In article ,
"N_Cook" wrote:

I picked up some these curiosities in a car boot sale, no known history.
Anyone have any info , particularly date.

They are made of 2 sandwiched very thick 1/8 inch glass slabs with obvious
epoxied over liquid filler-holes, otherwise size etc is much the same as
modern, standard sloping 7 segment displays, conductive lands and traces
etc. These ones 3 1/2 digit and annunciators for DVM. No built in
polarizers. The segments go cloudy white on 40 to 60V ac drive, the same
between added polarizers. Wrapped in tissue paper, then expanded polystyrene
and original cardboard wrapping , new unused, made by Hamlin Inc, type
number 3601-0

I have seen early LCDs that behaved just like that. The "cloudy white"
you describe is how the display is used in practice; there would be some
sort of edge light to enhance the effect, but the display sort of stuck
out the top of the box (in this case it was a calculator) and you could
see right through it. As I recall, it also was very slow (by today's
standards) in switching between "on" and "off".

Isaac