I'll admit I dont know Baird and the Televisor stuff. (Beyond the
"father of TV "stuff) Lasers though are can be pulse width modulated
(PWM) to pseudo change the spot intensity. In a air comms environment
they are pulsed at some "carrier" frequency and data then sits on top of
that. At the RX end they have a filter at the "carrier" frequency so you
dont get noise etc from other light sources.

Making a picture? Had a brief think about bending light but that physics
is kind of missing in my brain! I think if you used a rotating mirror
array on two axis in front of the beam you might get something
acceptable, be a real cow to manufacture though. Syncing would be
reasonably easy (assuming a standard TV picture signal) but I think the
spot would be a bit large unless you wall projected it.

Colour wouldnt work BTW as the (laser) spot will be one freq only. This
means any filtering or coloured mirrors wont work.

Those laser pointers sound like a nice cheap way to experiment with some
short haul data comms as well.

Bob

Plod's Conscience wrote:

My local garage is selling laser devices that project
a straight line for just under a fiver. I wonder if these
devices (with the lens removed so that they just
produce a single spot) could be modulated to be
the light source in a Baird Televisor?

Also, I wonder what is the smallest such Televisor
that has been produced?