US Patent 11378873 Projection display device

A projection display device of a front projection type includes a light valve that modulates light based on image data and emits the light and an image forming optical system that projects an optical image of the light modulated by the light valve onto a projection surface, in which the image forming optical system includes a first optical system that includes at least one lens and a first reflection member that reflects the light emitted from the light valve toward the first optical system, the first optical system and the first reflection member are configured to be rotatable in a pitch direction, and the first reflection member rotates by a pitch angle θ/2 in conjunction with rotation of the first optical system by a pitch angle θ.