Rear projection screens use lenticular lens films as light dispersing components. A single lenticular lens film includes lenticular lenses having different focal powers, or includes lenticular lenses formed in two dimensional patterns. The lenticular lens films improve the brightness uniformity over the entire screen as viewed by a viewer who is located at a specific position. The specific position is typically selected to be the most probable location of the viewer for the particular application.
A transmission screen includes a Fresnel lens sheet through which light is projected from a projector to a lenticular lens sheet arranged on a viewer side, as approximately parallel light, and the lenticular lens sheet receiving light passing through the Fresnel lens sheet, and emitting the approximately parallel light while horizontally widening, by a group of cylindrical lenses which are horizontally in parallel, wherein in at least one of the Fresnel lens sheet and the lenticular lens sheet, on a surface of a light diffusing substrate, in which a light diffusing material is dispersed, irregularities which constitute a lens section is formed, and in the light diffusing substrate, dispersion density of the light diffusing material differs in at least two layers in the thickness direction.
The present invention provides a technique suitable for making a set more compact by realizing reduction in height and reduction in depth. An image display apparatus of the present invention includes a reflecting mirror (4) for reflecting the image sent from a projection lens (2), and guiding the image to a transmissive screen (3). The reflecting-mirror (4) includes a planar mirror section (4a) for reflecting, of the entire image exiting the projection lens (2), only image portions projected onto the upper section of the transmissive screen (3), and a Fresnel mirror section (4b) with multiple reflective prisms for reflecting only image portions projected onto the lower section of the screen (3).
A transmission screen includes a Fresnel lens sheet through which light is projected from a projector to a lenticular lens sheet arranged on a viewer side, as approximately parallel light, and the lenticular lens sheet receiving light passing through the Fresnel lens sheet, and emitting the approximately parallel light while horizontally widening, by means of a group of cylindrical lenses which are horizontally in parallel, wherein in at least one of the Fresnel lens sheet and the lenticular lens sheet, on a surface of a light diffusing substrate, in which a light diffusing material is dispersed, irregularities which constitute a lens section is formed, and in the light diffusing substrate, dispersion density of the light diffusing material differs in at least two layers in the thickness direction.
