Patent ID: 7896500

Claim:
A projection type image display device, comprising: a lamp unit; a cooling fan for cooling the lamp unit; an optical system for generating color image light with the lamp unit providing a light source; and a projection lens for projecting the generated color image light toward a screen, the lamp unit comprising a light emitting tube having a spherical portion providing a light emitting portion; and a reflector for reflecting light emitted from the light emitting tube toward the optical system, the reflector having an air introduction hole formed only in the reflector for introducing air discharged from the cooling fan into the reflector, the air introduction hole being formed in a portion of the reflector near the spherical portion of the light emitting tube, and facing a vertical top of the spherical portion to blow the air on the top, wherein a center of the spherical portion of the light emitting tube forms an origin of an XYZ coordinate system having a Y-axis extending vertically, an X-axis extending in a light emission direction of the lamp unit and perpendicular to the Y-axis, and a Z-axis extending perpendicularly to both the X-axis and the Y-axis, and the air introduction hole of the reflector is provided in an area where a value of an X-coordinate in a direction opposite to the light emitting direction from the origin is not more than one-half the focal length of the reflector, a value of an X-coordinate in a light emission direction from the origin is not more than the focal length of the reflector, and an absolute value of a Y-coordinate is not more than an outside diameter of the spherical portion of the light emitting tube of the lamp unit.