Space light modulating apparatus, projector including same, process for manufacturing microstructure element used in same, and microstructure element manufactured by the same process

A projector comprising:

• a light source that supplies a first-color light, a second-color light, and a third-color light;
• a first-color space light modulating apparatus that modulates the first-color light based on an image signal;
• a second-color space light modulating apparatus that modulates the second-color light based on the image signal;
• a third-color space light modulating apparatus that modulates the third-color light based on the image signal;
• a color-synthesizing optical system that synthesizes the first-color light, the second-color light, and the third-color light, modulated by the first-color space light modulating apparatus, the second-color space light modulating apparatus, and the third-color space light modulating apparatus, respectively;
• and
• a projection lens that projects light synthesized by the color-synthesizing optical system, wherein
• each of the first-color space light modulating apparatus and the second-color space light modulating apparatus includes
• a modulating unit that modulates incident light based on an image signal, and outputs modulated light;
• and
• a refracting unit that is disposed on an output-side of the modulating unit, and refracts the light from the modulating unit, wherein
• the modulating unit includes
• a plurality of pixels arranged in a matrix format;
• and
• a light-shielding part placed between the pixels,
• the refracting unit includes a group of prisms formed with a prism element that has at least a refracting surface, and further includes a flat portion virtually parallel to a surface on which the pixels are formed,
• light from one of the pixels is incident on at least a part of the group of prisms,
• a direction of the refracting surface is such that a projection image of the pixels is guided onto a projection image of the light-shielding part on a projection surface at a predetermined distance from the refracting unit, and
• the refracting surface and a reference surface that is formed in a direction perpendicular to an optical axis make a predetermined angle, wherein
• the light transmitted through or reflected on the flat portion from among the light projected from the light source and incident on the pixels propagates substantially straight to form the projection image,
• when an area of one prism element of the group of prisms is defined as a unit area, a ratio between an area of the refracting surface and the unit area corresponds to light intensity of the projection image of the pixels, and
• a sum of intensities of light from the flat portion on the projection surface PW0 and a sum of intensities of light through the refracting surface on the projection surface PW1 satisfy an inequality PW0≧PW1.