Screened window for shielded enclosure
AssigneeThe Curran Company
InventorsRichard E. Sims, Joseph C. Weibler
Life of this patent
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Abstract
A window for electromagnetic interference shielded enclosures has a shielding screen system with two grids having dimensionally different mesh patterns to overcome optical interference and distraction resulting from the moire effect. The screens are supported in spaced, angularly offset positions on a continuous frame providing electrical continuity between the shielding system and the shielding layer of a surrounding wall.
Claims20
An EMI shielded enclosure comprising wall means enclosing an electromagnetic radiation shielded space, said wall means including a substantially continuous metal shield, a window opening in said wall means, and a window in said opening for blocking electromagnetic radiation while transmitting visible light;
- said window including a first shielding screen electrically connected to said continuous metal shield and lying in a first plane spanning said window;
- a second shielding screen electrically connected to said continuous metal shield and lying in a second plane spanning said window;
- said first and second planes being spaced apart from one another;
- both of said screens being formed of electrically conductive shielding material arrayed in mesh patterns, each of said mesh patterns being a grid;
- and the improvement in accordance with which the mesh count of the first screen is at least about twenty percent larger than the mesh count of the second screen.
A window for the window opening of an electromagnetic interference shielded enclosure comprising:
- an electrically conductive frame defining the periphery of the window and defining a frame sight opening;
- said frame including inner and outer screen mounting structures located adjacent the opposite sides of the frame;
- said frame including mounting means for mounting the frame in the window opening;
- a first wire cloth screen mounted in one of said screen mounting structures and covering said window sight opening;
- a second wire cloth screen mounted in the other of said screen mounting structures and covering said window sight opening;
- and
- said first screen having a mesh count between about twenty and one hundred percent larger than the mesh count of said second screen.
In an optically transmissive electromagnetic interference shielding system of the type including first and second, spaced apart shielding screens having mesh patterns, an improvement for reducing moire optical interference patterns in accordance with which the mesh counts of said first and second screens differ by at least about twenty percent.
Dependencies are inferred from the claim text.