Structured phosphors for dynamic lighting

• US 10,551,728 B1
• Filed: 04/10/2018
• Issued: 02/04/2020
• Est. Priority Date: 04/10/2018
• Status: Active Grant

• Current Assignee: Kyocera SLD Laser Incorporated (Kyocera Corporation)
• Original Assignee: Soraa Laser Diode, Inc. (Kyocera Corporation)
• Inventors: Novotny, Vlad Joseph, Trottier, Troy, Raring, James W., Rudy, Paul
• Primary Examiner(s): Williams, Joseph L
• Application Number:
  US15/949,608
• Time in Patent Office: 665 Days
• CPC Class Codes: G02B 1/11 Anti-reflection coatings
• CPC Class Codes: G02B 1/115 Multilayers
• CPC Class Codes: G03B 21/005 Projectors using an electronic spatial light modulator but not peculiar thereto
• CPC Class Codes: G03B 21/204 using secondary light emission, e.g. luminescence or fluorescence using different colours G03B33/00; if related to video signals H04N9/3197
• CPC Class Codes: H01L 27/15 including semiconductor components having potential barriers, specially adapted for light emission
• CPC Class Codes: H01L 33/0045 the devices being superluminescent diodes
• CPC Class Codes: H01L 33/64 Heat extraction or cooling elements
• CPC Class Codes: H01S 5/0071 for beam steering, e.g. using a mirror outside the cavity to change the beam direction
• CPC Class Codes: H01S 5/0087 for illuminating phosphorescent or fluorescent materials, e.g. using optical arrangements specifically adapted for guiding or shaping laser beams illuminating these materials
• CPC Class Codes: H01S 5/02469 Passive cooling, e.g. where heat is removed by the housing as a whole or by a heat pipe without any active cooling element like a TEC
• CPC Class Codes: H01S 5/02476 Heat spreaders, i.e. improving heat flow between laser chip and heat dissipating elements
• CPC Class Codes: H01S 5/3013 AIIIBV compounds
• CPC Class Codes: H01S 5/32341 blue laser based on GaN or GaP
• CPC Class Codes: H01S 5/4025 Array arrangements, e.g. constituted by discrete laser diodes or laser bar H01S5/42 takes precedence
• CPC Class Codes: H01S 5/4075 Beam steering
• CPC Class Codes: H01S 5/4087 emitting more than one wavelength

Abstract

A structured phosphor device includes a frame member comprising wall regions separating multiple openings of window regions. Further, the structured phosphor device includes a phosphor material filled in each of the multiple openings with a first surface thereof being exposed to an excitation light from one or more laser sources to generate an emitted light out of each window region. Additionally, the structured phosphor device includes an anti-reflective film overlying the first surface of the phosphor material. Furthermore, the structured phosphor device includes a substrate attached to a second surface of the phosphor material in each of the multiple openings. Alternatively, the structured phosphor device includes an array of phosphor pixels dividing a plate of single-crystalline or poly-crystalline phosphor material separated by optically reflective and thermally conductive walls. A dynamic lighting system based on the arrays of phosphor pixels for single or full color image projection is also disclosed.

Claims

1. A structured phosphor device comprising:

a phosphor configured for laser excitation, the phosphor comprising an array of pixel regions separated by boundary regions, wherein one or more pixel regions of the array of pixel regions are designed to be addressed by a laser light beam incident through a first surface of the phosphor into phosphor material thereof and generate at least a partially emitted light beam from the phosphor, wherein the boundary regions are configured to limit the cross-talk of the laser light beam and the emitted light beam between the one or more addressed pixel regions and adjacent pixel regions;

a surface layer with modification associated with the first surface of the phosphor; and

a substrate attached to a second surface of the phosphor.

2. The structured phosphor device of claim 1, wherein the emitted light beam from the phosphor with or without a portion of the laser light beam creates a substantially white light.

3. The structured phosphor device of claim 1, wherein the pixel region comprises a size of less than 1 mm×

1 mm.

4. The structured phosphor device of claim 1, wherein the pixel region comprises a size of less than 500 μ

m×

500 μ

m.

5. The structured phosphor device of claim 1, wherein the pixel region comprises a size of less than 250 μ

m×

250 μ

m.

6. The structured phosphor device of claim 1, wherein the pixel region comprises a size of less than 100 μ

m×

100 μ

m.

7. The structured phosphor device of claim 1, wherein the laser light beam is from a gallium and nitrogen containing laser diode emitting a blue wavelength or a violet wavelength.

8. The structured phosphor device of claim 1, wherein the laser light beam is modulated and guided by scanning mirror(s) to the first surface of the phosphor for individually addressing each of the array of pixel regions in a time period of a scan cycle.

9. The structured phosphor device of claim 1, wherein the laser light beam is modulated and guided by scanning mirror(s) to the first surface of the phosphor for collectively addressing multiple of the array of pixel regions in a same time period of a scan cycle.

10. The structured phosphor device of claim 1, wherein the surface layer with modification associated with the first surface of the phosphor comprises an anti-reflective coating or a surface roughening feature or a combination of both overlying the first surface.

11. The structured phosphor device of claim 2, further comprising an optically reflecting film between the second surface of the phosphor and the substrate to guide the substantially white light out of the first surface of the phosphor operated in a reflective mode.

12. The structured phosphor device of claim 11, wherein the substrate comprises a material characterized as thermally conductive and optically reflective to broadband wavelengths of the substantially white light.

13. The structured phosphor device of claim 2, further comprising an anti-reflective film formed between the second surface of the phosphor and the substrate to guide the substantial white light out of the second surface of the phosphor operated in a transmissive mode.

