ECRAN D'AFFICHAGE A DIODES ELECTROLUMINESCENTES A MATRICE ACTIVE POURVU DE MOYENS D'ATTENUATION

An active matrix light-emitting diode display screens, and in particular those with organic diodes is discussed. The display screen includes an active matrix of pixels, each pixel including a light-emitting diode, a control MOS transistor for applying a variable voltage or current to the anode of the diode, a selection transistor for applying a variable analog voltage representing a relative level of luminance of the pixel in the image, to the gate of the transistor, during a write phase of this pixel, a storage capacitor for maintaining this voltage on the gate of the transistor outside the write phase. A mean luminance attenuation circuit including a switch for periodically connecting one of the electrodes of the diode, preferably the cathode, to one or other of two fixed potentials, and a switch control circuit for switching with a variable duty cycle according to the desired attenuation.