Abstract: A display mechanism is provided particularly for use with a helmet mounted visor upon which an image is to be produced superimposed upon the view being observed through the visor. The area of the visor upon which the image is to be reflected is characterized by being composed of a plurality of partially reflecting surfaces arranged in a serrated manner. The partially reflective surfaces may be either flat so as to reflect radiant energy that is already collimated or may be curved so as to collimate the energy if a non-collimated source is employed. More than one set of serrated reflecting surfaces may be used when more than one superimposed image is desired.

Abstract: Wheel alignment apparatus for electrically indicating the alignment condition of a vehicle wheel in which there is sensing means, including an element adapted to be detachably secured to the wheel, for producing an electrical output dependent upon the extent of inclination of the wheel and an electrical display device having a movable member positioned in accordance with the electrical output of the sensing means. The sensing means is designed to selectively detect toe-in, camber, and caster.

Abstract: Helmet mounted display apparatus in which a reflective inside surface of a partially transparent visor is used as the primary optical element. A paraboloidal inside visor surface coated with a metallic film may be used. A light source image or a virtual image is positioned at the focal point of the inside surface of the visor. The outside surface of the visor may be coated with an anti-reflective coating.