14. The structured phosphor device of claim 13, wherein the substrate comprises a material characterized as thermally conductive and optically transparent to the substantially white light.

15. The structured phosphor device of claim 1, wherein the phosphor comprises one phosphor selected from YAG, LuAG, red nitrides, aluminates, oxynitrides, CaMgSi₂O₆:

Eu²⁺, BAM;

Eu²⁺, AlN;

Eu²⁺, (Sr,Ca)₃MgSi₂O₈;

Eu²⁺, and JEM.

16. The structured phosphor device of claim 1, wherein the boundary regions comprise a metalized conductive material being optically reflective to wavelengths of combined spectra of the incident light and the emitted light.

17. A structured phosphor device comprising:

a frame member comprising wall regions separating multiple opening of window regions;

a phosphor material filled in each of the multiple openings with a first surface thereof being exposed to an excitation light from one or more laser sources to generate an emitted light out of each window region;

a surface layer with modification associated with the first surface of the phosphor material; and

a substrate attached to a second surface of the phosphor material in each of the multiple openings.

18. The structured phosphor device of claim 17, wherein the phosphor material comprises a bulk solid sintered from powders filled in each window region, the powers being selected from one of YAG, LuAG, red nitrides, aluminates, oxynitrides, CaMgSi₂O₆:

Eu²⁺, BAM;

Eu²⁺, AlN;

Eu²⁺, (Sr,Ca)₃MgSi₂O₈;

Eu²⁺, and JEM.

19. The structured phosphor device of claim 18, wherein the powders comprise particles with sizes ranging from a few nano-meters to a few micrometers.

20. The structured phosphor device of claim 17, wherein the wall regions of the frame member comprise a minimum volume compared with that of the phosphor material filled in the multiple openings.

21. The structured phosphor device of claim 20, wherein the wall regions comprise a metalized film coated from an edge of the wall regions joined with the first surface to another edge of the wall regions joined with the second surface.

22. The structured phosphor device of claim 17, wherein the multiple openings of the frame member comprise a uniform size and shape, wherein the phosphor material filled in the multiple openings forms an array of phosphor pixels with each pixel size having the uniform size.

23. The structured phosphor device of claim 22, wherein the pixel size comprises a lateral dimension ranging from a few millimeters to less than 100 μ

m and a depth ranging from 100 μ

m to 200 μ

m or greater, and the array of phosphor pixels comprises total number of pixels ranging from 100×

100 pixels or less to 1024×

1920 pixels.

24. The structured phosphor device of claim 22, wherein each of the array of phosphor pixels comprises a rectangle including a square base shape with substantially vertical sides or a reversed pyramid shape with slopping sides.

25. The structured phosphor device of claim 17, wherein the surface layer comprises an anti-reflective film or a roughened surface structure or a combination of both.

26. The structured phosphor device of claim 25, wherein the anti-reflective film comprises a material that is configured to substantially minimize reflection of less than 1% to the excitation light and to less than 10% of the emitted light thereby.

27. The structured phosphor device of claim 17, further comprises an optically reflective layer formed between the second surface of the phosphor material and the substrate.

28. The structured phosphor device of claim 27, wherein the optically reflective layer comprises optical characteristics of substantially reflecting both the excitation light and the emitted light to allow the emitted light outputted from the first surface of the phosphor material.

29. The structured phosphor device of claim 28, wherein the substrate that is attached with the second surface of the phosphor material via the optically reflective layer comprises a thermal conductive material.

30. The structured phosphor device of claim 17, further comprises an optically transmissive layer to at least the emitted light for bonding the second surface of the phosphor material and the substrate.

31. The structured phosphor device of claim 30, wherein the substrate comprises a thermally conductive material that is at least transparent to the emitted light to allow the emitted light outputted from the second surface of the phosphor material and through the transmissive layer and the substrate.

32. A pixelated phosphor device comprising:

a plate of phosphor material configured to an array of pixels being mutually separated by a thin wall;

a first optical layer overlying a first surface of the plate of phosphor material which is subjected to an excitation light beam for inducing an emitted light beam out of each of the array of pixels;

a second optical layer overlying a second surface of the plate of phosphor material, the second surface being opposed to the first surface; and

a substrate attached to the second optical layer.

33. The pixelated phosphor device of claim 32, wherein the plate of phosphor material comprises a single-crystalline phosphor or poly-crystalline phosphor.

34. The pixelated phosphor device of claim 32, wherein the array of pixels comprises a uniform pixel size and pixel shape.

35. The pixelated phosphor device of claim 34, wherein the pixel size comprises lateral dimension ranging from a few millimeters to less than 100 μ

m and a depth ranging from 100 μ

m to 200 μ

m or greater, and the array of phosphor pixels comprises total number of pixels ranging from 100×

100 pixels or less to 1024×

1920 pixels.

36. The pixelated phosphor device of claim 32, wherein the thin wall comprises metalized material with optical reflection characteristics for both the excitation light beam and the emitted light beam.

37. The pixelated phosphor device of claim 32, wherein the first optical layer comprises an anti-reflective film characterized for substantially enhancing >

99% of the excitation light beam being passed into each of the array of pixels.

38. The pixelated phosphor device of claim 32, wherein the second optical layer comprises a reflective characteristic for substantially reflecting both the excitation light beam and the emitted light beam at the second surface to guide the emitted light out of the first surface of the phosphor material operated in reflective mode.

39. The pixelated phosphor device of claim 32, wherein the second optical layer comprises a transmissive characteristic for passing the emitted light beam out of the second surface of the phosphor material operated in transmissive mode.

40. The pixelated phosphor device of claim 39, wherein the substrate comprises a material being optically transparent at least for the emitted light beam and thermally conductive for dissipating heat of the phosphor material.