Patent ID: 7816637

Claim:
An image display projector, comprising: an optical engine for emitting light according to an inputted imaging signal; a Fresnel lens disposed to receive the light emitted from said optical engine, for emitting the incident light as collimated light; a diffusion member, placed in a position frontal to said Fresnel lens in the light-traveling direction, for emitting diffused light, by diffusing the collimated light emitted from said Fresnel lens; and a drive unit for moving either said Fresnel lens or said diffusion member, repeatedly along a predetermined track, in a parallel plane, the parallel plane being a plane parallel to either the plane from which the collimated light is emitted or the plane from which the diffused light is emitted, wherein: the moving velocity of either said Fresnel lens or said diffusion member is continuously larger than zero within said parallel plane during the movement of either said Fresnel lens or said diffusion member along said predetermined track, the drive unit further comprises: a motor; a first cam for rotating around a first shaft based on the driving force of said motor; a rotating member for rotating, according to the rotation of said first cam, around a second shaft disposed parallel to the first shaft; and a transmitting member, having a first hole for receiving said first cam and a second hole for receiving said rotating member, provided along the perimeter of either the Fresnel lens or the diffusion member, the first hole and the second hole are disposed in said parallel plane spaced apart by a predetermined distance from each other, and the transmitting member moves based on the driving force of said motor, transferred via said first cam, so that either said Fresnel lens or said diffusion member moves in the predetermined track.