# US 2025/0207751 A1 · Lighting device for vehicles, and control method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0207751 A1 - Document ID: US20250207751A1 - Status: Published application - Kind: A1 - Application number: 19/079,091 - Filed: 2025-03-13 - Published: 2025-06-26 - Earliest claimed: 2022-09-19 - Applicants: Hella GmbH & Co. KGaA - Inventors: Hamza Akin; Andreas Lintz; Maximilian Mevenkamp - Web page: https://patentgrep.com/patent/US20250207751A1 ## CPC - F21S 41/663: by switching light sources (by switching incandescent light sources F21S41/162) - F21S 41/25: Projection lenses - F21S 45/60: Heating of lighting devices, e.g. for demisting - F21S: NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS ## Abstract A lighting device for vehicles is provided with a housing with a lens that covers an opening in the housing. A light source unit is positioned inside the housing, and contains a plurality of light sources for generating a predefined light distribution. A control unit of the light source unit generates a control signal with which the light source unit can be controlled. The control signal switches off the light source unit with a switch-off protocol. Sections of the light sources in the light source unit are successively switched off and/or dimmed within an anti-condensation period (tA), such that no condensation accumulates on the inner surface of the lens. ## Claims ### Claim 1 A lighting device for vehicles, the lighting device comprising: a housing with an opening; a lens that covers the opening in the housing; a light source unit inside the housing, the light source containing: a plurality of light sources for generating a predefined light distribution, and a control unit for generating a control signal for controlling the light source; wherein the control signal switches off the light source unit with a switch-off protocol, according to which sections of the light sources in the light source unit are successively switched off and/or dimmed within an anti-condensation period (tA), such that no condensation accumulates on the inner surface of the lens. ### Claim 2 (depends on 1) The lighting device according to claim 1, wherein the switch-off protocol switches off and/or dims the light sources successively during the anti-condensation period, during which the temperature (TIN) inside the housing remains higher than the condensation temperature (TTAU). ### Claim 3 (depends on 1) The lighting device according to claim 1, wherein the switch-off protocol causes the temperature (TIN) on the inner surface of the lens to be higher than the condensation temperature (TTAU) by at least 2 Kelvin. ### Claim 4 (depends on 1) The lighting device according to claim 1, wherein the control protocol causes the light sources in the light source unit to be switched off successively. ### Claim 5 (depends on 1) The lighting device according to claim 1, wherein the control protocol causes at least some of the light sources to dim during the anti-condensation period (tA) to obtain a predefined, lower brightness (B). ### Claim 6 (depends on 1) The lighting device according to claim 1, wherein the light sources are controlled such that the brightness (B) of the light source unit during the anti-condensation period (tA) decreases linearly or in increments. ### Claim 7 (depends on 6) The lighting device according to claim 6, wherein the anti-condensation period (tA) lasts at least two hours. ### Claim 8 (depends on 1) The lighting device according to claim 1, wherein the light sources are controlled such that the decrease in the brightness (B) follows a parabolic curve during the anti-condensation period (tA). ### Claim 9 (depends on 1) The lighting device according to claim 1, the light sources are controlled at a start (t1) of the switch-off process (tA) to generate the low beam light distribution. ### Claim 10 (depends on 1) A method for controlling a light source unit that contains numerous light sources in a motor vehicle according to claim 1, the method comprising the step of: successively switching off and/or dimming at least some of the light sources in the light source unit, such that the brightness (B) of the light source unit decreases continuously during the switch-off process (tA), until the brightness (B) reaches a full blackout at an end (t2) of the switch-off process (tA). ### Claim 11 (depends on 10) The method according to claim 10, wherein when the brightness (B) of the light source unit during the switch-off period (tA) is reduced, the decrease in temperature on the inner surface of the lens and/or inside the housing is small enough that the temperature on the inner surface of the lens and/or the temperature (TIN) inside the housing remains higher than the dew point temperature (TTAU). ### Claim 12 (depends on 10) The method according to claim 10, wherein the brightness (B) of the light source unit decreases linearly during a switch-off period (tA) of at least two hours. ### Claim 13 (depends on 11) The method according to claim 11, wherein the decrease in the brightness (B) of the light source unit follows a parabolic curve during a switch-off period (tA) of at least 1 hour.