Miniature synthesized virtual image electronic display

Abstract

A synthesized virtual image electronic display is provided that includes a microdisplay for forming a source object which preferably has a surface area less than about 100 mm.sup.2, a first stage magnification optic for magnifying the source object to produce a magnified real image, an image synthesizing optic upon which the magnified real image is projected, and a second stage magnification optic for providing a magnified virtual image of the magnified real image projected on the synthesizing optic. The image synthesizing optic provides the synthesized display of the present invention with significant optical and ergonomic advantages over that which can be achieved using prior art simple magnification and compound magnification systems. Also provided is an electronic device which includes the synthesized display. The synthesized display is intended as an inexpensive component which may be incorporated into any electronic device in which an electronic display is needed. The two stages of magnification optics and intermediate image synthesizing optic used in the synthesized display provide the significant advantage of enabling the synthesized display to be positioned within a small volume. It is preferred that the synthesized display be positioned within a volume of less than about 375 cubic centimeters, more preferably within a volume of less than about 94 cubic centimeters. It is preferred that the first and second stage magnification optics provide a combined magnification of at least about 20, more preferably at least about 40. It is also preferred that the first stage magnification optic provide a magnification of between about 3 and 10 and a focal length of between about 3.5 and 37.5 mm. It is also preferred that the second stage magnification optic provide a magnification of between about 4 and 7 and an eye relief equal to or greater than about 15 mm, more preferably equal to or than about 35 mm, most preferably equal to or greater than about 50 mm.