Method and apparatus for setting transfer roller engagement

An electrophotographic printing machine, comprising:

• a belt having a photoconductive surface and a bottom surface opposite said photoconductive surface, said belt having a zero-deflection position,
• at least one transfer roller adjustably disposed relative to and for engaging said photoconductive surface;
• and
• an apparatus for measuring deflection of said belt, said apparatus comprising:
• an elongate arm member having a first end and a second end, said second end engaging said bottom surface of said belt;
• a gearbox having a plurality of gears interconnected into a gear arrangement, a gearbox shaft rotatable by said gear arrangement, said arm member coupled to said gear arrangement, said gear arrangement transferring displacement of said second end of said arm member to rotation of said gearbox shaft;
• an encoder associated with said gearbox shaft, said encoder including at least one encoder output, said encoder sensing rotation of said gearbox shaft and issuing a plurality of electrical pulses on said at least one encoder output, said plurality of electrical pulses being indicative of a magnitude and a direction of rotation of said gearbox shaft;
• and
• a counter including at least one counter input, said at least one counter input electrically interconnected with a corresponding one of said at least one encoder output, said counter counting said electrical pulses.

A method for setting the position of a transfer roller relative to a belt in an electrophotographic printing machine, said belt having a photoconductive surface and an underside disposed opposite said photoconductive surface, said belt being initially disposed in a zero-deflection position, said method comprising the steps of

• engaging said underside of the belt with one end of a deflection lever arm;
• adjusting the position of said transfer roller relative to said belt such that said transfer roller engages said photoconductive surface and deflects said belt from said zero-deflection position, deflection of said belt being transferred to corresponding displacement of said second end of said deflection lever arm;
• measuring the displacement of said deflection lever arm;
• and displaying the measured displacement of said second end of said deflection arm;
• converting the displacement of said second end of said deflection lever arm to rotation of a shaft;
• and
• sensing a direction and a magnitude of the rotation of said shaft.