A cartridge includes a pressing portion, a recessed portion, and an electrical contact. An apparatus body includes a contact unit that includes a contact and a protrusion. The contact and the protrusion are movable away from the mounting region against an elastic force. The contact unit is at a first position in a non-mounted state, a second position in a mounted state, and a third position in a middle state of transitioning from the non-mounted state to the mounted state. The second position is farther away from the mounting region than the first position by the protrusion being inserted into the recessed portion and the contact contacting with the electrical contact. The third position is farther away from the mounting region than the second position by the protrusion being pressed by the pressing portion so that the contact does not contact with the cartridge.

A region of an image bearing member facing a developer bearing member at a developing portion is set as a first region, a region of the image bearing member facing the developer bearing member at the developing portion after a region of the developer bearing member facing the first region makes one revolution is set as a second region, and a region of the image bearing member between the first region and the second region is set as a third region. A first pattern for performing exposure and a second pattern for not performing exposure or for performing exposure with an exposure amount smaller than an exposure amount used for the first pattern is formed in the third region. A length of the second pattern is larger than a length of the first pattern in a rotational direction, and the first pattern and the second pattern are repetitively formed.

A cartridge includes a pressing portion, a recessed portion, and an electrical contact. An apparatus body includes a contact unit that includes a contact and a protrusion. The contact and the protrusion are movable away from the mounting region against an elastic force. The contact unit is at a first position in a non-mounted state, a second position in a mounted state, and a third position in a middle state of transitioning from the non-mounted state to the mounted state. The second position is farther away from the mounting region than the first position by the protrusion being inserted into the recessed portion and the contact contacting with the electrical contact. The third position is farther away from the mounting region than the second position by the protrusion being pressed by the pressing portion so that the contact does not contact with the cartridge.