Patent ID: 7993018

Claim:
A projection optical system, comprising: a light source for emitting a light beam; a light homogenizer disposed on a propagation path of the light beam for homogenizing the light beam to form a homogenized beam; a light amount adjusting component disposed on the propagation path of the light beam and between the light source and the light homogenizer, the light amount adjusting component having a light incident surface upon which the light beam impinges, the light incident surface being provided with a surface structure for irregularly dispersing the light beam, wherein a slot is formed on the light amount adjusting component and a width of the slot changes along an extension direction of the slot to allow control of the amount of the light beam entering the light homogenizer when the light amount adjusting component moves or rotates; an imaging device disposed on a propagation path of the homogenized beam for modulating the homogenized beam to form an image beam; and a projection lens for receiving and then projecting the image beam.