Tubular plasma display.
Publication Date: 2002-May-15
The IP.com Prior Art Database
Tubular plasma display
A plasma discharge structure is made from narrow thin-walled long tubes. Each of the
tubes is coated on one side with a number of electrodes, made from e.g. transparent ITO as
shown in Figure, or by using thin metal electrodes.
The gap between the adjacent electrodes is such that a sustain discharge is created
inside the dielectric tube, in much the same way as is normally done when using a flat front
The tubes have a pitch equal to the size of a sub-pixel in the display. For a VGA-wide
panel of 42-inch diagonal size, the tubes are spaced at a pitch of 360 jum.
Using e.g. a quartz tube the wall thickness is chosen typically of the order of 5-10
//m, to allow a high transmission for the 172 nm VUV radiation by the standard Ne-Xe
This radiation then excites the phosphor layer outside the discharge tube. Visible light
from the phosphor is emitted in the usual way by the phosphor, and is then transmitted
through the dielectric tube towards the front side. Each columnar tube represents one color
per pixel on a row.
The discharge tube can be coated partially on the inside with MgO, to reduce the
sustain firing voltage. This can e.g. be done by sedimentation of a MgO sol-gel only on the
top side of the tube.
The tubular display can be used at the usual sub-atmospheric pressure, where both
phosphor and the tube are inside the same gas enclosure with the standard Ne-Xe mixture and
are hermetically sealed between two glass plates.