GB1457531A - Signs - Google Patents

Abstract

1457531 Controlling light CLAUDGEN Ltd 16 Sept 1974 [24 Sept 1973] 44704/73 Heading G2F [Also in Divisions G4 and G5] A sign consists of a display board bearing a design which may be rendered visible by reflected or transmitted light by the action of a light shutter comprising one or more liquid crystal panels parallel to and adjacent the board. Each panel consists of glass plates 1, 2 gold coated at 3, 4 and spaced by an electrically insulated peripheral gasket 7 and spacer discs 8, the space so formed being filled with a nematic liquid crystal 9. Plates 1, 2 are displaced to form overlaps 5, 6 exposing portions of the gold coatings for electrical connection by phosphor bronze strips 14 to opposed aluminium frame sections 10, 12 across which a voltage may be applied to control the liquid crystal 9. Frames 11 on the other two opposed sides are spaced at 13 from frames 10, 12. In manufacture of the panel, the plates and gasket are held in position by a temporary sealing strip on three sides, and liquid crystal material is injected into the fourth side, after which the plates are pressed together. The temporary seal is then replaced by a permanent epoxy resin seal 15. A heating current may be applied to one of the conductive plate surfaces to permit the liquid crystal to operate in cold weather. The plates may include spacing means in the form of a stencil integral with gasket 7 and forming a design. When more than one panel is used, the panels may be selectively actuated to reveal different parts of the display.