Patent ID: 7198374

Claim:
A prism structure, comprising: an integration of a plurality of modulators that modulate color light from a light source and a color combining prism that combines the light modulated by the plurality of modulators; a light shielding device having an opening in a center that is arranged between the modulators and the color combining prism; the light shielding device allowing image light to pass through the opening and blocking light from a periphery of the image light; a plate optical element being provided between the modulators and the color combining prism; the light shielding device being arranged between the plate optical element and the color combining prism; and the relationship d 1 <d 3 ≦d 2 holding, where the direction of d 1 , d 2 , and d 3 are in the same axial direction, where d 1 is a length in at least one of two axial directions perpendicular to a direction of light travel of an image formation area of the modulators, d 2 is a length in at least one of directions of an outer shape of the plate optical element, and d 3 is a length in at least one of directions of the opening of the light shielding device.