Semiconductor laser driving unit, optical scanner having semiconductor laser driving unit, and image forming apparatus

A semiconductor laser driving unit that outputs a driving current for driving a semiconductor laser, comprising:

• a driving current setting circuit that sets a value of the driving current;
• a correction current setting circuit that sets a value of a correction current used to determine a rising characteristic and/or a falling characteristic of the output;
• a data timing regulator circuit that regulates a timing for outputting the driving current and the correction current based on input image data;
• and
• a driver circuit that outputs the driving current and the correction current, wherein
• the data timing regulator circuit generates based on the input image data, and outputs to the driver circuit, a driver circuit input signal, and
• the data timing regulator circuit generates, and outputs to the correction current setting circuit, (i) a first correction circuit input signal that is turned on during a time period in which the driver circuit input signal is rising and (ii) a second correction circuit input signal that is turned on during a time period in which the driver circuit input signal is falling, and
• the correction current setting circuit, upon receiving the first correction circuit input signal, inputs an overshoot current to the driver circuit, and upon receiving the second correction circuit input signal inputs an undershoot current to the driver circuit.