Patent ID: 8860958

Claim:
A sheet conveyer device, which is configured to convey a sheet in a conveyer path along a conveying direction, comprising: a roller, which is rotatably arranged on a roller shaft to rotate about the roller shaft and is configured to convey the sheet by rotating in a normal direction; a holder, which is rotatably arranged on the roller shaft to rotate about the roller shaft, wherein the holder comprises: a roller gear system, which is arranged on the roller shaft and includes a roller driving gear to drive the roller and a roller gear arranged on the roller shaft; a shutter, which is rotatably arranged on a shutter shaft and is configured to restrict access of the sheet to the roller, the shutter shaft being arranged in an upstream position with respect to the roller shaft along the conveying direction; a shutter gear system, which is arranged to be movable in cooperation with the shutter shaft and is configured to connect a path between the roller gear system and the shutter, wherein the shutter gear system includes a shutter gear arranged on the shutter shaft, a quantity of gear teeth in the shutter gear being greater than a quantity of gear teeth in the roller gear; a one-way clutch, which is arranged in the roller gear system or the shutter gear system and is configured to disconnect the path between the roller gear system and the shutter when the roller rotates in the normal direction; and a torque limiter, which is arranged on the roller gear of the roller gear system and is configured to allow the roller to rotate in a reverse direction, the reverse direction being an opposite direction from the normal direction; and a shutter restrictive member, which is configured to restrict rotation of the shutter when the roller rotates in the reverse direction, wherein the holder is configured to rotate about the roller shaft in the same reverse direction as the roller when the roller rotates in the reverse direction.