JP2001142141A5 - - Google Patents

Claims (10)

Three reflective image forming members that form an image to be projected by modulating the polarization state for each color region of the red region, the green region, and the blue region;
A light source that emits light for illuminating these image forming members;
A projection lens system for projecting an image formed by the image forming member on a screen;
P-polarized light or S-polarized light out of the light from the light source on an incident / exit optical path where an incident optical path from the light source toward the image forming member and an outgoing optical path from the image forming member toward the projection lens system overlap. A polarization beam splitter that reflects one of the polarization components and transmits the other polarization component in a direction different by approximately 90 °;
A red dichroic film that separates a long wavelength region of red light and a shorter wavelength region than green light on an optical path between the polarizing beam splitter and the three image forming members, and a short wavelength region of blue light And a blue dichroic film that separates a longer wavelength region than the green light, and the light of one polarization component separated by the polarization beam splitter from the light source is converted into a red region and a green region. A function of separating the light into a blue region and guiding it to the corresponding image forming member, and color-combining the light of each of the regions that are separated and whose polarization state is modulated again by the image forming member and passing through the polarization beam splitter. The red dichroic film has a maximum reflectance of either one of the S-polarized light and the P-polarized light component of the red light. of 80% or more of the maximum reflectance of the light component, and in the blue dichroic film, the maximum reflectance of either the S-polarized light component or the P-polarized light component of blue light is 80% of the maximum reflectance of the other polarization component. The above dichroic prism,
A projector comprising: Three reflective image forming members that form an image to be projected by modulating the polarization state for each color region of the red region, the green region, and the blue region;
A light source that emits light for illuminating these image forming members;
A projection lens system for projecting an image formed by the image forming member on a screen;
P-polarized light or S-polarized light out of the light from the light source on an incident / exit optical path where an incident optical path from the light source toward the image forming member and an outgoing optical path from the image forming member toward the projection lens system overlap. A polarization beam splitter that reflects one of the polarization components and transmits the other polarization component in a direction different by approximately 90 °;
A red dichroic film that separates a long wavelength region of red light and a shorter wavelength region than green light on an optical path between the polarizing beam splitter and the three image forming members, and a short wavelength region of blue light And a blue dichroic film that separates a longer wavelength region than the green light, and the light of one polarization component separated by the polarization beam splitter from the light source is converted into a red region and a green region. A function of separating the light into a blue region and guiding it to the corresponding image forming member, and color-combining the light of each of the regions that are separated and whose polarization state is modulated again by the image forming member and passing through the polarization beam splitter. In this case, the red dichroic film has a P-polarized light reflectance of 50% in the wavelength region of 550 nm ≦ λ ≦ 700 nm. That the wavelength lambda _50P, when the reflectance of S-polarized light is a wavelength at which 50% and _{λ 50S, 10nm ≦ | λ 50P} -λ 50S | a ≦ 50 nm, and, 400nm ≦ λ ≦ in the blue dichroic film When the wavelength at which the reflectance of P-polarized light is 50% in the wavelength region of 550 nm is λ _50P and the wavelength at which the reflectance of S-polarized light is 50% is λ _50S , 10 nm ≦ | λ _50P −λ _50S | ≦ 50 nm A dichroic prism,
A projector comprising: In the dichroic prism, the red dichroic film and the blue dichroic film are arranged orthogonally, and the incident surface of the polarizing beam splitter and the incident surface of these dichroic films are arranged substantially orthogonally. The projector according to claim 1 or 2, wherein In the dichroic prism, the red dichroic film and the blue dichroic film are arranged orthogonally, and incident light is provided with a substantially uniform shift angle with respect to the red dichroic film and the blue dichroic film. The projector according to claim 1, wherein the projector is disposed so as to be incident. In the dichroic prism, the red dichroic film and the blue dichroic film are arranged orthogonally, and an incident angle of 45 ° with respect to any one of the red dichroic film and the blue dichroic film. An incident light having a predetermined incident angle of less than or equal to an incident angle of 45 ° or more is incident on the other film. The projector according to 1 or 2. 6. The projector according to claim 1, further comprising an illumination system having at least a pair of fly-eye lens plates on an incident optical path from the light source to the polarization beam splitter. A first eye arranged in the vicinity of a light condensing position of the fly-eye lens plate by arranging at least one fly-eye lens plate and a plurality of cylindrical lenses on an incident optical path from the light source to the polarizing beam splitter. And an illuminating system including a second lenticular disposed at a stage subsequent to the first lenticular and having a plurality of cylindrical lenses arranged in a direction orthogonal to the arrangement direction of the cylindrical lenses. The projector according to any one of claims 1 to 5. 8. The projector according to claim 7, further comprising a polarization alignment function element that aligns a random light beam with only one polarization component on an optical path between the first lenticular and the second lenticular. At least one fly-eye lens plate and a plurality of cylindrical lenses arranged, a first lenticular arranged near the light condensing position of the fly-eye lens plate, and arranged after the first lenticular And a second lenticular in which a plurality of cylindrical lenses are arranged in a direction orthogonal to the arrangement direction of the cylindrical lenses. 10. The illumination system according to claim 9, further comprising: a polarization alignment functional element that aligns a random light beam with only one polarization component on an optical path between the first lenticular and the second lenticular.