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US 4,397,930 AGranted
Record carrier for deformation images
AssigneeU.S. Philips Corporation
InventorsUlrich Killat, Gert Rabe, Hans J. Schmitt
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AssigneeU.S. Philips Corporation
InventorsUlrich Killat, Gert Rabe, Hans J. Schmitt
Estimating the term…
The record carrier according to the invention comprises a substrate on which an electrode is provided which, on the side remote from the substrate, has a low-ohmic photoconductive layer which is covered with a second transparent electrode which is provided wihh a thermoplastic layer. For storing information the electrodes are connected to a voltage source and the thermoplastic layer is charged electrostatically and exposed in known manner. Upon exposure of an area of the thermoplastic layer, the light will fall through the transparent electrode on the low-ohmic photoconductive layer. As a result of the current passage, Joulean heat is produced which heats the thermoplastic layer in the place of the exposed area and softens it thereby deforming the layer by electrostatic forces in accordance with the charge. The thermoplastic layer may, in known manner, also have photoconductive properties or be provided with a further photoconductive layer.
A record carrier for storing information comprising a substrate, a first electrode disposed on said substrate, a second, transparent electrode spaced from said first electrode, a photoconductive layer disposed between said first and second electrodes, said photoconductive layer being the only layer provided between said electrodes, and a thermoplastic layer disposed on the side of said second electrode remote from said photoconductive layer so that when said electrodes are connected to a voltage source and a region of said record carrier is exposed to radiation, due to decrease in the resistance of said photoconductive layer in the exposed region, current flowing through said region and between said electrodes heats an area of said thermoplastic layer opposite said exposed region.
Dependencies are inferred from the claim text.