Roadway and vehicular-mounted reflectors incorporating a field of discrete crystal reflectors and retroreflectors
Roadway and vehicular-mounted safety reflectors include a reflective field that incorporates a plurality of discrete crystals that internally reflect light and return the light in a desired directional pattern determined by the internal reflection characteristics and orientation of the crystals. The directional pattern is chosen to optimize the visibility and functionality of the reflector.
1. A reflector including a reflective field comprising a plurality of crystals that internally reflect incident light and return the internally reflected light in a desired directional pattern determined by the internal reflection characteristics and orientation of the crystals, wherein at least a portion of the crystals are metallic oxide crystals, and wherein at least a portion of the crystals return the incident light in a direction approximately normal to the face of the reflective field.
2. The reflector of claim 1 , wherein at least a portion of the crystals are formed from a material selected from the group consisting of single crystalline aluminum oxide (Al 2 O 3 ) and single crystalline zirconium oxide (ZrO 2 ).
3. A reflector including a reflective field comprising a plurality of crystals that internally reflect incident light and return the internally reflected light in a desired directional pattern determined by the internal reflection characteristics and orientation of the crystals, wherein at least a portion of the crystals are carbide crystals.
4. The reflector of claim 3 , wherein at least a portion of the crystals are formed from a material selected from the group consisting of single crystalline silicon carbide (SiC) and single crystalline boron carbide (BC 4 ).
5. The reflector of claim 1 , wherein at least a portion of the crystals are faceted with a bevel that is exposed to incident light.
6. The reflector of claim 1 , wherein at least a portion of the crystals are faceted with a crown, a bevel and a main body portion, and the crown and bevel are exposed to incident light.
7. The reflector of claim 1 , wherein at least a portion of the crystals return the incident light in a direction parallel to the incident light.
8. The reflector of claim 7 , wherein at least a portion of the crystals are retroreflectors.
9. The reflector of claim 1 , wherein the reflector is monolithic.
10. The reflector of claim 9 , wherein the material forming the reflector is selected from the group consisting of a single oxide crystal and a single carbide crystal.
11. The reflector of claim 1 , wherein at least a portion of the crystals are doped to return incident light at a known wavelength spectrum.
12. The reflector of claim 1 , wherein at least a portion of the crystals are doped to return incident light in the red spectrum.
13. The reflector of claim 1 , wherein at least a portion of the crystals are doped to return incident light in the blue spectrum.
14. The reflector of claim 1 , wherein the reflective field comprises a plurality of crystals that return incident light at different, known wavelengths.
15. The reflector of claim 14 , wherein crystal retroreflectors that return light at each of the different known wavelengths are grouped together in zones within the reflective field.
16. The reflector of claim 1 , including a substrate formed of a thermoplastic material having the crystals secured thereto to form the reflective field.
17. The reflector of claim 1 , including a lens to block light at wavelengths above or below a specified wavelength.
18. The reflector of claim 1 , including phosphors to create a stimulated emission of a desired wavelength distribution of light.
19. The reflector of claim 18 , wherein the phosphors are coated on at least a portion of the crystals.
20. The reflector of claim 1 , mounted at roadside.
21. The reflector of claim 1 , mounted on a motor vehicle.
22. The reflector of claim 1 , located on a traffic-facing surface of an embedded highway marker.
23. The reflector of claim 1 , wherein the reflective field comprises a material selected from the group consisting of paints, tapes and resins.
24. A system for enhancing vehicular safety comprising a plurality of roadway reflectors, each roadway reflector comprising a plurality of crystals that internally reflect incident light and return the internally reflected light in a desired directional pattern determined by the internal reflection characteristics and orientation of the crystals, wherein at least a portion of the crystals are metallic oxide crystals.
25. The system of claim 24 , further comprising vehicular-mounted reflectors, each vehicular-mounted reflector comprising a plurality of crystals that internally reflect incident light and return the internally reflected light in a desired directional pattern determined by the internal reflection characteristics and orientations of the crystals.