Abstract An electro-optical cell, forming part of a luminous display device, has two light-transmissive walls formed by a pair of parallel transparent or translucent plates and a conductive coating on the inner surface of each plate, at least one of these coatings having discontinuities which form a pattern outlining, for example, an alphanumerical character. Each coating comprises several superposed thin metallic layers, including a layer of a noble metal (e.g. gold) bonded to the plate surface by a bismuth layer. Another bismuth layer may form a protective covering for the exposed side of the noble-metal layer. The space between the plates is filled with a liquid crystal whose light transmissivity is modified by the application of a voltage thereacross.
A display device as defined in claim 1 wherein said noble metal is gold.
Claim 2
Dependent Claim
20 words
A display device as defined in claim 1, further comprising a protective layer of bismuth overlying said highly conductive layer.
Claim 3
Dependent Claim
18 words
A display device as defined in claim 3 wherein said protective layer is heavier than said bonding layer.
Claim 4
Dependent Claim
50 words
A display device as defined in claim 3 wherein the thickenss of said bonding layer ranges between substantially 20 and 60 A, the thickness of said highly conductive layer ranges between substantially 20 and 80 A and the thickness of said protective layer ranges between substantially 20 and 100 A.
Claim 5
Dependent Claim
25 words
A display device as defined in claim 5 wherein said bonding layer, said highly conductive layer and said protective layer are of progressively increasing thickness.
Claim 6
Dependent Claim
41 words
A display device as defined in claim 6 wherein said bonding layer has a thickness of substantially 30 A, said highly conductive layer has a thickness of substantially 40 A and said protective layer has a thickness of substantially 60 A.
Claim 7
Dependent Claim
27 words
A display device as defined in claim 1 wherein said coating has discontinuities in the form of cuts extending through all layers thereof to said inner surface.
Claim 8
Dependent Claim
14 words
A display device as defined in claim 1 wherein said liquid crystal contains nitrobenzene.
Claim 9
Dependent Claim
49 words
A display device as defined in claim 1 wherein said wall means comprises a second light-transmissive plate confronting the first-mentioned plate, the other of said electrodes including a second light-transmissive coating on said second plate of substantially the same composition and thickness as the coating on said first-mentioned plate.