Patent ID: 8690343

Claim:
A light source device, comprising: first and second solid-state light source units that are disposed opposite to each other, each unit including a plurality of solid-state light sources and a plurality of condensing lenses; a reflection unit that reflects exiting light beams from the first and second solid-state light source units in one direction; a first condensing part that condenses reflected light beams from the reflection unit; a fluorescence emission plate that is excited with light condensed by the first condensing part and emits fluorescence and has a phosphor layer disposed on a light incident side thereof and a reflective film disposed at the back of the phosphor layer in a light incident direction, a dichroic mirror that polarization separates light from the first condensing part into a first polarization component and a second polarization component and that combines blue color light and green and red color lights; a retardation plate that converts a polarization direction of the second polarization component; and a reflection plate that reflects light having been transmitted through the retardation plate so that the light reenters the retardation plate, wherein the plurality of solid-state light sources in each of the first and second solid-state light source units are arranged two-dimensionally with optical axes thereof being oriented in an x-axis direction in a yz plane in a rectangular coordinate system composed of x, y and z axes, each column of the solid-state light sources aligned in the z-axis direction in the first solid-state light source unit and each column of the solid-state light sources aligned in the z-axis direction in the second solid-state light source unit are arranged alternately in the y-axis direction, the reflection unit is disposed so as to reflect each of the exiting light beams from the first and second solid-state light source units in the z-axis direction and arrange the reflected light beams into a two-dimensional array in a xy plane, in which a density of the reflected light beams in the x-axis direction is higher than a density of an arrangement of the solid-state light sources in the z-axis direction, the first polarization component enters the fluorescence emission plate and fluorescence emitted is reflected toward the dichroic mirror, and green and red color lights from the fluorescence emission plate and blue color light from the reflection plate are combined by the dichroic mirror and exit as white light.