EMI Mesh Circular Polariser Display or Window
Emiclare CPOL is an EmiClare emi, emc mesh window incorporating a neutral density
circular polariser for maxmium contrast enhancement and
"sunlight readability". Effectively an EMC, EMI
circular polariser. High levels of EMC, EMI, RFI shielding are
achieved by using Emiclare high transparency mesh. Other
mesh, such as 100 opi, can also be used.
EmiClare®CPOL
windows are available in glass with VRD140 non glare or
Anti-Reflective coating on the front surface or in
polycarbonate with hard coated surfaces and a non-glare or
AR Anti Reflective front surface.
General
Circular
polarisers are well established as the most efficient form
of contrast enhancement available. Their use in emi
windows has been largely restricted to designs using a
conductive coating as the shielding element which results
in a significant compromise in shielding performance. In
some applications a emi metal mesh and circular polariser
are used giving a light transmission of the finished
window in the the order of 18-22%. Optical interference
patterns can also be a problem due interaction between the
mesh and circular polariser.
Circular
polarisers have a light transmission of 38-42% and when
combined with a high light transmission EmiClare mesh less
than 5% light transmission is lost, optical interference
patterns are eliminated and high level broad band
shielding is achieved.
Technical
Specification
| Substrates |
Glass
or Polycarbonate. |
| Surface
finish |
Glass
- plain.
- Anti-Reflective coating(Raverage < 0.5% )
Polycarbonate
- Clear hard coat.
- Non-glare hard coat (75 gloss @ 60') |
| Thickness |
from
2.0mm. |
| Size |
450x1250mm
(maximum) |
| Mesh |
EmiClare. |
| Light
transmission |
>32%
(visible). |
| C.E.
ratio |
40:1 |
Typical
EMI shielding characteristics.
| Electric
Field |
| Freq.(MHz) |
1 |
2 |
4 |
7 |
10 |
|
| Atten.
(dB) |
70 |
68 |
68 |
68 |
65 |
|
| Electric
Field |
| Freq.(MHz) |
20 |
50 |
100 |
200 |
500 |
1000 |
| Atten.
(dB) |
50 |
63 |
70 |
68 |
62 |
55 |
| Test
data to MIL-STD285, 12x12" aperture. |
Termination
and Edge Form
Square
and step edge forms are available with a silver busbar
termination as shown below.
Edges
are clean cut and ground in glass and machined in
polycarbonate. The busbar covers the edge and the front or
back face as required.
Step
edges are machine in polycarbonate and built in during the
lamination of glass windows. Conductive gaskets and
environmental seals can be added.
Quality
EmiClare
windows are manufactured in Optical filters' ISO9001
approved facility and inspected to the Optical Inspection
Standard OIS/3.
|