Re: Special Offer from Peter Keller to TekScopes Members: The Cathode Ray Tube, Technology, History, and Applications"


Chuck Harris <cfharris@...>
 

Well, that is sort of right.

There was only one electron gun structure, but it had 3 cathodes, one
for each color. There was no fancy electronic stuff, though. It was
exactly the same as the other color crt's in that regard.

The shadow mask was where it was all at. Because there was only one
gun structure, and the cathodes (emitters) for that gun were lined up
horizontally, the shadow mask was able to be made with a far simpler
structure. It was simply a bunch of very fine wires, under high tension,
that went from the top to the bottom of the screen.

Because a shadow mask gets hit by the high energy electron beam, it gets
hot and expands... especially when displaying a bright screen. This
caused the conventional shadow mask, with its triad holes, to smear its
colors when very bright... The trinitron's high tension wire shadow mask
simply grew longer, and stayed taught. This kept the colors accurate at
high screen brightness... a major win for Sony.

The special sauce was the lack of tops and bottoms to the phosphor stripes.

The vertical wires allowed much more exposed phosphor to be excited, and
as a result a much brighter screen could be had with a trinitron than was
possible with a shadow mask drilled full of holes.

Because the wires that formed the shadow mask were under tension, and
were vertical required the screen to be cylindrical, rather than
spherical as was used in the GE triple gun CRT's. This was simpler, and
allowed greater accuracy.... only being curved in one dimension.

It really was an economy in design. The electronics was simplified,
and the accuracy and brightness of the screen was greatly improved.

-Chuck Harris

Stephen Hanselman wrote:

I don’t have hard knowledge of that but the big deal about Trinitron wasn't the mask. It was the fact that there was only one electron gun and some pretty intricate electronic stuff done to emulate the three-gun standard color tubes. The benefit was overcoming the very difficult task of keeping the three gun cluster aligned in manufacture.

I can also say from experience if you don't feel real confident and have detailed instructions and test equipment don't try to align a Trinitron. The 9845 color head was one of the best it had a very nice calibration program built in

Steve


-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of snapdiode via groups.io
Sent: Monday, November 16, 2020 9:59 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Special Offer from Peter Keller to TekScopes Members: The Cathode Ray Tube, Technology, History, and Applications"

I'm a bit confused about the Trinitron having "dots", the Trinitron relies on stripes and the mask is an aperture grille.











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