Patent ID: 7911424
Filing Date: 2011-03-22
Classification: G09G

Abstract:
1. A device for regulating the bias voltage of circuits for controlling columns of a matrix display formed of light-emitting diodes distributed in lines and in columns, the column control circuits configured to select columns to turn on the light-emitting diodes of the selected columns and of a selected line of the matrix display, the device comprising: a first measurement circuit providing a first measurement signal representative of a highest voltage among voltages of the selected columns; a second measurement circuit-configured to measure the voltages of the selected columns and to provide a second measurement signal representative of a single lowest voltage among the voltages of the selected columns; and an adjustment circuit receiving the first and second measurement signals and configured to decrease the bias voltage if the first measurement signal is smaller than a first comparison signal and to increase the bias voltage if the second measurement signal is greater than a second comparison signal.