Image Forming Apparatus

An image forming apparatus, comprising:

• a first photosensitive drum;
• a first developing roller;
• a first shifting member configured to move between a contacting position, in which the first developing roller contacts the first photosensitive drum, and a separating position, in which the first developing roller is separated from the first photosensitive drum;
• a motor;
• a first joint configured to transmit a driving force from the motor to the first developing roller, the first joint comprising a first joint gear configured to receive the driving force from the motor, the first joint being configured to rotate about a first axis extending in an axial direction by the driving force received by the first joint gear;
• a first clutch configured to operate in one of a transmittable condition, in which the first clutch is transmittable of the driving force from the motor to the first joint gear, and a discontinuing condition, in which the first clutch discontinues transmission of the driving force from the motor to the first joint gear;
• a first shifting cam configured to move the first shifting member, the first shifting cam being configured to rotate about a second axis extending in the axial direction by the driving force received from the motor, the first shifting cam being configured to rotate between a first position, in which the first shifting cam locates the first shifting member at the contacting position, and a second position, in which the first shifting cam locates the first shifting member at the separating position;
• and
• a first switching cam configured to switch the conditions in the first clutch, the first switching cam being configured to rotate about the second axis alongside the first shifting cam, the first switching cam being configured to rotate between a third position, in which the first switching cam places the first clutch in the transmittable condition, and a fourth position, in which the first switching cam places the first clutch in the discontinuing condition, the first switching cam being configured to be located at the third position in a state where the first shifting cam is located at the first position and configured to be located at the fourth position in a state where the first shifting cam is located at the second position.