Transmission type projection screen

Abstract

Abstract PURPOSE:To reduce the thickness of a device and to guide projection light effectively in an observation direction, by arranging the light-transmissive surface having a saw-tooth wave in cross section whose slanting surfaces and vertical surfaces are formed at nearly equal angles and pitch repeatedly, at least on an incident light source side. CONSTITUTION:Vertical surfaces 7 perpendicular to the flat rear surface of a screen 4' and slanting surfaces 8 having a specific angle are arranged alternately at nearly equal pitch to form the saw-tooth wave section. Light beams 9, 10, and 11 incident to the light-transmissive screen 4' are refracted in incidence and projection to obtain projected light beams 9', 10', and 11', and even when they are incident slantingly to the normal of the screen 4, they are refracted and projected in parallel to the normal, so mirrors 2' and 3', and surfaces 5' and 6' are arranged nearly in parallell, reducing the depth of the device. The slanting surfaces and vertical surfaces of the saw-tooth wave section are adjusted to refract the projected light to an observers' position.

Inventors

• 👤 Akira Izawa
• 👤 伊沢　晃

Bibliographic Details