Note: Descriptions are shown in the official language in which they were submitted.
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Background of the Invention
The principles of the invention relate to display
panels of the ~ype known as SELF-SCAN*panels which are manu- .
factured and sold by Burroughs Corporation. These panels are
dot matrix devices which display characters by energizing and
8enerating light in selected cells in a ma~rix of cells,
usually a 5 x 7 matrix, with the total number of energized r
cells displayin~ a character. SELF-SCAN*panels include -
separate arrsys of scanning cells and display cells which are
electrically connected to form a plurality of such 5 x 7 or ~ -
other matrices, with the scanning cells being adapted to assist
in the energization of selected display cells in accordance with
input signal information. One form of SELF-SCAN*panel is shown .
and described in our U.S. Patent No. 3,821,586 (June 28~ 1974). Panels
of this type have achieved commercia1 success; however, there is a
constant need for simplification in the component parts and structure
of such devices for mass production manufacture.
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It is an object of the present invention'to provide a display
panel whereln, at least in a described embodiment, such simplification
is provided.
--................... According to the present invention, there is provided a display
panel comprising a gas-filled enve].ope including a base plate and
a face plate having a viewing window; a plurality of columns of
coplanar operating cathode areas which are electrically connected
in each such column, all of said cathode operating areas having
upper surfaces facing said viewing window; said columns of cathode
~ areas including display cathode areas and priming cathode areas,
said priming cathode areas providing excited particles for said
display cathode areas through gas communication paths extending along
said columns of cathode areas; said display areas and said priming
areas also being disposed in rows; barrier means between said base
plate and face plate.and having portions which delineate said rows
of display areas and said rows of priming areas, and a priming anode
overlying each row of priming cathode areas and a display anode
-overlying each row of display cathode areas, said barrier means also
effectively separating adjacent anodes from each other.
. Embodiments of the invention will now be described with
reference to the accGmpanying drawings in which:- .
1053737
Fig. l is an exploded plan view of the parts of a
display panel;
Fig. 2 is an enlarged view of a portion of the panel
of l~ig. 1;
Fig. 3 is a sectional v~ew of a portion of the panel
of Fig. 1 assembled;
Fig. 4 is a sectional view along the lines 4-4 in
Fig. l showing the panel assembled;
I0 Fig~ 5 is a sectlonal view along the lines 5-5 in
Fig. 1 showing the panel assembled;
Fig. 6 is a schematic representation of the panel o~
Fig. l and a clrcuit in which it can be operated;
Fig. 7 is a plan view of a modification of a portion
15 of the panel of Fig. l;
Fig. 8 is a perspectire view, partly in section, of a
panel modification;
Fig. 9 is an exploded perspective view of the panel
of Fig. 8;
20 Fig. 10 is an exploded plan view of the panel of
Fig. 8;
Fig. 11 is on the same sheet as-Fi~. 9 and is a sectional
view of the panel of Fig. 8; and
Fig. 12 is an enlarged view of a portion of the panel
25 of Fig. 8 shown to illustrate current flow therein.
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~ 053737
Description Or the Preferred ~mbot!ime.nts
~ display panel lO,-referring ~o Figs..lj 2 and 3,
includes a ba.se plate ? of insulatillg material . .~ j
such as glass, ceramic, or the like, and having a top surface 30 '~
on which are provided a plurality of rectangular strips 40 of
conductive material arrayed parallel to each other. The conduc-
tive strips or electrodes 40 are formed preferably by a screen
printing process using any suitable material such as a mixtnre
of nicl~el and glass frit in a suita~le binder.
An auxiliary conductive strip 41, used as a reset.
cathode in a scanning operation to be described, is disposrd if
adjacent to the first strip 40 at the left-hand end of panel 10. -
This is arbitrarily considered to be the end at which the scan-
ning cycle will begin. In addition, at least one keep-alive
cell is provided near the reset cathode and comprising two
electrodes, a cathode 43 and an anode 45, both of t,-fhich are
preferably formed on the base plate.
