Heat reflection using reflector in fixing device and image forming apparatus

An image forming apparatus comprising:

• a cassette;
• and
• an image forming unit configured to form a toner image on a sheet supplied from the cassette, wherein
• the image forming unit includes a fixing unit configured to fix the toner image on the sheet, the fixing unit including
• a belt that is rotatable in a rotational direction,
• a roller positioned to be in contact with an outer peripheral surface of the belt so as to form a nip between the roller and the belt,
• a heater disposed within an inner circumference of the belt, and
• a reflector disposed within the inner circumference of the belt, the reflector including a first portion that is in contact with and protrudes outwardly the belt at a first region downstream with respect to the nip in the rotational direction and a second portion configured to reflect heat generated by the heater toward an inner surface of the belt at a second region upstream with respect to the nip in the rotational direction.