Abstract: An optical system comprising three lenses concentrically housed in a frame is aligned with a screen on which a televisual image of a virtual reality application is displayed. The compact and high power lenses permit the eye of a viewer when placed at eye position to have a wide field of view of the magnified virtual image of the screen. To train the eye of the user along the optical axis of the system the lenses vignette the image on the screen when the eye is not closely aligned with the axis. By plastics moulding one or more of the lenses so that they are of truncated form it is possible for injection points of the mould to be adjacent truncated side faces thereby permitting a balanced generally free flow of material through the mould cavity which results in minimal optical stresses in the finished lens.

Abstract: A head mounted display for use in virtual reality applications and typically in the form of a slim visor is provided with binocular magnifying optics which permit the binocular viewing of an image displayed by a single miniature LCD video screen magnified at infinity focus at left and right exit pupils. A vertically offset beamsplitter is provided having two elements being substantially mutually perpendicular planar semi-reflecting mirrors disposed respectively above or below the horizontal optical axis of the LCD. A single image viewed from the LCD passes through the semi-reflecting mirrors to be reflected off a concave mirror. One reflection part of the image is reflected off one of the elements and then by a right hand fold mirror towards the right hand exit pupil. Another part of the image is similarly reflected off another of the elements and left hand fold mirror towards the left hand exit pupil.

Abstract: In a head mounted display (1) an annular body (2) worn generally horizontally about the head of wearer supports a forwardly disposed optical display device (3) adapted to seat on the bridge of the nose of a user. At either side of the body (2) projections (10,11) extend toward respective ear positions. At the free end of the projection (10) earphone means (14) are provided to rotate eccentrically about a thumbscrew 20 at least between a plurality of angular positions. Thus, an ear-pad (15) can move between the position illustrated and positions such as C, D and E shown by chain dotted lines, thereby permitting the position of the earphone means 14 to be altered to accomodate different ear positions of the user.