Abstract: There is disclosed a thin plate optical element of the Fresnel type having refracting and magnifying properties. One face of the thin plate element is formed with a plurality of straight line, parallel and evenly spaced triangular prisms and the opposite face of the element has a plurality of coaxial, arcuate prisms of varied face angles in a progressive order of decreasing face angles extending outwardly from the center of the optical element. The arcuate prisms can be a single, continuous helical prism with a continuously variable and decreasing face angle along its length from the center of the element or, preferably, can be a plurality of concentric circular prisms of incrementally increasing diameter and decreasing face angles. One face of the optical element thus functions as a magnification lens while the other face of the optical element functions to refract the stereoscopic images the necessary degree for fusing of these images into a single three dimensional illusion.

Abstract: There is disclosed an optical stereoscopic system having a prism window which permits free viewing of left and right steroscopic images by an observer. The prism window comprises a pair of prisms positioned with their long sides medially and their short sides laterally, and in abutting and joined relationship. Preferably, the prisms are thin plate prisms, each having a plano face and an opposite prism face formed with a plurality of parallel V-grooves to form, therebetween, a plurality of parallel triangular prisms. The optical system includes left and right stereoscopic imaging surfaces for display of normal, i.e., unreversed, left and right stereoscopic images. The prism window is placed in front of the imaging surfaces and a three dimensional image can be seen by an observer witnessing through a prism window.

Abstract: An optical system to permit viewing of adjacent stereoscopic images in which the observers each wear a pair of eyeglasses to view the display. Polarizing light filters are positioned in front of each of the stereoscopic images and these filters have different angles of polarization to encode each image. Each eyepiece includes a polarized filter which decodes the image for its respective eye, and a rotatably adjustable prism which deviates the line of sight a sufficient degree that both stereoscopic images are fused in the fovea of the eye. The rotatably adjustable prism can be a solid prism or a Fresnel prism and Fresnel prisms are preferred. The rotation of the prism permits the observer to adjust the refractory angle of the image regardless of the observer's distance to the image source, and thus permits the observer to move about the displayed images and permits a plurality of observers to view the display.

Abstract: There is disclosed a system for the stereoscopic imaging of right and left stereoscopic optical images as these images are projected and displayed on a screen or video monitor. The system uses encoded right and left stereoscopic images with corresponding decoding right and left filters through which the stereoscopic image is viewed. Either polarized or monochromatic light can be used as the right and left image coding medium. A thin face Fresnel prism is positioned between the observer or observers and the projected or displayed right and left stereoscopic images and is located to fuse the two images so that, when they are observed through the decoding filters, an illusion of a three dimensional object is created. For maximum clarity, the Fresnel prism can be vibrated parallel to the original imaging surface.

Abstract: There is disclosed an image orientation and projection system for use with stereoscopic viewing and projection systems.The preferred embodiment utilizes a stereoscopic viewing system of one or two prisms, preferably each having a plano face and an opposite face bearing a plurality of spaced-apart, straight and parallel V-grooves. Reflective surfaces are positioned in relation to said prisms to permit the employment of left and right stereoscopic images in their normal (left - right) and unreversed orientation to each other.

Abstract: There is disclosed a stereoscopic viewing system utilizing one or two prisms to direct the line of sight from a viewer's eyes to each of a pair of stereoscopic images. The single lens sytem employs different occluded angles between the prism faces and the facing image planes to avoid lateral distortion of the images. In the preferred embodiment, the prisms have a plano face and an opposite face bearing a plurality of equally-spaced, straight and parallel V-grooves, forming a plurality of equally-spaced, longitudinal triangular prisms therebetween. The preferred viewing system employs, in the simplest embodiment, one of these prisms mounted with its grooved face at an occluded angle of from 40.degree. to about 60.degree. to one of a pair of stereoscopic images. The second stereoscopic image is mounted on a planar imaging surface at an occluded angle of from 2.degree. to about 15.degree. to the plano face of the prism.