Image forming apparatus which prevents damage to sheet detection flag

An image forming apparatus comprising:

• an image forming portion configured to form a toner image on a recording material;
• a fixing device detachably mounted on a main assembly of the image forming apparatus and configured to fix the toner image formed on the recording material by the image forming portion;
• wherein the fixing device includes a heating rotatable member configured to heat the toner image on the recording material, a pressing rotatable member configured to form a nip portion by being in contact with the heating rotational member, and a detecting unit disposed upstream of the nip portion with respect to a conveyance direction of the recording material and configured to detect the recording material, and
• wherein when a surface of the recording material on which the toner image is formed by the image forming apparatus is defined as a front surface and a surface opposite to the front surface is defined as a back surface, the detecting unit includes a detecting flag, which is provided to be movable and capable of contacting the back surface of the recording material,
• the image forming apparatus further comprising:
• a moving mechanism including a cam and configured to cause the detecting flag and the pressing rotatable member to move,
• wherein the moving mechanism is configured to cause the detecting flag to move between a first position located in a conveyance path of the recording material and a second position retracted from the first position by rotating the cam, and configured to be capable of changing the state between a contact state in which the pressing rotatable member is in contact with the heating rotatable member, and a separation state in which the pressing rotatable member is spaced apart from the heating rotatable member by rotating the cam,
• wherein when the cam is positioned in a first cam position, the detecting flag is in the second position and the pressing rotatable member is in the contact state,
• wherein when the cam is positioned in a second cam position, the detecting flag is in the first position and the pressing rotatable member is in the separation state, and
• wherein when the cam is positioned in a third cam position, the detecting flag is in the second position and the pressing rotatable member is in the separation state.