Abstract: 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.

Abstract: A touch-sensitive apparatus operates by light frustration (FTIR) and comprises a light transmissive panel (1) that defines a front surface (5) and a rear surface (6), a light emitter optically connected to the panel (1) so as to generate light that propagates by total internal reflection inside the panel, and a light detector (3) optically connected to the panel to receive propagating light from the emitter. The emitter is a VCSEL array including a number of VCSELs (21) driven to collectively form one light emitter, and a light coupling mechanism connecting the emitter to the panel is configured to give light from a plurality of the VCSELs in the VCSEL array substantially the same spread in the panel.

Abstract: A light conversion sheet for application on top of a solar cell panel. The light conversion sheet has a front surface configured to face the sun and a back surface configured to face a solar cell, and comprises a photo luminescent layer, configured to emit light at a photo luminescent wavelength upon absorption of light of shorter wavelengths; and a spectrally selective mirror arranged between the photo luminescent layer and the front surface, configured to reflect light of the photo luminescent wavelength.

Abstract: An arrangement for a touch sensitive apparatus comprises a light transmissive panel having a front surface and an opposite rear surface defining an optical media for transmitting light signals via total internal reflection. A shield layer is arranged at the rear surface of the light transmissive panel and is substantially non-transparent to visible light from the front surface. A refractive layer is arranged between the light transmissive panel and the shield layer and allows a light signal to propagate by total internal reflection within the light transmissive panel. At least one aperture is arranged through the shield layer and the refractive layer and is configured to allow a light signal to pass through the aperture. The shield layer, the refractive layer, and the aperture are arranged at the periphery of the light transmissive panel.

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).

Abstract: A touch-sensitive apparatus operates by light frustration (FTIR) and comprises a light transmissive panel (1) that defines a front surface (5) and a rear surface (6), light emitters optically connected to the panel (1) so as to generate light that propagates by total internal reflection inside the panel, and light detectors (3) optically connected to the panel (1) so as to define a grid of propagation paths inside the panel (1) between pairs of light emitters and light detectors (3). Each light detector (3) is optically connected to the panel (1) via an angular filter (20). The filter (20) is applied to an outcoupling region on at least one of the front and rear surfaces (5, 6) 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 ?min to an upper angle limit ?max.

Abstract: A touch-sensitive apparatus operates by light frustration (FTIR) and comprises a light transmissive panel (1) with a front surface (5) and a rear surface (6). Light emitters (2) are optically coupled to the panel (1) at entry ports along a periphery region of the panel (1), and light detectors (3) are optically coupled to the panel (1) at exit ports along the periphery region for detecting light transmitted inside the panel (1). At least one optical sheet (20) is provided on the rear surface (6) in the periphery region. In an outcoupling installation, the light detectors (3) are arranged at the respective optical sheet (20) to receive, on a respective light-sensitive surface (3A); light from the optical sheet (20), and each light detector (3) is arranged with the light-sensitive surface (3A) essentially perpendicular to the rear surface (6).

Abstract: A touch-sensitive FTIR apparatus (100), comprising a light-transmissive panel (1) having a front surface (5), an opposite rear surface (6), and a side edge (13) connecting the front and rear surfaces. A light emitter (2) is connected to input light at a first side edge portion and a detector (3) is connected to receive light output at a second side edge portion. A light-transmissive sheet (60) is laminated over the front surface of the panel and extends beyond the side edge of the panel to cover the emitter and the detector; wherein a lower surface (62) of the light-transmissive sheet is in optical contact with the front surface of the panel, so as to allow input light to propagate between the emitter and the detector through the panel and the light-transmissive sheet via total internal reflection in an upper surface (61) of the light-transmissive sheet.

Abstract: A laminated optical element is provided for a touch-sensitive apparatus which operates by light frustration (FTIR), and comprises: a light-transmissive panel (1) that defines a front surface (5) and an opposite, rear surface (6); a light-coupling mechanism for light input to and output from the panel, arranged along a perimeter of a touch-sensitive region (4) of the optical element; a shielding element (70) applied at the front surface (5) over the light-coupling mechanism; and a light-transmissive sheet (60) disposed overlapping the shielding element and covering the front surface of the panel within the shielding element, wherein a lower surface of the light-transmissive sheet is in optical contact with the front surface of the panel, so as to allow light within a predetermined wavelength range to propagate between at least first and second positions of the light-coupling mechanism by total internal reflection in an upper surface of the light-transmissive sheet.

