| 摘要 |
<p>964,881. Optical/thermoplastic record/ erase processes. GEVAERT PHOTO-PRODUCTEN N. V. May 17,1961 [May 7, 1960], No. 23486/63. Divided out of 964, 880. Heading G5R. [Also in Division H1] A thermoplastic recording process utilizing a photoconductive record tape layer,first charges the layer by corona discharge means, modulates the charge according to a pattern of electromagnetic radiation, which causes local discharging, and the layer is then developed into a permanent record by heating to the melting point, the charges causing local deformation. The layer is erased by heating it to the melting point in the presence of light. The preferred form of tape comprises a conductive base carrying a layer of polypropenylcarbazole,prepared as in Specification 964,875, ester gum and methylene chloride,the dried layer being 1¢- 2 Á thick. Other suitable materials are described in Specifications 964,871, 964,875, and 964,877 and 964,879. As compared with the previous thermoplastic recording processes (Glenn, J. Appl. Phys. 30 (1959) pp. 1870-73 is referred to) the need for any form of vacuum enclosure is eliminated. Playback is by conventional optical means.</p> |
