Projection image display device

A projection-type image display device comprising:

• a light source configured to radiate white light;
• a rod lens with a square cross section configured to receive the white light from the light source enter, and to output light with uniformly dispersed illuminance;
• an optical modulation element arranged near an outgoing surface of the rod lens, and configured to modulate the light output from the rod lens as incoming light according to an image signal to form a display image;
• and
• a projecting lens configured to enlarge and project the display image modulated in the optical modulation element, wherein
• the rod lens includes
• only a pair of rods formed divided along an optical axis to divide the rod lens into equal two parts with long sides of the square cross section of the rod lens, and having a thin film formed on a part of a periphery of mutually facing surfaces, and
• a cover unit that covers an external periphery of the pair of rods, holds the pair of rods to face each other, slightly separated with the thin film formed on the mutually facing surfaces, and forms openings in an incoming side and an outgoing side of the rod lens,
• wherein the cover unit includes an external wall that covers the external periphery of the pair of rods, and a plurality of holding frame parts protruding from an inner surface of the external wall in a frame manner, and abutting on the external periphery of the pair of rods, and an opening in the incoming side of the cover unit is formed in a square manner such that the thin film formed on the facing surface of the pair of rods is positioned outside the opening when the rod lens is viewed from a side of the opening.