Constructive occlusion with a transmissive component
View Patent ↗Constructive occlusion type lighting systems utilize a reflective mask to cover a portion of an active optical surface, typically a Lambertian surface formed by the aperture of a diffusely reflective cavity, in order to distribute radiant energy with a tailored intensity distribution. Adjustment of the parameters of the constructive occlusion system enables the system designer to tailor the system performance to a wide range of applications. As disclosed herein, the constructive occlusion type distribution is combined with a diffuse distribution of a transmissive component, emitted through a wall of the system. For example, a diffusely reflective wall of the cavity may also be partially transmissive, to allow some energy to pass through and provide an additional illumination component, while continuing to maintain the characteristics to support the constructive occlusion component.
1. An indirect lighting system, comprising:
a light source;
an optical cavity for receiving light from the source and having a wall, wherein at least a section of the cavity wall exhibits both a transmissive characteristic and at least a partially diffusely reflective characteristic, wherein the transmissive characteristic enables the section of the cavity wall to pass a first portion of the light from the source through the section of the cavity wall toward a first field of illumination, and the at least partially diffusely reflective characteristic enables the section of the cavity wall to diffusely reflect some of the light from the source within the cavity;
a baffle that is at least partially transmissive, positioned outside the cavity and between the section of the cavity wall and the first field of illumination, for passing at least some of the first portion of the light through to the first field of illumination;
an aperture of the optical cavity, facing toward a second field of illumination;
a mask outside the cavity spaced from the aperture and having a reflective surface facing toward the aperture, wherein the mask is positioned relative to the aperture so as to occlude a substantial part of the aperture and to thereby provide a tailored distribution of a second portion of the light emerging from between the mask and aperture over the second field of illumination; and
a support, for attaching the lighting system in relation to a face structure in such a manner that the diffused first portion of the light provides direct illumination in the first field, and the second portion of the light illuminates the second field onto the face structure for reflection and indirect illumination of the first field with reflected light from the second portion.
2. The system as in claim 1 , wherein the source and cavity are arranged to provide emission of a third portion of the light from the source over a third field of illumination.
3. The system as in claim 2 , wherein the arrangement of the source and cavity includes a port through the cavity wall, for emitting the third portion of the light from the source toward the third field of illumination.
4. The system as in claim 3 , further comprising a deflector coupled to the port and having a reflective surface expanding outward as the deflector extends from the port toward the third field of illumination, for directing the third portion of light from the source over the third field of illumination.
5. The system as in claim 1 , further comprising a reflective shoulder along at least a portion of a perimeter of the aperture.
6. The system as in claim 1 , wherein the support is adapted to mount the lighting system on a wall or ceiling of a space to be illuminated by the system.
7. The system of claim 1 , wherein the section of the cavity wall comprises a diffusely reflective material providing at least 85% reflectivity of the light from the source back within the cavity.
8. The system as in claim 7 , wherein the section of the cavity wall is substantially white and exhibits a reflectivity of approximately 96% with respect to the light from the source.
9. The system of claim 7 , wherein the reflective surface of the mask comprises a diffusely reflective material providing at least 85% reflectivity of the light from the source back within the cavity.
10. The system as in claim 9 , wherein:
the section of the cavity wall is substantially white and exhibits a reflectivity of approximately 96% with respect to the light from the source; and
the reflective surface of the mask is substantially white and exhibits a reflectivity of approximately 96% with respect to the light from the source.
11. The system of claim 1 , wherein the baffle is also at least partially reflective, so as to reflect some of the first portion of the light back toward the section of the cavity wall.
12. The system of claim 11 , wherein the baffle comprises a substantially white diffuser.
13. The system of claim 12 , wherein the diffuser comprises a translucent plastic material.
14. An indirect lighting system, comprising:
a light source;
an optical cavity for receiving light from the source and having a wall, wherein at least a section of the cavity wall exhibits both a transmissive characteristic and at least a partially diffusely reflective characteristic, wherein the transmissive characteristic enables the section of the cavity wall to pass a first portion of the light from the source through the section of the cavity wall toward a first field of illumination, and the at least partially diffusely reflective characteristic enables the section of the cavity wall to diffusely reflect some of the light from the source within the cavity, the cavity wall comprising a substantially white material providing at least 85% reflectivity of light from the source;
a partially transmissive baffle located outside the cavity and between the section of the cavity wall and the first field of illumination for processing and passing at least some of the first portion of the light to the first field of illumination;
an aperture of the optical cavity, facing toward a second field of illumination;
a mask outside the cavity spaced from the aperture and having a reflective surface facing toward the aperture, wherein the mask is positioned relative to the aperture so as to occlude a substantial part of the aperture and to thereby provide a tailored distribution of a second portion of the light emerging from between the mask and aperture over the second field of illumination;
a support, for attaching the lighting system in relation to a face structure in such a manner that the diffused first portion of the light provides direct illumination in the first field, and the second portion of the light illuminates the second field onto the face structure for reflection and indirect illumination of the first field with reflected light from the second portion; and
means for providing emission of a third portion of the light from the source over a third field of illumination.
15. The system as in claim 14 , wherein the partially transmissive baffle comprises a diffuser, for diffusing light over the first field of illumination.
16. The system as in claim 14 , wherein the means comprises a port for allowing emission of light from the cavity toward the third field of illumination.
17. The system as in claim 16 , wherein the means further comprises a light deflector having a reflective surface coupled to the port.
18. The system as in claim 14 , wherein the section of the cavity wall is substantially white and exhibits a reflectivity of approximately 96% with respect to the light from the source.
19. The system of claim 14 , wherein the reflective surface of the mask comprises a diffusely reflective material providing at least 85% reflectivity of the light from the source back within the cavity.
20. The system as in claim 19 , wherein:
the section of the cavity wall exhibits a reflectivity of approximately 96% with respect to the light from the source; and
the reflective surface of the mask is substantially white and exhibits a reflectivity of approximately 96% with respect to the light from the source.