Analysis and reduction of dark zone in ultra-thin wedge-plate displays

Abstract

A wedge plate can be used as the screen of a display, and the thickness of the display can be incredibly thin. In this paper, a basic formula for ray tracing in such a wedge plate is deduced. The fundamental limitation on the display quality of a wedge plate is explored, and the formation of a dark zone on the display screen is analyzed and verified numerically. Experimental exploration and confirmation of one 14-in. acrylic wedge plate with a white-light-emitting diode is also provided. Two approaches to eliminate the dark zone are proposed, and the corresponding numerical demonstration of a 52-in. wedge-plate display is also shown.