Abstract: A device for weakening the incident light passing through a transparent emissive display system so as not to drown the emitted light is disclosed which utilizes two polarizing filters one at least of which is placed before the screen so as to selectively attenuate the incident light. A photoelectric cell measures this incident light and controls a motor which rotates one of the filters so as to adjust the attenuation to the initial intensity.

Abstract: The subject matter of the invention is a method of substituting an electronic component (A1) for an analogous component (1) connected to the conductive tracks (3) of a support substrate (2) by connection wires (4). The conductive tracks are cut beyond, relative to the component (1) to be taken out of service, the zones where the connection wires (4) are connected to the tracks, then the replacement component (A1) is placed on the upper glued face of the component (1), and is connected to the tracks by connection wires (4A) independent from the preceding wires.This invention is particularly applicable to integrated circuits and to vacuum-deposited resistive thin film circuits.

Abstract: A two dimensional display unit with an electrically controlled fluid and a method of manufacturing it. A layer of liquid crystal whose birefringence is electrically controlled is disposed between two thin glass plates which bear transparent electrodes and are connected together by metal studs regularly spaced apart over the whole useful surface so as to maintain a gap of constant thickness, the cell thus constituted being illuminated by parallel light and placed between crossed polarizer and analyzer. The invention applies to displaying various images at a low cost.