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US 4,359,749 AGranted
Recording medium and method for making a record on the recording medium
AssigneeLicentia Patent-Verwaltungs-G.m.b.H.
InventorManfred Schiekel
Life of this patent
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AssigneeLicentia Patent-Verwaltungs-G.m.b.H.
InventorManfred Schiekel
Estimating the term…
A recording medium of the type having a first coat which is discolorable by the limited application of heat in a limited area includes a second coat of a material having heat-conducting and electrically insulating properties applied on the first coat and a third coat of a material which is electrically conductive applied on the second coat. The third coat is removable in a limited area by the action of an electric arc which is limited in time and area. A record is made on the recording medium by a technique which includes the steps of igniting an electric arc between the third coat and an electrode, maintaining the electric arc until an opening is formed in a portion of the third coat corresponding to the shape of the electrode, and heating the second coat through the opening to an extent that the amount of heat passing into the first coat from the second coat adjacent the opening causes permanent discoloration of the first coat.
A recording medium of the type having a first coat which is discolorable in a limited area by area-limited heating, comprising, a second coat applied on the first coat, said second coat comprising a material which has heat-conducting and electrically insulating properties, and a third coat applied on said second coat, said third coat comprising a material which is electrically conductive, and said third coat being removable in a limited area by the action of an electric arc which is limited in time and area and wherein said second coat is more resistant to the action of said electric arc than said first coat so that it is not markedly removed by the action of said arc.
Dependencies are inferred from the claim text.