Projection-type image display device

A projector-type image display device comprising:

• a plurality of liquid crystal display devices which each form images;
• an illumination optical system for dividing light from a light source into a plurality of different color lights, and illuminating each of said liquid crystal display devices with a matching color light;
• a color synthesizing optical system for synthesizing the images from each of the color lights from said plurality of liquid crystal display devices, said color synthesizing optical system comprising:
• an odd-number reflection optical path wherein an image of a color light from one liquid crystal display device of said plurality of liquid crystal display devices reflects an odd number of times on an optical path leading from said one liquid crystal display device to a projection optical system;
• and
• an even-number reflection optical path wherein an image of a color light from another liquid crystal display device of said plurality of liquid crystal display devices is non-reflective or reflects an even number of times on an optical path leading from said another liquid crystal display device to a projection optical system;
• and
• the projection optical system for projecting an image synthesized by said color synthesizing optical system,
• wherein at least one optical system of said illumination optical system and said projection optical system has different f-numbers at a plurality of directions from said at least one optical system, according to contrast properties of each direction of said liquid crystal display device and said reflection optical paths of said color synthesizing optical system.

A projector-type image display device comprising:

• a plurality of liquid crystal display devices which each form images;
• an illumination optical system for dividing light from a light source into a plurality of different color lights, and illuminating each of said liquid crystal display devices with a matching color light;
• a color synthesizing optical system for synthesizing the images from each of the color lights from said plurality of liquid crystal display devices, said color synthesizing optical system comprising
• an odd-number reflection optical path wherein an image of a color light from one liquid crystal display device of said plurality of liquid crystal display devices reflects an odd number of times on an optical path leading from said one liquid crystal display device to a projection optical system, and
• an even-number reflection optical path wherein an image of a color light from another liquid crystal display device of said plurality of liquid crystal display devices is non-reflective or reflects an even number of times on an optical path leading from said another liquid crystal display device to a projection optical system;
• a projection optical system for projecting an image synthesized by said color synthesizing optical system;
• and
• a diaphragm member disposed on at least one optical system of said illumination optical system and said projection optical system,
• wherein an aperture is formed in said diaphragm member;
• wherein said aperture has a shape such that the f-numbers at a plurality of directions from said at least one optical system are different f-numbers, according to contrast properties of each direction of said liquid crystal display device and said reflection optical path of said color synthesizing optical system.

A projector-type image display device comprising:

• a liquid crystal display device for forming an image;
• an illumination optical system for guiding light from a light source to said liquid crystal display device;
• a projection optical system for projecting an image formed by said liquid crystal display device;
• and
• a diaphragm member disposed on at least one of said illumination optical system and said projection optical system,
• wherein an aperture is formed in said diaphragm member,
• and wherein the width of said aperture differs for each direction said aperture faces.

A projector-type image display device comprising:

• a plurality of liquid crystal display devices which each form images;
• an illumination optical system for dividing light from a light source into a plurality of different color lights, and illuminating each of said liquid crystal display devices with a matching color light;
• a color synthesizing optical system for synthesizing the images from each of the color lights from said plurality of liquid crystal display devices, said color synthesizing optical system comprising
• an odd-number reflection optical path wherein an image of a color light from one liquid crystal display device of said plurality of liquid crystal display devices reflects an odd number of times on an optical path leading from said one liquid crystal display device to a projection optical system, and
• an even-number reflection optical path wherein an image of a color light from another liquid crystal display device of said plurality of liquid crystal display devices is non-reflective or reflects an even number of times on an optical path leading from said another liquid crystal display device to a projection optical system;
• a projection optical system for projecting an image synthesized by said color synthesizing optical system;
• and
• a diaphragm member disposed on at least one optical system of said illumination optical system and said projection optical system,
• wherein an aperture is formed in said diaphragm member and the width of said aperture differs for each direction said aperture faces.