Patent ID: 6967645

Claim:
An encoder device for generating a signal indicative of movement of a roller, comprising: a movement-conversion unit; a roller-supporting unit; and an electricity-conducting unit; wherein said roller is rotatably supported by said roller supporting unit, wherein said roller is rotatable relative to the roller supporting unit, wherein said movement conversion unit is arranged to reciprocate in response to rotation of said roller and intermittently cause electrical conduction in said electricity-conducting unit, thereby generating said intermittent electrical signal indicative of movement of the roller, wherein said reciprocating movement of said movement conversion unit intermittently causes electrical contacts in said electricity-conducting unit to engage each other and thereby cause said electrical conduction, wherein said movement-conversion unit and electricity conducting unit are positioned within an open side of said roller, and further comprising a depressing unit arranged such that when the roller is depressed, the roller-supporting unit is deformed simultaneously to activate a micro switch.