Patent ID: 7742020

Claim:
A personal computer having an electroluminescent display device, said display device comprising: a plurality of signal lines; a plurality of pixels, each pixel including one thin film transistor and an electroluminescent element, wherein a source electrode of the thin film transistor is connected with one of the plurality of signal lines; and a signal line driving circuit configured to input signals to the plurality of signal lines, wherein the signal line driving circuit comprises: a digital signal sampling circuit configured to sample inputted digital gradation signals over one line period; a storage circuit configured to store therein sampled digital gradation signals for one line period; a time setting circuit configured to convert stored digital gradation signals into pulses of corresponding durations by comparing the stored digital gradation signals with counter signals inputted to the time setting circuit; and a constant current circuit configured to receive signals from the time setting circuit and output currents of constant value to the signal lines for the durations of the pulses.