The conductive strips 40 are subdivided into rows of
rectangular areas 42 by means of thin parallel longitudinal
lines 60 of insulating material formed on the top surface of
the plate and on the strips 40. The lines 60 extend along the t
length of the base plate. In addition, each of the rectangular
areas 42 of the strips 40 is subdivided by means of insulating
. strips 62 formed on each rectangular area to subdivide each
such portion into a first, relatively large-area portion 44,
to be operated as a display cathode, and a second generally
rectangular but smaller portion 46, to be operated as a
scanning or priming cathode. The display cathode portion 44
is connected to the scanning cathode portion 46 by a narrow
portion 48 which lies between the insulating portions 62. If
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lQ53737
a 5 x 7 dot matrix is to be used to form characters in panel 10,
then five subdivisions 42 are provided in each strip 40.
The insulating strips 60 and 62 may be formed by a
screen printing process.
It is noted that each portion 42 of a strip 40, refer-
ring to Fig. 2, thus comprises an electrode pair including
electrode 44 and electrode 46, and the electrode pairs and
their component electrodes are all arrayed in rows and
columns.
The panel 10 includes an insulating plate 70 seated
on the base plate 20 and resting on the insulating lines 60
and portions 62 which have a thickness or height of about 2
mils so that they can support the insulating plate 70 above
the conductive strips 40. With plate 70 resting on insulating
portions 62, gas communication paths are provided between each
display cathode 44 and its associated scan cathode 46 through
a path 74 extending along the narrow, constricted space 48
between strips 62, as shown in Figs. 2 and 3.
The insulating plate 70 includes a plurality of
horizontal slots 76 and 78, each slot 76 overlaying a row of
display cathodes 44, and each slot 78 overlaying a row of
scan cathodes 46. The lands or ribs 79 between each slot 76
and the adjacent slot 78 overlay insulating portions 62 or
insulating lines 60.
The panel 10 also includes a transparent face plate
80 of glass or the like, hermetically sealed to the center
plate and the base plate by a seal 95, and carrying on its
inner surface 82 a plurality of transparent conductive anode
electrodes 90 of tin oxide or the like, each anode overlaying
a slot 76 in the center plate and a row of display cathodes.
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The face plate also carries on its inner surface a plurality
of opaque scan anodes 94, each overlaying a slot 7~ ànd
row of scan cathodes.
The panel 10 is filled with a suitable ionizable
gas such as neon, xenon, or the like, singly or in combination,
at a suitable pressure. The gas atmosphere also includes
mercury vapor to minimize cathode sputtering.
In panel lO, various parameters are selected to
insure that one column of cathodes glows at a time even though
io they are connected in groups. These parameters include the
spacing of the columns of cathodes from each other, which, in
one panel, was about six mils; the spacing of the face plate
from the base plate, which was about 25 mils, and the pressure
of the gas filling, which in such one panel was about 400 Torr.
Those skilled in the art will be readily able to
modify these parameters to achieve the desired operation of
modifications of panel lO.
In one mode of operation of panel lO, the strips 40
are electrically connected in groups by means of leads 50A,
50B, 50C, with every fourth electrode being in the same group
so that there are three such groups of electrodes. The inter
connections 50 can be formed on base plate 20 at the same time
as the strips-are formed, or they may be provided in any other
suitable manner. It will be clear to those skilled in the art,
from the following description of the invention and from
information already known about SEL~-SCA~*panels, that other
electrode groupings can be used or even that each electrode
can be separately connected to an external circuit. However,
the electrode groupings provide economies in circuit operation~
.
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1053737
A system for operating panel 10 is shown in Fig. 6.
In the system, the keep-alive electrodes 43 and 45 are
connected to a source of potential V, by means of which the
keep-alive cell is maintained continually energized and
generating excited particles. The reset cathode 41 is
connected to a reset driver 96, and the groups of cathodes
40 are connected by their conductors 50 to separate cathode
drivers 100 for connecting each cathode group in an operating
circuit. All of the scan anodes 94 are connected together
through a suitable resistive path, if required, to a source
of generally positive operating potential 110. Each of the
display anodes 90 is connected through a separate, suitably
resistlve path to a source~of information signals which
themselves are connected to a data source 120 which may include
a computer, encoders, decoders, character generator, and the
like circuit modules. Suitable synchronizing control circuits
130 are provided for interrelating the various circuit elements
to operate as described below.
With the keep-alive cell ON, and all of the scan
anodes 94 energized, a pulse or other signal is applied by
source 50R to the reset cathode 40R which turns on, exhibits
cathode glow, and generates excited particles.
The excited particles thus generated are present near
the first column of scan cathodes 46, and, when the first
cathode driver 50A is operated to connect the first column of
scan cathodes in circuit with the scan anodes, these scan
cathodes turn on, exhibit cathode glow, and generate excited
particles. Although other columns of scan cathodes in the
same group are energized at the same time, they do not glow.
