Patent ID: 8556256
Filing Date: 2013-10-15
Classification: B65H,Y10S

Abstract:
1. An image forming apparatus, comprising: a conveyance device to convey a sheet of recording media; an image forming device disposed opposing the conveyance device to form an image on the sheet conveyed by the conveyance device; a switchback device rotatable in forward and reverse directions and disposed downstream from the conveyance device to switch back the sheet after the image forming device forms an image on a first face of the sheet on an opposing surface of the conveyance device opposing the image forming device; a refeeding device to refeed, toward the image forming device again, the sheet switched back by reverse rotation of the switchback device; a reverse path to guide the sheet refed by the refeeding device to a non-opposing surface of the conveyance device opposite to the opposing surface, reverse the sheet, and guide the sheet to the opposing surface of the conveyance device again; a single driving source to drive the conveyance device and the switchback device; a driving assembly to transmit driving force of the driving source to the conveyance device; a clutch assembly disposed at a position other than the driving assembly to switch rotation of the switchback device between forward rotation and reverse rotation; and an activation device to activate the clutch assembly to switch rotation of the switchback device between forward rotation and reverse rotation, wherein each of the driving source and the conveyance device is rotatable in forward and reverse directions, the conveyance device serves as the activation device, and the clutch assembly is activated by a certain amount of reverse rotation of the conveyance device to switch rotation of the switchback device between forward rotation and reverse rotation, and wherein the conveyance device has a conveyance belt looped around at least two rotary members for circulation to convey the sheet with the sheet attached on the conveyance belt, the refeeding device refeeds and guides the sheet switched back to a belt surface of the conveyance belt at a non-opposing side of the conveyance belt not opposing the image forming device, the reverse path guides the sheet so that the sheet is attracted again on the belt surface of the conveyance belt at an opposing side of the conveyance belt opposing the image forming device after the sheet is once separated from the belt surface of the conveyance belt at the non-opposing side, and when a front end of the sheet switched back is placed at a position of the reverse path upstream from a position at which the front end of the sheet is attracted on the belt surface of the conveyance belt at the opposing side again after the front end is once separated from the conveyance belt at the non-opposing side, the conveyance device is rotated in reverse to activate the clutch assembly to switch rotation of the switchback device from reverse rotation to forward rotation.