Our Ref. 350/PJC/EAC
18th January, 1972.
Mining Surveys Ltd.,
Holroyd Road,
Reading,
Berks.
Dear Pete,
Permit me to introduce you to the facility of facsimile transmission.
In facsimile a photocell is caused to perform a raster scan over the subject copy. The variations of print density on the document cause the photocell to generate an analogous electrical video signal. This signal is used to modulate a carrier, which is transmitted to a remote destination over a radio or cable communications link.
At the remote terminal, demodulation reconstructs the video signal, which is used to modulate the density of print produced by a printing device. This device is scanning in a raster scan synchronised with that at the transmitting terminal. As a result, a facsimile copy of the subject document is produced.
Probably you have uses for this facility in your organisation.
Yours sincerely,
P.J. CROSS
Group Leader - Facsimile Research