Light-emitting element array driver circuit

摘要

A driver IC of a light-emitting diode array head for an electronic photograph printer includes a current mirror circuit having a reference element and at least an output element so as to produce a reference current by use of a digital signal as an input thereto, a reference current source capable of outputting a plurality of reference current values, a selection circuit for specifying and selecting one of a plurality of reference current values from the reference current source to be applied as an input current to the current mirror circuit, and an output control circuit for controlling the on and off states of an output current to be supplied to the output element of the current mirror circuit in accordance with a light emission control signal externally supplied. The output control circuit achieves a multi-stage control of the driver output current volume, which is to be delivered to the light emitting diodes, thereby facilitating the driving operation to correct the fluctuation in the light emission power of the light-emitting diode array and the change of the light emission power thereof with the lapse of time.