Lighting device for headlights with a phase modulator

• US 9,829,858 B2
• Filed: 02/06/2013
• Issued: 11/28/2017
• Est. Priority Date: 02/07/2012
• Status: Active Grant

• Current Assignee: Envisics Ltd.
• Original Assignee: Daqri Holographics Ltd (Envisics, LLC)
• Inventors: Christmas, Jamieson, Masiyano, Dackson, Collin, Mikael
• Primary Examiner(s): Gramling, Sean
• Application Number:
  US14/376,974
• Publication Number:
  US 20150009695A1
• Time in Patent Office: 1,756 Days
• CPC Class Codes: B60Q 1/06 adjustable, e.g. remotely-controlled from inside vehicle B60Q1/05 takes precedence
• 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 1/12 due to steering position
• CPC Class Codes: B60Q 1/16 illuminating the way asymmetrically
• CPC Class Codes: B60Q 2300/056 Special anti-blinding beams, e.g. a standard beam is chopped or moved in order not to blind
• CPC Class Codes: B60Q 2300/122 Steering angle
• CPC Class Codes: B60Q 2300/312 Adverse weather
• CPC Class Codes: B60Q 2300/32 Road surface or travel path
• CPC Class Codes: B60Q 2300/322 Road curvature
• CPC Class Codes: B60Q 2300/33 Driving situation
• CPC Class Codes: B60Q 2300/331 characterised by the driving side, e.g. on the left or right hand side
• CPC Class Codes: B60Q 2300/42 oncoming vehicle
• CPC Class Codes: B60Q 2300/45 Special conditions, e.g. pedestrians, road signs or potential dangers
• CPC Class Codes: F21S 41/12 characterised by the type of emitted light
• CPC Class Codes: F21S 41/125 Coloured light
• CPC Class Codes: F21S 41/13 Ultraviolet light; Infrared light
• CPC Class Codes: F21S 41/14 characterised by the type of light source
• CPC Class Codes: F21S 41/16 Laser light sources
• CPC Class Codes: F21S 41/25 Projection lenses
• CPC Class Codes: F21S 41/27 Thick lenses
• CPC Class Codes: F21S 41/285 : Refractors, transparent cover plates, light guides or filters not provided in groups F21S41/24-F21S41/28
• CPC Class Codes: F21S 41/60 : characterised by a variable light distribution
• CPC Class Codes: F21S 41/645 : by electro-optic means, e.g. liquid crystal or electrochromic devices
• CPC Class Codes: F21S 43/13 : characterised by the type of light source
• CPC Class Codes: F21S 43/26 : Refractors, transparent cover plates, light guides or filters not provided in groups F21S43/235 - F21S43/255
• CPC Class Codes: G01S 17/89 : for mapping or imaging
• CPC Class Codes: G01S 17/931 : of land vehicles
• CPC Class Codes: G01S 7/4814 : of transmitters alone
• CPC Class Codes: G01S 7/4911 : Transmitters
• CPC Class Codes: G01S 7/4915 : Time delay measurement, e.g. operational details for pixel components signal extraction and conditioning G01S7/493; Phase measurement
• CPC Class Codes: G03H 1/0005 : Adaptation of holography to specific applications holographic optical element G02B5/32; holographic scanner G02B26/106; recognition using holographic mask G06V10/88; holographic memories G11B7/0065, G11C13/042
• CPC Class Codes: G03H 1/02 : Details of features involved during the holographic process; Replication of holograms without interference recording
• CPC Class Codes: G03H 1/2249 : Holobject properties
• CPC Class Codes: G03H 1/2294 : Addressing the hologram to an active spatial light modulator
• CPC Class Codes: G03H 2001/0212 : Light sources or light beam properties G03H1/06, G03H1/24 take precedence; corresponding details, see subgroups of G03H2222/00
• CPC Class Codes: G03H 2001/0216 : Optical components G03H2001/0224, G03H1/0256 take precedence; corresponding details, see subgroups of G03H2223/00
• CPC Class Codes: G03H 2001/0224 : Active addressable light modulator, i.e. Spatial Light Modulator [SLM] corresponding details, see subgroups of G03H2225/00
• CPC Class Codes: G03H 2001/2263 : Multicoloured holobject
• CPC Class Codes: G03H 2001/2271 : RGB holobject
• CPC Class Codes: G03H 2001/2284 : Superimposing the holobject with other visual information
• CPC Class Codes: G03H 2001/2297 : using frame sequential, e.g. for reducing speckle noise
• CPC Class Codes: G03H 2001/306 : Tiled identical sub-holograms
• CPC Class Codes: G03H 2210/20 : 2D object
• CPC Class Codes: G03H 2210/22 : 2D SLM object wherein the object beam is formed of the light modulated by the SLM SLM per se G03H2001/0224
• CPC Class Codes: G03H 2222/16 : Infra Red [IR]
• CPC Class Codes: G03H 2222/17 : White light G03H1/24 takes precedence
• CPC Class Codes: G03H 2223/26 : Means providing optical delay, e.g. for path length matching
• CPC Class Codes: G03H 2223/55 : Arranged at a Fourier plane
• CPC Class Codes: G03H 2225/25 : Optically addressed SLM [OA-SLM]
• CPC Class Codes: G03H 2225/32 : Phase only
• CPC Class Codes: G03H 2225/52 : Reflective modulator
• CPC Class Codes: G03H 2225/61 : for multicolour processing
• CPC Class Codes: G03H 2226/05 : Means for tracking the observer
• CPC Class Codes: G06V 10/145 : Illumination specially adapted for pattern recognition, e.g. using gratings
• CPC Class Codes: G06V 20/56 : exterior to a vehicle by using sensors mounted on the vehicle
• CPC Class Codes: G08G 1/16 : Anti-collision systems road vehicle drive control systems for predicting or avoiding probable or impending collision otherwise than by control of a particular sub-unit B60W30/08