This is because the first co~umn of scan cathodes 46 turns on
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pref~rentia~ly beeause it is close to the reset catllode lOOR
and to the excited partic]es generated tllereby. These
particles do not diffuse to the other columns of scan cathodes
in the group. In addition, when the first column of scan
cathodes turns onJ it quickly assumes sustaining potential
which is lower than the required firing potential for the
other columns of scan cathodes in its group.
As each of the cathode drivers 100 is operated in
turn, each of the columns of scan cathodes is energized and
exhibits cathode glow, in turn, with each column providing
excited particles for the ne~t adjacent column. The scan
cathode glow is not visible to a viewer since-the scan anodes
94 are o~a~ue.
As each of the columns of scan cathodes is energized
and the scan cathodes glow, information signals applied to
selected display anodes 90 cause cathode glow to transfer from
the scan cathode beneath and adjacent to the selected display
anodes through the constricted path 48 to the adjacent display
cathode, beneath the selected display anode. The display
csthode now glows, and this glow is visible to a viewer
through the transparent display anodes. This operation is
repeated for each column of electrode pairs, and the total
scanning operation is repeated cyclically throughout the panel
- at such a rate that the display cathodes which are energized
present an apparently stationary but changeable message. This
mode of operation described above is generally similar to that
employed in SELF-SC~N*panels of the type described in the above
mentioned patent.
The panel 10 may also use modified cathode strips 40
(~ig. 7) in which the rectangular areas 42 are subdivided by
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*Trademark
10~;~737
rectangular insulating strips 62' formed on each such
subdivided portion 42 and positioned close to strips 60 to
form a relatively large-area display cathode portion 44' and
a relatively small-area scan cathode portion 46'. The strips
62' are spaced from the left and right edges of the cathode
strips 40 to provide a narrow constricted path 48' on each
side of the strip. In operation of a panel with cathode
strips of the type shown in Fig. 7, glow transfer takes
place from a scan cathode 46' to a display cathode 44' through
the two gas communication paths 48'.
A panel 200 embodying a modification of the invention
and sho~n in Figs. 8-12 includes a base plate 210 of glass or
other suitable insulating material having a top surface 220
on which is formed a plurality of parallel conductive strips
230 disposed generally transverse to the longitudinal axis
of the base plate. The conductive strips 230 are operated as
cathode electrodes in the completed panel, and they may be
formed by a screen printing process as above. If desired, the
conductive strips may also comprise individual metallic
elements suitably secured to the base plate.
A slotted insulating plate 240 is seated on the
cathodes 230 to divide them into generally rectangular
elemental areas 230D and 230S. The slots ~44 and 246 in the
plate are alternately wide and narrow so that the cathodes 230
are divided into alternately large and small areas which, as
can be seen, are arrayed in rows and columns. In operation of
the panel, the relatively small cathode areas 230S are operated
as scanning or priming cathodes, and the relatively large
areas 230D are operated as display cathodes.
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,
The panel is completed by a glass face plate 250
which carries, on its inner surface 260, a plurality of
alternate wide and narrow anode strips 270D and 270S,
respectively, insulated from each other and disposed parallel
to the longitudinal axis of the face plate and the panel.
The relatively wide anode strips 270D may be made of material
such as tin oxide, and each of these overlays a row of display
cathodes 230D. Adjacent to each transparent anode is an
opaque anode film or strip 270S of any suitable material, each
of which overlays a row of scanning or priming cathodes 230S.
Thus, when display cathodes are energized and exhibit cathode
glo~7, the glow is visible through their anodes 270D, and when
scanning cathodes are energized and exhibit cathode glow, the
glow is not visible through their anodes 270S.
Although they are not shown, panel 200 would include
a reset cathode and a suitable keep-alive arrangement as
required and as described above.
The operation of panel 200 is essentially the same as
the operation of the other panels described above except that,
as columns of scanning cells are energized by the application
of operating potential to the cathode strips and the scan
anodes, and information signals are applied to the display
anodes, it is believed that glow is transferred from a scan
cathode to the selected adjacent display cathode along the left
and right hand edges of the cathode strip through the space
between insulating plate 240 and the top surface of base plate
210 as illustrated by the dash lines in Fig. 12.
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