Magnifying Roller Blind for Display Terminal
Original Publication Date: 1982-Jul-01
Included in the Prior Art Database: 2005-Feb-09
Fresnel lenses made from embossed plastic sheet are well known. Such a Fresnel lens can be made into the form of a roller blind which is mounted above and in front of a display terminal. To magnify the displayed characters, the operator can pull the blind down in front of the screen, as required. If the embossed surface is on the outside, as viewing the screen, the embossing tends to diffract light from extraneous light sources and can, under certain ambient conditions, improve the contrast ratio.