On Thu, 27 Mar 2008 08:19:31 -0500, chrisv
<chrisv@nospam.invalid> wrote:

>Bob Myers wrote:
>
>>"chrisv" wrote:
>>>
>>> Well, when I wrote "why have phosphor there", I meant "why have
>>> phosphor and shadow mask" there, or, phrased another way, why have
>>> usable display area there (if one really ought not use it).
>>
>>Again, because of the way the phosphor screen is produced.
>>and other needs (re the aluminization step I mentioned) to make
>>the CRT producible. "You can't easily NOT have phosphor
>>there" is the short form answer,
>
>But you CAN easily not have shadow-mask there.


Having the option for the user to display this area is
better than not, and allows a manufacturer to create any
given screen size for lower cost than haiving to use a
bigger tube then not allow using the more distorted region
around the edge at all.