Semiconductor light source apparatus

• US 8,851,694 B2
• Filed: 03/07/2012
• Issued: 10/07/2014
• Est. Priority Date: 03/07/2011
• Status: Active Grant

• Current Assignee: Stanley Electric Company Limited
• Original Assignee: Stanley Electric Company Limited
• Inventors: Harada, Mitsunori
• Primary Examiner(s): Hanley, Britt D
• Application Number:
  US13/414,702
• Publication Number:
  US 20120230011A1
• Time in Patent Office: 944 Days
• Field of Search: None
• US Class Current: 362/84
• CPC Class Codes: F21S 41/16 Laser light sources
• CPC Class Codes: F21S 41/176 Light sources where the light is generated by photoluminescent material spaced from a primary light generating element
• CPC Class Codes: F21V 13/14 the elements being filters or photoluminescent elements, reflectors and refractors
• CPC Class Codes: F21V 9/32 characterised by the arrangement of the photoluminescent material
• CPC Class Codes: F21W 2131/103 of streets or roads
• CPC Class Codes: F21W 2131/406 for theatres, stages or film studios
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: F21Y 2115/30 Semiconductor lasers

Abstract

A semiconductor light source apparatus can include a clad layer, a phosphor layer surrounded by the clad layer and a laser diode emitting a laser light. The phosphor layer can include a cavity having an opening for receiving the laser light, a phosphor material and a light-emitting surface of the apparatus. The laser light entering into the cavity can repeatedly reflect on an inner surface of the phosphor layer many times, each and every time most of the laser light entering into the phosphor layer. The laser light can be efficiently wavelength-converted by the phosphor material and the wavelength converted light can be emitted from the light-emitting surface having various shapes exposed from the clad layer. Therefore, the disclosed subject matter can include providing semiconductor light source apparatuses having a high light-emitting efficiency and high light-emitting density such that the devices can be used for a headlight, general lighting, etc.

Claims

1. A semiconductor light source apparatus, comprising:

a phosphor layer having a top surface, a bottom surface, an inner surface, an outer surface, a cavity, a top edge located between the top surface and the outer surface and a bottom edge located between the bottom surface and the outer surface, and including at least one phosphor material, the at least one phosphor material configured to convert at least one energy of blue light and ultraviolet light into light having a wavelength, the top surface including at least one of a planar surface, a convex surface and a concave surface, the bottom surface having a ring shape, the cavity defined at least in part by the inner surface of the phosphor layer, an opening surrounded by the bottom surface and an end of the cavity located opposite the opening, and the cavity configured to narrow from the opening toward the end of the cavity;

a clad layer having a first opening, a second opening and an inner surface, and configured in a ring shape, the inner surface of the clad layer including a reflective material and being located adjacent the outer surface of the phosphor layer, the first opening of the clad layer located adjacent the top edge of the phosphor layer, and the second opening of the clad layer located adjacent the bottom edge of the phosphor layer; and

a semiconductor laser diode having an optical axis and configured to emit a laser light including at least one of a blue light and an ultraviolet light when the semiconductor laser diode operates, the optical axis of the semiconductor laser diode intersecting with the inner surface of the phosphor layer at an intersection location so that a first portion of the laser light enters into the phosphor layer at the intersection location and a second portion of the laser light is reflected by the inner surface of the phosphor layer, wherein the inner surface of the phosphor layer is configured to again receive and allow entry of at least a part of the second portion of the laser light at a location closer to the end of the cavity in the phosphor layer than the intersection location.

2. The semiconductor light source apparatus according to claim 1, wherein each of the top edge and the bottom edge of the phosphor layer is a substantially same shape and each shape having a central point, and the outer surface of the phosphor layer is substantially parallel to a central axis connecting the central point of the top edge to the central point of the bottom edge of the phosphor layer.

3. The semiconductor light source apparatus according to claim 1, wherein each of the top edge and the bottom edge of the phosphor layer is formed in a substantially similar shape and each shape having a central point, and the similar shape shrinks from the bottom edge of the phosphor layer toward the top edge of the phosphor along a central axis connecting the central point of the top edge to the central point of the bottom edge of the phosphor layer.

4. The semiconductor light source apparatus according to claim 1, wherein the cavity of the phosphor layer is formed in a conical shape in which the opening of the cavity is defined as a base of the conical shape and the end of the cavity is defined as a vertex of the conical shape.

5. The semiconductor light source apparatus according to claim 2, wherein the cavity of the phosphor layer is formed in a conical shape having a central axis, in which the opening of the cavity is defined as a base of the conical shape, the end of the cavity is defined as a vertex of the conical shape, and the central axis of the conical shape coincides with the central axis connecting the central point of the top edge to the central point of the bottom edge of the phosphor layer.

6. The semiconductor light source apparatus according to claim 3, wherein the cavity of the phosphor layer is formed in a conical shape having a central axis, in which the opening of the cavity is defined as a base of the conical shape, the end of the cavity is defined as a vertex of the conical shape, and the central axis of the conical shape coincides with the central axis connecting the central point of the top edge to the central point of the bottom edge of the phosphor layer.

7. The semiconductor light source apparatus according to claim 1, wherein the cavity of the phosphor layer is formed in a bullet shape, in which the opening of the cavity is defined as a base of the bullet shape and the end of the cavity is defined as a vertex of the bullet shape.

8. The semiconductor light source apparatus according to claim 1, wherein the cavity of the phosphor layer is formed in a tapered cylinder shape such that the cavity is defined by a diagonal cut in a cylinder from a top edge to a halfway point located on an opposite side of the top edge, in which the opening of the cavity is defined as a base of the tapered cylinder shape and the end of the cavity is defined as a vertex of the tapered cylinder shape.

