High contrast rear projection screen
View Patent ↗A projection screen includes a transparent substrate having a first side and a second side, an array of lenses disposed along the first side of the transparent substrate, a dark film disposed across the second side of the transparent substrate, an array of holes disposed through the dark film, and an array of diffusing spots each aligned with a corresponding one of the array of holes.
1. A projection screen, comprising:
a transparent substrate having a first side and a second side;
an array of lenses disposed along the first side of the transparent substrate;
a dark film disposed across the second side of the transparent substrate;
an array of holes disposed through the dark film; and
an array of diffusing spots each aligned with a corresponding one of the array of holes,
wherein the array of lenses are each separated by a first separation pitch and the array of holes are each separate by a second separation pitch, wherein the first and second separation pitches are different.
2. The projection screen of claim 1 , wherein the array of diffusing spots comprises diffusing material disposed in or on each of the holes disposed through the dark film.
3. The projection screen of claim 2 , wherein the diffusing material comprises light diffusing particles suspended within a photoresist that is patterned into the array of holes.
4. The projection screen of claim 3 , wherein the light diffusing particles comprises at least one of polytetrafluroethylene particles or Barium sulfate.
5. The projection screen of claim 2 , wherein the diffusing spots comprise a light color paint.
6. The projection screen of claim 2 , wherein the diffusing material fills each of the holes in the dark film and rises above a front side surface of the dark film.
7. The projection screen of claim 1 , wherein the array of lenses correspond to the array of holes on a one-to-one basis.
8. The projection screen of claim 1 , wherein each lens of the array of lenses is aligned to focus display light incident on a rear side of the projection screen through a corresponding one the array of holes and wherein the array of diffusing spots scatters the display light for emission out a front side of the projection screen.
9. The projection screen of claim 1 , wherein the second separation pitch of the array of holes is larger than the first separation pitch of the array of lenses to accommodate display light incident on the array of lenses from a rear side of the projection screen that is divergent.
10. The projection screen of claim 1 , wherein the array of lenses comprises:
an array of microlenses having a first refractive index disposed along the first side of the transparent substrate; and
a planarization material having a second refractive index surrounding the array of microlenses, wherein the first refractive index is different than the second refractive index.
11. The projection screen of claim 1 , wherein the array of lenses comprises:
an array of double-sided microlenses having a first refractive index disposed along the first side of the transparent substrate; and
a transparent material having a second refractive index surrounding the array of double-sided microlenses, wherein the first refractive index is different than the second refractive index.
12. The projection screen of claim 1 , wherein the diffusing spots include phosphor or quantum dots.