Image forming apparatus

An image forming apparatus comprising:

• an image carrier in which an electrostatic latent image is to be formed on its outer circumferential surface and which is rotatably supported;
• a developing unit including:
• a development container for internally containing a toner-containing developer;
• and a developer carrier which is rotatably supported by the development container and which carries the developer, the developing unit being supported so as to be swingable among:
• a contact position in which an outer circumferential surface of the developer carrier is in contact with the outer circumferential surface of the image carrier, allowing the toner to be fed to the outer circumferential surface of the image carrier;
• a first separate position in which the developer carrier is separate from the image carrier;
• and a second separate position in which the developer carrier is separate from the image carrier farther than in the first separate position;
• a moving mechanism for reciprocating the developing unit between the contact position and the second separate position;
• and
• a drive input gear for inputting, to the developing unit, driving force for driving rotation of the developer carrier, wherein
• the developing unit includes a drive transmission gear for transmitting the driving force of the drive input gear to the developer carrier, and
• while the developing unit is in the contact position or the first separate position, the drive transmission gear is engaged with the drive input gear;
• and while the developing unit is being moved from the first separate position to the second separate position, the drive transmission gear is separated from the drive input gear.