The invention provides an optical head which has simple structure and can align irradiancy lightness discrepancy. In the optical head (10A), light-emitting components (36) of a block (B1) are driven by demultiplexer DMP1 and unit electrocircuits U1-U4. The unit electrocircuits U1-U4 correspond to the aligning data stored in memorizers M1-M4 and set up the driving current so as to adjust light-emitting components (36) irradiancy lightness in the block. The irradiancy lightness between blocks is adjusted into uniform through control signals E1-En during irradiancy duration. The magnitude of driving current is utilized to adjust irradiancy lightness with smaller scope, and the length of irradiancy duration is utilized to adjust irradiancy lightness with larger scope.