Image forming apparatus performing warm-up operation by rotation of a motor

An image forming apparatus comprising:

• a motor that generates driving force;
• an image formation-transfer section that includes an image carrier and a transfer section, the image formation-transfer section state-changing between a first contact state and a first separate state by the driving force generated by the motor, the first contact state being a state in which the image carrier and the transfer section are in contact with each other, the first separate state being a state in which the image carrier and the transfer section are separated away from each other, the image formation-transfer section forming a developer image on a medium or the transfer section in the first contact state;
• a switching mechanism that transmits and cuts off the driving force to the image formation-transfer section;
• a fixing section that includes a first rotating member and a second rotating member, the fixing section state-changing between a second contact state and a second separate state by the driving force generated by the motor, the second contact state being a state in which the first rotating member and the second rotating member are in contact with each other, the second separate state being a state in which the first rotating member and the second rotating member are separated away from each other, the fixing section performing fixing operation in the second contact state, the fixing operation being operation of fixing the developer image to the medium;
• and
• a controller that controls the motor and the switching mechanism and thereby causes part or all of a first period and part or all of a second period to overlap each other, the first period being a period in which the fixing section state-changes from the second separate state to the second contact state, the second period being a period in which the image formation-transfer section state-changes from the first separate state to the first contact state, wherein
• a first timing is same as or after a second timing, the first timing being an end timing of the first period, the second timing being an end timing of the second period,
• the fixing section state-changes from the second separate state to the second contact state one or more times in a period from the second timing to the first timing, and
• rotation of the motor in a first rotation direction causes each of the first rotating member and the second rotating member in the second contact state to rotate in a direction of conveying the medium away from the image formation-transfer section, and
• rotation of the motor in a second rotation direction repeatedly causes the first rotating member and the second rotating member to be in the second contact state and the second separate state alternately, the second rotation direction being opposite to the first rotation direction.