Fixing device and image forming apparatus

An image forming apparatus comprising:

• an image forming device to form a toner image;
• and
• a fixing device disposed downstream from the image forming device in a recording medium conveyance direction to fix the toner image on a recording medium,
• the fixing device including:
• a fixing belt being endless and rotatable in a rotation direction;
• a primary heater, disposed opposite an inner circumferential surface of the fixing belt, to heat the fixing belt, the primary heater including a center heat generator disposed opposite a center span of the fixing belt in an axial direction of the fixing belt;
• a secondary heater, disposed opposite the inner circumferential surface of the fixing belt, to heat the fixing belt, the secondary heater including a lateral end heat generator disposed opposite a lateral end span of the fixing belt in the axial direction of the fixing belt;
• a nip formation pad disposed opposite the inner circumferential surface of the fixing belt;
• and
• an opposed rotator to press against the nip formation pad via the fixing belt to form a fixing nip between the fixing belt and the opposed rotator, the fixing nip through which the recording medium bearing the toner image is conveyed,
• the nip formation pad including:
• a base;
• and
• at least one thermal conductor being interposed between the base and the fixing nip and having a thermal conductivity greater than a thermal conductivity of the base,
• the at least one thermal conductor including an outboard edge disposed between an inboard edge and an outboard edge of the lateral end heat generator in the axial direction of the fixing belt and disposed outboard from a conveyance span of the fixing belt in the axial direction of the fixing belt, the conveyance span where the recording medium is conveyed over the fixing belt.