PURPOSE: To provide a light emitting diode array, a driver circuit and a driving method thereof which improves influence to a light emitting diode array due to operation and to a light emission amount due to heat generation of a driver IC for precision printing of high gradation.

CONSTITUTION: This light emitting diode array is formed of a pair of a writing light emitting diode 31 and a light screening light emitting diode 32. Meanwhile, a switch circuit 50 inside a driver IC 51 controls to which of a pair of light emitting diode arrays a current supplied from an output driver circuit 54 in accordance with a gradation signal is energized. Since a total current amount supplied to the light emitting diode pair is thereby fixed, temperature of the light emitting diode pair and temperature distribution on a light emitting diode array chip 35 are also fixed, thus making it possible to write an image on a photosensitive drum in good gray scale.