# US 2023/0068643 A1 · Improved touch-sensing apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2023/0068643 A1 - Document ID: US20230068643A1 - Status: Published application - Kind: A1 - Application number: 17/759,836 - Filed: 2021-01-25 - Published: 2023-03-02 - Earliest claimed: 2020-02-10 - Assignees: FlatFrog Laboratories AB - Applicants: Flatfrog Laboratories AB - Inventors: Håkan Bergström; Tomas Svensson - Web page: https://patentgrep.com/patent/US20230068643A1 ## CPC - G06F 3/0428: {by sensing at the edges of the touch surface the interruption of optical paths, e.g. an illumination plane, parallel to the touch surface which may be virtual (sensing beam interruptions in a planar beam grid of an optical touch-screen G06F3/0421)} - G06F 3/0421: {by interrupting or reflecting a light beam, e.g. optical touch-screen} - G06F 2203/04103: Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract A touch sensing apparatus is disclosed comprising a panel having a touch surface, emitters and detectors arranged along a perimeter, a light directing portion arranged adjacent the perimeter and comprising a light directing surface, the emitters and/or the detectors are arranged opposite a rear surface of the panel to emit and/or receive light through a channel in a frame element, the channel is arranged opposite the rear surface and extends in a direction of a normal axis of the touch surface, the light directing surface and the channel are arranged on opposite sides of the panel and overlap in the direction of the plane, the light directing surface receive light from the emitters, or direct light to the detectors, through the panel and through the channel, in the direction of the normal axis. A method of manufacturing a frame element for a touch sensing apparatus is disclosed. ## Claims ### Claim 1 A touch sensing apparatus comprising: a panel that defines a touch surface extending in a plane having a normal axis, a plurality of emitters and detectors arranged along a perimeter of the panel, and a light directing portion arranged adjacent the perimeter and comprising a light directing surface, wherein the emitters are arranged to emit light and the light directing surface is arranged to receive the light and direct the light across the touch surface, wherein the panel comprises a rear surface, opposite the touch surface, and the emitters and/or the detectors are arranged opposite the rear surface to emit and/or receive light through a channel in a frame element, the channel is arranged opposite the rear surface and extends in a direction of the normal axis, wherein the light directing surface and the channel are arranged on opposite sides of the panel and overlap in the direction of the plane, and whereby the light directing surface receive light from the emitters, or direct light to the detectors, through the panel and through the channel, in the direction of the normal axis. ### Claim 2 (depends on 1) The touch sensing apparatus according to claim 1, wherein an angle (v) between the light directing surface and the plane of the touch surface is less than 45 degrees, or above 45 degrees. ### Claim 3 (depends on 1) The touch sensing apparatus according to claim 1, the panel having edges extending between the touch surface and the rear surface, the channel extending in a direction parallel with the plane with a width (d1) between a first channel wall, arranged closest to a respective edge of the panel, and an opposite second channel wall, wherein the first channel wall extends with an angle towards the direction of the normal axis. ### Claim 4 (depends on 1) The touch sensing apparatus according to claim 1, wherein the light directing surface extends from an edge portion of the light directing portion being arranged closest to the touch surface to a protrusion of the light directing portion, the protrusion extending in a direction parallel with the plane to shield ambient or stray light from being reflected towards the channel. ### Claim 5 (depends on 1) The touch sensing apparatus according to claim 1, wherein the emitters and/or detectors are mounted to a substrate, the substrate comprising a chamfered edge to be arranged opposite a corresponding mating surface of the frame element forming an angle with the normal axis. ### Claim 6 (depends on 1) The touch sensing apparatus according to claim 1, wherein walls of the channel comprise a diffusive light scattering surface. ### Claim 7 (depends on 1) The touch sensing apparatus according to claim 1, wherein the emitters and/or detectors are mounted to a substrate, wherein a support is attached to the substrate, the support extending in a direction parallel with the plane between the substrate and a frame wall of the frame element. ### Claim 8 (depends on 1) The touch sensing apparatus according to claim 1, wherein the panel having edges extending between