PROJECTION TELEVISIONS WITH MIRRORS INCIDENT ON HOLOGRAPHIC SCREENS

摘要

A projection television (10) has a screen (22) with a three-dimensional hologram (26) on a film substrate (24) for collecting light over a range of incident angles and redirecting the light more nearly forward. Vertical and horizontal holograms which can have varying gain across a horizontal viewing span of +/- 40 DEG and a vertical viewing span of +/- 20 DEG can be stacked. Image projection tubes (14, 16, 18) project an image onto at least one mirror (20) that reflects the image along an optical path that converges at an angle of projection, phi , between about 0 DEG and 30 DEG relative to an axis orthogonal to the screen. Each tube (14, 16, 18) can have a separate mirror. The hologram (26) redirects the images reflected to an angle of display relative to the orthogonal axis of the screen of from 0 to 5 DEG . The hologram (26) also forms an interference pattern effective to minimize color shift that otherwise occurs in displayed images due to off axis projection, achieving a color shift between two and five for angles of incidence between about 0 DEG and 30 DEG .