64 line flying spot projector

[M3DVQ]

Those who attended the 2007 convention would have seen Jeremy Jago's excellent 32 line mirror drum projector, which used a laser diode sourced from a DIY laser spirit level from "poundland"

It occurs to me that the resolution of such a system could be easily doubled by having two diodes, one modulated by each stereo channel, giving two overlapping 32 line rasters, a 64 line display.
if the two signals were 16 lines out of phase, the visible flicker would be reduced by a half and by offsetting the two rasters correctly the horizontal resolution doubled.
Obviously special software would be needed to create the video signal.

I can see no obvious limit to the number of times you can multiply up the number of lines, beyond the limitation of two stereo channels. It would all just come down to the alignment of optics.

another thought is that with a red, a green, and a blue laser diode (very pricey though) a full colour NBTV projector could be constructed

just a little idle musing anyway

[Stephen]

It occurs to me that the resolution of such a system could be easily doubled by having two diodes, one modulated by each stereo channel, giving two overlapping 32 line rasters, a 64 line display.

Yes, a mirror drum scanner for camera and display purposes is very versatile. JLB used a 30 mirror drum for the camera and theatre display of 90 line resolution live broadcasts of the Derby in 1930 and 1931. The camera had three offset photocells to generate three 30 line video signals and each theatre display had three offset modulated light sources to reproduce each of the three 30 line signals side by side. Mr Baird transmitted the centre 30 line signal over the air for reception by ordinary 30 line televisors.

[Stephen]

For reference, I have posted the patent Mr Baird's three zone camera and projection display system for producing 90 line images with a mirror drum in the Patents and Articles section of the forum. It is British Patent 360,942, filed 6 August 1930.