Image forming apparatus

1 . An image forming apparatus comprising:

an apparatus main body housing an image forming unit which forms an image on a medium;

a reading unit provided on an upper portion of the apparatus main body in an openable and closable manner, and readable an image of a document;

a document cover provided on an upper portion of the reading unit in an openable and closable manner, and pressing the document placed on the reading unit; and

a lock part which holds one of the reading unit and the document cover in a closed state when the other of the reading unit and the document cover is in an opened state, wherein

the lock part includes:

a turning member supported in an inside of the reading unit in a slidable manner in a horizontal direction and in a turnable manner around a rotational shaft;

a first protrusion member protruded from the upper portion of the apparatus main body, and configured to enter the inside of the reading unit in the closed state and be disposed on one side of a sliding direction of the turning member;

a second protrusion member protruded from a lower portion of the document cover, and configured to enter the inside of the reading unit when the document cover is in the closed state and be disposed on the other side of the sliding direction of the turning member;

a slide biasing member biasing the turning member to one side of the sliding direction; and

a turn biasing member biasing the turning member to one side of a turning direction, and

the turning member has:

a first hook portion configured to be engageable with the first protrusion member below the rotational shaft; and

a second hook portion configured to be engageable with the second protrusion member above the rotational shaft, wherein

in a case where the reading unit and the document cover are in the closed state, the turning member is pushed by the first protrusion member to the other side of the sliding direction against a biasing force of the slide biasing member to be disposed in a first position, and is pushed by the second protrusion member to the other side of the turning direction against a biasing force of the turn biasing member to be in a release posture where the first hook portion and the second hook portion are separated from the first protrusion member and the second protrusion member,

in a case where the document cover is in the opened state, the second protrusion member is separated from the turning member, the turning member is disposed in the first position, is biased by the turn biasing member to be turned to one side of the turning direction and is in a first engagement posture where the first hook portion is engaged with the first protrusion member, and

in a case where the reading unit is in the opened state, the first protrusion member is separated from the turning member, the turning member is biased by the slide biasing member to one side of the sliding direction to be disposed in a second position, is biased by the turn biasing member to be turned to one side of the turning direction, and is in a second engagement posture where the second hook is engaged with the second protrusion member.

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

the slide biasing member and the turn biasing member are coupled to be formed integrally.

3 . The image forming apparatus according claim 1 , wherein

the first hook portion has a first inclined surface portion which is in contact with the first protrusion member when the reading unit is turned from the opened state to the closed state,

the second hook portion has a second inclined surface portion which is in contact with the second protrusion member when the document cover is turned from the opened state to the closed state,

the first protrusion member has:

a first engagement surface portion with which the first hook portion is to be engaged;

a first contact surface portion abutting on the turning member disposed in the first position; and

a first guide inclined surface portion configured to slide on the first inclined surface portion of the turning member in the second engagement posture at the second position when the reading unit is turned from the opened state to the closed state, and to slide the turning member to the other side of the sliding direction while turning the turning member to the other side of the turning direction, and

the second protrusion member has:

a second engagement surface portion with which the second hook portion is to be engaged;

a second contact surface portion abutting on the turning member in the release posture; and

a second guide inclined surface portion configured to slide on the second inclined surface portion of the turning member in the first engagement posture at the first position when the document cover is turned from the opened state to the closed state, and to turn the turning member to the other side of the turning direction.

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

a first auxiliary protrusion and a second auxiliary protrusion are extended parallel to the rotational shaft on both sides of the turning member in the sliding direction in the inside of the reading unit,

the first auxiliary protrusion faces the first guide inclined surface portion of the first protrusion member when the reading unit is in the closed state, and

the second auxiliary protrusion faces the second guide inclined surface portion of the second protrusion member when the document cover is in the closed state.

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

the sliding direction of the turning member is along a front-and-rear direction, and the rotational shaft is along a left-and-right direction perpendicular to the front-and-rear direction.

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

the reading unit is supported on a rear portion of the upper portion of the apparatus main body in a turnable manner,

the document cover is supported on a rear portion of the upper portion of the reading unit, and

the lock part is provided in front portions of the apparatus main body, the reading unit and the document cover.