A generally cylindrical opening roller unit of an open-end spinning device includes a unitary ring body having card clothing formed of at least one helical groove formed in the ring body, at least one helical ridge between courses of the groove, and saw teeth defined by transverse cuts on the ridge. In the robot system, footprint is reduced and a production line having a short tact time between steps is formed. The yaw control is not actuated if the opposite direction from the steering direction coincides with the lane departure direction. Timing at which accumulated electric charges are read from the respective regions is changed, thereby changing the light exposure of an image signal read from each of the regions. 17 kg of slurry is atomized per m3 of incoming drying gas. An n\xd7n cross-connect is coupled to the TDM interface and operable to switch and assign the STS-n data to any one of n STS-1 time slots.