FR2526981A2 - Illuminated alphanumeric display panel - includes liquid crystal elements controlling transmission of light from matrix of fibre=optic waveguides - Google Patents

Abstract

The display panel includes a rectangular array of 121 circular holes (3) arranged in eleven rows (L1 - L11) and eleven columns (C1 - C11). Each hole correspd. to the position of the end of an optical fibre, the individual fibres being strapped together and exposed to a common light source. Each opening in the panel is covered by a mask of liq. crystal material (24). The liq. crystal masks may be independently made transparent, under the control of a separate unit (25). According to the combination which is illuminated, a partic. letter of the alphabet may be displayed.

Description

 In the first claim of the main patent, a display device was claimed comprising several optical fibers, the free ends of which open, opposite the openings of a panel arranged in a certain configuration, behind retractable opaque flaps specific to each fiber. and each flap is associated with a retraction control device which is specific to it.

 This device provides the decisive advantages mentioned in the main patent. I1 still has the disadvantage of requiring a retractable flap, that is to say a mechanical part having to make a movement and therefore prone to jamming or distorting.

 The invention overcomes this drawback by replacing the opaque retractable flap with a fixed mask made of a material capable of becoming transparent under the action of a command.

 The mask consists in particular of a liquid crystal. A device, capable of controlling the state of transparency of each of the masks or of a given group of them, independently of each other, is associated with them. When the mask is not ordered, it remains opaque. By ordering certain masks, they are made transparent to the light coming from their optical fiber. You can thus achieve the display you want.

 The single figure of the accompanying drawing, given solely by way of example, illustrates the invention.

 The display device comprises a panel 1 pierced with one hundred and twenty-one circular openings 2, identical, regularly distributed in eleven rows L1 to L11 and in eleven columns C1 to C11.

 In each opening is threaded the free end of an optical fiber 3. The other ends of the optical fibers 3 are united in a harness and exposed jointly to a light source.

 In front of each opening 2 is placed a mask 24 in liquid crystal which is normally opaque.

Each mask 24 can be made transparent independently of the others by an electrical control device 25. Thus in the figure, the masks 24, corresponding to the openings defined by the positions L2C3, L2C4, L3C2, L3C5, Lac2 '4 L5C2,
L5C4, 5C5, L6C2 and L6C5, are made transparent. The free ends of the optical fibers 3 thus appear luminous to constitute the first letter of the alphabet on a non-luminous background dQ to the fact that the free ends of the other optical fibers 3 remain offended.

 Of course, the control can also be carried out so that the free ends of the optical fibers 3 appear through the liquid crystals 24, except when the latter are made opaque by the control device 25.

Claims (2)

 1. Display device comprising several optical fibers, the free ends of which open, opposite the openings of a panel arranged in a certain configuration, behind opaque shutters specific to each fiber, characterized in that the shutters are replaced by fixed masks (24) made of a material capable of becoming transparent under the action of a command, and a control device (25), capable of controlling the state of transparency of each of the masks (24) or of a group given of them, independently of each other, is associated with them.  2. Device according to claim 1, characterized in that the masks are made of liquid crystals.