A sheet feeding device of the present invention includes a feeding mechanism including a belt and a reverse roller, and circular collars or similar spacing members adjoining the belt for spacing the reverse roller and belt. The piezoelectric element includes a laminate of at least two piezoelectric layers. If the criterion checked is satisfied, checking whether operation of the discharge lamp satisfies the other of the two criteria is carried out. Each of the base sockets is oriented in an upward direction. The at least one hinge mounting structure can be a pin or like structure provided as part of a pair of pins connected directly or indirectly to the support member.