The mention to Image Orthicons reminds me that the
cameras that used them normally had a feature called
"Orbital". This was a device that avoided that a static
image could became fixed to the sensitive target making
the tube useless. I think that some of them used a motor
to slow drive (1 cycle per min or so) a potentiometer to
send sine-cosine currents to a pair of deflecting coils.
The image movement was quite small but enough for saving
the TV camera to become a photo camera.
This could be done for MCP scopes and wisely designed it
could operate only when the readout was in action without
affecting the normal traces. Maybe it is a good idea for
a backwards patent that now is useless.
On 29/07/2013 1:21, Don Black
I don't have experience with MCPs but their glass
channel wear out sounds similar to the problems with
Image Orthicon camera tube targets. These are thin
glass discs that have an electron image built up on
the lmage side which has to leak through the glass
between scans to form a charge on the scanned side.
The original targets were made of doped glass that was
slightly "ionic"conductive and they only had a life of
a few hundred hours before they wore out as their
resistance increased. A different type of glass was
introduced (by EEV I think) called Elcon (electron
Conduction) that used a resistive mode and that
increased tube life ten fold plus was much less prone
to "sticking" (image retention) than the old type. I
guess similar developments were made to the glass
channels in MCPs.
I mean later MCP CRTs which are still used in
applications. I base this on the links posted
here in a MCP
discussion thread some time ago which
discussed MCP lifetime and
wearout mechanisms. I suspect the MCPs
Tektronix used had unusually
short rated lifetimes but maybe they wear out
quickly because of how
they are applied.