# US 10,119,682 B2 · Luminaire having improved uniformity of output > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,119,682 B2 - Document ID: US10119682B2 - Status: Granted - Kind: B2 - Application number: 15/623,420 - Filed: 2017-06-15 - Published: 2018-01-11 - Granted: 2018-11-06 - Earliest claimed: 2016-07-05 - Assignees: Philips Lighting Holding B.V. - Applicants: Philips Lighting Holding B.V. - Inventors: Jing Bao; Liang Zhou; Qin Li - Web page: https://patentgrep.com/patent/US10119682B2 ## CPC - F21S 8/04: intended only for mounting on a ceiling or the like overhead structures (F21S8/02 takes precedence; {details of ceiling bases F21V21/03}) - F21V 3/02: characterised by the shape - F21V 5/045: {the lens having discontinuous faces, e.g. Fresnel lenses} - F21V 7/0008: {providing for indirect lighting} - F21V 7/0091: {using total internal reflection} - F21V 7/28: characterised by coatings - F21V 13/04: the elements being reflectors and refractors {(for vehicle rear lights F21S43/40)} - F21Y 2103/10: comprising a linear array of point-like light-generating elements - F21Y 2103/33: annular - F21Y 2105/18: annular; polygonal other than square or rectangular, e.g. for spotlights or for generating an axially symmetrical light beam - F21Y 2115/10: Light-emitting diodes [LED] - F21S: NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS - F21V: FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR - F21Y: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED ## Abstract The invention provides a luminaire comprising an optical element configured to spread light uniformly across a full visible face of the luminaire. The optical element comprises a central region and an outer peripheral region, each configured to receive light emitted by a light source arrangement and to direct this light out through a respective region of the light exit area of the luminaire. The central region receives light through a central transmissive surface portion which partially bounds it across its top. A further reflective tapered portion of the central region acts to reflect light incident at either of its two opposing sides, and provides a mixing function both within the central region of the optical element and within an inner compartment of the luminaire which extends between the optical element and the housing. ## Claims ### Claim 1 A luminaire, comprising: a housing including a compartment having a reflective inner surface and an optical element comprising: a light entry surface arrangement facing the compartment and including a central transmissive surface portion separated from a peripheral transmissive surface portion by a tapered surface portion having opposing reflective surfaces and tapering outwardly towards a light exit surface arrangement including a central stepped profile stepping toward the compartment, the central stepped profile including a transmissive roof section facing the central transmissive surface portion and one or more tapered total internal reflection sidewall sections each facing a reflective surface of the tapered surface portion, the transmissive roof section having a smaller cross-section than the central transmissive surface portion; and a light source arrangement in the compartment arranged to emit a first fraction of light onto the central transmissive surface portion and a second fraction of light onto at least one of the reflective inner surface, the tapered surface portion and the peripheral transmissive surface portion. ### Claim 2 (depends on 1) A luminaire as claimed in claim 1, wherein the central transmissive surface portion of the optical element comprises one or more inclined surfaces meeting in a point facing the stepped profile. ### Claim 3 (depends on 1) A luminaire as claimed in claim 1, wherein the tapered surface portion of the optical element is concavely inflected, comprising adjoining inclined surface sections. ### Claim 4 (depends on 3) A luminaire as claimed in claim 3, wherein said adjoining inclined surface sections are of unequal length, such that a vertex of said inflection is located closer to a boundary with the central transmissive surface portion of the optical element than to a boundary with the peripheral transmissive surface portion. ### Claim 5 (depends on 1) A luminaire as claimed in claim 1, wherein said peripheral transmissive surface portion of the optical element comprises a collimating lens plate. ### Claim 6 (depends on 5) A luminaire as claimed in claim 5, wherein said collimating lens plate is a Fresnel plate. ### Claim 7 (depends on 1) A luminaire as claimed in claim 1, wherein a section of the reflective inner surface of the housing is bow-shaped. ### Claim 8 (depends on 1) A luminaire as claimed in claim 1, wherein the reflective inner surface is diffusively reflective. ### Claim 9 (depends on 1) A luminaire as claimed in claim 1, wherein the light exit surface arrangement has a total surface area which includes a surface area opposite the central transmissive surface portion and tapered surface portion of the light entry surface arrangement, and wherein the first fraction of light emitted onto the central transmissive surface portion corresponds to a proportion of a total luminous output of the light source arrangement equal to said surface area as a proportion of the total surface area. ### Claim 10 (depends on 9) A luminaire as claimed in claim 9, wherein the light source arrangement has a total light emitting area, and is positioned opposite to a boundary between the central transmissive surface portion and the tapered surface portion such that a first portion of said total light emitting area faces the central transmissive surface portion, said first portion corresponding to a fraction of the total light emitting area equal to said surface area opposite the central transmissive surface portion and tapered surface portion as a fraction of said total surface area. ### Claim 11 (depends on 1) A luminaire as claimed in claim 1, wherein the central transmissive surface portion and the tapered surface portion are separated by a circular boundary, and wherein the light source arrangement comprises an annular arrangement of light sources positioned opposite to said boundary. ### Claim 12 (depends on 1) A luminaire as claimed in claim 1, wherein the central transmissive surface portion and the tapered surface portion of the optical element are separated by a pair of parallel opposing linear boundaries, and wherein the light source arrangement comprises a plurality of rows of light sources. ### Claim 13 (depends on 1) A luminaire as claimed in claim 1, wherein the peripheral transmissive surface portion has a circular outer perimeter, or a rectangular outer perimeter. ### Claim 14 (depends on 1) A luminaire as claimed in claim 1, wherein the central transmissive surface portion is formed of an optical grade polymer material. ### Claim 15 (depends on 1) A luminaire as claimed in claim 1, wherein the opposing reflective surfaces of the tapered surface portion are formed by a specularly reflective metal coating.