Projection device and projection-type video display device

A projection device displaying video corresponding to each screen on a plurality of the screens, comprising:

• an optical element comprising a hologram recording medium capable of diffusing a coherent light beam, the hologram recording medium comprising a plurality of regions, each region diffusing a coherent light beam to an illuminated region corresponding to the region;
• an irradiation device configured to irradiate the optical element with the coherent light beam so as to allow the coherent light beam to scan the hologram recording medium;
• spatial light modulators, each spatial light modulator disposed to a position which overlaps each illuminated region;
• and
• projection optical systems, each projection optical system projecting a modulation image obtained on each spatial light modulator on corresponding screen,
• wherein each coherent light beam incident to a position existing in each region of the hologram recording medium is diffused to an entire region of the illumated region corresponding to the region in order to illuminate the spatial light modulator corresponding to the illuminated region.

A projection device displaying video corresponding to each screen on a plurality of the screens, comprising:

• an optical element comprising a plurality of light diffusion elements, each light diffusion element capable of changing a propagation direction of an incident light beam, each light diffusion element diffusing a coherent light beam to an illuminated region corresponding to the light diffusion element;
• an irradiation device configured to irradiate the optical element with the coherent light beam so as to allow the coherent light beam to scan each light diffusion element;
• spatial light modulators, each spatial light modulator disposed to a position which overlaps each illuminated region, and
• projection optical systems, each projection optical system projecting modulation image obtained on each spatial light modulator on corresponding screen,
• wherein each coherent light beam incident to a position of the light diffusion element is diffused to an entire region of the illuminated region corresponding to the light diffusion element in order to illuminate the spatial light modulator corresponding to the illuminated region.