Glare management of reflective and thermoreflective surfaces
The reflectivity and transmissivity of building and vehicle surfaces is maintained while employing partial, variable, selective, or asymmetric diffusers between a surface and an external light source such that the reflected light is diffused to produce a reduction in glare, while minimally effecting the specular or collimated transmission (if any) of light through the surface. Glare is also reduced by utilizing diffuser devices that reflect light in a temperature dependent manner.
1. An energy-efficient device that reduces glare from reflection of incident light comprising a first reflective polarizer;
a second reflective polarizer;
a thermochromic depolarizer positioned between the first reflective polarizer and the second polarizer;
a transparent substrate affixed to the second reflective polarizer; and
an at least partially diffusive filter affixed to the first reflective polarizer.
2. The energy-efficient device of claim 1 further comprising incorporating an electrochromic depolarizer in conjunction with the thermochromic depolarizer.
3. The energy-efficient device of claim 1 , wherein the at least partially diffusive filter is a variable diffuser with a light scattering ability controllable by one or more external conditions.
4. The energy-efficient device of claim 3 , wherein the one or more external conditions comprise a temperature and/or an applied electric field.
5. The energy-efficient device of claim 3 , wherein the variable diffuser further comprises a thermodiffusive filter that is mostly transparent within a first temperature range and that is mostly diffusive within a second temperature range.
6. The energy efficient device of claim 5 , wherein the thermodiffusive filter comprises
a first transparent material; and
beads or bubbles of a second transparent material, wherein
within a first temperature range, an index of refraction of the first transparent material is substantially the same as an index of refraction of the second transparent material; and
within a second temperature range, one or both of the index of refraction of the first transparent material and the index of refraction of the second transparent material change such that there is a substantial mismatch between the index of refraction of the first transparent material and the index of refraction of the second transparent material.
7. The energy efficient device of claim 6 , wherein the first transparent material and the second transparent material are selected such that the thermodiffusive filter functions as a thermochromic diffusive Bragg reflector.
8. The energy-efficient device of claim 1 , wherein the partially diffusive filter is a selective diffuser that only diffuses light of particular wavelengths or particular polarities.
9. The energy-efficient device of claim 1 , wherein the partially diffusive filter is an asymmetric diffuser that scatters light passing through the device in a first direction more strongly than light passing through the device in a second direction.