Exposure unit containment mechanism and image-forming apparatus

1. An exposure unit containment mechanism comprising:

an exposure unit that performs exposure in accordance with image data; and

a frame that defines a space having an opening and containing the exposure unit inserted therein through the opening,

wherein

the exposure unit includes:

first protrusions provided at a position spaced apart from a center of gravity of the exposure unit in a direction of insertion of the exposure unit into the space, such that the first protrusions protrude left and right with respect to the direction of insertion;

a second protrusion that protrudes in a direction having a downward component; and

third protrusions provided at a position spaced apart from the first protrusions and the second protrusion in a direction opposite to the direction of insertion, such that the third protrusions protrude in the left and right directions, and

the frame includes:

a guide member that contacts the first protrusions from above to limit movement of the first protrusions in an upward direction and guide the insertion of the exposure unit;

a first limiting member that, when the exposure unit is guided by the guide member into the space, contacts the second protrusion from the left and from the right to limit left and right movement of the second protrusion;

a second limiting member that, in a state where the movement of the second protrusion is limited by the first limiting member, contacts the first protrusions from underneath to limit downward movement of the first protrusions;

a first pressing member that presses the first protrusions from above when the first protrusions are in contact with the second limiting member;

a supporting member that supports the third protrusions from underneath;

a third limiting member that, in a state where the first protrusions are pressed by the first pressing member, contacts the third protrusions in the direction opposite to the direction of insertion to limit movement of the third protrusions in the direction of insertion; and

a second pressing member that presses the third protrusions, whose movement in the direction of insertion is limited by the third limiting member, against the third limiting member and against the supporting member.

2. The exposure unit containment mechanism according to claim 1 , wherein

the frame includes a supporting plate that supports the exposure unit from underneath when the exposure unit is contained in the space, and

the first limiting member includes an insertion groove formed in the supporting plate, the insertion groove having an opening that faces in the direction opposite to the direction of insertion and receiving the second protrusion of the exposure unit when the exposure unit is inserted into the space.

3. The exposure unit containment mechanism according to claim 1 , wherein

the frame includes a first stopper member that, when the first protrusions move a predetermined distance in the upward direction against the pressing by the first pressing member, contacts the first protrusions to prevent upward movement of the exposure unit.

4. The exposure unit containment mechanism according to claim 1 , wherein

the frame includes a second stopper member that, when the third protrusions move a predetermined distance in a direction against the pressing by the second pressing member, contacts the third protrusions to prevent movement of the exposure unit against the pressing by the second pressing member.

5. The exposure unit containment mechanism according to claim 1 , wherein

the exposure unit has a trailing-end contact surface facing in the direction opposite to the direction of insertion, and

the frame includes a third stopper member that, when the exposure unit contained in the space moves a predetermined distance in the direction opposite to the direction of insertion, contacts the trailing-end contact surface of the exposure unit to prevent the movement of the exposure unit in the direction opposite to the direction of insertion.

6. The exposure unit containment mechanism according to claim 1 , wherein

the exposure unit includes:

a left contact surface facing in the left direction; and

a right contact surface facing in the right direction, and

the frame includes:

a left stopper member that, when the exposure unit contained in the space moves a predetermined distance in the left direction, contacts the left contact surface of the exposure unit to prevent the movement of the exposure unit in the left direction; and

a right stopper member that, when the exposure unit contained in the space moves a predetermined distance in the right direction, contacts the right contact surface of the exposure unit to prevent the movement of the exposure unit in the right direction.

7. An image-forming apparatus comprising:

the exposure unit containment mechanism according to claim 1 : and

an image-forming device that develops a latent image in accordance with exposure performed by the exposure unit contained in the space defined by the frame of the exposure unit containment mechanism, transfers the developed image onto a medium, and fixes the transferred image.

8. An exposure unit containment mechanism comprising:

a frame that defines a space having an opening through which an exposure unit is inserted,

wherein the frame includes:

a guide member that contacts first protrusions of the exposure unit from above to limit movement of the first protrusions in an upward direction and guide the insertion of the exposure unit, the first protrusions being provided at a position spaced apart from a center of gravity of the exposure unit in a direction of insertion of the exposure unit into the space, such that the first protrusions protrude left and right with respect to the direction of insertion;

a first limiting member that, when the exposure unit is guided by the guide member into the space, contacts a second protrusion of the exposure unit from the left and from the right to limit left and right movement of the second protrusion, the second protrusion protruding in a direction having a downward component;

a second limiting member that, in a state where the movement of the second protrusion is limited by the first limiting member, contacts the first protrusions from underneath to limit downward movement of the first protrusions;

a first pressing member that presses the first protrusions from above when the first protrusions are in contact with the second limiting member;

a supporting member that supports third protrusions of the exposure unit from underneath, the third protrusions being provided at a position spaced apart from the first protrusions and the second protrusion in a direction opposite to the direction of insertion, such that the third protrusions protrude in the left and right directions;

a third limiting member that, in a state where the first protrusions are pressed by the first pressing member, contacts the third protrusions in the direction opposite to the direction of insertion to limit movement of the third protrusions in the direction of insertion; and

a second pressing member that presses the third protrusions, whose movement in the direction of insertion is limited by the third limiting member, against the third limiting member and against the supporting member.