Projection display device
View Patent ↗In a projection display device that is provided with a relay lens for converting flux that is emitted from a light source to a parallel flux for illuminating an image display element (DMD), and a total internal reflection prism for both directing flux that is emitted from the relay lens to the DMD and directing flux that is reflected by the DMD toward a projection lens, the relay lens is unified with the prism as a lens-integral prism by bonding the relay lens to the total internal reflection surface of the prism.
1. A projection display device, comprising:
a relay lens for making flux that is emitted from a light source, a parallel flux for illuminating an image display element; and
a total internal reflection prism that both guides the flux that is emitted from the relay lens to the image display element and directs the flux that is reflected by the image display element toward a projection lens;
wherein said relay lens is placed opposite to the total internal reflection surface of said prism, and fixed to said prism;
said prism is configured as a triangle prism with a first side, a second side and a third side;
said first side of said prism is said total internal reflection surface;
said second side of said prism is arranged to confront said image display element; and
said third side of said prism is arranged to confront said projection lens.
2. A projection display device according to claim 1 , wherein:
a micro-space air gap is interposed between said relay lens and said prism.
3. A projection display device according to claim 1 , wherein:
an adhesive with a glass bead additive is used to bond said relay lens and said prism.
4. A projection display device according to claim 1 , wherein:
said relay lens is a plano-convex lens, the planar surface of which is arranged opposite to the total internal reflection surface of said prism.
5. A projection display device according to claim 1 , wherein:
a reinforcing plate is provided for joining said relay lens and said prism.
6. A projection display device according to claim 1 , wherein:
said lens is integrated with said prism.
7. A projection display device according to claim 6 , wherein:
said lens is bonded with an adhesive to said prism.
8. A projection display device according to claim 7 , wherein:
a reinforcing plate is provided for joining said relay lens and said prism.