Rear projection apparatus

A rear projection apparatus for displaying a color image comprising:

• red, green and blue color image sources located horizontally to each other in this order for producing respective color images of different colors;
• projection lenses located respectively in front of said image sources for projecting light fluxes from said respective image sources along converging optical paths;
• and
• a screen located at convergent points of said projected light fluxes and including a light-transmitting lenticular sheet having an input surface and an exit surface for the projected light fluxes;
• said input surface of the lenticular sheet being constituted by diffusing lenticular profiles having a ratio of lenticulated depth X.sub.v to close-axis-curvature radius R.sub.1 (X.sub.v /R.sub.1) which is within a range of 0.5 to 1.8, said profiles being prolonged along the optical axis and constituting aspherical input lenticular lenses,
• said lenticular sheet having a thickness of approximately ##EQU19## times said radius R.sub.1 where n is refractive index of a material of said sheet,
• said aspherical input lenticular lenses refracting projected input light flux of the red color and the blue color having a path extending at an angle to the normal of said screen in such a way as to provide coma aberration at said exit surface of the lenticular sheet,
• said exit surface of the lenticular sheet having output lenticular lenses extending in the same direction as said input lenticular lenses and having light-stopping black stripes incorporated thereon and extending in parallel with said input lenticular lenses,
• said output lenticular lenses refracting light flux of the red color and the blue color in accordance with said coma aberration formed thereon, said coma aberration and said output lenticular lenses being such that center light fluxes of said red color and said blue color projected at center portions of said input lenticular lenses arrive at portions of said output lenticular lenses which are more tilted and closer-to-valley portions of said output lenticular lenses other than portions of said output lenticular lenses and such that side light fluxes of said red color and said blue color projected close to valley portions of said input lenticular lenses arrive at portions of said output lenticular lenses which are less tilted and closer-to-center portions of said output lenticular lenses,
• said black stripes being located at an area where substantially no efficient light flux exits.

A rear projection apparatus for displaying a color image comprising:

• first, second and third color image sources disposed horizontally with respect to each other for producing respective color images of different colors;
• projection lenses located respectively in front of said image sources for projecting light fluxes from said image sources for projecting light fluxes from said respective image sources;
• and
• a screen for receiving the projected light fluxes, said screen being located at convergent points of said projected light fluxes and including a light-transmitting lenticular sheet having an input surface and an exit surface for the projected light fluxes;
• said input surface of said lenticular sheet being constituted by horizontally diffusing lenticular profiles having a ratio of lenticulated depth X.sub.v to close-axis curvature radius R.sub.1 (X.sub.v /R.sub.1) which is within a range of 0.5 to 1.8, said profiles being prolonged along the optical axis and constituting aspherical input lenticular lenses,
• said lenticular sheet having a thickness of approximately ##EQU20## times the radius R.sub.1 where n is a refractive index of a material of said sheet,
• said aspherical input lenticular lenses refracting projected input light fluxes of said first and third colors having a path extending at an angle to the normal of said screen so as to provide coma aberration at said exit surface of said lenticular sheet, said aspherical input lenticular profiles being ellipsoids having an eccentricity substantially equal to 1/n,
• said exit surface of said lenticular sheet having output lenticular lenses extending in the same direction as said input lenticular lenses and having light-stopping black stripes incorporated thereon and extending in parallel with said input lenticular lenses,
• said output lenticular lenses refracting light fluxes of said first and third colors in accordance with said coma aberration formed thereon, said coma aberration and said output lenticular lenses being such that center light fluxes of said first color and said third color projected at center portions of said input lenticular lenses arrive at portions of said output lenticular lenses which are more tilted and closer-to-valley portions of said output lenticular lenses than other portions of said output lenticular lenses and such that side light fluxes of said first color and said third color projected close-to-valley portions of said input lenticular lenses arrive at portions of said output lenticular lenses which are less tilted and closer-to-center portions of said output lenticular lenses,
• said black stripes being located at an area where substantially no efficient light flux exits.