# US 11,299,086 B2 · Method for operating a lighting device in a motor vehicle > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,299,086 B2 - Document ID: US11299086B2 - Status: Granted - Kind: B2 - Application number: 17/058,486 - Filed: 2019-07-08 - Published: 2021-07-01 - Granted: 2022-04-12 - Earliest claimed: 2018-07-24 - Assignees: Bayerische Motoren Werke Aktiengesellschaft - Applicants: Bayerische Motoren Werke Aktiengesellschaft - Inventors: Stev Grimm; Thomas Vogl; Christian Wagner; Katrin Wildenhof - Web page: https://patentgrep.com/patent/US11299086B2 ## CPC - B60Q 1/1423: {Automatic dimming circuits, i.e. switching between high beam and low beam due to change of ambient light or light level in road traffic} - B60Q 3/80: Circuits; Control arrangements (for dashboards B60Q3/16; for mass transit vehicles B60Q3/47) - H05B 45/20: Controlling the colour of the light - H05B 47/18: via data-bus transmission - B60Q 2400/20: Multi-color single source or LED matrix, e.g. yellow blinker and red brake lamp generated by single lamp - B60Q: ARRANGEMENT OF SIGNALLING OR LIGHTING DEVICES, THE MOUNTING OR SUPPORTING THEREOF OR CIRCUITS THEREFOR, FOR VEHICLES IN GENERAL - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL ## Abstract A lighting device in a motor vehicle includes a number of illumination devices, which each generate colored light via a plurality of color channels. The illumination devices can be controlled using an electronic control unit. An illumination state of a respective illumination device can be adjusted by color component values and a brightness end value for all color channels. The electronic control unit calculates a color value from the illumination state to be adjusted for each color channel based on the color component value of the respective color channel and the brightness value. The color value is supplied to the respective illumination device. The electronic control unit processes a brightness threshold value used during a dimming-down/dimming-up process for switching-off/on the respective illumination device. The brightness threshold value is determined by the electronic control unit and increases as the lowest color component value decreases. ## Claims ### Claim 1 A method for operating a lighting device in a motor vehicle, comprising: calculating, by the electronic control unit, a color value from an illumination state to be set for a respective illumination device of a plurality of illumination devices, wherein the illumination state is defined by: a plurality of color component values of a plurality of color channels; and a brightness end value of the plurality of color channels; and the color value is calculated for each color channel of the plurality of color channels based on: a color component value of a respective color channel of the plurality of color channels; and a brightness value; providing, by an electronic control unit, the color value to a respective illumination device of the plurality of illumination devices that each generate colored light via the plurality of color channels based on the provided color value; determining, by the electronic control unit, a brightness threshold value at the beginning of a dimming-down process for switching off a respective illumination device of the plurality of illumination devices and/or a dimming-up process for switching on a respective illumination device of the plurality of illumination devices, wherein the brightness threshold value depends on a lowest color component value that is not equal to zero from the plurality of color channels for a current illumination state of a respective illumination device; and the brightness threshold value increases as the lowest color component value decreases; and ensuring, during the dimming-down process and/or the dimming-up process, that the color value provided to the illumination devices is: not equal to zero; and calculated by the electronic control unit based on brightness values greater than or equal to the brightness threshold value. ### Claim 2 (depends on 1) The method according to claim 1, further comprising: when carrying out the dimming-down process, decreasing, by the electronic control unit, the brightness values of the current illumination state of the respective illumination device progressively until the brightness end value for the dimming-down process is reached without altering the color component values; until the brightness threshold value is reached by the progressively decreased brightness values: calculating, by the electronic control unit, the corresponding color value from the progressively decreased brightness value and the unaltered color component values; and providing, by the electronic control unit, the corresponding color value to the respective illumination device; and when the progressively decreased brightness values fall below the brightness threshold value: switching off, by the electronic control unit, the respective illumination device; or providing, by the electronic control unit, the color values calculated from the brightness threshold value and the unaltered color component values as constant color values to the respective illumination device. ### Claim 3 (depends on 1) The method according to claim 1, further comprising: when carrying out the dimming-up process: increasing, by the electronic control unit, the brightness values of the current illumination state of the respective illumination device progressively until the brightness end value for the dimming-up process is reached without altering the color component values; and until the brightness threshold value is reached by the progressively increased brightness values: keeping, by the electronic control unit, the respective illumination device in the switched-off state; and providing, by the electronic control unit, the color values calculated from the brightness threshold value and the unaltered color component values as constant color values to the respective illumination device; and when the brightness threshold value is exceeded by the progressively increased brightness values: calculating, by the electronic control unit, the corresponding color values from the progressively increased brightness values and the unaltered color component values; and providing the corresponding color values to the respective illumination device. ### Claim 4 (depends on 1) The method according to claim 1, wherein the color value is calculated for the illumination state to be set for each respective color channel such that the color value for the respective color channel contains a product of the color component value of the respective color channel and the brightness value. ### Claim 5 (depends on 1) The method according to claim 1, wherein the brightness threshold value is determined by the electronic control unit such that the brightness threshold value is indirectly proportional to the lowest color component value that is not equal to zero of the color channels for the current illumination state of the respective illumination device. ### Claim 6 (depends on 1) The method according to claim 1, wherein the color values are integer values; and the brightness threshold value of a respective color channel is calculated such that a calculated color value of 1 results from the lowest color component value that is not equal to 0 from the color channels for the current illumination state of the respective illumination device. ### Claim 7 (depends on 1) The method according to claim 1, wherein the plurality of illumination devices comprises one or more RGB LEDs. ### Claim 8 (depends on 1) The method according to claim 1, wherein the color values are provided to a respective illumination device with the interposition of a communication bus. ### Claim 9 (depends on 1) The method according to claim 1, wherein the lighting device is an interior lighting facility in the motor vehicle or an exterior lighting facility on the exterior of the motor vehicle. ### Claim 10 A lighting device for a motor vehicle, comprising: a plurality of illumination devices that each generate colored light via a plurality of color channels; and an electronic control unit to: control the plurality of illumination devices; calculate a color value for an illumination state to be set for a respective illumination device of the plurality of illumination devices, wherein the illumination state is defined by: a plurality of color component values of the plurality of color channels; and a brightness end value of the plurality of color channels; and the color value is calculated for each color channel of the plurality of color channels based on: a color component value of a respective color channel of the plurality of color channels; and a brightness value; provide the color value to a respective illumination device of the plurality of illumination device that generates the colored light via the plurality of color channels based on the provided color value; determine a brightness threshold value at the beginning of a dimming-down process for switching off a respective illumination device of the plurality of illumination devices and/or a dimming-up process for switching on a respective illumination device of the plurality of illumination devices, wherein the brightness threshold value depends on a lowest color component value that is not equal to zero from the plurality of color channels for a current illumination state of a respective illumination device; and the brightness threshold value increases as the lowest color component value decreases; and ensure, during the dimming-down process and/or the dimming-up process, that the color value provided to the illumination device is: not equal to zero; and calculated based on brightness values greater than or equal to the brightness threshold value. ### Claim 11 (depends on 10) A motor vehicle comprising one or more lighting devices of claim 10.