Image forming apparatus with dark current compensation for automatic power control (APC)

摘要

An image forming apparatus, including: a laser light source supplied with a bias current and a superimposed current to emit laser light; a splitting unit configured to split the laser light into first and second laser lights; a photoelectric conversion unit configured to output a voltage corresponding to a light intensity of the second laser light; a voltage holding unit configured to hold a voltage output from the photoelectric conversion unit with not the superimposed current but the bias current being supplied to the laser light source; a voltage conversion unit configured to remove the voltage held by the voltage holding unit from the voltage from the photoelectric conversion unit which receives the second laser light; and a current control unit configured to control, based on a voltage from the voltage conversion unit, a value of the superimposed current supplied to the laser light source based on image data.

主权项

1. An image forming apparatus, comprising:
a laser light source configured to emit laser light, the laser light source being supplied with a bias current and a superimposed current which is superimposed on the bias current; a splitting unit configured to split the laser light, which is emitted from the laser light source supplied with a current obtained by superimposing the superimposed current on the bias current, into first laser light and second laser light, the first laser light exposing a photosensitive member; a photoelectric conversion unit configured to receive the second laser light to output a voltage corresponding to a light intensity of the received second laser light; a voltage holding unit configured to hold a voltage output from the photoelectric conversion unit in a state in which the bias current is supplied to the laser light source, but the superimposed current is not supplied to the laser light source; a voltage conversion unit configured to remove the voltage held by the voltage holding unit from the voltage output from the photoelectric conversion unit which receives the second laser light; and a current control unit configured to control, based on a voltage converted by the voltage conversion unit, a value of the superimposed current to be supplied to the laser light source based on image data.