Waveguide-based touch system employing interference effects
First Claim
1. A touch system for use atop a display unit and for sensing a localized touch event, comprising:
- first and second waveguides that define first and second separate optical paths having respective first and second optical path lengths that respectively change by first and second amounts by the localized touch event occurring directly on an upper surface of the first waveguide and causing a first amount of deformation in the first waveguide and a second amount of deformation in the second waveguide that is different from the first amount of deformation;
at least one light source system operably arranged relative to respective input ends of the first and second waveguides and configured to input first and second light beams into the first and second waveguides, respectively; and
at least one detector system operably arranged relative to respective output ends of the first and second waveguides and configured to interfere and detect the first and second light beams and generate a detector signal representative of the amount of deformation in the first and second waveguides caused by the localized touch event.
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Accused Products
Abstract
A touch system that employs interference effects is disclosed. The touch system includes first and second waveguides that have first and second optical paths that define an optical path difference. The first and second waveguides are configured so that a touch event deforms at least one of the waveguides in a manner that causes the optical path difference to change. The change in the optical path difference is detected by combining the light traveling in the two waveguides to form interfered light. The interfered light is processed to determine the occurrence of a touch event. The time-evolution of the deformation at the touch-event location can also be determined by measuring the interfered light over the duration of the touch event.
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Citations
19 Claims
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1. A touch system for use atop a display unit and for sensing a localized touch event, comprising:
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first and second waveguides that define first and second separate optical paths having respective first and second optical path lengths that respectively change by first and second amounts by the localized touch event occurring directly on an upper surface of the first waveguide and causing a first amount of deformation in the first waveguide and a second amount of deformation in the second waveguide that is different from the first amount of deformation; at least one light source system operably arranged relative to respective input ends of the first and second waveguides and configured to input first and second light beams into the first and second waveguides, respectively; and at least one detector system operably arranged relative to respective output ends of the first and second waveguides and configured to interfere and detect the first and second light beams and generate a detector signal representative of the amount of deformation in the first and second waveguides caused by the localized touch event. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A method of sensing a localized touch event on a touch system arranged atop a display unit and that includes first and second waveguides, comprising:
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sending first and second light beams through input ends of the first and second waveguides that respectively have first and second separate optical paths that define an optical path difference, with the first and second waveguides configured so that the localized touch event occurs directly on an upper surface of the first waveguide and causes a change in the optical path difference by deforming both of the first and second waveguides by different amounts; combining the first and second light beams at output ends of the first and second waveguides to form interfered light; and detecting the interfered light to generate a detector signal representative of the change in the optical path difference. - View Dependent Claims (18, 19)
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Specification