Patent ID: 6839408

Claim:
A grid, adaptable for use with an electromagnetic energy emitting device, comprising: at least one metal layer comprising: top and bottom surfaces and a first and second edge extending in first and second direction transverse of each other; a plurality of integrated, intersecting walls, each of which extending from said top to bottom surface and having a plurality of side surfaces, said side surfaces of said walls being arranged to define a plurality of openings extending entirely through said layer, each intersection point of said intersection walls including additional wall material in at least one of the metal layers which extends into at least one of said openings; said each respective additional wall material is arranged such that a total amount of material of said walls intersected by a line propagating in a first direction for the length of one period along the grid is substantially the same for any period along the first direction; and said each respective additional wall material is arranged such that a total amount of material of said walls intersected by a line beginning at said second edge and propagating in a first direction for a first distance including at least one period along the grid and extending substantially parallel to said first edge is substantially the same as another total amount of material of said walls intersected by another line beginning at said second edge at any distance from a point on said second edge from which the first direction extends and propagating in a second direction, substantially parallel to said first direction, for a second distance substantially equal to said first distance.