the touch surface and the rear surface, wherein the frame element forms a cavity, wherein the emitters and/or detectors are mounted to a substrate and the substrate is arranged in the cavity so that the emitters and/or detectors are arranged closer to the respective edge of the panel than the substrate. ### Claim 9 (depends on 8) The touch sensing apparatus according to claim 8, wherein the cavity extends in a direction parallel with the plane with a width (d2) between a first frame wall, arranged closest to the respective edge of the panel, and an opposite second frame wall, wherein the substrate is arranged in the cavity so that the emitters and/or detectors are arranged closer to the first frame wall than the substrate. ### Claim 10 (depends on 8) The touch sensing apparatus according to claim 8, wherein the substrate extends with an elongated shape in a direction of the normal axis. ### Claim 11 (depends on 1) The touch sensing apparatus according to claim 1, wherein the light directing surface is anodized metal. ### Claim 12 (depends on 1) The touch sensing apparatus according to claim 1, wherein the light directing surface is etched metal, sand blasted metal, bead blasted metal, or brushed metal for increasing surface roughness and to diffusively reflect the light over the touch surface. ### Claim 13 (depends on 11) The touch sensing apparatus according to claim 11, wherein the frame element comprises the light directing portion, wherein the frame element is formed from said metal, whereby the light directing surface is an anodized metal surface of the frame element, and/or an etched metal surface, sand blasted metal surface, bead blasted metal surface, or brushed metal surface of the frame element. ### Claim 14 (depends on 13) The touch sensing apparatus according to claim 13, wherein the metal surface is concave towards the touch surface. ### Claim 15 (depends on 11) The touch sensing apparatus according to claim 11, wherein the frame element forms a cavity in which the emitters and/or detectors are arranged. ### Claim 16 (depends on 1) The touch sensing apparatus according to claim 1, wherein the light directing surface has a surface roughness defined by a slope RMS (Δq) between 0.1-0.25. ### Claim 17 (depends on 16) The touch sensing apparatus according to claim 16, wherein the light directing surface has a surface roughness defined by a slope RMS (Δq) between 0.13-0.20. ### Claim 18 (depends on 1) The touch sensing apparatus according to claim 1, wherein the light directing surface has a surface roughness defined by a slope RMS (Δq) between 0-0.1. ### Claim 19 (depends on 1) The touch sensing apparatus according to claim 1, wherein the light directing portion comprises an outer surface opposite the light directing surface, wherein the light directing surface has a higher reflectance than the outer surface. ### Claim 20 (depends on 1) The touch sensing apparatus according to claim 1, wherein walls of the channel have a higher specular reflectance than the light directing surface. ### Claim 21 A touch sensing apparatus comprising: a panel that defines a touch surface extending in a plane having a normal axis, a plurality of emitters and detectors arranged along a perimeter of the panel, a light directing portion arranged adjacent the perimeter and comprising a light directing surface, wherein the emitters are arranged to emit light and the light directing surface is arranged to receive the light and direct the light across the touch surface, the panel comprises a rear surface, opposite the touch surface, the emitters and/or the detectors are arranged opposite the rear surface to emit and/or receive light through a channel in a frame element, the light directing surface receive light from the emitters, or direct light to the detectors, through the panel and through the channel, wherein the frame element is formed from a metal and comprises the light directing portion, and the light directing surface is an anodized metal surface of the frame element. ### Claim 22 Method of manufacturing a frame element for a touch sensing apparatus, comprising extruding the frame element to form a light directing portion and a cavity adapted to receive a substrate comprising emitters and/or detectors, and milling a wall portion of the cavity to form a channel so that, in use, a light directing surface of the light directing portion receive light from the emitters, or direct light to the detectors, through the channel. ### Claim 23 (depends on 22) Method according to claim 22, comprising etching, or bead-or sand blasting the light directing surface. ### Claim 24 (depends on 22) Method according to claim 22, comprising milling a top portion of the extruded light directing portion so that a height (h) of the light directing portion above a touch surface of a panel, when arranged in the frame element, is reduced.