Image forming apparatus including transfer and feeding unit

1. An image forming apparatus, comprising:

a main body;

an image carrier;

a housing provided with a rotation fulcrum in a lower part thereof;

a transfer roller that is disposed in the housing and configured to be opposite to the image carrier when the housing is rotated around the rotation fulcrum;

a transfer roller pressing member that is disposed in the housing and configured to urge the transfer roller toward the image carrier;

a guide that is disposed in the housing and configured to feed transfer paper;

a fixing hook that is disposed in the housing and configured to be urged in a direction to lock the housing about the main body;

a transfer roller releasing lever that is disposed in the housing and configured to separate the transfer roller from the image carrier against urging performed by the transfer roller pressing member;

a transfer roller positioning part that is disposed in the main body and configured to position the transfer roller; and

an operation part configured to cause the fixing hook to rotate in a direction to unlock the housing such that the transfer roller releasing lever rotates in a direction to release the transfer roller from the image carrier.

2. The image forming apparatus according to claim 1 , wherein

the transfer roller releasing lever is urged onto the transfer roller pressing member such that the fixing hook is restricted from moving to a position to unlock the housing, when the transfer roller is positioned with respect to the image carrier.

3. The image forming apparatus according to claim 1 , wherein

the operation part is a handle to open and close a panel that constitutes a part of an outer wall of the main body.