Shaped phosphor to reduce repeated reflections
Pre-formed wavelength conversion elements are attached to light emitting elements and are shaped to reduce repeated occurrences of total internal reflection. The sides of the shaped elements may be sloped or otherwise shaped so as to introduce a change in the angle of incidence of reflected light upon the light extraction surface of the wavelength conversion element. The pre-formed wavelength conversion elements may be configured to extend over an array of light emitting elements, with features between the light emitting elements that are shaped to reduce repeated occurrences of total internal reflection.
1. A light emitting device comprising:
light emitting elements, each light emitting element comprising a light emitting surface having outer edges defining an outer perimeter surrounding the light emitting surface, the light emitting elements arranged with their light emitting surfaces coplanar, and
a wavelength conversion element disposed on the light emitting surfaces of the light emitting elements, the wavelength conversion element comprising:
wavelength conversion material distributed throughout the wavelength conversion element;
a light extraction surface oppositely positioned from the light emitting elements and one or more contact surfaces in direct contact with the light emitting surface of at least one of the light emitting elements; and
reflective surfaces that are oriented neither orthogonally nor parallel to the light emitting surfaces, the reflective surfaces comprising a reflective material and arranged around the full outer perimeter of at least one light emitting surface and extending outwards away from the outer perimeter of the light emitting surface toward the light extraction surface of the wavelength conversion element.
2. The device of claim 1 , wherein at least one reflective surface of the reflective surfaces comprises a specularly reflective coating.
3. The device of claim 1 , wherein at least one reflective surface of the reflective surfaces is a sloped planar surface.
4. The device of claim 1 , wherein at least one reflective surface of the reflective surfaces is specularly reflective.
5. The device of claim 1 , wherein the wavelength conversion element extends across the light emitting elements.
6. The device of claim 1 , wherein at least one reflective surface of the reflective surfaces is diffusely reflective.
7. The device of claim 1 , wherein the wavelength conversion element comprises crystalline material with embedded wavelength conversion particles.
8. The device of claim 1 , wherein each of the reflective surfaces comprises a specularly reflective coating.
9. The device of claim 1 , wherein each of the reflective surfaces is a sloped planar surface.
10. The device of claim 9 , wherein each of the reflective surfaces comprises a specularly reflective coating.
11. The device of claim 6 , wherein at least one different reflective surface of the reflective surfaces is specularly reflective.
12. The device of claim 1 , wherein the wavelength conversion element overlaps three or more light emitting elements.
13. The device of claim 1 , wherein the wavelength converting element further comprising second reflective surfaces that are parallel to the light extraction surface.
14. The device of claim 13 , wherein the second reflective surfaces are diffusely reflective.
15. The device of claim 1 , wherein the wavelength converting element further comprising second reflective surfaces that are hemispherical.