Discussion of large systems

[Tony Duell]

> Yes.., I recall those. The cool part about them, *if* I recall correctly, is
> that the 'printing' was done by leading the individual light sources up to
> the fixed print bar (which was full width) via fiber optics...., i.e., they
> could obtain fine resolution without having to locate a mechanical device. I
> can not for the life of me , recall how the light source(s) were controlled.

I thought it wsa a spexial 1-axis CRT with the deflection axis 
perpendicual to the direction of paper movement.

Although the printer was noramlly used with a vector display, the printer 
was really a raster device. It's possibke to read out the stored charge 
image in a storage CRT, this was done by scanning an electron beam over 
it. The horixontal deflection of the beam was syncronised to the 
deflection of the beam in the printer's CRT, the vertical deflection of 
the readout beam to the paper motion.

_Somewhere_ I have the service manual to one of these printers, but I 
can't instantly put my hand on it.

> 
> Which leads me to wonder if anyone ever produced a general purpose
> oscillagraphic device for conventional printing use, as opposed to a plotter
> or recorder?

There have been, of coruse, many oscilloscope cameras over the years, 
normally using a Polaroid film.

I have something called a Polaroid Videoprinter 4. Polaroid claim they 
never made it, but anyway. What it consists of is a small CRT monitor (TV 
rates, monochrome CRT), a wheel with R,G,B colour filters, a Polaroid 
camera (SX70 film back + enlarger lens (which is, of course, designed to 
be used at that sort of object/image distance) and a bit of electronics 
to control it.

You feed in RGB video, it selects each in turn and feeds it to the 
monitor wit hthe appropriate filter in the path between the CRT and lens. 
After all 3 colours have been used, the print is ejected in the normal way.

I've heard of other, higher-resolution versions, I think Sigma Graphics 
made one.

-tony