earliest graphics display system in your collection?

Jim Beacon jim at g1jbg.co.uk
Sun Apr 23 04:14:29 CDT 2006

From: "woodelf" <bfranchuk at jetnet.ab.ca>

> Jim Beacon wrote:
> > I have a high speed scanner from a 405 line mechanical scan TV, from
> > 1938:
> >
> > www.g1jbg.co.uk/tv1.htm
> >
> > Not computer related, but interesting in its own right.
> But a little off with the discription of the way the light was
> modulated. This was a great invention but limited only to B&W
> scanning. Similar to a mercury delay line for digital data,
> this passed a entire scan line so that you got a full intensity
> scan line to be sent to rotating mirrors then to the projection
> screen.

Yes, I need to update that page - when I wrote it I didn't fully understand
the Jefferies cell.

I have recently acquired a number of early 30's "Television and Shortwave
Review" magazines (1934 to 1939), which have a lot of articles about the
Scophony system, which I need to scan and add to the page.

>Alas WWII killed the company, and everybody by then
> with CRT's improved do to WWII has continued using them to this day.

The rapid need for RADAR progress pushed CRT technology on at a fantastic
rate, such that the need for mechanical scan and high intensity light source
was replaced by the daylight-view CRT by the end of the war, and projection
CRTs were available (Skiatron?), reliable projection TV sets made there
appearance in the UK shortly after WW2 (using a 2.5" tube with a 25KV EHT,
and a very clever optical unit).


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