PURPOSE: To obtain a high emitted light intensity even when a light emission output is corrected by a method wherein data in a first latch circuit of an optical printer head are transmitted to input parts of a second latch circuit.

CONSTITUTION: Lighting/extinguishing signals for light emitting parts 10 inputted from a data input terminal 18 are serial/parallel converted in a decoder circuit 15. The lighting/extinguishing signals corresponding to the respective light emitting parts 10 are transmitted to input parts of a first latch circuit 14. On a signal inputted from a first latch signal input terminal 19, the data are held and transmitted to input parts of a first drive circuit 13. The circuit 13 passes a predetermined electric current to the light emitting parts 10 in accordance with the lighting/extinguishing signals from the latch circuit. On the other hand, the data outputted from the circuit 14 are transmitted to corresponding input parts of a second latch circuit 17 and again latched on a signal from a second latch signal input terminal 20. Upon receiving this signal, a second drive circuit passes a predetermined electric current to a second light emitting element array 12 to light the light emitting element array 12 with an improved emitted light intensity.