Method of operating a headlight having a laser light source in a motor vehicle

Patent metadata

Field	Value
Publication number	US-9827900-B2
Application number	US-201414460686-A
Country	US
Kind code	B2
Filing date	Aug 15, 2014
Priority date	Aug 21, 2013
Publication date	Nov 28, 2017
Grant date	Nov 28, 2017

Abstract

A method is provided for operating a headlight having a laser light source in a motor vehicle. The headlight generates a light distribution from the light of the laser light source. The laser light source is activated such that the operating power of the laser light source is switched from a first power value to a deactivated operating state or is lowered to a second power value when the speed of the motor vehicle falls below a first speed threshold. The operating power of the laser light source is increased from the deactivated operating state or from the second power value to the first power value, when the speed of the motor vehicle exceeds a second speed threshold, which is greater than or equal to the first speed threshold.

First claim

What is claimed is:

1. A method of operating a headlight in a motor vehicle, the headlight having a laser light source and generating a light distribution from light of the laser light source, the method comprising the acts of:
lowering an operating power of the laser light source from a first power value to a second power value or to a deactivated operating state when a speed of the motor vehicle falls below a first speed threshold; and
increasing the operating power of the laser light source from the second power value to the first power value or from the deactivated operating state to the first power value when the speed of the motor vehicle exceeds a second speed threshold, the second speed threshold being greater than the first speed threshold.

2. The method according to claim 1 , further comprising the act of: operating the laser light source in compliance with Class 1 or 1M or 2 or 2M according to IEC 60825-1 Standard when generating the light distribution by the headlight.

3. The method according to claim 1 , wherein the first speed threshold is between 20 km/h and 120 km/h, and the second speed threshold is between 30 km/h and 130 km/h.

4. The method according to claim 3 , wherein the second power value is 50% or less of the first power value.

5. The method according to claim 3 , wherein the second power value is 25% or less of the first power value.

6. The method according to claim 1 , wherein the first speed threshold is between 20 km/h and 60 km/h, and the second speed threshold is between 30 km/h and 70 km/h.

7. The method according to claim 6 , wherein the second power value is 20% or less than the first power value.

8. The method according to claim 1 , wherein the headlight comprises at least one further light source in addition to the laser light source, the method further comprising the act of: maintaining the at least one further light source constantly switched-on when generating the light distribution by the headlight.

9. The method according to claim 8 , wherein the at least one further light source comprises an LED light source, a halogen light source, and/or a xenon light source.

10. The method according to claim 8 , wherein the at least one further light source comprises a further laser light source, the method further comprising act of: operating the further laser light source in compliance with Class 1 or 1M or 2 or 2M according to IEC 60825-1 Standard when the light distribution is generated by the headlight.

11. The method according to claim 1 , further comprising the acts of:
generating several different light distributions by the headlight; and
implementing the lowering and increasing acts for at least one of the several different light distributions.

12. The method according to claim 11 , wherein the several different light distribution comprise one or more low-beam distributions and/or one or more high-beam light distributions.

13. The method according to claim 1 , further comprising the act of: determining the speed of the motor vehicle via sensor data of one or more rotational wheel speed sensors, the sensor data being placed on a bus of the motor vehicle and being retrieved from the bus for determining the speed of the motor vehicle.

14. The method according to claim 13 , further comprising the acts of:
determining the speed of the motor vehicle in a central control unit of the motor vehicle, the central control unit retrieving the sensor data from the bus;
generating commands via the central control unit for changing the operating power of the laser light source based on the determined speed of the motor vehicle; and
changing the operating power of the laser light source via a headlight control unit based on the commands generated by the central control unit, the commands generated by the central control unit being placed on the bus and being retrieved from the bus by the headlight control unit.

15. The method according to claim 13 , further comprising the acts of:
determining the speed of the motor vehicle via a headlight control unit; and
changing the operating power of the laser light source via the headlight control unit, the headlight control unit retrieving the sensor data of the rotational wheel speed sensors via the bus.

16. A headlight for a motor vehicle, comprising:
a laser light source providing light for generating a light distribution during operation of the headlight, wherein
the laser light source is activatable such that operating power of the laser light source is lowered from a first power value to a second power value or to a deactivated operating state when a speed of the motor vehicle falls below a first speed threshold, and
the laser light source is activatable such that the operating power of the laser light source is increased from the deactivated operating state or from the second power value to the first power value when the speed of the motor vehicle exceeds a second speed threshold greater than the first speed threshold.

17. The headlight according to claim 16 , further comprising: at least one further light source, wherein the at least one further light source is constantly switched-on when the headlight generates the light distribution.

18. The headlight according to claim 17 , wherein the at least one further light source comprises an LED light source, a halogen light source, a xenon light source and/or a further laser light source.

19. The headlight according to claim 16 , wherein the laser light source is configured in compliance with Class 1 or 1M or 2 or 2M according to IEC 60825-1 Standard when the headlight generates the light distribution.

20. A motor vehicle, comprising:
one or more headlights, each headlight comprising a laser light source providing light for generating a light distribution during operation of the headlight, wherein
the laser light source is activatable such that operating power of the laser light source is lowered from a first power value to a second power value or to a deactivated operating state when a speed of the motor vehicle falls below a first speed threshold, and
the laser light source is activatable such that the operating power of the laser light source is increased from the deactivated operating state or from the second power value to the first power value when the speed of the motor vehicle exceeds a second speed threshold greater than the first speed threshold.

Assignees

• Bayerische Motoren Werke Ag

Inventors

• Weber Stefan
• Erdl Helmut
• Aulbach Johannes

Classifications

• F21S48/1145

  Mechanical Engineering · mapped topic

• B60Q1/085 Primary

  due to special conditions, e.g. adverse weather, type of road, badly illuminated road signs or potential dangers (B60Q1/10, B60Q1/12, B60Q1/1423 take precedence) · CPC title

• B60Q1/1423 Primary

  Automatic dimming circuits, i.e. switching between high beam and low beam due to change of ambient light or light level in road traffic · CPC title

• F21S48/1195

  Mechanical Engineering · mapped topic

• B60Q2300/112

  Vehicle speed · CPC title