Transparent projection screen
According to some embodiments, a transparent screen includes a first transparent substrate having a first transparent substrate index of refraction and including a surface relief pattern, a partially reflective coating formed on the surface relief pattern, and a second transparent substrate bonded over the partially reflective coating with an optical adhesive having the first transparent substrate index of refraction.
1. A transparent screen comprising:
a first transparent substrate having a first transparent substrate index of refraction and including a surface relief pattern forming a random scattering surface having a spatial frequency spectrum that is substantially flat over a range of spatial frequencies in a frequency range including spatial frequencies having a wavelength of visible light;
a partially reflective coating formed on the surface relief pattern; and
a second transparent substrate bonded over the partially reflective coating with an optical adhesive having the first transparent substrate index of refraction.
2. The transparent screen of claim 1 , wherein the surface relief pattern is substantially continuous and smoothly varying.
3. The transparent screen of claim 1 , wherein the partially reflective coating in combination with the surface relief pattern has refractive scattering properties, the optical adhesive to substantially null the refractive scattering properties.
4. The transparent screen of claim 1 , wherein the partially reflective coating is a wire-grid polarizer.
5. The transparent screen of claim 1 , wherein the first transparent substrate is formed from a first material and the second transparent substrate is formed from the first material.
6. The transparent screen of claim 1 , wherein the surface relief pattern has a scattering profile and the scattering profile is substantially circular.
7. The transparent screen of claim 1 , wherein the surface relief pattern has a scattering profile and the scattering profile is substantially elliptical.
8. The transparent screen of claim 1 , wherein the surface relief pattern has a scattering profile and the scattering profile is substantially angled off-axis.
9. The transparent screen of claim 1 , wherein the surface relief pattern has a scattering profile and the scattering profile is substantially space-variant with converging scattering directions.
10. The transparent screen of claim 1 , further comprising a polarizer bonded to the second transparent substrate.