HEADLAMP WITH DIGITAL MICROMIRROR DEVICE AND STATIC REFLECTOR

• US 20180259149A1
• Filed: 11/14/2017
• Published: 09/13/2018
• Est. Priority Date: 03/10/2017
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: BHAKTA, Vikrant R., FARRIS, Jeff, SHAW, Stephen A.
• Granted Patent: US 10,317,032 B2
• Time in Patent Office: Days
• CPC Class Codes: B60Q 1/0023 the element being a sensor, e.g. distance sensor, camera
• CPC Class Codes: B60Q 1/085 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 Class Codes: B60Q 1/143 combined with another condition, e.g. using vehicle recognition from camera images or activation of wipers
• CPC Class Codes: B60Q 2300/146 Abnormalities, e.g. fail-safe
• CPC Class Codes: B60Q 2300/31 Atmospheric conditions
• CPC Class Codes: B60Q 2300/314 Ambient light
• CPC Class Codes: F21S 41/141 Light emitting diodes [LED]
• CPC Class Codes: F21S 41/321 the reflector being a surface of revolution or a planar surface, e.g. truncated
• CPC Class Codes: F21S 41/336 with discontinuity at the junction between adjacent areas
• CPC Class Codes: F21S 41/337 the reflector having a structured surface, e.g. with facets or corrugations
• CPC Class Codes: F21S 41/36 Combinations of two or more separate reflectors
• CPC Class Codes: F21S 41/663 by switching light sources by switching incandescent light sources F21S41/162
• CPC Class Codes: F21S 41/675 by moving reflectors
• CPC Class Codes: F21S 45/10 Protection of lighting devices cooling of lighting devices F21S45/40; waterproofing of lighting devices F21S45/50

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.

Claims

1. A headlamp, comprising:

a digital micromirror device (DMD) reflector comprising;

a DMD;

a static reflector disposed on a plurality of sides of the DMD;

a light source disposed to illuminate the DMD reflector; and

projection optics configured to project light reflected by the DMD and light reflected by the static reflector via a same lens system.

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

a portion of the static reflector is moveable from a first position to a second position;

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 static reflector comprises one or more of:

a flat mirror configured to reflect light from the light source to the projection optics;

a curved mirror configured to reflect light from the light source to the projection optics; and

a Fresnel element configured to reflect light from the light source to the projection optics.

7. The headlamp of claim 6, further comprising control circuitry configured to:

monitor temperature of the DMD; and

move the portion of the static reflector from the first position to the second position responsive to the temperature of the DMD being less than a predetermined limit.

8. The headlamp of claim 6, further comprising control circuitry 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 the intensity of illumination external to the headlamp being less than a predetermined limit.

9. The headlamp of claim 1, further comprising control circuitry configured to modulate intensity of the light produced by the light source that is directed to the static reflector.

10. A headlamp, comprising:

a digital micromirror device (DMD) reflector comprising;

a DMD;

a static reflector disposed on a plurality of sides of the DMD, the static reflector comprising;

a fixed portion;

a mobile portion; and

an actuator configured to move the mobile portion from a first position to a second position; and

a light source disposed to illuminate the DMD reflector.

11. The headlamp of claim 10, wherein in the first position the mobile portion of the static reflector is disposed to block the DMD from light exposure, and in the second position the mobile portion of the static reflector is disposed to enable exposure of the DMD to light.

12. The headlamp of claim 10, further comprising control circuitry configured to:

monitor temperature of the DMD; and

trigger the actuator to move the mobile portion of the static reflector from the first position to the second position based on the temperature of the DMD being less than a predetermined limit.

13. The headlamp of claim 10, further comprising control circuitry 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 based on the intensity of light external to the headlamp being less than a predetermined limit.

14. The headlamp of claim 10, wherein the static reflector comprises a static reflective grating with a groove angle that is at least as large as a tilt angle of mirrors of the DMD.

15. The headlamp of claim 10, 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.

16. The headlamp of claim 10, 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.

17. The headlamp of claim 10, further comprising control circuitry configured to modulate intensity of the light produced by the light source that is directed to the static reflector.

18. A lamp reflector comprising:

a digital micromirror device (DMD); and

a static reflector disposed on a plurality of sides of the DMD, wherein the static reflector comprises a static reflective grating and wherein a tilt angle of the grating is at least as large as a tilt angle of mirrors of the DMD.

19. The lamp reflector of claim 18, wherein a portion of the static reflector is moveable from a first position that blocks the DMD from light exposure to a second position that exposes the DMD to light.

20. The lamp reflector of claim 19, further comprising an actuator coupled to the portion of the static reflector that is moveable, the actuator configured to move the portion of the static reflector that is moveable from the first position to the second position.

21. A headlamp, comprising:

a reflector module comprising;

a spatial light modulator;

a static reflector disposed on a plurality of sides of the spatial light modulator;

a light source disposed to illuminate the reflector module; and

projection optics configured to project light from the spatial light modulator and light reflected by the static reflector via a same lens system.

22. The headlamp of claim 21, wherein a portion of the static reflector is moveable from a first position that blocks the spatial light modulator from light exposure to a second position that exposes the spatial light modulator to light.

23. The headlamp of claim 21, further comprising an actuator coupled to the portion of the static reflector that is moveable, the actuator configured to move the portion of the static reflector that is moveable from the first position to the second position.