidewall;

wherein first sides of the plurality of transmitters and the plurality of receivers are mounted along a common axis in a line on a flex cable that includes patterned conductors that connect the transmitters and the receivers to a circuit board connector of the flex cable, and second sides of the plurality of transmitters and the plurality of receivers on the same flex cable are coupled to the internal side of the device sidewall opposite an external touch input side of the device sidewall via an adhesive on each of the second sides different from the first sides mounted on the flex cable, and a receiver included in the line of transmitters and receivers on the flex cable is equidistant from two adjacent transmitters included in the line of transmitters and receivers on the flex cable.

2. The system of claim 1 , wherein identifying the touch input includes identifying a location of the touch input on a one-dimensional axis on the external surface of the device sidewall.

3. The system of claim 1 , wherein the propagating medium is metal.

4. The system of claim 1 , wherein at least two of the propagating signals emitted by the transmitters include different signal content.

5. The system of claim 1 , wherein a second device sidewall of the system is configured to accept a second touch input.

6. The system of claim 1 , wherein the propagating medium is at least a part of a device housing and the internal side of the device sidewall is within the device housing.

7. The system of claim 1 , wherein one or more of the plurality of transmitters are coupled to the propagating medium in a pocket within the device sidewall.

8. The system of claim 1 , wherein the adhesive is an epoxy.

9. The system of claim 1 , wherein one or more of the plurality of transmitters and the plurality of receivers are mounted on fingers extending from the linear flex cable.

10. The system of claim 1 , wherein identifying the touch input includes analyzing the one or more detected propagating signals that have been disturbed by the touch input to identify a force of the touch input.

11. The system of claim 10 , wherein the force of the touch input is utilized to detect a user command associated with the touch input.

12. The system of claim 11 , wherein the user command is detected in the event the force is greater than a threshold value.

13. The system of claim 1 , wherein a detected duration of the touch input is utilized to identify a user command associated with the touch input.

14. The system of claim 1 , wherein a detected gesture of the touch input is utilized to identify a user command associated with the touch input.

15. The system of claim 1 , wherein the touch input was provided on a physical button and the touch input was detected without physically actuating the physical button.

16. The system of claim 1 , wherein a plurality of touch inputs are detected by analyzing the detected propagating signals that have been disturbed by the touch inputs.

17. The system of claim 1 , wherein the propagating medium is not a part of a display surface.

18. The system of claim 1 , wherein the plurality of transmitters and the plurality of receivers are transducers.

19. The system of claim 1 , wherein the propagating signals are ultrasonic signals.

20. A method for detecting a touch input, comprising:

emitting from a plurality of transmitters coupled to a propagating medium, propagating signals through the propagating medium;

receiving at a plurality of receivers coupled to the propagating medium one or more of the propagating signals that have been disturbed by the touch input, wherein the plurality of transmitters and the plurality of receivers are coupled to the propagating medium on an internal side of a device sidewall; and

using a processor to analyze one or more detected propagating signals that have been disturbed by the touch input to identify the touch input on an external surface of the device sidewall, wherein analyzing the one or more detected propagating signals includes identifying a portion of the one or more detected propagating signals that has been disturbed by the touch input and propagated through the device sidewall and determining an amount of a force magnitude of the touch input including by comparing to a reference value a magnitude of a signal amplitude associated with the identified portion of the one or more detected propagating signals emitted prior to the touch input and disturbed by the touch input, and the magnitude of the signal amplitude associated with the identified portion indicates an amount of disturbance to one or more of the propagating signals emitted prior to the touch input and propagated through the device sidewall;

wherein first sides of the plurality of transmitters and the plurality of receivers are mounted along a common axis in a line on a flex cable that includes patterned conductors that connect the transmitters and the receivers to a circuit board connector of the flex cable, and second sides of the plurality of transmitters and the plurality of receivers on the same flex cable are coupled to the internal side of the device sidewall opposite an external touch input side of the device sidewall via an adhesive on each of the second sides different from the first sides mounted on the flex cable, and a receiver included in the line of transmitters and receivers on the flex cable is equidistant from two adjacent transmitters included in the line of transmitters and receivers on the flex cable.