For providing a rear-projection type display apparatus, and a translucent type sheet for use therein, in particular, using an image modulation element, such as, a liquid crystal or a DMD (Digital Micro-mirror Device), etc., dissolving the speckle disturbances, thereby obtaining a picture being high in brightness and superior in resolution (focus property) thereof, wherein the translucent type screen comprises, a Fresnel sheet (6), at least on a light exit surface of which is formed a Fresnel lens (8), and a lenticular sheet (7), at least on a light incident surface of which is formed a lenticular lens (10) for diverging the light in horizontal direction, and the Fresnel sheet contains light diffusion material (9-1) while the lenticular sheet contains diffusion material (9-2), and being constructed so as to satisfy the condition as described below:
A light diffusing laminated plate including a first light diffusing layer containing particles of a transparent light diffusing material dispersed therein and having a concave cross-section, and a second light diffusing layer containing particles of an opaque light diffusing material dispersed therein and having a convex cross-section. The first and second light diffusing layers are laminated together such that the convex and concave surfaces are face to face contact with each other to form a curved interface therebetween. The first and second light diffusing layers have a substantially uniform cross-section in one direction. A transmissive screen for a rear projection display device having a light image source, including the above light diffusing laminated plate and a lens system disposed such that a light image from the source is projected through the light diffusing laminated plate and the lens system and displayed on the screen.
Color lights from image projecting sections (207) that enlarge and project images of red, green and blue, respectively, are made incident on a transparent screen at different angles of incidence, so that image synthesis is carried out. The color lights projected are converted into telecentric light by a Fresnel lens (211), and after principal rays of the respective color lights are converted into substantially parallel rays by a color shading eliminating means (219) provided with lenticular lenses on both sides thereof, the rays are incident on a light diffusing means (224). The light diffusing means (224) is formed with a transparent substrate sheet and a plurality of transparent micro beads made to adhere onto a light-incident surface of the substrate sheet with an opaque adhesive. Image light passes through light transmitting portions between the substrate sheet and the micro beads to be diffused. This configuration enables to provide a rear-projection image display whose display images are hardly affected by external light, which has an increased angle of visibility, and which undergoes less color shading, without a decrease in light utilization efficiency.
A light transmitting filter including a light absorbing layer and a transparent layer having a microstructured front surface and a microstructured back surface, wherein the front surface is embedded in the light absorbing layer. The microstructures of the front surface provide a path for light transmittance through the light absorbing layer and the microstructures of the back surface focus the transmitted light thorough the path. The light filter can include an optically clear conformable coating covering the microstructured back surface of the transparent layer.