Patent ID: 8757769

Claim:
An image forming apparatus comprising: a recording head that discharges liquid droplets; a waste liquid receiving member that receives waste liquid that is discharged from the recording head for a purpose unrelated to image formation; a waste liquid tank that accommodates the waste liquid received by the waste liquid receiving member; a needle member that is connected to the waste liquid receiving member and includes a needle part that is detachably inserted into the waste liquid tank; and a fastening member that is fixed at an apparatus main frame and is configured to detachably fasten the needle member to the apparatus main frame; wherein the fastening member includes a lock part that locks the needle member and receiving faces that are arranged into circular arcs opening towards an upper side when viewed as a cross-section perpendicular to a liquid flow direction of the needle member; the needle member includes a lock lever part that locks with the lock part of the fastening member; the needle member includes a connection part that connects the needle part to a discharge tube to connect flow paths of the needle part and the discharge tube respectively; the lock lever of the needle member is disposed to rotate the needle member along a cross-section perpendicular to the axis direction, and the lock lever part includes a protrusion that locks with the lock part of the fastening member, and when the needle member is rotated by the lock lever part until the protrusion goes over the lock part, the lock lever part is locked and fastened to the lock part; the needle member and the fastening member include fitting parts that fit together when the needle member is rotated; the fitting part of the fastening member is arranged into a circular arc when viewed as a cross-section perpendicular to the axis direction; and by rotating the needle member, the fitting parts of the needle member and the fastening member are fit together.