ELECTRONIC UTILITY DEVICES INCORPORATING A COMPACT VIRTUAL IMAGE DISPLAY

摘要

An electronic utility device is provided. The device includes a user input interface and a user output interface, the user output interface including a compact virtual display for providing visual information (22) to the user, the compact virtual display including (a) a light-transmissive substrate (16); (b) an input diffractive optical element (12) integrally formed with the light-transmissive substrate; (c) an output diffractive optical element (14) integrally formed with the light-transmissive substrate laterally of the input diffractive optical element; and (d) an image source (18) for producing a real image (24), the image source optically communicating with the input diffractive optical element (12) so as to collimate the real image into plane waves transmittable along an optical path through the light-transmissive substrate, such that when the plane waves impinges on the output diffractive optical element the plane waves are focused to form a virtual image (22) which correspond to the real image and which is viewable by the user.