Abstract: A system for making a device temperature dependent whose operation is dependent on the local heating applied to a thermo-active material layer. The invention uses the heating electrodes of the device as temperature sensors, the information detected by these sensors being stored in a memory and used as bases for establishing the temperature dependence.

Abstract: The invention relates to display devices with a mixed thermal and electrical effect. The invention relates to a special addressing mode making it possible to display a writing line, while limiting the control voltages to be applied from the outside to the display screen.

Abstract: The invention relates to planar display screens and more particularly to smectic liquid crystal screens.One of the problems of high definition display screens (approximately 100 to 1000 lines and columns) is caused by the devices for controlling the heating current on the lines. The complexity of the installation and costs limit the increase in the definition. The invention arranges the N lines of a screen into .sqroot.N groups of lines supplied at each of their ends by .sqroot.N control devices functioning sequentially, i.e. 2.sqroot.N devices in all. Moreover, each line has a diode placed between the heating resistor and the common point of the circuit.Application to the display of images transmitted in the form of a video signal for television and display peripheral equipment in teletransmission.