# US 11,306,895 B2 · Troffer-style fixture > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,306,895 B2 - Document ID: US11306895B2 - Status: Granted - Kind: B2 - Application number: 17/102,852 - Filed: 2020-11-24 - Published: 2021-03-18 - Granted: 2022-04-19 - Earliest claimed: 2010-08-31 - Assignees: IDEAL Industries Lighting LLC - Applicants: IDEAL Industries Lighting LLC - Inventors: Mark Edmond; Dong Lu; Paul Pickard; Nick Nguyen; Gerald Negley; Gary David Trott - Web page: https://patentgrep.com/patent/US11306895B2 ## CPC - F21V 7/0008: {providing for indirect lighting} - F21S 8/026: {intended to be recessed in a ceiling or like overhead structure, e.g. suspended ceiling} - F21V 7/24: characterised by the material - F21V 7/30: the coatings comprising photoluminescent substances - F21V 29/745: {the fins or blades being planar and inclined with respect to the joining surface from which the fins or blades extend} - F21V 29/75: with fins or blades having different shapes, thicknesses or spacing - 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 2113/13: comprising an assembly of point-like light sources - F21Y 2115/10: Light-emitting diodes [LED] - F21V: FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR - F21S: NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS - 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 An indirect troffer. Embodiments of the present invention provide a troffer-style fixture that is particularly well-suited for use with solid state light sources, such as LEDs. The troffer comprises a light engine unit that is surrounded on its perimeter by a reflective pan. A back reflector defines a reflective interior surface of the light engine. To facilitate thermal dissipation, a heat sink is disposed proximate to the back reflector. A portion of the heat sink is exposed to the ambient room environment while another portion functions as a mount surface for the light sources that faces the back reflector. One or more light sources disposed along the heat sink mount surface emit light into an interior cavity where it can be mixed and/or shaped prior to emission. In some embodiments, one or more lens plates extend from the heat sink out to the back reflector. ## Claims ### Claim 1 A wall washer lighting unit, comprising: a back reflector defining a bottom edge and having a first longitudinal side and a second longitudinal side, the back reflector further comprising a longitudinal spine region that runs longitudinally down the back reflector adjacent the first longitudinal side; a heat sink extending along the longitudinal spine region, the heat sink comprising a top-side mount surface, wherein a space between the heat sink and the back reflector defines an interior cavity; and a plurality of light emitters on the mount surface and aimed to emit light toward the back reflector, the mount surface facing the back reflector, and wherein the plurality of light emitters are substantially in line with the longitudinal spine region in a first direction; the mount surface offset from the back reflector such that the mount surface is entirely below the bottom edge of the back reflector in a second direction perpendicular to the first direction. ### Claim 2 (depends on 1) The lighting unit of claim 1, wherein the back reflector defines an asymmetrical cross-section. ### Claim 3 (depends on 1) The lighting unit of claim 1, further comprising a lens plate that extends from the heat sink toward the second longitudinal side. ### Claim 4 (depends on 3) The lighting unit of claim 3, wherein the lens plate extends from the heat sink to the second longitudinal side. ### Claim 5 (depends on 4) The lighting unit of claim 4, wherein the heat sink is at least partially exposed. ### Claim 6 (depends on 1) The lighting unit of claim 1, wherein the plurality of light emitters combine to emit white light during operation. ### Claim 7 (depends on 1) The lighting unit of claim 1, wherein the back reflector comprises a diffuse white reflector. ### Claim 8 (depends on 1) The lighting unit of claim 1, further comprising a pan structure comprising an inner reflective surface defining a perimeter; the back reflector mounted inside of the pan structure such that the inner reflective surface surrounds the back reflector. ### Claim 9 (depends on 1) The lighting unit of claim 1, wherein the back reflector is one of parabolic, flat and corrugated. ### Claim 10 A lighting unit, comprising: a back reflector comprising a bottom edge; a first heat sink and a second heat sink, the first heat sink comprising a first mount surface that faces towards a first area of the back reflector and the second heat sink comprising a second mount surface that faces towards a second area of the back reflector; and a first plurality of light emitters on the first mount surface and a second plurality of light emitters on the second mount surface, wherein the first plurality of light emitters and the second plurality of light emitters extend in a first direction; the first heat sink and the second heat sink being offset from the back reflector such that the first heat sink and the second heat sink are below the bottom edge of the back reflector in a second direction perpendicular to the first direction. ### Claim 11 (depends on 10) The lighting unit of claim 10, wherein the first area and the second area are at least one of parabolic, flat and corrugated. ### Claim 12 (depends on 10) The lighting unit of claim 10, further comprising a center lens plate that extends between the first heat sink and the second heat sink. ### Claim 13 (depends on 12) The lighting unit of claim 12, further comprising a first side lens plate that extends from the first heat sink and a second side lens plate that extends from the second heat sink. ### Claim 14 (depends on 10) The lighting unit of claim 10, wherein the first heat sink is parallel to the second heat sink. ### Claim 15 (depends on 10) The lighting unit of claim 10, wherein the first heat sink and the second heat sink are at least partially exposed. ### Claim 16 (depends on 10) The lighting unit of claim 10, wherein the first plurality of light emitters and the second plurality of light emitters emit white light. ### Claim 17 (depends on 10) The lighting unit of claim 10, wherein the first mount surface comprises two flat areas each facing at an angle toward different portions of the first area. ### Claim 18 (depends on 10) The lighting unit of claim 10, further comprising a pan structure comprising an inner reflective surface defining a perimeter; the back reflector mounted inside of the pan structure such that the inner reflective surface at least partially surrounds the back reflector. ### Claim 19 (depends on 10) The lighting unit of claim 10, further comprising a central region between the first area and the second area. ### Claim 20 (depends on 19) The lighting unit of claim 19, wherein the central region comprises one of a flat center, and a shape defined by a vertex.