Patent ID: 7880965

Claim:
A projection-type image display device comprising: an optical engine that emits light in response to an image signal; a screen that includes a Fresnel lens that converts the light incident thereon from the optical engine to substantially collimated light, and a diffusing member that converts the collimated light incident thereon from the Fresnel lens to a diffuse light; a screen driving unit that displaces any of the Fresnel lens and the diffusing member, serving as a driven member, in a plane parallel to the screen; and a housing that accommodates the optical engine, the screen, and the screen driving unit, wherein the screen driving unit includes an elastic retaining unit that is supported on the housing and that holds the driven member so as to be capable of displacing in the plane parallel to the screen; a pair of driving sources that apply driving forces to the elastic retaining unit in mutually intersecting directions each at an angle substantially greater than 0 degrees and substantially less than 90 degrees with respect to the horizontal axis of the plane parallel to the screen; and a control circuit that drives the pair of driving sources with driving waveforms having a prescribed phase difference therebetween, wherein, when projecting an image on the screen, the driving forces are applied to the elastic retaining unit from the pair of driving sources to cause the driven member to make continuous motion in the plane parallel to the screen.