Projector system with hollow light pipe optics
First Claim
Patent Images
1. A light engine for an optical projector system comprising:
- lamp means to generate light;
collector means to collect and direct the generated light; and
a light pipe having an entrance pupil, a central section, an exit pupil along a straight optical axis, and reflecting walls;
characterized in thatthe light pipe is hollow, and with internal walls, the light pipe is double tapered with the exit pupil being rectangular and the area of the entrance pupil being at least 50% larger than a cross-sectional area perpendicular to the optical axis of the center section, and a cold mirror coating is coated on the internal walls.
1 Assignment
0 Petitions
Accused Products
Abstract
A projector system includes a light pipe integrator (LPI) between its lamp and its projection lens system. The LPI is hollow, formed from sheet metal, and has an internal cold mirror coating which reflects visible light and passes infra-red radiation. The reflector is a compound reflector having profiles of two ellipses with different eccentricities.
-
Citations
24 Claims
-
1. A light engine for an optical projector system comprising:
-
lamp means to generate light; collector means to collect and direct the generated light; and a light pipe having an entrance pupil, a central section, an exit pupil along a straight optical axis, and reflecting walls;
characterized in thatthe light pipe is hollow, and with internal walls, the light pipe is double tapered with the exit pupil being rectangular and the area of the entrance pupil being at least 50% larger than a cross-sectional area perpendicular to the optical axis of the center section, and a cold mirror coating is coated on the internal walls.
-
-
2. A projector system comprising:
-
lamp means to generate light; collector means to gather and re-direct the generated light; a light pipe having an entrance pupil, an exit pupil, a center section, internal walls and an optical axis, the light from the collector means being directed on the entrance pupil; an image forming means to form an image and having an image gate, the exit pupil directing light on the image gate; and a projector lens;
whereinthe light pipe is hollow in shape, the internal walls are mirrors, the internal walls are open to ambient air; and wherein the mirrors comprise cold mirror means to reflect visible light and transmit infra-red light. - View Dependent Claims (3, 4, 5, 6, 7)
-
-
8. A projector system comprising:
-
lamp means to generate light; a reflector to gather and re-direct the generated light; a light pipe having an entrance pupil, an exit pupil, a center section, internal walls and an optical axis, the light from the reflector being directed on the entrance pupil; an image forming means to form an image and having an image gate, the exit pupil directing the light on the image gate; and a projector lens; wherein the light pipe is hollow in shape, the internal walls are mirrors, the internal walls are open to ambient air; and wherein the reflector is curved and concave in shape in cross-sections through the axis, and the curvature comprises at least two ellipses having different eccentricities and both eccentricities are in the range of 0.60-0.90.
-
-
9. A projector system comprising:
-
(a) a metal halide arc lamp having an arc gap in the range of 1-6 mm; (b) a reflector having a central axis;
the lamp arc gap being along the reflector'"'"'s axis;the reflector being circular in cross-sections perpendicular to the central axis and being curved in at least two elliptical curves having different eccentricities in cross-sections through the central axis; (c) a hollow light pipe having an entrance pupil, a rectangular exit pupil, a center section between the entrance and exit pupils, an optical axis, flat reflecting walls made of metal, and a tapered shape in which the exit pupil is at least 50% larger than the area of a cross-section through the center section taken perpendicular to the optical axis; (d) a cold mirror coating means on the reflecting walls to reflect visible light and to transmit visible light; (e) an LCD (Liquid Crystal Display) panel illuminated by light from the exit pupil; and (f) a projector lens means to project images formed by the LCD panel onto a screen. - View Dependent Claims (10, 11)
-
-
12. An elongated light pipe having an optical axis, an entrance pupil and an exit pupil, for use in a projector system, characterized in that:
-
(a) the light pipe is hollow and has internal mirror walls and is not filled with a dielectric; (b) the mirror walls are flat and of metal; (c) a cold mirror coating means is coated on the mirror walls to reflect visible light and transmit infra-red light. - View Dependent Claims (13, 14)
-
-
15. A light engine for an optical projector system comprising:
-
(a) lamp means to generate light; (b) a reflector which is circular in cross-sections perpendicular to a central axis and having first and second curved sectors, the sectors in profile having two different curvatures, the reflector producing a first beam from the first reflector sector and a second beam from the second reflector sector, each beam having a free end focus spot; (c) a hollow light pipe integrator having a tapered entry section with an entry pupil, a central section, an exit pupil and internal mirror walls, a cross-section of the entry pupil being at least 50% larger in area than a cross-section of the center section; and (d) reflector means to focus the first beam so that it does not reflect from the walls of the entry section and its free end spot is within the entry section. - View Dependent Claims (16, 17, 18)
-
-
19. A light engine for an optical projector system comprising:
-
(a) lamp means to generate light; (b) a reflector which is circular in cross-sections perpendicular to a central axis and having first and second curved sectors, the sectors in profile having two different curvatures, the reflector producing a first beam from the first reflector sector and a second beam from the second reflector sector, each beam having a free end focus spot; (c) a hollow light pipe aligned in sequence along an optical axis, a tapered entry section having an entry pupil and an exit pupil and internal mirror walls, the entry pupil being at least 50% larger in area than the section exit pupil; and (d) reflector means to focus the first beam and second beam to substantially overlap at the exit pupil. - View Dependent Claims (20, 21)
-
-
22. A light engine for an optical projector system comprising:
-
(a) lamp means to generate light; (b) a reflector which is circular in cross-sections perpendicular to a central axis and having first and second curved sectors, the sectors in profile having two different curvatures, the reflector producing a first beam from the first reflector sector and a second beam from the second reflector sector, each beam having a free end focus spot; (c) a hollow light pipe integrator having a tapered entry section with an entry pupil, a central section, an exit pupil and internal mirror walls, a cross-section of the entry pupil being at least 50% larger than a cross-section of the center section; and (d) the free end focus spot of the first beam being focus point F1 and the free end focus spot of the second beam being focus point F2 which is separated from F1 in the range of 10-40 mm. - View Dependent Claims (23, 24)
-
Specification