Reversible memory structure with thermo-optical writing and optical reading and process for writing and erasing said structure
AssigneeThomson-CSF
InventorJean Cornet
Life of this patent
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Abstract
The invention relates to a reversible memory structure with thermo-optical inscription or writing and optical reading on a moving support. According to the invention, the memory structure deposited on a substrate (1) is constituted by a double layer (2 and 3). A second alloy layer (3) at ambient temperature in the martensitic phase is deposited on a first thermally deformable layer (2). A heat pulse creates a deformation in the first layer, which deforms the martensitic alloy layer. A more powerful heat pulse raises the alloy layer to a temperature above its transformation point from the martensitic phase to another crystallographic phase and erases the inscribed deformation. Particular application to optical disks.
Claims7
A reversible memory structure with thermo-optical writing or inscription and optical reading, supported by a substrate performing a forward movement, wherein the substrate is a material having a low expansion coefficient and the inscribable layer deposited on the substrate is formed by at least two individual layers, constituted by a first layer made from a material which, under the action of heat, deforms a second superimposed layer of a relatively inexpansible alloy which is at ambient temperature in a martensitic phase and has a transformation to another crystallographic phase at a temperature below the melting temperature of the first layer.
Dependencies are inferred from the claim text.