Fixing device and image forming apparatus incorporating same

A fixing device comprising:

• an endless belt;
• an opposed rotator opposite the belt;
• a nip formation pad disposed inside a loop of the belt and configured to contact the opposed rotator via the belt to form a fixing nip between the opposed rotator and the nip formation pad,
• the nip formation pad having a plurality of projections in a longitudinal direction of the nip formation pad;
• a heater configured to heat the belt, disposed inside the loop of the belt;
• a stay disposed inside the loop of the belt to support the nip formation pad;
• and
• a positioner configured to position the nip formation pad in the fixing device, disposed between the nip formation pad and the stay,
• the positioner having a plurality of insertion holes arranged in a longitudinal direction of the positioner and configured to accept the plurality of projections and restrict movement of the nip formation pad with respect to the positioner in a rotation direction of the belt and a direction opposite the rotation direction of the belt,
• the plurality of insertion holes including an insertion hole disposed at a position corresponding to an end portion of the nip formation pad and configured to accept two or more projections of the plurality of projections arranged in the longitudinal direction of the nip formation pad.