Commissariat a L'energie Atomique

Bruno Dargent

Jacques Robert

Joseph Borel

Guy Labrunie

The invention relates to a process for producing conductors for integrated circuits using planar technology. According to this process, on a substrate is deposited an insulating material coating. A masking sheet is deposited on the insulating material coating and this sheet is cut to form windows corresponding to the conductors to be obtained. The insulating material sheet is etched facing the windows. A conductive material is deposited on the cut masking sheet. The masking sheet and the conductive material covering it are removed. This process consists of choosing a masking sheet having a first coating covering the insulating material coating and a second masking coating covering the first coating. The first coating is cut chemically facing the windows and after cutting the second masking coating, the edges of the first coating on the periphery of the windows are eroded by chemical cutting. Application to the production of planar integrated circuits.

Process for producing conductors for integrated circuits using planar

An analog liquid crystal display apparatus comprising a liquid crystal film band inserted between a first conductive electrode and a second resistive electrode; a first voltage source is connected between said first and second electrodes; a second power supply is connected between the two ends of the resistive electrode; the liquid crystal presents a first optical state on a first part of the band and a second optical state on the remainder of the band. The liquid crystal is of the type having a critical relaxation frequency which is either a load relaxation frequency or a dielectric relaxation frequency, the first power supply supplying a voltage at a first frequency and the second power supply supplying a voltage at a second frequency, said two frequencies being on either side of said critical frequency; one of the voltage is then a display voltage and the other is a voltage which inhibits the display.

Liquid crystal display apparatus

A display cell comprises a liquid-crystal film interposed between two groups of electrodes to which is applied a set of low-frequency voltages in order to produce an optical state '0' at desired points and a set of high-frequency voltages in order to produce an optical state '1' at other predetermined points. In the composite excitation applied to each zone, the low-frequency fraction of excitation exceeds the high-frequency fraction in the '0' display zones and the high-frequency fraction exceeds the low-frequency fraction in the '1' display zones.

Method of control of a liquid-crystal display cell

A method for controlling an optical characteristic of a material which is intercalated between two electrodes driven by periodic excitation signals having a zero mean value consists in applying to the electrodes signals having the same time-duration and the same recurrence frequency but in which one signal has a phase shift .phi. with respect to the other, the phase shift being modified in order to adjust the optical characteristic.

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Grenoble, France

Bruno Dargent