Advanced technology, high quality products
   and in-depth application expertise combine
   to provide cost effective solutions
   to EMI/RFI shielding challenges.

 

Shielded Optical Windows

Shielded windows protect electronic equipment from EMI/RFI radiation. Shielding Express Inc. shielded windows come in two constructions: woven screen laminated between polycarbonate or glass and wire mesh homogeneously imbedded in molded acrylic. Each provides up to 95% optical transmissivity in viewing of characters and displays while, at the same time, dramatically attenuating EMI/RFI.

 

High level shielding effectiveness against EMI/RFI with high optical transmissivity

Some electronic equipment operation can be temporarily impaired or it may become irrevocably damaged by exposure to radiated electrical energy in the form of EMI/RFI.  Often times it is the most sensitive, most expensive and critical equipment which may experience this type of degradation.  In these cases, the EMI/RFI signals may gain access to the sensitive electronics circuitry inside the equipment through various indicative type performance or viewing devices, that are necessary for human interaction/interpretation such as digital read-outs or displays (including touch-screens).  These read-outs and displays are designed specifically for high visual optical transmissivity, but generally also exhibit low shielding effectiveness against EMI/RFI.

Shielding Express Inc. has developed a complete product line of shielded optical windows that are designed to provide high visual optical transmissivity while preventing the transmission of deleterious EMI/RFI.  These windows can be installed so as to become an integral part of an equipment display.   Shielded windows are available with both woven conductive metal screen laminated between polycarbonate or glass and knitted wire-mesh homogeneously imbedded in a clear or colored acrylic substrate. These unique windows are designed to allow up to 95% clarity in viewing characters or displays while, at the same time, introducing a high degree of shielding, thus preventing equipment damage due to incident radiated electrical energy.

Key Features

  1. Windows are constructed using a full-lamination process that results in the conductive wire mesh being completely encased. This permits operation under severe environmental conditions.

  2. Different wire mesh patterns and metal alloys allow for a selection of performance characteristics most suitable to the customer's needs.

  3. The molded plastic window substrate can be supplied in several preferred colors for improved viewing.

  4. Windows may be mounted directly to the equipment interface via a conductive gasket and fasteners, or mounted within a metallic bezel.

Typical Shielding Effectiveness (dB):
 
7" X 9" Test Window with Woven Screen Mesh SS/Ag Blackened 0.0012" dia. wire 200MHz 400MHz 800Mhz 1000 MHz
50 opi 49 50 50 50
80 opi 62 59 57 56
100 opi   64 63 62

Note: Shielding effectiveness will vary depending upon the selection of wire diameter, metal alloy, and screen openings per inch (OPI).  The values of shielding effectiveness for the windows listed in the table above are typical.  The results were obtained from tests conducted at Shielding Express Inc. utilizing a modified version of MIL-STD-285.  Test windows were nominally 7" X 9"
A wide variety of shielding materials and window features are available (see information below) to meet the requirements of your application.

  Materials and Features:

 

Thickness of Window:

.062" to .250"

 

Knitted Wire Screen:

0.0012 - 0.0022 dia. wire, 50 - 145 OPI (Std) Woven Copper or Stainless Steel, Blackened.

 

Color:

Clear (STD) or contrast enhancement

 

Optical Finish:

Anti-reflection coatings; Non-glare, various gloss levels available; Chemical and scratch resistant

 

Terminations:

Silver filled bus; Extended wire mesh; Compression gaskets

 

Environmental:

MIL-STD-202A Thermal, Vibration, Moisture, and Temperature Cycling.

 

Optical Medium:

Cast Acrylic per Federal Specification L-P-391, Type 1, Grade C (Std) Glass and Polarizers (Optional).

 


Typical Edge Termination:


            
Available materials; glass, ploycarbonate, acrylic, and polarizer.


Product Categories
I Shielded Optical Windows I
 I Oriented Wire Shield and Seal I Foil Shield and Seal
 I
 I
Woven Shield and Seal
 I Thermally Conductive Materials I
  I Frame Shield
 I Knit Shield I Knit Shield and Seal I Knit Shield Wrap I
  I Particle Filled Conductive Silicone Gasketing I Shielded Air Ventilation Panels I

  
I Shielded Screen Filter Ventilation Panels I Conductive Caulking & Adhesives I
  I Knit Shield Ring and Contact Buttons I

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Shielding Express Inc.
29 Mozzone Blvd. • Taunton, MA 02780 USA
Tel: (508) 880-0987 • Fax: (508) 880-0334
E-mail: sales@shielding.com
       tech-info@shielding.com