Patent ID: 9551917
Date: 2017-01-24
CPC Classifications: G03B

Claim:
1. A light source unit for use with or in a projection display system that projects an image onto a plane, said light source unit comprising: a first solid-state light source emitting two-dimensional light fluxes of a first color to be projected; a second solid-state light source emitting two-dimensional light fluxes of a second color to be projected; a third solid-state light source emitting two-dimensional light fluxes of a third color to be projected; a wedge-shaped dichroic mirror having a first dichroic surface and a second dichroic surface which are located opposite to each other in a non-parallel relationship to each other, the first dichroic surface reflecting the light fluxes from the first solid-state light source, the second dichroic surface reflecting the light fluxes from the second solid-state light source, the light fluxes from the third solid-state light source being transmitted through the first and second dichroic surfaces; and a lens array for smoothing an illuminance distribution of light fluxes incident from the wedge-shaped dichroic mirror; wherein the light fluxes from the third solid-state light source define an optical axis that is bent by the wedge-shaped dichroic mirror so as to be coincident with an optical axis of the lens array and incident on the lens array; wherein the light fluxes from the first solid-state light source and the light fluxes from the second solid-state light source are reflected symmetrically about the optical axis of the lens array by the wedge-shaped dichroic mirror and enter the lens array; wherein the light fluxes from said first solid-state light source and the light fluxes from said second solid-state light source enter said lens array symmetrically about the optical axis of the lens array and at given angles to the optical axis of the lens array; wherein the optical axis of the light fluxes from said first solid-state light source and the optical axis of the light fluxes from said second solid-state light source pass through a position spaced from an intersection of the optical axis of said lens array and said first dichroic surface by a given amount and are symmetrically incident on the lens array at a given angle to the optical axis of the lens array; and wherein a relation given by is satisfied, where D is the distance between the position on said first dichroic surface through which the optical axis of the light fluxes from said first solid-state light source or from said second solid-state light source passes and the optical axis of said lens array, L is the vertical distance between the intersection and the lens array, W is the length of one side of one lens surface of the lens array, and θ is the angle made between the optical axis of the light fluxes which is incident on the lens array after being emitted from the first solid-state light source or from the second solid-state light source and the optical axis of the lens array.