Patent ID: 11953841
Assignee: SHARP KABUSHIKI KAISHA
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. An image forming apparatus comprising:
a photoconductor drum;
a charging roller that charges a surface of the photoconductor drum, and is capable of contacting with and separating from the photoconductor drum by a contact and separation mechanism;
a developer that forms a toner image on the surface of the photoconductor drum;
an image detector that detects the toner image formed by the developer;
a charge power supply that applies a bias voltage to the charging roller;
a development power supply that applies a bias voltage to the developer; and
a controller, wherein
the controller causes the charge power supply and the development power supply to output respective predetermined bias voltages for predetermined time, and is capable of executing a contact and separation determination mode in which a contact and separation state of the charging roller is determined based on whether or not a toner image is detected by the image detector after output of the respective bias voltages.