| 摘要 |
PURPOSE:To prevent the occurrence of turbulent flow of cooling air, to improve cooling efficiency and to miniaturize a device by arranging condenser lenses at the light emitting port of a color separation part having a wave-length selective reflection surface which separates light from a light source into at least two, and closing the light emitting port. CONSTITUTION:The light from the light source 1 is separated by the color separating part. The blue light is reflected by a mirror 6 via a dichroic mirror 2, the green light is reflected by a dichroic mirror 3 and the red light is reflected by mirrors 4 and 5. After that, each light is made incident on a dichroic prism 13 via liquid crystal valves 7 - 9. The blue, green and red lights made incident on the dichroic prism 13 are composed, and condensed to the incident pupil location of a projective lens 14. Each light emitting port 30 of the color separation part is closed by the condensing lenses 12a, 12b and 12c. Therefore, the cooling air flows smoothly on the surfaces of the liquid crystal valves 7, 8 and 9, the turbulent flow does not occur, and the cooling efficiency is improved. |
