Optical coupling of light into touch-sensing systems
First Claim
1. A touch-sensitive apparatus, comprising:
- a light transmissive panel that defines a front surface and an opposite, rear surface;
a plurality of light emitters and a plurality of light detectors arranged to optically face the rear surface along a perimeter of a touch-sensitive region on the light transmissive panel; and
at least one diffusively reflecting element arranged on the front surface along the perimeter of the touch-sensitive region;
wherein the plurality of light emitters are configured to emit respective beams of light onto said at least one diffusively reflecting element, said at least one diffusively reflecting element configured to generate propagating light that propagates by total internal reflection inside the light transmissive panel across the touch-sensitive region; and
wherein the plurality of light detectors are configured to receive detection light generated as the propagating light impinges on said at least one diffusively reflecting element, to define a grid of propagation paths across the touch-sensitive region between pairs of light emitters and light detectors.
1 Assignment
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Accused Products
Abstract
A touch-sensitive apparatus operates by light frustration (FTIR) and comprises a light transmissive panel (1) with a front surface and a rear surface. Light emitters (2) and light detectors (3) optically face the rear surface along a perimeter of a touch-sensitive region (4) on the panel (1). At least one diffusively reflecting element (40) is arranged on the front surface (5) along the perimeter of the touch-sensitive region (4). The light emitters (2) are arranged to emit a respective beam of light onto the diffusively reflecting element (40), so as to generate propagating light that propagates by total internal reflection inside the panel (1) across the touch-sensitive region (4), and the light detectors (3) are arranged to receive detection light generated as the propagating light impinges on the diffusively reflecting element (40), so as to define a grid of propagation paths (D) across the touch-sensitive region (4) between pairs of light emitters (2) and light detectors (3).
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Citations
21 Claims
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1. A touch-sensitive apparatus, comprising:
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a light transmissive panel that defines a front surface and an opposite, rear surface; a plurality of light emitters and a plurality of light detectors arranged to optically face the rear surface along a perimeter of a touch-sensitive region on the light transmissive panel; and at least one diffusively reflecting element arranged on the front surface along the perimeter of the touch-sensitive region; wherein the plurality of light emitters are configured to emit respective beams of light onto said at least one diffusively reflecting element, said at least one diffusively reflecting element configured to generate propagating light that propagates by total internal reflection inside the light transmissive panel across the touch-sensitive region; and wherein the plurality of light detectors are configured to receive detection light generated as the propagating light impinges on said at least one diffusively reflecting element, to define a grid of propagation paths across the touch-sensitive region between pairs of light emitters and light detectors. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A touch-sensitive apparatus, comprising:
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a light transmissive panel that defines a front surface and an opposite, rear surface; a plurality of light emitters arranged to optically face the rear surface along a perimeter of a touch-sensitive region on the light transmissive panel; a plurality of light detectors optically connected to the light transmissive panel; and at least one diffusively reflecting element arranged on the front surface along the perimeter of the touch-sensitive region; wherein the plurality of light emitters are configured to emit respective beams of light onto said at least one diffusively reflecting element, said at least one diffusively reflecting element configured to generate propagating light that propagates by total internal reflection inside the light transmissive panel across the touch-sensitive region; and wherein the plurality of light detectors are configured to define a grid of propagation paths across the touch-sensitive region between pairs of light emitters and light detectors.
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21. A touch-sensitive apparatus, comprising:
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a light transmissive panel that defines a front surface and an opposite, rear surface; a plurality of light emitters optically connected to the light transmissive panel to generate propagating light that propagates by total internal reflection inside the light transmissive panel across a touch-sensitive region on the light transmissive panel; a plurality of light detectors arranged to optically face the rear surface along a perimeter of the touch-sensitive region on the light transmissive panel; and at least one diffusively reflecting element arranged on the front surface along the perimeter of the touch-sensitive region; wherein the plurality of light detectors are configured to receive detection light generated, by diffusive reflection of the propagating light by said at least one diffusively reflecting element, to define a grid of propagation paths across the touch-sensitive region between pairs of light emitters and light detectors.
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Specification