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From: torkil@psivax.UUCP (Torkil Hammer)
Newsgroups: sci.electronics
Subject: Re: funny phosphorus illumination after power to tv has been turned off
Message-ID: <3209@psivax.UUCP>
Date: 10 Jan 90 01:28:00 GMT
References: <6805@lindy.Stanford.EDU> <6834@lindy.Stanford.EDU>
Reply-To: torkil@psivax.UUCP (Torkil Hammer)
Organization: Pacesetter Systems Inc., Sylmar, CA
Lines: 14

Relax, folks.  There is a natural explanation for funny afterimages
on a TV screen.

1. Afterglow.  You get afterglow from the "phosphor" (actually some
less dangerous chemical) when it has been activated either by electrons
making a TV picture, or by room lighting.  Afterglow lasts for hours.
Try covering half of the TV screen and expose it with a lamp, then
turn off all room light and watch the show.

2. Electrostatic buildup.  When the TV is on, electrons travel from
the cathode to the phosphor, then have to find their way home, usually
through some resistive carbon film.  When the stream is cut off, the
decay lasts for something like 3 seconds and forms a peculiar pattern
on the screen.