Abstract: A projection-type video display apparatus includes: light sources, an illumination optical system, a display element, and a projection optical system. The illumination optical system includes: a mirror that reflects the illumination light toward the display element; a lens that is placed between the mirror and the display element on an optical path of the illumination light; a mirror angle adjustment mechanism that adjusts an angle of the mirror; a light-shielding plate that blocks unwanted light which is a portion of the illumination light reflected off the mirror toward the display element via the lens; and a light-shielding plate movable mechanism that is able to move the light-shielding plate between a first position to block the unwanted light and a second position to permit the unwanted light to illuminate the display element.

Abstract: A lens shift mechanism 32 of the projection-type image display device 10 includes a horizontal movable base 60 for horizontally shifting a projection lens 31, a vertical movable base 70 for vertically shifting the projection lens 31, and a horizontal drive actuator 61 and a vertical drive actuator 71 for driving these bases 60, 70. Driving forces of these actuators 61, 71 are transmitted via respective lead screws 671 (751) and a pair of lead nuts 672, 672b (752, 752b) meshing with the lead screws to shift the bases 60, 70. A pair of lead nuts are installed with elastic bodies 672c (752c) applying a pressure such that the pair of lead nuts recede from or approach each other in the axial direction of the lead screw. In this configuration, a delay in the shift operation is removed by reducing a backlash in the lens movement.

Abstract: A projection-type video display apparatus includes: light sources, an illumination optical system, a display element, and a projection optical system. The illumination optical system includes: a mirror that reflects the illumination light toward the display element; a lens that is placed between the mirror and the display element on an optical path of the illumination light; a mirror angle adjustment mechanism that adjusts an angle of the mirror; a light-shielding plate that blocks unwanted light which is a portion of the illumination light reflected off the mirror toward the display element via the lens; and a light-shielding plate movable mechanism that is able to move the light-shielding plate between a first position to block the unwanted light and a second position to permit the unwanted light to illuminate the display element.

Abstract: A lens shift mechanism 32 of the projection-type image display device 10 includes a horizontal movable base 60 for horizontally shifting a projection lens 31, a vertical movable base 70 for vertically shifting the projection lens 31, and a horizontal drive actuator 61 and a vertical drive actuator 71 for driving these bases 60, 70. Driving forces of these actuators 61, 71 are transmitted via respective lead screws 671 (751) and a pair of lead nuts 672, 672b (752, 752b) meshing with the lead screws to shift the bases 60, 70. A pair of lead nuts are installed with elastic bodies 672c (752c) applying a pressure such that the pair of lead nuts recede from or approach each other in the axial direction of the lead screw. In this configuration, a delay in the shift operation is removed by reducing a backlash in the lens movement.