Flatfrog Laboratories Ab

Anoto Ab

Thomas Craven-Bartle

Håkan Bergström

Ola Wassvik

Ivan Karlsson

Lars Rippe

Ola Strömberg

Tomas Svensson

Christer Fahraeus

Leif Ek

Peter Gredinger

Bjorn Le Normand

Magnus Hollstr{dot Over (o)}m

Lars Petterson

Hakan Bergström

Olov Von Hofsten

David Sernelius

Håkan BERGSTRÖM

Ola Wasswik

A touch sensing apparatus is provided comprising: a light transmissive panel that defines a touch surface, a plurality of light emitters and detectors arranged along a perimeter of the light transmissive panel, a plurality of optical components arranged along the perimeter of the light transmissive panel, wherein the light emitters are arranged to emit a respective beam of emitted light and the optical components are configured to direct the emitted light to a path across the light transmissive panel. Optionally, optical components comprise a light guide arranged to receive light from the light emitters through a first surface and couple out light travelling in the light guide to the touch surface through a second surface. The second surface may be diffusively transmissive. The light guide may further comprise a reflective surface configured to internally reflect light travelling in the light guide from the first surface to the diffusive surface. The reflective surface may be diffusely reflective, partially diffusely reflective, or specularly reflective.

Optical component

A touch sensing apparatus is disclosed comprising a panel that defines a touch surface, a plurality of emitters and detectors arranged along a perimeter of the light transmissive panel, and a light directing arrangement arranged adjacent the perimeter. The emitters are arranged to emit a respective beam of emitted light and the light directing arrangement is arranged to direct the light along a light path from the emitters to the touch surface. A diffusive light scattering element is arranged in the light path.

Detection line broadening

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

The invention provides an optical component for transferring light between an opto-electronic device and a light transmissive panel which defines two opposing boundary surfaces, the optical component having a shape formed from a geometric shape having a base surface, a lateral front surface and an axis, wherein the geometric shape is truncated by a plane intersecting the front surface, the base surface, and the axis, forming a back surface. The base surface is configured for mounting the optical component to the light transmissive panel and for coupling light into the light transmissive panel. The front surface being configured for coupling light from the front surface, through the base surface, and into the light transmissive panel for the light to propagate by total internal reflection within the light transmissive panel.

Optical component for light coupling

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 apparatus comprises a light transmissive panel (), an illumination arrangement and a detection arrangement. The illumination arrangement is configured to couple light into the panel () via an incoupling site (B) such that the light propagates by total internal reflection (TIR) in opposite top and bottom surfaces () of the panel and such that an object touching the top or bottom surface () causes a change in the propagating light. The detection arrangement comprises a light detector arranged to detect the change in the propagating light. A compact and robust incoupling site (B) is defined by a sheet-like micro-structured surface portion () which is fixedly arranged on one of the top and bottom surfaces () and configured to transmit light having an angle of incidence that enables light propagation by TIR inside the panel (). The surface portion () may be integrated in the panel or implemented by a thin and flexible film () of light transmissive plastic material, formed with the micro-structured surface portion and adapted for attachment to the top or bottom surface ().

Optical incoupling for touch-sensitive systems

A touch-sensitive apparatus operates by light frustration and comprises a light transmissive panel with a front surface and a rear surface. Light emitters and light detectors optically face the rear surface along a perimeter of a touch-sensitive region on the panel. At least one non-imaging, diffusively transmitting optical element is arranged on the rear surface along the perimeter of the touch-sensitive region. The light emitters are arranged to emit a respective beam of light onto the non-imaging optical element so as to generate, by diffuse transmission, propagating light that propagates by total internal reflection inside the panel across the touch-sensitive region, and the light detectors are arranged to receive detection light generated, by diffuse transmission, as the propagating light impinges on the non-imaging optical element, so as to define a grid of propagation paths across the touch-sensitive region between pairs of light emitters and light detectors.

