# US 9,519,110 B2 · Detector, light guide and utility meter > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,519,110 B2 - Document ID: US9519110B2 - Status: Granted - Kind: B2 - Application number: 14/432,118 - Filed: 2013-11-12 - Published: 2015-09-10 - Granted: 2016-12-13 - Earliest claimed: 2012-11-13 - Assignees: Itron, Inc. - Applicants: Itron GmbH - Inventors: Karsten Hugler - Web page: https://patentgrep.com/patent/US9519110B2 ## CPC - G02B 6/353: {the optical element being a shutter, baffle, beam dump or opaque element (absorbers on light guide termination G02B6/243)} - G01D 5/34723: {involving light-guides} - G02B 6/4214: {the intermediate optical element having redirecting reflective means, e.g. mirrors, prisms for deflecting the radiation from horizontal to down- or upward direction toward a device (G02B6/4246 takes precedence)} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G01D: MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR ## Abstract A detector is provided for detecting the interruption of a light path, the detector comprising a light emitter, a light receiver, and a light guiding arrangement disposed opposite the light emitter and receiver. A gap is defined between the light guiding arrangement and at least one of the light emitter and receiver to receive a movable part capable of interrupting the light path there between. Also provided is a light guide for use with such a detector and a utility meter comprising such a detector. In one specific embodiment, an opto electronic detector for detecting rotation of a coding wheel in a utility meter is provided. ## Claims ### Claim 1 A light guide comprising: an entry surface shaped to collimate light entering the light guide in an entry direction along an optical axis; and a plurality of planar reflective surfaces arranged to reflect light inside the light guide along the optical axis to exit the light guide at an exit surface in an exit direction, the exit direction having a component in a direction opposite the entry direction, wherein the light guide comprises two limbs extending from either end of a back portion, free ends of the limbs being respectively shaped to provide the entry and exit surfaces, wherein the ends of the back portion are shaped to each provide a reflective portion, and wherein one of the limbs is shorter than another one of the limbs, thereby providing a space for accepting a movable part including at least one of polarizing portion or a filtering portion, the moveable part capable of intersecting the optical axis. ### Claim 2 (depends on 1) A light guide as claimed in claim 1, wherein the optical axis at the exit surface is parallel to the optical axis at the entry surface. ### Claim 3 (depends on 1) A light guide as claimed in claim 1, wherein the optical axis at the exit surface is parallel to the optical axis at the entry surface, and the plurality of reflective surfaces are two reflective surfaces. ### Claim 4 (depends on 1) A light guide as claimed in claim 1, wherein the exit surface is shaped to focus light exiting the light guide along the optical axis. ### Claim 5 (depends on 1) A light guide as claimed in claim 1, wherein the light guide is one or more of moulded and machined as one piece. ### Claim 6 (depends on 1) A light guide as claimed in claim 1, further comprising one or more further entry surfaces to define one or more further optical axes, wherein the one or more further optical axes are parallel to the optical axis between the entry surface and the exit surface. ### Claim 7 (depends on 1) A detector for detecting interruption of a light path, the detector comprising: a light emitter; a light receiver; and a light guide according to claim 1, wherein the light guide is disposed opposite the light emitter and the light receiver to define the space between the light guide and at least one of the light emitter and the light receiver, wherein a light path between the light emitter and the light receiver is interruptable by the moveable part in the space. ### Claim 8 (depends on 7) A detector as claimed in claim 7, wherein the light guide comprises a concentrator arranged to focus light from the light guide towards the light receiver. ### Claim 9 (depends on 7) A detector as claimed in claim 7, wherein the light guide comprises a first reflective surface arranged to reflect light received from the entry surface to a second reflective surface arranged to direct the received light towards the light receiver. ### Claim 10 (depends on 9) A detector as claimed in claim 9, wherein the first and second reflective surfaces are perpendicular to each other. ### Claim 11 (depends on 7) A detector as claimed in claim 7, further comprising one or more further light emitters, one or more further light receivers, and one or more further guiding arrangements arranged to enable detecting an interruption of one or more further light paths by the moveable part. ### Claim 12 (depends on 7) A utility meter comprising a detector of claim 7, wherein the moveable part is coupled to a consumption sensor such that movement of the moveable part is indicative of a quantity sensed by the consumption sensor. ### Claim 13 (depends on 1) A light guide as claimed in claim 1, wherein the light guide is to be statically mounted within a utility meter. ### Claim 14 An apparatus, comprising: a utility meter; a coding wheel rotatably coupled within the utility meter, wherein the coding wheel includes at least one of a polarizing portion or a filtering portion; and a light guide to guide light along an optical path between an emitter and a receiver, the light guide, including: a first portion including an entrance, the first portion to collimate light entering the light guide; a second portion including an exit; and a third portion disposed between the first portion and the second portion, the first portion extending from a first end of the third portion, the second portion extending from a second end of the third portion, the first portion being shorter than the second portion to provide a space to enable the coding wheel to intersect the optical path at the exit. ### Claim 15 An apparatus, comprising: a printed circuit board defining a first portion and a second portion; an emitter to be disposed adjacent the first portion; a receiver to be disposed adjacent the second portion; a light guide coupled between the first portion and the second portion, the light guide to guide light from the emitter along an optical path between the emitter and the receiver, a first end of the light guide to be coupled to the first portion; and a space being defined between a second end of the light guide and the second portion to enable a coding wheel to be received within the space to intersect the optical path, wherein the first portion includes a first aperture and the second portion includes a second aperture, the emitter to emit the light through the first aperture, the receiver to receive the light through the second aperture. ### Claim 16 (depends on 15) The apparatus of claim 15, wherein a first axis of the first aperture is substantially parallel to a second axis of the second aperture.