| 摘要 |
1447134 Resistance heating element HOECHST AG 11 July 1974 [11 July 1973] 30779/74 Heading H5H [Also in Division G2] Heating elements used to produce frost images (see Division G2) comprise an insulating support 1, e.g. glass, on which is vacuum deposited through a screen parallel paths of an electrically conductive transparent substance 2, e.g. indium oxide or tin oxide, over which is deposited an insulating layer 3, e.g. silicon dioxide and then parallel paths of an electrically conductive substance 4 which intersect the first set of paths, preferably at right angles, to form a grid which can be locally heated at the intersection of the paths, and then a thermoplastic coating 5 is applied. Preferably a higher voltage is applied through paths 4 to ensure heating of layer 5 and a resistance of 13 ohms/square is specified. Cooling elements may be present in the support to dissipate surplus heat, e.g. channels in the support through which coolant flows or using a Peltier element. This may be provided by placing the support 1 on a copper plate 6 having conical apertures 7 and connected to Peltier element 8. |
