Image forming apparatus having a pair of chains wound around a fixing roller and a transfer roller

An image forming apparatus comprising:

• a fixing cylinder that is rotatably supported, that has a groove formed in an outer portion thereof in a rotational radial direction thereof, and that causes an image transferred to a recording medium to be fixed to the recording medium when the recording medium passes along an outer surface of the fixing cylinder in the rotational radial direction;
• a delivery cylinder that is rotatably supported;
• a circulating member that is loop-shaped and wrapped at least around the fixing cylinder and the delivery cylinder;
• a plurality of holding members configured to hold the recording medium when the recording medium passes around the delivery cylinder toward the fixing cylinder, the holding members being supported by the circulating member such that the holding members are arranged in a length direction of the circulating member with predetermined intervals therebetween, each holding member being disposed in the groove when the holding member passes along the outer portion of the fixing cylinder;
• a pressure unit that is rotatably supported and that causes the recording medium to pass between the pressure unit and the fixing cylinder while a pressure is applied between the pressure unit and the fixing cylinder, the pressure unit coming into contact with the fixing cylinder when none of the plurality of holding members is performing a holding operation, wherein a holding operation occurs during a period from when one of the plurality of holding members begins to close until the holding member finishes closing;
• a transfer cylinder that is rotatably supported, that has a first groove formed in an outer portion thereof in a rotational radial direction thereof, and that causes the image to be transferred to the recording medium when the recording medium passes along an outer surface of the transfer cylinder in the rotational radial direction;
• a transfer roller that is rotatably supported and disposed at a location close to the transfer cylinder;
• and
• a first motor that rotates the transfer cylinder about a first axis;
• and
• a second motor that rotates the fixing cylinder about a second axis,
• wherein the groove in the fixing cylinder is a second groove,
• wherein the circulating member is wrapped at least around the transfer cylinder, the fixing cylinder, and the delivery cylinder,
• wherein each holding member is disposed in the first groove when the holding member passes along the outer portion of the transfer cylinder,
• wherein the transfer roller opposes the first groove when the pressure unit comes into contact with a rotationally upstream end portion of the second groove in the fixing cylinder, and
• wherein a moment of inertia of the transfer cylinder about the first axis is set to be less than a moment of inertia of the fixing cylinder about the second axis.