Headlamp with digital micromirror device and static reflector

Patent metadata

Field	Value
Publication number	US-10317032-B2
Application number	US-201715811752-A
Country	US
Kind code	B2
Filing date	Nov 14, 2017
Priority date	Mar 10, 2017
Publication date	Jun 11, 2019
Grant date	Jun 11, 2019

Abstract

A headlamp includes a digital micromirror device (DMD) reflector, a light source, and projection optics. The DMD reflector includes a DMD and a static reflector disposed on a plurality of sides of the DMD. The light source is disposed to illuminate the DMD reflector. The projection optics are configured to project light reflected by the DMD and light reflected by the static reflector via a same lens system.

First claim

What is claimed is:

1. A headlamp, comprising:
a digital micromirror device (DMD) reflector comprising: a DMD; and a static reflector disposed on a plurality of sides of the DMD;
a light source disposed to illuminate the DMD reflector;
projection optics configured to project light reflected by the DMD and light reflected by the static reflector via a same lens system, the static reflector: being disposed to reflect light from the light source to the projection optics; and comprising at least one of a flat mirror, a curved mirror or a Fresnel element; and
control circuitry configured to: monitor a temperature of the DMD; and move a portion of the static reflector from a first position to a second position responsive to the temperature of the DMD being less than a limit.

2. The headlamp of claim 1 , wherein the static reflector comprises a static reflective grating with an angle that is at least as large as an angle of mirrors of the DMD.

3. The headlamp of claim 1 , wherein the DMD is laterally centered with respect to the static reflector, such that area of the static reflector adjacent each lateral edge of the DMD is equal.

4. The headlamp of claim 1 , wherein the DMD is laterally offset with respect to the static reflector, such that only one lateral edge of the DMD is adjacent to the static reflector.

5. The headlamp of claim 1 , wherein:
in the first position, the static reflector blocks the DMD from light exposure; and
in the second position, the DMD is exposed to light.

6. The headlamp of claim 1 , wherein the limit is a first limit, and the control circuitry is configured to:
monitor illumination external to the headlamp; and
move the portion of the static reflector from the first position to the second position responsive to an intensity of the illumination external to the headlamp being less than a second limit.

7. The headlamp of claim 1 , wherein the control circuitry is configured to modulate an intensity of light produced by the light source that is directed to the static reflector.

8. The headlamp of claim 1 , wherein the portion is a mobile portion, and the static reflector comprises:
a fixed portion; and
an actuator configured to move the mobile portion from the first position to the second position.

9. The headlamp of claim 8 , wherein: in the first position, the mobile portion of the static reflector is disposed to block the DMD from light exposures; and in the second position, the mobile portion of the static reflector is disposed to enable exposure of the DMD to light.

10. The headlamp of claim 8 , wherein the control circuitry is configured to:
trigger the actuator to move the mobile portion of the static reflector from the first position to the second position responsive to the temperature of the DMD being less than the limit.

11. The headlamp of claim 8 , wherein the limit is a first limit, and the control circuitry is configured to:
monitor light external to the headlamp; and
trigger the actuator to move the mobile portion of the static reflector from the first position to the second position responsive to an intensity of the light external to the headlamp being less than a second limit.

12. The headlamp of claim 8 , wherein the static reflector comprises a static reflective grating with an angle that is at least as large as an angle of mirrors of the DMD.

13. The headlamp of claim 8 , wherein the DMD is laterally centered with respect to the fixed portion of the static reflector, such that area of the fixed portion of the static reflector adjacent each lateral edge of the DMD is equal.

14. The headlamp of claim 8 , wherein the DMD is laterally offset with respect to the fixed portion of the static reflector, such that only one lateral edge of the DMD is adjacent to the fixed portion of the static reflector.

15. The headlamp of claim 8 , wherein the control circuitry is configured to modulate an intensity of light produced by the light source that is directed to the static reflector.

16. A headlamp, comprising:
a reflector module comprising: a spatial light modulator; and a static reflector disposed on a plurality of sides of the spatial light modulator;
a light source disposed to illuminate the reflector module;
projection optics configured to project light from the spatial light modulator and light reflected by the static reflector via a same lens system, the static reflector: being disposed to reflect light from the light source to the projection optics; and comprising at least one of a flat mirror, a curved mirror or a Fresnel element; and
control circuitry configured to: monitor a temperature of the spatial light modulator; and move a portion of the static reflector from a first position to a second position responsive to the temperature of the spatial light modulator being less than a limit.

17. The headlamp of claim 16 , wherein: in the first position, the portion of the static reflector blocks the spatial light modulator from light exposure; and in the second position, the portion of the static reflector enables exposure of the spatial light modulator to light.

18. The headlamp of claim 16 , further comprising an actuator coupled to the portion of the static reflector, the actuator configured to move the portion of the static reflector from the first position to the second position.

19. The headlamp of claim 18 , wherein the control circuitry is configured to:
trigger the actuator to move the portion of the static reflector from the first position to the second position responsive to the temperature of the spatial light modulator being less than the limit.

20. The headlamp of claim 16 , wherein the limit is a first limit, and the control circuitry is configured to:
monitor illumination external to the headlamp; and
move the portion of the static reflector from the first position to the second position responsive to an intensity of the illumination external to the headlamp being less than a second limit.

21. The headlamp of claim 16 , wherein the control circuitry is configured to modulate an intensity of light produced by the light source that is directed to the static reflector.

Assignees

• Texas Instruments Inc

Inventors

• Bhakta Vikrant R
• Farris Jeff
• Shaw Stephen A

Classifications

• F21S41/141

  Light emitting diodes [LED] · CPC title

• B60Q1/085

  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

• B60Q2300/146

  Abnormalities, e.g. fail-safe · CPC title

• F21S41/675

  by moving reflectors · CPC title

• F21S41/663

  by switching light sources (by switching incandescent light sources F21S41/162) · CPC title