摘要 |
<p>Heating devices, in which a conductive pattern is carried on an insulating surface and a pair of spaced apart electrodes are electrically connected to the conductive pattern, are characterized in that the conductive pattern in at least one heating area of the device defines a two-dimensional array of areas that are devoid of conductive material (''voids'') within a continuous ''mesh'' of conductive material. In preferred embodiments in which the conductive pattern comprises either a printed conductive graphite ink layer or a vacuum-deposited metal layer, the centers of the adjacent voids are at the corners of equilateral triangles and each void is a hexagon.</p> |