Overhead projector with high illuminance lamp as light source

An overhead projector comprising:

• a housing including a stage which is formed on a top wall thereof and on which a transparency bearing an image to be projected is placed and an air outlet formed in one of two side walls thereof;
• an exhaust fan provided in the housing for exhausting air in the housing through the air outlet out of the housing;
• a projection light source provided in the housing for illuminating the transparency on the stage from inside the housing;
• a projection head provided for projecting a magnified image from the transparency on a screen and including a focusing lens and a reflecting mirror;
• a column mounted on the housing to hold the projection head over the stage;
• a Fresnel lens disposed inside the stage to converge light from the light source on the focusing lens of the projection head;
• a cooling fan;
• and
• air guide means for guiding air delivered from the cooling fan so that the air flows along a surface of the stage and wherein:
• the cooling fan is disposed in the housing a vent hole and an air inlet each communicating with the inside and the outside of the housing are formed in the other side wall of the housing, the air guide means includes an outer guide member mounted outside the vent hole and an inner guide member provided in the housing, and an external air is drawn into the housing through the air inlet by the cooling fan so that the drawn air is guided by the inner guide member through the vent hole to the outer guide member and is further guided by the outer guide member to flow along the surface of the stage.