User input displays for mobile devices

1. A mobile device for detecting user input on a display, the mobile device comprising: a hand-held display unit comprising: a display having an electromagnetic radiation detector is configured to detect an electromagnetic radiation profile responsive to a position of a user input object when the position of the user input object is spaced apart from the display; and a controller configured to identify a user input from the electromagnetic radiation profile; wherein the display further comprises an electromagnetic radiation emitter configured to emit electromagnet radiation in a direction away from the display, and the electromagnetic radiation detector is configured to detect electromagnetic radiation reflected from a user input object in a direction toward the display, wherein the electromagnetic radiation detector comprises a first electromagnetic radiation detector, the display further comprising an electromagnetic radiation emitter, a second electromagnetic radiation detector, and a refractive medium, wherein the electromagnetic radiation emitter is configured to emit electromagnetic radiation in a direction toward the refractive medium, and the refractive medium is configured to reflect electromagnetic radiation in a direction toward the second electromagnet radiation detector, the refractive medium being further configured to change a direction of reflected electromagnetic radiation responsive to contact from a user input object, wherein the controller is further configured to identify a user input responsive to an amount of electromagnetic radiation detected by the second electromagnetic radiation detector.

2. The mobile device of claim 1 , wherein the electromagnetic radiation detector is configured to detect an obstruction of background electromagnetic radiation responsive to a position of a user input object.

3. The mobile device of claim 1 , wherein the electromagnetic radiation detector is configured to detect thermal radiation from a user input object, wherein the user input object comprises a digit of a user's hand.

4. The mobile device of claim 1 , wherein the controller is configured to display an icon on the display responsive to the detection of electromagnetic radiation reflected from a user input object in a direction toward the display.

5. The mobile device of claim 4 , wherein the controller is configured to track movement of the user input object by displaying the icon in a region responsive to movement of the user input object.

6. The mobile device of claim 5 , wherein the display further comprises a touch-sensitive display, and the controller is configured to perform an operation responsive to contact with the user input object.

7. The mobile device of claim 1 , wherein the electromagnetic radiation detector is configured to detect infrared light.

8. The mobile device of claim 1 , wherein the electromagnetic radiation emitter is configured to emit electromagnetic radiation in a direction away from the electromagnetic radiation detector such that electromagnetic radiation emitted by the electromagnetic radiation emitter is not received by the electromagnetic radiation detector when the user input object is not positioned to reflect the electromagnetic radiation toward the electromagnetic radiation detector.

9. A touch-sensitive display system comprising:

a display comprising an electromagnetic radiation emitter, an electromagnetic radiation detector, and a refractive medium, wherein the electromagnetic radiation emitter is configured to emit electromagnetic radiation in a direction toward the refractive medium, and the refractive medium is configured such that the electromagnetic radiation passes through the refractive medium and is reflected in a direction toward the detector in an absence of contact from a user input object and to change the refractive medium changes a direction of reflected electromagnetic radiation responsive to contact from a user input object; and

a controller configured to identify a user input responsive to an amount of electromagnetic radiation detected by the electromagnetic radiation detector.

10. The display system of claim 9 , wherein the refractive medium is configured to direct at least a portion of the reflected electromagnetic radiation away from the electromagnetic radiation detector responsive to contact from the user input object and the controller is configured to identify a user input responsive to a reduced amount of electromagnetic radiation detected by the electromagnetic radiation detector.

11. The display system of claim 9 , wherein the refractive medium changes a refractive index thereof responsive to contact of the user input object.

12. The display system of claim 9 , wherein the display comprises an array of respective electromagnetic radiation emitters and electromagnetic radiation detectors, wherein the electromagnetic radiation emitters are configured to emit electromagnetic radiation in a direction toward the refractive medium, and the refractive medium is configured to reflect electromagnetic radiation in a direction toward one of the respective electromagnetic radiation detectors in an absence of contact from a user input object and to change a direction of reflected electromagnetic radiation responsive to contact from the user input object.

13. The display system of claim 12 , wherein the array of electromagnetic radiation detectors outputs an electromagnetic radiation profile to the controller, and the controller is configured to identify a location of contact of the user input object based on the electromagnetic radiation profile.

14. The display system of claim 13 , wherein the location of contact of the user input object comprises a region of reduced electromagnetic radiation.

15. The display system of claim 12 , wherein the display comprises a substrate having a plurality of LEDs thereon, and wherein the array of electromagnetic radiation emitters and electromagnetic radiation detectors are on the substrate.

16. The display system of claim 15 , wherein the refractive medium comprises a layer on the substrate and having a surface that reflects electromagnetic radiation emitted from the electromagnetic radiation emitters.

17. The display system of claim 9 , wherein the electromagnetic radiation emitter is an infrared emitter and the electromagnetic radiation detector is an infrared detector.

18. A method for detecting user input on a display, the method comprising: emitting electromagnetic radiation away from the display; the display comprising a refractive medium; detecting an electromagnetic radiation profile using an array of detectors on the display, wherein the electromagnetic radiation profile comprises electromagnetic radiation reflected from a user input object towards the display when a position of the user input object is spaced apart from the display and electromagnetic radiation that is reflected in a direction toward the detector by the refractive medium in an absence of contact from the user input object, wherein the refractive medium changes a direction of reflected electromagnetic radiation responsive to contact from the user input object; and identifying a user input responsive to the electromagnetic radiation profile.