Driving device, driving method, and light-emitting unit

A driving device comprising:

• setting circuitry configured to set at least one of a bias current of a light-emitting element or a target current for setting output light from the light-emitting element to desired intensity on a basis of a result of detection of an offset light amount when the light-emitting element does not emit light, the detection being performed by a light-receiving element that receives a portion of the output light;
• and
• an output controller configured to control an output of a driving current of the light-emitting element on a basis of at least one of the set bias current or the set target current, wherein
• the output controller includes a current mirror circuit having a variable current mirror ratio, and controls an output of a driving current in which an output current of the current mirror circuit and the bias current are added up, and
• the current mirror ratio is reduced after passage of a predetermined delay time from the start of the output of the output current.

A driving method implemented by a driving device, the driving method comprising:

• setting at least one of a bias current of a light-emitting element or a target current for setting output light from the light-emitting element to desired intensity on a basis of a result of detection of an offset light amount when the light-emitting element does not emit light, the detection being performed by a light-receiving element that receives a portion of the output light;
• and
• controlling an output of a driving current of the light-emitting element on a basis of at least one of the set bias current or the set target current wherein
• controlling the output of the driving current uses a current mirror circuit having a variable current mirror ratio, and controls an output of a driving current in which an output current of the current mirror circuit and the bias current are added up, and
• the current mirror ratio is reduced when an output of the output current is started.