A display panel includes a number of light emitting elements arranged in a matrix fashion. A light emitting element driving circuit for use in the display panel can reduce fluctuations in brightness among the light emitting elements. A pulse supply circuit is formed so as to charge/discharge a capacitor based on a clock signal and drive the light emitting element based on the resulting discharge current. The amplitude of a drive current for each of the light emitting elements is not controlled by a transistor in a TFT circuitry, but controlled by external factors installed outside the display panel. The external factors may be a pulse supply circuit providing drive power source voltage and clock frequency. The external factors can be determined precisely.