GB1359499A - Optical systems - Google Patents

Abstract

1359499 Optical system PILKINGTON PE Ltd 11 Oct 1972 [23 Sept 1971] 44316/71 Heading G2J An optical system, e.g. for use in a head-up display system, comprises a pair of opposed parallel surfaces 13, 14 for transmitting light by internal reflection, means, e.g. a fibre optic bundle 17, for introducing light for transmission, at least one surface 19, 20 which is at least partially reflecting, located between and inclined to the surfaces 13, 14 to reflect at least a portion of the light so that it emerges from one of the surfaces 14, and means e.g. a lens 23 for projecting further light through the surfaces 13, 14 to emerge in the same direction 20, 21 as the emergent reflected light. In the embodiment illustrated the surface 20 is suitably masked to provide an illuminated object of the form in Fig. 1 (not shown) and the lens 23 provides an illuminated object of the form in Fig.2 (not shown), the light for the bundle 17 and lens 23 coming from the same source 15, or from different sources. Movement of the objects is achieved by moving the plate 12 defining the surfaces 13, 14, and the bundle 24 supplying light to the lens 23. The plate 12 is a composite plate, see Fig. 5, (not shown), and may be curved, e.g. cylindrical or spherical, see Fig.4 (not shown). In modifications, the surfaces 13, 14 are provided by grooves (29, 30) in the top face of the plate 12, and the surfaces (48, 49) may be at right angles to each other, see Fig. 8, (not shown), fibre optic bundles (51, 53) delivering light to two or more adjacent edges (50, 52) of the plate. In further modifications, the plate is a disc (54), Fig. 9 (not shown) having circumferential and radial grooves (55), a fibre optics bundle (56) being disposed around the disc, which is rotatable about its axis. In Fig.10 the disc 57 has a bevelled edge 58 to lead light from 59 through the disc which has grooves 61.