# US 12,181,147 B2 · Laser-based lighting device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,181,147 B2 - Document ID: US12181147B2 - Status: Granted - Kind: B2 - Application number: 18/038,817 - Filed: 2021-11-25 - Published: 2024-06-27 - Granted: 2024-12-31 - Earliest claimed: 2020-12-01 - Assignees: Signify Holding B.V. - Applicants: Signify Holding B.V. - Inventors: Robert Van Asselt; Dominique Maria Bruls; Rifat Ata Mustafa Hikmet - Web page: https://patentgrep.com/patent/US12181147B2 ## CPC - F21V 9/40: with provision for controlling spectral properties, e.g. colour, or intensity - F21V 25/02: coming into action when lighting device is disturbed, dismounted, or broken - F21V 5/04: of lens shape - F21V 9/30: Elements containing photoluminescent material distinct from or spaced from the light source (shades F21V1/17; globes, bowls or cover glasses F21V3/08, F21V3/12; refractors F21V5/10; reflectors F21V7/26, F21V7/30; elements with provision for controlling the spectral properties or intensity F21V9/40) - F21V 9/32: characterised by the arrangement of the photoluminescent material - F21V 13/02: Combinations of only two kinds of elements - H05B 45/18: using temperature feedback - F21Y 2115/30: Semiconductor lasers - F21V: FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL - 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 This invention relates to a safety measure taken against unsafe exposure of high-intensity laser light that is relevant for the reliable and safer operation of laser-based lighting devices. According to this invention, a lighting device comprises a first light-emitting semiconductor device and a light-conversion device. The first light-emitting semiconductor device is a laser device configured to generate a first light output and the 5light-conversion device is configured to receive the first light output and convert at least part of the first light output into a converted light output. The lighting device further comprises an optical element configured to receive the converted light output from the light-conversion device. The optical element is configured to transmit the converted light output and the first light output, and attenuate the first light output above a threshold value of the first light output. ## Claims ### Claim 1 A lighting device comprising, a first light-emitting semiconductor device, the first light-emitting semiconductor device being a laser device configured to generate a first light output, a light-conversion device configured to receive the first light output and to convert at least part of the first light output into a converted light output to be directed in an illumination direction, and an optical element configured to receive the converted light output from the light-conversion device, wherein the optical element comprises a bistable optical material that can change from an optical transmissive state to an optical attenuative state depending on a threshold value of the first light output, wherein the optical element is configured to transmit the converted light output and the first light output, wherein the optical element is configured to attenuate the first light output above a threshold value of the first light output, and wherein the optical element is configured for one of collimating, focusing, blurring, or diffusing light in the illumination direction. ### Claim 2 (depends on 1) A lighting device according to claim 1, wherein the light-conversion device further comprises a light reflector, and wherein the light reflector is located on the opposite side of a light entry surface of the light-conversion device. ### Claim 3 (depends on 2) A lighting device according to claim 2, wherein the lighting device further comprises a first optics arrangement that is located between the first light-emitting semiconductor device and the light-conversion device, wherein the first optics arrangement is configured to transmit the first light output towards the light-conversion device and reflect the converted light output and the first light output reflected from the light reflector of the light conversion device towards the illumination direction, and wherein the optical element is configured to receive the reflected light from the first optics arrangement. ### Claim 4 (depends on 2) A lighting device according to claim 2, wherein the lighting device further comprises a first optics arrangement that is located between the first light-emitting semiconductor device and the light-conversion device, wherein the first optics arrangement is configured to transmit the first light output towards the light-conversion device and reflect the converted light output and the first light output reflected from the light reflector of the light conversion device towards the illumination direction, and wherein the optical element is located in between the light-conversion device and the light reflector. ### Claim 5 (depends on 4) A lighting device according to claim 4, wherein the lighting device comprises an optical lens located downstream from the first optics arrangement, and wherein the optical lens is configured for one of collimating, focusing, blurring, or diffusing light in the illumination direction. ### Claim 6 (depends on 1) A lighting device according to claim 1, wherein the lighting device further comprises: a second light-emitting semiconductor device configured to generate a second light output, and a second optics arrangement, wherein the second optics arrangement is configured to combine the second light output from the second light-emitting semiconductor device and the transmitted light from the optical element towards an illumination direction. ### Claim 7 (depends on 6) A lighting device according to claim 6, wherein the light-conversion device is configured to convert substantially all of the first light output into the converted light output. ### Claim 8 (depends on 6) A lighting device according to claim 6, wherein the lighting device comprises an optical lens located downstream from the second optics arrangement, and wherein the optical lens is configured for one of collimating, focusing, blurring, or diffusing light in the illumination direction. ### Claim 9 (depends on 1) A lighting device according to claim 1, wherein the lighting device comprises an optical lens located downstream from the optical element, and wherein the optical lens is configured for one of collimating, focusing, blurring, or diffusing light in the illumination direction. ### Claim 10 (depends on 1) A lighting device according to claim 1, wherein the optical element comprises one of a photochromic or thermochromic material that is configured to absorb or scatter the first light output above the threshold value of the first light output. ### Claim 11 (depends on 1) A lighting device according to claim 1, wherein the optical element comprises an optical phase change material that is configured to reflect, absorb, and/or scatter the first light output above the threshold value of the first light output. ### Claim 12 (depends on 1) A lighting device according to claim 1, wherein the threshold value of the first light output is a laser power density of 0.5 watts per square millimeter. ### Claim 13 (depends on 1) A lighting device according to claim 1, wherein the first light-emitting semiconductor device has a spectral power distribution in a range of 405 to 470 nm. ### Claim 14 (depends on 1) A lighting device according to claim 1, wherein the lighting device comprises a thermal sensor and a controller, wherein the thermal sensor is attached to the optical element for detecting the temperature of the optical element, wherein the thermal sensor is communicatively connected to the controller, and wherein the controller is configured to turn off the first light-emitting semiconductor device when the detected temperature exceeds a predetermined temperature threshold value. ### Claim 15 (depends on 1) A lighting device according to claim 1, wherein the change from an optical transmissive state to an optical attenuative state depending on a threshold value of the first light output occurs as a gradual change. ### Claim 16 (depends on 1) A lighting device according to claim 1, wherein the change from an optical transmissive state to an optical attenuative state is reversible.