Original Publication Date: 1985-May-01
Included in the Prior Art Database: 2005-Feb-18
A credit or similar card has an additional strip embedded in the material thereof, which strip can be temporarily affected by a printer of a terminal into which the card is inserted, to render information therefrom temporarily visible. A credit card of plastic material has a shallow groove formed in one surface thereof, which groove is filled with liquid crystal material. The surface with the material in position is then covered by a transparent plastic sheet and laminated. At normal temperatures up to 40ŒC, such material forms a homogeneous plain colored layer, but when heated to a high temperature, such as 55ŒC, the heated crystals change color or tint and become visible. Selective heating enables characters to be displayed. Upon cooling, the crystals return to their normal temperature appearance.