Recording body for electrostatic recording

摘要

1,078,434. Selective printing. FUJITSU Ltd. July 6, 1964 [July 6, 1963], No. 27835/64. Heading B6F. [Also in Division G2] A recording sheet for electrostatic recording comprises an image-accepting layer and at least one other layer, the image-accepting layer having a surface conductivity of 10-11 to 10-13# per square and the other layer having a volume conductivity of 10-8 to 10-11# per cm. In one embodiment the sheet comprises a base layer 1 of paper or resin, a relatively conducting layer 2, an image accepting layer 3 and an anti-curling layer 4. In modifications of the sheet, layers 2 and 4 may be dispensed with or layer 2 situated on the opposite side of layer 1 to layer 3. Various surface and volume conductivities for the layers are specified but it is preferred that the layer adjacent layer 3 has a surface conductivity of 10-9 to 10-10 Q per square and volume conductivity of 10-6 to 10-10 Q per cm. The image accepting layer should preferably have a volume conductivity of 10-8 to 10-10 # per cm. The image layer may have a thickness of 1 to 10Á. The imageaccepting layer 3 may be of polystyrene, polycarbonate, polymethylmethacrylate, polyvinylacetal, PVC, polyvinyl acetate, polyethylene, polypropylene, PTFE, polyethylene terephthalate cellulose acetate, cellulose polyacetate, ethyl cellulose and polyisobutylene. The anticurl layer 4 may be of PVA, polymethymethacrylate and polyvinylacetate. The conductive layer 2 may be of PVA, methyl cellulose, polyacrylic acid sodium salt or Gum arabic impregnated with LiCl, NaNO 3 , CH 3 , CO 2 , Na; or polycarbonate, PVC, polystyrol, polymethylmethacrylate, polyvinyl acetate or acetal containing a polar surface-active agent or a chargepreventing solvent. The conductivity of layers 1 and 4 may be adjusted including therein finely divided ZnO, ZnS, Cu 2 O, CdS or CdSe; or by vacuum coating with a layer of CdS, ZnS, Ge, Si, Zn or Ag. The sheet is used by placing it between an electrode bearing the image to be recorded and another electrode, forming an electrostatic image and developing the image with powdered dielectric material. A number of sheets may be simultaneously charged with the image by stacking the sheets on top of one another and charging them with the shaped electrode. The sheets are then separated and each developed. Five sheets may be exposed in this way. Characters formed by a series of elements.- The characters may be formed by a pin-matrix electrode (72, Fig. 7A). Single-point stylus.-A stylus (82, Fig. 8), may form the characters as the drum (555) rotates and the stylus travels across the printing line. Impression adjustment.-Variations of the image are obtained by variations in the electrostatic charge.