Abstract

There is provided a lighting device arranged to produce a controllable light beam for illuminating a scene. The device comprises an addressable spatial light modulator arranged to provide a selectable phase delay distribution to a beam of incident light. The device further comprises Fourier optics arranged to receive phase-modulated light from the spatial light modulator and form a light distribution. The device further comprises projection optics arranged to project the light distribution to form a pattern of illumination as said controllable light beam.

Claims

1. A lighting device arranged to produce a controllable light beam for illuminating a scene, the lighting device comprising:

a source of a beam of coherent incident light;

an addressable liquid crystal on silicon phase-only spatial light modulator arranged to provide a dynamically variable phase delay distribution to the beam of coherent incident light;

Fourier optics arranged to receive phase-modulated light from the spatial light modulator, perform a frequency-space transformation upon the received phase-modulated light to form an image in the spatial domain; and

projection optics arranged to project the image to form a pattern of illumination in space as a controllable light beam, the controllable light beam being suitable for illuminating the scene,

wherein the lighting device is configured as a vehicle headlamp.

2. The lighting device as claimed in claim 1, wherein the projection optics magnify the image.

3. The lighting device as claimed in claim 1, wherein the phase delay distribution comprises a representation of the pattern of illumination in the Fourier domain.

4. The lighting device as claimed in claim 1 wherein the Fourier optic is a Fourier lens.

5. The lighting device as claimed in claim 1 wherein the spatial light modulator is reflective.

6. The lighting device as claimed in claim 1, wherein the phase delay distribution is selectable to steer the controllable light beam.

7. The lighting device according to claim 1, wherein the lighting device lacks moving parts.

8. The lighting device according to claim 1, wherein the spatial light modulator is a reflective spatial light modulator.

9. The lighting device according to claim 1, wherein the image is not a real image in space.

10. A vehicle comprising a lighting device according to claim 1, mounted on the vehicle, configured such that the scene to be illuminated is outside the vehicle.

11. A method of illuminating a scene, the method comprising:

providing a lighting device according to claim 1;

illuminating the spatial light modulator with the beam of coherent incident light;

providing, using the spatial light modulator, a dynamically variable phase delay distribution to the beam of coherent incident light to provide an exit beam;

applying the exit beam to Fourier optics to perform a frequency-space transformation upon the received phase-modulated light to form an image in the spatial domain; and

using projection optics to project the image to form a pattern of illumination in space, the pattern of illumination in space illuminating the scene.

12. The method of claim 11, comprising selecting the phase delay distribution to illuminate chosen areas of the scene while not illuminating other areas.

13. The method of claim 11, comprising reading pre-calculated phase distributions from a memory.

14. The method of claim 11, comprising dynamically varying the phase delay distribution to steer the controllable light beam.

15. The method of claim 11, wherein providing the dynamically variable phase delay distribution to the beam of coherent incident light comprises

providing a first phase delay distribution to the beam of coherent incident light, then

providing a second phase delay distribution to the beam of coherent incident light, thereby steering the exit beam from a first position to a second position.

16. The method of claim 11, wherein providing the dynamically variable phase delay distribution to the beam of coherent incident light comprises

providing a first phase delay distribution to the beam of coherent incident light, then

providing a second phase delay distribution to the beam of coherent incident light, thereby changing the distribution of light in the exit beam.

17. The method of claim 11, wherein providing the dynamically variable phase delay distribution to the beam of coherent incident light comprises

providing a first phase delay distribution to the beam of coherent incident light, then

providing a second phase delay distribution to the beam of coherent incident light, thereby changing the distribution of light in the exit beam.

18. The method of claim 11, wherein providing the dynamically variable phase delay distribution to the beam of coherent incident light comprises

providing a first phase delay distribution to the beam of coherent incident light, then

providing a second phase delay distribution to the beam of coherent incident light, wherein the first delay distribution is changed to the second phase delay distribution in response to changed road or driving conditions.

19. The method of claim 11, wherein the lighting device lacks moving parts.

20. The method of claim 11, wherein the spatial light modulator is a reflective spatial light modulator.

21. The method of claim 11, further comprising providing a set of predetermined phase delay distributions, and wherein the individual phase delay distributions of the dynamically variable phase delay distributions are read from the set of predetermined phase delay distributions.

22. The method of claim 11, wherein the lighting device is mounted on a vehicle, and the scene to be illuminated is outside the vehicle.

23. The method of claim 22, wherein the vehicle is in motion.

24. The method of claim 11, wherein the lighting device is configured to illuminate a road.

25. The method of claim 11, wherein the image is not a real image in space.