Rear projection display device having multiple mirrors that are substantially parallel to a screen
View Patent ↗The ultra-thin rear projection display device described herein includes a wide angle lens system and one or more planar mirrors that are parallel to a screen on which an image is to be displayed. In one embodiment, the screen that has multiple groove angles to provide better illumination than screens with a single groove angle.
1. A display device comprising:
a screen;
a wide angle lens system with a field angle of at least 100 degrees, the wide angle lens system configured to generate a distorted intermediate image, the wide angle lens system further configured to project a focused image suitable for viewing; and
a substantially planar back plate mirror to reflect the image to the screen, wherein the back plate mirror is substantially perpendicular to the optic axis of the wide angle lens system and substantially parallel to the screen.
2. The display device of claim 1 further comprising a substantially planar intermediate mirror to reflect the image projected by the wide angle lens system to the back plate mirror, the intermediate mirror being substantially parallel to the back plate mirror.
3. The display device of claim 1 wherein the screen comprises a total internal reflection (TIR) Fresnel lens.
4. The display device of claim 1 wherein the screen comprises a refractive Fresnel lens.
5. The display device of claim 1 wherein the wide angle lens system projects the image using approximately one-half of the lens field.
6. The display device of claim 1 wherein the wide angle lens system projects the image using less than one-half of the lens field.
7. The display device of claim 1 , wherein the substantially planar back plate mirror does not change the polarization of the reflected light.
8. A display device comprising:
a fixed screen to display an image;
a wide angle lens system with a field angle of at least 100 degrees, the wide angle lens system configured to generate a distorted intermediate image, the wide angle lens system further configured to project the image, the wide angle lens system having an optic axis substantially perpendicular to the screen; and
at least one mirror to direct the image to the screen.
9. The display device of claim 8 , wherein the at least one mirror is a back plate mirror configured to reflect the image to the screen.
10. The display device of claim 9 , wherein the optic axis of the wide angle lens system is substantially perpendicular to the back plate mirror.
11. The display device of claim 9 , further comprising an intermediate mirror to reflect the image projected by the wide angle lens system to the back plate mirror, wherein the optic axis of the wide angle lens system is substantially perpendicular to the intermediate mirror.
12. The display device of claim 9 , wherein the at least one mirror is a planar mirror.
13. A display device comprising:
a screen;
a wide angle lens system with a field angle of at least 100 degrees, the wide angle lens system configured to project an image using less than one-half of the lens field, the wide angle lens system further configured to generate a distorted intermediate image, the wide angle lens system having an optic axis substantially perpendicular to the screen; and
a back plate mirror configured to reflect the image to the screen.