US Patent 7258447 Image projection apparatus

An image projecting apparatus including a base, a ballast unit disposed on a top of the base, a display device disposed adjacent to the ballast unit, a cooling fan disposed on the base and introducing external air to the ballast unit, and a guide duct in communication with the ballast unit, guiding the external air blown by the cooling fan to the display device. Thus cooling down of heat generating units such as a lamp unit, a ballast unit, a colorwheel unit, etc., with a minimized number of fans is provided while reducing noise generated therefrom and increasing cooling efficiency.