Patent GB-438884-A (GB)
Title: Improvements in and relating to decorative panels or the like
IPC: B44F1/04
Filed: 1934-04-24
Abstract: 438,884. Changing signs. HOLOPHANE, Ltd., and WILLIAMS, R. G., Elverton Street, Vincent Square, London. April 24, 1934, No. 12335. [Class 3 (i)] [See also Groups XI and X] Relates to decorative lighting systems of the kind comprising directional light sources and panels, walls, or the like which are illuminated thereby and are provided on the surface with suitably arranged flutes, ribs, or the like whereby different parts of the panel or the like are made visible to an observer within a particular area by illuminating the panel or the like from different directions. According to the invention, the flutes, ribs, or the like are polished, burnished, silvered, or similarly treated, to give them a directional reflective effect and are made of a curved cross-section so that substantially the same effect is visible from a wide area. The panel shown in Fig. 1 is provided with four ribbed regions 1, 4, the ribs in each region being parallel and of substantially semicircular cross-section. The ribs may be made reflective by silver paint or silver leaf. Four light sources 5, 6 are arranged parallel to the sides of the panel, and a little in front, so as to direct their light across the panel. The ribs in squares 1, 4 are parallel with the light sources 5, 7, and the ribs in squares 2, 3 are parallel with the sources 6, 8. To an observer within a fairly wide range of positions, the sources 5, 7 will illuminate the squares 1, 4, since the incident light from these sources will be reflected over a large region in front of the panel, and the squares 2, 3 will be unilluminated because the incident rays will be re-directed almost in the plane of the panel. The sources 6, 8 will illuminate the squares 2, 3 only. The sources on opposite sides may be of different colours so that alternate stripes of the two colours will appear in each square. One pair of light sources may be of different colour or colours from the other pair so that the respective squares will appear in different colours if all the light sources are in use together. The four squares 11, 14 of the panel shown in Figs. 3 and 4 are made up of ribs parallel with the light sources 9, 10, but the ribs in square 11, 14 are shaped so that, to an observer, they are only responsive to the source 10, and those in square 12, 13 respond only to the source 9. The longer edge of each rib in squares 12, 13 is curved so that rays from the source 9 will be re-directed to cover the angle E shown in Fig. 4; the short edge of each rib is substantially perpendicular to the rays from the source 10. The ribs in squares 11, 14 are arranged oppositely to the ribs in squares 12, 13. The two light sources may be of different colours In another form, some regions of a panel may be provided with a series of parallel shallow flutes of curved cross-section which are arranged over part of their width with narrow cross ribs. When light is directed from an edge of the panel along the flutes, the latter will be more or less invisible and the ribs illuminated; when light is directed from an edge of the panel across the flutes, the latter will be illuminated and the ribs will be more or less invisible. Certain regions of the panels may be responsive to light from all sources by providing them with a general irregular surface which may be silvered or provided with a glossy coating. Portions of the panels may be finished with a coloured reflecting surface. In the case of wall surfaces, the flutes, ribs or the like may be of fibrous plaster which is worked in situ. The light sources may be of such kind as will allow the colour to be controlled.