Abstract: A driving-force transmitter and a process cartridge. The process cartridge has a photosensitive drum and the driving-force transmitter mounted on the end of the photosensitive drum. The driving-force transmitter having a fitting part and multiple protrusions protruding from an end surface of the fitting part. The multiple protrusions are distributed equiangularly on a circle which is in the end surface of the fitting part. The center of the circle is on the axis of the fitting part. There is an engaging-part on the farthest end of each protrusion from the axis of the fitting part. An anti-separating groove is provided on the engaging-part.

Abstract: A valve core of an ink cartridge includes an elastic valve sheet having an inner portion and an outer portion. The outer portion extends outwards from the inner portion and protrudes towards an upstream side of the valve core. The outer portion is adapted to sealingly engage and disengage with a valve seat in which the valve core is mounted.

Abstract: A valve core of an ink cartridge includes an elastic valve sheet having an inner portion and an outer portion. The outer portion extends outwards from the inner portion and protrudes towards an upstream side of the valve core. The outer portion is adapted to sealingly engage and disengage with a valve seat in which the valve core is mounted.

Abstract: The invention involves seal rings useful for ink cartridges. The invention also involves ink cartridges having such seal rings. The seal ring comprises a tube-shaped, elastic part having an insertion opening at its lower end for receiving an ink supply needle. The top of the insertion opening includes a top sealing film. The top sealing film closes in its natural state and prevents ink from leaking through. The seal ring of the invention is simple in structure and effective in preventing ink from leaking out.