Abstract: A touch-sensitive apparatus operates by light frustration (FTIR) and comprises a light transmissive panel (1) with a front surface (5) and a rear surface (6). Light emitters (2) and light detectors are optically coupled to the panel (1) to define a grid of light propagation paths inside the panel (1) between pairs of light emitters (2) and light detectors. A light in coupling structure comprises a diffusively reflective element (20) on the rear surface (6) and a specularly reflective element (22) on the front surface (5). Each light emitter (2) is arranged to project a beam of light onto a transmissive surface portion (24) on the rear surface (6), such that at least a portion of the beam of light enters the light transmissive panel (1) through the transmissive surface portion (24), is specularly reflected against the specularly reflective element (22) and impinges on the diffusively reflective element (20) from inside the light transmissive panel (1).

Abstract: 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.

Abstract: A touch-sensitive apparatus is configured to propagate energy inside a panel (1) so as to define a grid of transmission paths across a touch surface (4) of the panel (1). The apparatus comprises a first subset of components on a first end of the touch surface (4), and a second subset of components on a second end which is opposite to and parallel with the first end. The components include emitters and detectors, each emitter being operable for propagating a diverging energy beam (e.g. radiation) across the touch surface (4) inside the panel (1), and each detector being operable for detecting transmitted energy from at least two emitters. The components in at least one of the first and second subsets are systematically arranged in spatially separate groups along at least one of the first and second ends, so as to achieve a reduced spacing and/or an increased uniformity of the transmission paths along a center line between the first and second ends compared to an equidistant arrangement of all components.

Abstract: A touch-sensitive apparatus for determining a location of at least one object on a touch surface. The touch-sensitive apparatus extends in a direction of depth and comprises a light transmissive panel, a display arranged behind the light transmissive panel, and a first compartment and second compartment arranged behind the display. Light from a light emitter arrangement in the first compartment is introduced into the light transmissive panel for propagation by internal reflection. The light is thereafter coupled out to be received by a light detection arrangement in the second compartment. The first and second compartments are separated, such that light from the light emitter arrangement is prevented from reaching the light detection arrangement without first having propagated in the light transmissive panel.

Abstract: 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.

Abstract: 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.

Abstract: A touch-sensitive apparatus for determining a location of at least one object on a touch surface. The touch-sensitive apparatus extends in a direction of depth and comprises a light transmissive panel, a display arranged behind the light transmissive panel, and a first compartment and second compartment arranged behind the display. Light from a light emitter arrangement in the first compartment is introduced into the light transmissive panel for propagation by internal reflection. The light is thereafter coupled out to be received by a light detection arrangement in the second compartment. The first and second compartments are separated, such that light from the light emitter arrangement is prevented from reaching the light detection arrangement without first having propagated in the light transmissive panel.

Abstract: A device for measuring birefringence in an optical data carrier has a laser light source with a polarization modifier, a beamsplitter, a polarizer, a photodetector, and a controller operatively connected to the photodetector. The laser light source illuminates various spots on the optical data carrier by means of a laser beam. The photodetector receives a reflected laser beam, converts it into an electric signal and supplies this signal to the controller, which determines a value for the birefringence in the illuminated spot on the optical data carrier. Furthermore, the device is provided with a transparent reference element with known birefringence properties, a mirror, and for directing the laser beam towards the reference element in a first calibration position; directly towards the mirror in a second calibration position; and towards the optical data carrier during non-calibration time.

Abstract: The invention relates to a process for the preparation of an essentially sulfide-free alkali liquor starting from a pulp mill alkali sulfide source, characterized by reacting in alkaline medium the alkali sulfice source with copper (II) oxide and/or copper (I) oxide, optionally with the addition of water, in a mole ratio oxide to sulfide (calculated as alkali sulfide) (charging) of at least 0.9 and allowing the mixture obtained to react at a temperature of from 30.degree. to 130.degree.0 C. to form hydroxide in an amount equivalent to the amount of sulfide and to precipitate a solid phase consisting essentially of copper (I) sulfide, copper (II) sulfide or a mixture thereof, whereupon the solid phase is separated in a way known per se to obtain an essentially sulfide-free alkali liquor, the reaction time of the precipitation reaction being adjusted with regard to the charging and temperature selected so that the residual concentration of copper ions in the final alkali liquor is below 1 mmole/l.