Conveyor unit, controller for a driving roller for use in the conveyor unit, and zone controlled conveyor system incorporating the conveyor unit

A zone controlled conveyor system comprising a plurality of zones for control arranged in a row in the direction of conveyance of articles, each of the zones having a conveyor unit,

• the conveyor unit in each of the zones comprising a driving roller for conveying an article, a motor for powering the driving roller, and a controller adapted to adjust the motor so as to control the driving roller,
• the motor comprising a permanent magnet and an armature having a plurality of armature coils,
• the controller having an interrupter adapted to repeat shunting and deshunting of at least one of the coils,
• the controller further having a rotation detector adapted to detect an externally forced rotation of the motor in response to an electromotive force induced in at least one of the coils,
• wherein in the case that the motor is not driven, the controller maintains operations of the interrupter and outputs a presence signal by determining that an article is conveyed onto the conveyor unit upon detection of the rotation of the motor by means of the rotation detector,
• each controller being adapted to output the presence signal to controllers in a plurality of adjacent upstream zones, and simultaneously receive presence signals from controllers in a plurality of adjacent downstream zones.