Note: Descriptions are shown in the official language in which they were submitted.
The present invention relates to a method and apparatus for
intercepting the movement of electrically-charged particles in
display screen environments to provicle a portable, radiation-and
static-electricity-suppression, and anti-glare screen.
This application is a division of copending application
Serial No. 406,105 filed June 28, 1982.
More and more readers of display screens are becoming
affected by skin troubles, as well as eye and throat irritation.
Display screens generate an electric field with potentials up to
+15,000 V. The display reader also becomes charged, e.g. by
rubbing the feet on the floor. The potential for the reader is
+3,000 V to -6,000 V. The field strength between the display
unit and reader can reach 40,000 V/m. The particles in the
surrounding air become electrically charged, and this leads to a
flow of particles in the electric field between the screen and
the reader. These particles become deposited on the reader's
face, where they adhere, causing the afflictions mentioned above.
An object of an aspect of the present invention is to
provide a method and an apparatus for intercepting the movement
of such particles and thereby inhibiting the impingement of such
particles on the reader.
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An object of another aspect of the invention is to provide
such a method and apparatus which also reduces the reflection from
the display screen, i.e. to provide an anti-glare screen.
By one aspect of the invention as provided by the present div-
isional application, a portable, racliation-and-static-electricity
suppression and anti-glare screen is provided herein which is in-
tended to be placed in front of a display screen, such anti-glare
screen comprising: an electrically-conductive, free-standing frame
intended for grounding; a fine mesh net of an electrically-non-con-
ductive plastics material stretched over, and mounted in such
frame, such fine mesh net being unsupported by a rigid backing, an
electrically-conductive, transparent layer in contact with such
fine mesh net and in electrical contact with such electrically-con-
ductive frame; and means for grounding such electrically-conductive
frame.
In this aspect of the invention, the fine mesh net is prefer-
ably a nylon net.
By another aspect of the invention as provided by the present
divisional application, apparatus is provided for intercepting the
movement of electrically charged particles in a display screen en-
vironment, and for minimizing glare from such display screen, such
apparatus comprising: free-standing, electrically-conductive frame
means having an open area for placement in front of such display
screen; a fine mesh nylon net stretched across such open area of
such frame means, such fine mesh net being unsupported by a rigid
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backing; an electrically-conductive transparent layer physically-
connected at least to the rear face of such fine mesh nylon net and
electrically-connected to such electrically-conductive frame means;
and means for grounding such electrically-conductive frame means.
The transparent electrically-conductive layer is preferably
applied to such fine mesh nylon net.
By yet another aspect of this invention as now provided by the
present divisional application, a method is provided for intercept-
ing the movement of electrically-charged particles in a display
screen environment having an electric field present in front of the
display screen from a reader thereof, such method comprising: pos-
itioning, in an exposed condition between such display screen and
such reader, a screen comprising a grounded, free-standing electri-
cally-conductive frame, such frame having an open area for place-
ment in front of such display screen, a fine mesh nylon net stret-
ched across such open area of such frame means, such fine mesh
nylon net being unsupported by a rigid backing, an electrically-
conductive transparent layer ~hysically-connected at least to the
rear face of such fine nylon mesh net and electrically-connected to
such electrically-conductive frame means; and means for grounding
such electrically-conductive frame means; and connecting such
electrically-conductive frame to a ground potential.
In the accompanying drawings,
Figure 1 is a plan view of the screen in accordance with one
embodiment of the invention disclosed and claimed in the above-
identified parent application;
Figure 2 is a vertical cross-section through the apparatus o:l
Figure 1; and
Figure 3 is a cross-section as in Fi3ure 1, but through a
modified screen in accordance with an embodiment of this invention
provided by the present divisional application.
