Patent ID: 7798653

Claim:
A projection display comprising: a light source for emitting a light; an integrator for homogenizing the light from the light source; a light valve for modulating the light from the integrator; a projection lens for projecting the light modulated by the light valve; and an optical aperture unit arranged between the light source and the integrator, wherein the optical aperture unit comprises: a first light intercepting plate and a second light intercepting plate, openable and closable, for partially intercepting the light from the light source, a motor for driving the first light intercepting plate and the second light intercepting plate, a pinion gear to be coupled with a motor axis of the motor, a first base to be coupled with the first light intercepting plate, and having a first gear abutting on a first side surface of a channel of the pinion gear a second gear abutting on a second side surface of a channel of the pinion gear and a third gear installed at a side surface different from said first and second gears, a second base to be coupled with the second light intercepting plate, and having a fourth gear meshing with the third gear, and a spring for biasing the first gear and the second gear each in a direction for abutting each of the first and second ears on the pinion gear, wherein the integrator is formed by a first and a second array lenses, the optical aperture unit is arranged between the first array lens and the second array lens, the first and second gears are superimposed, and the spring is a torsion coil spring, and one end thereof is coupled with the first gear and the other end thereof is coupled with the second gear.