Video projection apparatus

Claim 1

An apparatus, receiving a polarized light, for providing a color image on a projection lens, comprising: (a) first, second and third display device for modulating incident light in response to a video signal to display respective component images; (b) a first dichroic layer for separating the polarized light into a first light component and a first mixed light of different wavelength regions from each other and for providing said first light component to said first display device; (c) a second dichroic layer for separating said first mixed light into second and third light components of different wavelength regions from each other, and for providing said second and said third light components to said second and third display devices, respectively; (d) a third dichroic layer for synthesizing first and second information lights from said first and second display devices; and (e) a fourth dichroic layer for further synthesizing the light synthesized by said third dichroic layer with a third information light from said third display device; and wherein said first, second, third, and fourth dichroic layers extend parallel to each other, and wherein said first dichroic layer separates the polarized light after it passes through an optical element for rotating a plane of polarization of the polarizing light by 90° and generates a first polarizing beam which does not pass through the optical element and a second polarized beam which passes through the optical element and has a same plane of polarization as the first polarized beam.

Claim 2

An apparatus, receiving a polarized light, for providing a color image on a projection lens, comprising: (a) first, second and third display device for modulating incident light in response to a video signal to display respective component images; (b) a first dichroic layer for separating the polarized light into a first light component and a first mixed light of different wavelength regions from each other and for providing said first light component to said first display device; (c) a second dichroic layer for separating said first mixed light into second and third light components of different wavelength regions from each other, and for providing said second and said third light components to said second and third display devices, respectively; (d) a third dichroic layer for synthesizing first and second information lights from said first and second display devices; and (e) a fourth dichroic layer for further synthesizing the light synthesized by said third dichroic layer with a third information light from said third display device; and wherein said first, second, third, and fourth dichroic layers extend parallel to each other, and wherein said first dichroic layer separates the polarized light after it passes through an optical element for rotating a plane of polarization of the polarizing light by 90° and generates a first polarizing beam which does not pass through the optical element and a second polarized beam which passes through the optical element and has a same plane of polarization as the first polarized beam.

Claim 12

An apparatus for providing a color image on a projection lens, comprising: (a) an illumination device for generating illumination light which passes through a polarizing beam splitter to provide a polarized beam, said beam splitter having an optical element for rotating a plane of polarization of the polarizing beam by 90° and generating a first polarizing beam which does not pass through said optical element and a second polarizing beam which passes through said optical element and has a same plane of polarization as said first polarizing beam; (b three display devices for modulating said illumination light incident thereon in response to a video signal to display respective component images, wherein said display devices are liquid crystal displays each having no polarizer; (c) component light forming means, comprising dichroic layers, for receiving said illumination light, wherein said dichroic layers are of different wavelength separation characteristics for successively separating said illumination light into red, blue and green components, and for providing said red, blue, and green components to said three display devices respectively, wherein said dichroic layers extend parallel to each other; and (d) information light synthesizing means for conducting information lights of red, blue and green from aid display devices successively to dichroic layers of different wavelength separation characteristics to synthesize said red, blue, and green information lights.

Claim 13

An apparatus for providing a color image on a projection lens, comprising: (a) an illumination device for generating illumination light which passes through a polarizing beam splitter to provide a polarized beam, said beam splitter having an optical element for rotating a plane of polarization of the polarizing beam by 90° and generating a first polarizing beam which does not pass through said optical element and a second polarizing beam which passes through said optical element and has a same plane of polarization as said first polarizing beam; (b three display devices for modulating said illumination light incident thereon in response to a video signal to display respective component images, wherein said display devices are liquid crystal displays each having no polarizer; (c) component light forming means, comprising dichroic layers, for receiving said illumination light, wherein said dichroic layers are of different wavelength separation characteristics for successively separating said illumination light into red, blue and green components, and for providing said red, blue, and green components to said three display devices respectively, wherein said dichroic layers extend parallel to each other; and (d) information light synthesizing means for conducting information lights of red, blue and green from aid display devices successively to dichroic layers of different wavelength separation characteristics to synthesize said red, blue, and green information lights.