Curved triple-mirror screen for projection-type three-dimensional display.

A screen consisting of a number of tiny triple mirrors (cubic corners) is an autocollimating screen which reflects back the incident ray of light always into the original direction. Such a screen can be used in a projection-type three-dimensional display. Proposed in this paper is a curved triple-mirror screen which is composed of many tiny triple mirrors having one cylindrical and two flat reflecting surfaces. Such a screen has a diffusing property in the vertical direction in addition to the autocollimating property in the horizontal direction. These properties enable us to furnish a wider observable field of view without reducing the image quality when it is used in a 3-D display system. Another advantage of this screen is that it has high reflection efficiency. It is found that the design theory and experiment show a good agreement, and that a horizontal directivity (autocollimation) of 0.5 degrees is attainable with a screen having 1-mm pitch.