Patent ID: 7248524

Claim:
A heating and temperature control system for a data storage apparatus comprising at least one matrix addressable ferroelectric or electret memory device, wherein the at least one memory device comprises: a ferroelectric or electret memory material provided as a global or patterned thin film forming a memory layer in the memory device, a first set of parallel stripe-like electrodes provided in direct or indirect contact with the memory layer on a surface thereof, a second set of parallel stripe-like electrodes oriented orthogonally to the electrodes of the first set and in the same relationship to the memory layer, but on the opposite surface thereof, such that the electrodes of one set constitutes word lines of the at least one memory device and the electrodes of the other set bit lines thereof, wherein a memory cell is defined in a volume of the memory material between a word line and a bit line, such that the number of memory cells in the at least one memory device is given by the number of crossings between word lines and bit lines therein, wherein stored data are represented by one of two specific memory cell polarization states which can be set, detected or changed into the opposite polarization state by applying a potential difference over the memory cell as given by appropriately selected voltage levels applied to the word line and bit line electrodes defining the memory cell, the potential difference corresponding to a switching voltage V s selected higher than a temperature dependent coercive voltage V c of the memory cell, and wherein the heating and temperature control system includes: at least one thin film Joule heating means provided proximal to the memory layer and in thermal contact therewith, controller circuitry connected with the at least one Joule heating means, a temperature determining means connected with the controller circuitry for determining an ambient temperature of the memory device or an instant temperature of the memory material thereof, said ambient or instant temperature being compared with a nominal optimal operating temperature value of the memory device and as set in the controller circuitry, an external power supply connected respectively with the at least one Joule heating means and the controller circuitry for supplying power or current to the Joule heating means under control of the controller circuitry such that the memory material before and/or during an addressing operation is set to a specific desired operating temperature above the ambient or instant temperature and lying in a temperature range around the optimal operating temperature value and as given by a defined upper and lower bound.