Fixing device and image forming apparatus including the same

A fixing device has a flexible endless fixing member; a heater to heat the fixing member; a nip forming member to contact the fixing member directly or via a slide member; a pressure member, rotatably disposed opposite the fixing member and the nip forming member; and a back curl correction structure that includes a drive roller disposed on a side where a back curl appears in the recording sheet; a driven roller disposed opposite the drive roller; an auxiliary nip portion to feed the recording sheet; a guide member to guide the recording sheet fed out from the auxiliary nip portion to bend in a direction opposite a curled direction of the back curl of the recording sheet. A driving connection between the drive roller and the pressure member is performed by a connection between a drive roller side connection gear and a pressure member side connection gear.