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 that is endless and rotatable in a rotation direction;
• a nip former stretching the fixing belt;
• a pressure rotator to press against the nip former via the fixing belt to form a fixing nip between the fixing belt and the pressure rotator, the fixing nip through which the recording medium bearing the toner image is conveyed;
• a separator disposed downstream from the nip former in the recording medium conveyance direction and isolated from the pressure rotator via the fixing belt, the separator stretching the fixing belt;
• a presser, interposed between an exit of the fixing nip and an upstream end of the separator in the rotation direction of the fixing belt, to come into contact with an inner circumferential surface of the fixing belt to press the fixing belt against the pressure rotator;
• a pressure adjuster, contacting the pressure rotator, to change a pressing position of the pressure rotator relative to the fixing belt to adjust pressure exerted from the pressure rotator to the fixing belt;
• and
• a presser position adjuster, contacting the presser, to change a presser position of the presser relative to the fixing belt according to the pressing position of the pressure rotator,
• wherein the presser separably contacts the fixing belt,
• the fixing device further comprising a controller to determine whether or not to cause the presser position adjuster to separate the presser from the fixing belt based on a type of the recording medium conveyed toward the fixing nip,
• wherein the controller determines whether or not to cause the presser position adjuster to separate the presser from the fixing belt based on an amount of heat to be conducted to the fixing belt to fix the toner image on the recording medium.