Method and system for providing a frustrated total internal reflection touch interface

• US 20060114237A1
• Filed: 11/17/2004
• Published: 06/01/2006
• Est. Priority Date: 11/17/2004
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Crockett, Timothy W., Fortenberry, Robert S.
• Granted Patent: US 8,599,140 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 2203/04109 FTIR in optical digitiser, i.e. touch detection by frustrating the total internal reflection within an optical waveguide due to changes of optical properties or deformation at the touch location
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

A method and system for providing a touch interface on a display are described. The method and system include providing an emitter on a first side of the display and providing a detector on a second side of the display. The emitter provides an electromagnetic signal to the display. The electromagnetic signal has a path from the emitter to the detector through the display in the absence of a user'"'"'s touch such that the electromagnetic signal is detected by the detector in the absence of the user'"'"'s touch. The path includes at least one total internal reflection in the display. The emitter and the detector are configured such that the user'"'"'s touch at any of the at least one total internal reflection alters the path such that a portion of the electromagnetic signal does not reach the detector.

Claims

1. A system for providing a touch interface for a display comprising:

an emitter on a first side of the display, the emitter providing an electromagnetic signal to the display; and

a detector on a second side of the display, the electromagnetic signal having a path from the emitter to the detector through the display in the absence of a user'"'"'s touch such that the electromagnetic signal is detected by the detector in the absence of the user'"'"'s touch, the path including at least one total internal reflection in the display;

wherein the emitter and the detector are configured such that the user'"'"'s touch at any of the at least one total internal reflection alters the path such that a portion of the electromagnetic signal does not reach the detector.

2. The system of claim 1 further including:

a barrier corresponding to the emitter, the barrier residing between the emitter and the display, the barrier for blocking a zero mode path between the emitter and the detector for the electromagnetic signal.

3. The system of claim 1 further including:

a detector barrier corresponding to the detector, the detector barrier residing between the detector and the display, the detector barrier for blocking a zero mode path between the emitter and the detector for the electromagnetic signal.

4. The system of claim 1 wherein the display includes a third side having an interface between the display and air.

5. The system of claim 1 wherein the second side is opposite to the first side.

6. The system of claim 1 wherein the detector indicating that the portion of the electromagnetic signal failed to reach the detector corresponds to the user'"'"'s touch.

7. The system of claim 1 wherein at least one of the first side and the second side of the display includes at least one beveled edge.

8. A system for providing a touch interface for a display comprising:

a plurality of emitters on a first side of the display, each of the plurality of emitters providing an electromagnetic signal to the display;

a plurality of detectors on a second side of the display, the electromagnetic signal having a path from each of the plurality of emitters to a corresponding detector of the plurality of detectors through the display in the absence of a user'"'"'s touch such that the electromagnetic signal is detected by the corresponding detector in the absence of the user'"'"'s touch, the path including at least one total internal reflection in the display;

a plurality of barriers corresponding to the plurality of emitters, the plurality of barriers residing between the plurality of emitters and the display, each of the plurality of barriers for blocking a zero mode path between the emitter and the corresponding detector for the electromagnetic signal;

a plurality of detector barriers corresponding to the plurality of detectors, the plurality of detector barriers residing between the plurality of detectors and the display, each of the plurality of detector barriers for blocking the zero mode path between the emitter and the corresponding detector for the electromagnetic signal

wherein the plurality of emitters and the plurality of detectors are configured such that the user'"'"'s touch at any of the at least one total internal reflection alters the path such that a portion of the electromagnetic signal does not reach the corresponding detector.

9. The system of claim 8 further comprising:

a first plurality of emitters on a third side of the display, each of the first plurality of emitters providing a first electromagnetic signal to the display;

a first plurality of detectors on a fourth side of the display, the fourth side opposing the third side, the first electromagnetic signal having a first path from each of the first plurality of emitters to a corresponding first detector of the first plurality of detectors through the display in the absence of the user'"'"'s touch such that the first electromagnetic signal is detected in the absence of the user'"'"'s touch, the path including at least one additional total internal reflection in the display;

a first plurality of barriers corresponding to the first plurality of emitters, the first plurality of barriers residing between the first plurality of emitters and the display, the first plurality of barriers for blocking a first zero mode path between the first plurality of emitters and the first plurality of detectors for the first electromagnetic signal,

a first plurality of detector barriers corresponding to the first plurality of detectors, the first plurality of detector barriers residing between the first plurality of detectors and the display, each of the first plurality of detector barriers for blocking the zero mode path between the first emitter and the first corresponding detector for the electromagnetic signal

wherein the first plurality of emitters and the first plurality of detectors are configured such that the user'"'"'s touch at one of the at least one additional total internal reflection alters the first path such that the first electromagnetic signal does not reach the corresponding first detector.

10. A method for providing a touch interface for a display comprising:

providing an electromagnetic signal to the display from a first side of the display;

determining whether the electromagnetic signal is detected at a second side of the display, the electromagnetic signal having a path between the first side and the second side through the display in the absence of a user'"'"'s touch such that the electromagnetic signal is detected at the second side of the display in the absence of the user'"'"'s touch, the path including at least one total internal reflection in the display, the user'"'"'s touch at one of the at least one total internal reflection altering the path such that a portion of the electromagnetic signal is not detected on the second side.

11. The method of claim 10 further including:

blocking a zero mode path between the emitter and the detector for the electromagnetic signal.

12. The method of claim 10 wherein the display includes a third side having an interface between the display and air.

13. The method of claim 10 further comprising:

indicating the user'"'"'s touch in response to the corresponding detector indicating that the portion of the electromagnetic signal has not been detected.

14. The method of claim 10 wherein the second side is opposite to the first side.

15. The method of claim 10 wherein at least one the first side and the second side display includes at least one beveled edge.

16. A method for providing a touch interface for a display comprising:

providing a plurality of electromagnetic signals to the display from a first side of the display;

determining whether each of the plurality of electromagnetic signals is detected at a second side of the display, each of the plurality of electromagnetic signals having a path through the display in the absence of a user'"'"'s touch such that the plurality of electromagnetic signals are detected in the absence of the user'"'"'s touch, the path including at least one total internal reflection in the display, a user'"'"'s touch at one of the at least one total internal reflection altering the path such that a portion of a corresponding electromagnetic signal of the plurality of electromagnetic signals is not detected; and

blocking a zero mode path for each of the plurality of electromagnetic signals.

17. The method of claim 16 further comprising:

providing a first plurality of electromagnetic signals to the display from a third side of the display;

determining whether each of the first plurality of electromagnetic signals is detected at a fourth side of the display, the first plurality of electromagnetic signals being detected in the absence of a user'"'"'s touch, each of the first plurality of electromagnetic signals having a first path through the display in the absence of the user'"'"'s touch, the first path including at least one additional total internal reflection in the display, the user'"'"'s touch at one of the at least one additional total internal reflection altering the first path such that the first corresponding electromagnetic signal is not detected; and

blocking a first zero mode path for each of the first plurality of electromagnetic signals.