The apparatus depicted in Figures 1 and 2 includes a screen
1, which is shown to be rectangular, although it may be square,
or may have any other suitable geometric shape. It has
sufficient area to cover a display screen (not shown), in front
of which it is intended to be placed. As shown in Figures 1 and
2, the screen of one embodiment of this invention disclosed and
claimed in the above-identified parent application comprises a
rectangular, electrically-conductive frame 2 with a fine mesh
nylon net 3 stretched over it, and with electrically-conductive
wires 4 stretched between opposing parts in the frame 2, in
physical contact with the net 3. The numeral 5 denotes the frame
connection to earth potential, i.e. the grounding means. The
number of wires 4 is suited to the size of the frame 2, and in
turn the latter is adjusted to the size of the display screen in
front of the image tube of a visual display unit. Instead of
being applied in physical contact with the net 3 according to
Figures 1 and 2, the wires 4 may be woven into the nylon net 3,
or may be intertwined to a greater or less extent with it, i.e.
they may run adjacent to, and across the netting threads.
The described portable screen l is adapted to be mounted in
front of the appropriate display screen, as used in visual
display units. The particle flows generated by the electrical
field between the display screen and the reader will thus become
neutralized by the screen 1, with its nylon netting 3 carrying
the electrically-conductive wires 4, which are connected to the
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~2~;8~03
-- 5
earthed (grounded~ frame 2, so that the face of the reader is not
subjected to any particle bombardment. In this way, the risk of
skin trouble and eye or throat irritation are greatly minimized.
The electrical properties of the combination of the net 3 and the
electrically-conductive wires 4 are sufficient to screen off that
electric field.
The present invention, as now provided by the present
divisional application, is depicted in Figure 3. The screen 6
includes as with the screen 1, an electrically-conductive frame 2
with a nylon net 3 stretched across it, but the wires 4 of the
screen 1 have been replaced by a transparent, electrically-
conductive layer 7, applied to the net 3, and electrically-
connected to the frame ~.
lS The screen 6 is suitably mounted so that the conductive
layer 7 will be nearest the display screen, i.e. facing it. This
embodiment of the invention also effectively inhibits the flow of
charged particles towards the reader, particularly towards the
face of the reader.
The embodiment of the invention provided by the present
divisional application may be modified within the scope of the
invention. For example, the frame may be constructed solely from
two opposing frame portions, which may be mounted in holders or
on the display unit to be read. The means arranged for screening
the electric fields, i.e. the nylon netting may be in the form of
other suitable embodiments. Instead of nylon, any other electri-
cally-non-conductive plastic material may be used.
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- SD 6 -
Supplementary Disclosure
The Principal Disclosure provided a portable, radiation-and-
static-electricity-suppression and anti-glare screen intended to be
placed in front of a display screen. That screen included: an
electrically-conductive free-standing frame intended for grounding;
a fine mesh net of an electrically-non-conductive plastics material
stretched over, and mounted in, the frame, the fine mesh net being
unsupported by a rigid backing; an electrically-conductive, trans-
parent layer in contact with said fine mesh net and in electricalcontact with said electrically-conductive frame; and means for
grounding said electrically-conductive frame.
An object of the present Supplementary Disclosure is to pro-
vide a further embodiment of such transparent, electrically-conduc-
tive layer on the fine mesh net.
By the invention now provided by the present SupplementaryDisclosure, the electrically-conductive means comprises a fine mesh
net of an electrically-non-conductive plastics material coated with
a transparent, electrically-conductive material, i.e. all the
exposed surfaces of the fine mesh net are coated with a transparent
electrically-conductive material. Preferably, the
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6~2~3
- 5D 7 -
fine mesh net is formed of nylon and the fine mesh nylon net is
coated with an electrically-conductive material by an immersion
technique.
In the practice of this embodiment of the invention as now
provided by the present Supplementary Disclosure, a nylon net is
manufactured which has the necessary mesh size and is formed of
sufficiently fine threads. The net is immersed in a solution,
well known in the prior art, for providing a transparent
electrically-conductive coating, e.g. an aqueous solution of zinc
o chloride as taught in French Patent No. 1,055,568. This provides
a transparent electrically-conductive layer all around the
threads of the nylon mesh net. The net which is now provided
~ith the transparent, electrically-conductive coating around all
the threads of the net, is now mounted within the electrically-
conductive frame, to provide the free standing nylon mesh and the
transparent, electrically-conductive layer unsupported by any
rigid backing.
