Toner process roller for photocopier - has magnetic stop to hold roller still with thin toner coating opposite drum to prevent toner clogging

摘要

The toner process roller for a photocopier has the toner layer in a modulating pattern on the surface of the roller and with a magnetic stop (21) to hold the roller in a rest position where one of the low spots in the toner layer is opposite the process drum (3). This prevents toner from clogging the drum in the standby mode. The process roller has a series of magnetic cores which rotate inside a non magnetic shell. The magnetic stop is arranged so that the core stops with two poles straddling the contact zone with the drum. The roller is coupled to the drive by a freewheel clutch so that an accurate magnetic alignment is possible without a complex drive.