Sheet stop mechanism and image forming apparatus

A sheet stop mechanism provided at a downstream end portion in a sheet discharge direction of a sheet loading surface configured to receive a sheet discharged from a sheet discharge port, the sheet stop mechanism comprising:

• a sheet stopper supported rotatably around a shaft portion, and including a movement restriction portion formed on a first side of the shaft portion and an operation portion and a locked portion formed on a second side of the shaft portion;
• a first operation restriction portion configured to form a first step between the first operation restriction portion and a first operation portion which is a part of the operation portion and restrict downward movement of a finger which pushes down the first operation portion;
• a second operation restriction portion configured to form a second step larger than the first step between the second operation restriction portion and a second operation portion which is a part of the operation portion and restrict downward movement of the finger which pushes down the second operation portion;
• a first locking portion configured to lock the locked portion to hold the sheet stopper in a housed state in which the movement restriction portion is housed in a recess formed in the sheet loading surface, and release the locking of the locked portion by being elastically deformed by a force received from the locked portion when a first push of pushing down the first operation portion to a position of the first operation restriction portion or a second push of pushing down the second operation portion to a position of the second operation restriction portion is performed;
• a second locking portion configured to, when the sheet stopper is rotated in response to the first push, lock the locked portion to stop the sheet stopper in a first upright state in which the movement restriction portion extends from the sheet loading surface in an obliquely upward direction on a downstream side of the sheet discharge direction and, when the sheet stopper is rotated in response to the second push, be elastically deformed by a force received from the locked portion to allow the sheet stopper to rotate beyond the first upright state;
• and
• a third locking portion configured to, when the sheet stopper is rotated beyond the first upright state, locks the locked portion to stop the sheet stopper in a second upright state in which an acute angle formed with respect to the sheet loading surface is smaller than that in the first upright state.