Optical coupling in touch-sensing systems using diffusively transmitting element

A touch-sensitive apparatus operates by light frustration (FTIR) and comprises a light transmissive panel () with a front surface and a rear surface. Light emitters () and light detectors () optically face the rear surface along a perimeter of a touch-sensitive region () on the panel (). At least one diffusively reflecting element () is arranged on the front surface () along the perimeter of the touch-sensitive region (). The light emitters () are arranged to emit a respective beam of light onto the diffusively reflecting element (), so as to generate propagating light that propagates by total internal reflection inside the panel () across the touch-sensitive region (), and the light detectors () are arranged to receive detection light generated as the propagating light impinges on the diffusively reflecting element (), so as to define a grid of propagation paths (D) across the touch-sensitive region () between pairs of light emitters () and light detectors ().

Optical coupling of light into touch-sensing systems

A touch-sensitive aparatus operates by light frustration (FTIR) and comprises a light transmissive panel () with a front surface () and a rear surface (). Light emitters () are optically coupled to the panel () at entry ports along a periphery region of the panel (), and light detectors () are optically coupled to the panel () at exit ports along the periphery region for detecting light transmitted inside the panel (). At least one optical sheet () is provided on the rear surface () in the periphery region. In an outcoupling installation, the light detectors () are arranged at the respective optical sheet () to receive, on a respective light-sensitive surface (A); light from the optical sheet (), and each light detector () is arranged with the light-sensitive surface (A) essentially perpendicular to the rear surface (). In an incoupling installation, each light emitter () is arranged at the respective optical sheet () to emit diverging light with a main direction that is essentially parallel to the rear surface () such that a portion of the diverging light impinges on the optical sheet () so as to define a respective entry port.

Optical coupling in touch-sensing systems

A touch-sensitive apparatus comprises a light transmissive panel, an illumination arrangement and a detection arrangement. The illumination arrangement is configured to couple light into the panel via an incoupling site such that the light propagates by total internal reflection in opposite top and bottom surfaces of the panel and such that an object touching the top or bottom surface causes a change in the propagating light. The detection arrangement comprises a light detector arranged to detect the change in the propagating light. A compact and robust incoupling site is defined by a sheet-like micro-structured surface portion which is fixedly arranged on one of the top and bottom surfaces and configured to transmit light having an angle of incidence that enables light propagation by TIR inside the panel.

A coupling element () for use in a touch-sensitive apparatus is arranged to transfer light between an electro-optical device () and a panel () for light transmission. The electro-optical device () is an emitter or a detector and has an operative solid angle given by orthogonal device divergence angles. The coupling element () is an optical component with a first light transmission surface () for facing the electro-optical device (), and a second light transmission surface () for mounting on the panel (). The coupling element () has an optical structure () that directs the light between the first and second light transmission surfaces () by one or more reflections while expanding one device divergence angle (&#x3b1;x) into a component divergence angle at the second light transmission surface (). Thereby, the component divergence angle defines a divergence (&#x3c6;p) in the plane of the panel () with respect to light propagating by internal reflections inside the light transmissive panel ().

Light coupling structures for optical touch panels

A touch-sensitive apparatus operates by FTIR (Frustrated Total Internal Reflection) to detect touches on a surface of a light transmissive panel. An illumination arrangement is controlled to propagate light by internal reflection from an elongated incoupling site on the panel to an elongated outcoupling site on the panel, and a detection arrangement is controlled to detect light reaching the outcoupling site. The illumination arrangement is controlled to sweep a first set of individual beams of light along different subsets of the incoupling site to generate a full beam sweep along the incoupling site. Thereby, the individual beams are be controlled to generate a 'sub-sweep' of the incoupling site, which enables a compact design of the illumination arrangement and/or use of comparatively simple sweep generating devices and/or identical re-direction components in the illumination arrangement.

Growing community of inventors

Sodra Sandby, Sweden

Thomas Craven-Bartle