9. The semiconductor light source apparatus according to claim 1, wherein the clad layer extends toward the opening of the cavity in a range such that the clad layer does not shade the laser light emitted from the semiconductor laser diode.

19. The semiconductor light source apparatus according to claim 1, wherein the semiconductor laser diode is a blue light-emitting device and the phosphor layer is one of a yellow glass phosphor layer and a yellow phosphor ceramic.

20. The semiconductor light source apparatus according to claim 2, further comprising:

an optical lens having an optical axis and being located adjacent the top surface of the phosphor layer, wherein the optical axis of the optical lens coincides with the central axis connecting the central point of the top edge to the central point of the bottom edge of the phosphor layer.

10. A semiconductor light source apparatus, comprising:

a phosphor layer having a top surface, a bottom edge, an inner surface, an outer surface, a cavity and a top edge located between the top surface and the outer surface, and including at least one phosphor material, the at least one phosphor material configured to convert at least one energy of blue light and ultraviolet light into light having a wavelength, the top surface including at least one of a planar surface, a convex surface and a concave surface, the bottom edge having a ring shape and being located between the outer surface and the inner surface of the phosphor layer, the cavity being defined by the inner surface of the phosphor layer, an opening surrounded by the bottom edge and a convex surface located opposite the opening, the convex surface having a top end and a central axis formed in a rotational plane with respect to the central axis and connecting to the inner surface of the phosphor layer, and therefore the inner surface of the phosphor layer forming the convex surface in the cavity, and the phosphor layer configured such that the cavity narrows from the opening toward the top end of the convex surface along the central axis of the convex surface;

a clad layer having a first opening, a second opening and an inner surface, and having a ring shape, the inner surface of the clad layer including a reflective material and being located adjacent the outer surface of the phosphor layer, the first opening of the clad layer located adjacent the top edge of the phosphor layer, and the second opening of the clad layer located adjacent the bottom edge of the phosphor layer; and

a semiconductor laser diode having an optical axis configured to emit laser light, including at least one of a blue light and an ultraviolet light, toward the convex surface when the semiconductor laser diode operates, the optical axis of the semiconductor laser diode corresponding to the central axis of the convex surface in the cavity of the phosphor layer so that the laser light enters into the phosphor layer from the convex surface, wherein the convex surface is configured to diffuse another portion of the laser light not entering into the phosphor layer from the convex surface.

11. The semiconductor light source apparatus according to claim 10, wherein the phosphor layer further includes a plurality of convex portions located on the inner surface of the phosphor layer near the convex surface so as to project in a direction of the central axis of the convex surface and side by side in an extending direction of the clad layer, and each of the convex portions includes a planar surface extending in a direction substantially perpendicular to the central axis of the convex surface and an inclined surface inclined in a direction toward the opening of the cavity.

12. The semiconductor light source apparatus according to claim 10, wherein the inner surface of the phosphor layer includes a rough surface, in which an average roughness Ra of the rough surface of the phosphor layer is between 1.0 a and 50 a.

13. The semiconductor light source apparatus according to claim 10, wherein the clad layer extends over the opening of the cavity in a range that does not shade the laser light emitted from the semiconductor laser diode.

14. The semiconductor light source apparatus according to claim 11, wherein the clad layer extends toward the opening of the cavity in a range that does not shade the laser light emitted from the semiconductor laser diode.

15. The semiconductor light source apparatus according to claim 12, wherein the clad layer extends toward the opening of the cavity in a range that does not shade the laser light emitted from the semiconductor laser diode.

16. A semiconductor light source apparatus, comprising:

a phosphor layer having an outer surface, an inner surface, a bottom surface and a cavity, the phosphor layer being formed in a dome shape, and the phosphor layer including at least one phosphor material, the at least one phosphor material configured to convert at least one energy of blue light and ultraviolet light into light having a wavelength, the outer surface including a light-emitting surface, the light-emitting surface of the outer surface including at least one of a planar surface, a convex surface and a concave surface, the bottom surface formed in a ring shape and being located between the outer surface and the inner surface of the phosphor layer, the cavity being defined by the inner surface of the phosphor layer that is formed in a dome shape, an opening surrounded by the bottom surface and a convex surface located opposite the opening, the convex surface having a top end and a central axis formed in a rotational plane with respect to the central axis and connecting to the inner surface of the phosphor layer, and therefore the inner surface of the phosphor layer forming the convex surface in the cavity;

a clad layer having a first opening, a second opening and an inner surface, and formed in a ring shape, the inner surface of the clad layer including a reflective material and being located adjacent the outer surface of the phosphor layer, the first opening of the clad layer exposing the light-emitting surface of the phosphor layer from the outer surface of the phosphor layer, and the second opening of the clad layer located adjacent the bottom surface of the phosphor layer; and

a semiconductor laser diode having an optical axis and configured to emit a laser light, including at least one of a blue light and an ultraviolet light, toward the convex surface in the cavity when the semiconductor laser diode operates, the optical axis of the semiconductor laser diode corresponding to the central axis of the convex surface in the cavity of the phosphor layer so that at least a portion of the laser light enters into the phosphor layer from the convex surface, wherein the convex surface in the cavity of the phosphor layer is configured to diffuse another portion of the laser light not entering into the phosphor layer from the convex surface.

17. The semiconductor light source apparatus according to claim 16, wherein the inner surface of the phosphor layer includes a rough surface, in which an average roughness Ra of the rough surface of the phosphor layer is between 1.0 a and 50 a.

18. The semiconductor light source apparatus according to 16, wherein the clad layer extends over the opening of the cavity in a range that does not shade the laser light emitted from the semiconductor laser diode.