Flatfrog Laboratories Ab

Ivan Karlsson

Håkan Bergström

Ola Wassvik

Thomas Craven-Bartle

Gunnar Klinghult

Mats Petter Wallander

Mattias Krus

David Sernelius

An embodiment of the invention provides a touch sensing apparatus, comprising: a light transmissive element () that defines a touch surface; a set of emitters () arranged around the periphery of the touch surface to emit beams of light into the light transmissive element, wherein a first portion of the beams () of light propagate inside the light transmissive element while illuminating the touch surface such that an object touching the touch surface causes an attenuation of the propagating light, and wherein a second portion of the beams () of light pass out of the light transmissive element and are reflected to travel above the touch surface, a set of light detectors () arranged around the periphery of the touch surface to receive light from the set of emitters from the transmissive element and from above the touch surface, wherein each light detector is arranged to receive light from more than one emitter.

Optical touch system comprising means for projecting and detecting light beams above and inside a transmissive panel

A touch-sensitive apparatus operates by light frustration (FTIR) and comprises a light transmissive panel () that defines a front surface () and a rear surface (), light emitters optically connected to the panel () so as to generate light that propagates by total internal reflection inside the panel, and light detectors () optically connected to the panel () so as to define a grid of propagation paths inside the panel () between pairs of light emitters and light detectors (). Each light detector () is optically connected to the panel () via an angular filter (). The filter () is applied to an outcoupling region on at least one of the front and rear surfaces () and is configured to transmit light only within a confined range of angles with respect to the normal of the outcoupling region. The confined range extends from a lower angle limit &#x3b8;to an upper angle limit &#x3b8;. The lower angle limit &#x3b8;is equal to or larger than a critical angle &#x3b8;, which is given by &#x3b8;=arcsin(1/n), with nbeing the refractive index of the light transmissive panel () at the outcoupling region.

TIR-based optical touch systems of projection-type

A touch-sensitive display, comprising a transmissive panel defining the touch surface, a first set of OLED emitters forming display pixels, a second set of OLED emitters configured to emit light via an adjacent cell into the transmissive panel for propagation therein via total internal reflection, and a set of detectors configured to receive light from the second set of OLED emitters after the light has propagated inside the transmissive panel via total internal reflection. The first set and the second set of OLED emitters are arranged on the same substrate.

Touch-sensing OLED display with tilted emitters

Invention principally regards a remotely controllable touch-sensing apparatus. The apparatus comprises a planar light guide, a plurality of light emitters arranged to emit light into the light guide for propagation by total internal reflection inside the light guide, and a plurality of light detectors, each being arranged to detect at least a portion of the emitted light propagating inside the light guide and at least a portion of the ambient light, said detectors being distributed along the periphery of the touch surface such that the optical plane of detection of light coincides with the plane of the light guide, at least one of said detectors being adapted to detect light emitted by an external device configured to emit light. The apparatus also comprises a processor unit configured to, ultimately, generate a digital signal containing data regarding light generated by the external device. Invention also regards a method for enabling control of a touch-sensing apparatus by an external device.

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Lund, Sweden

Ivan Karlsson