Image formation apparatus, driving control method, and computer program product

摘要

An image formation apparatus includes an image carrier; a driving source generating a driving force for the image carrier; a drive transmission unit; a driving control unit controlling the driving source; an image formation unit forming an image on a surface of the image carrier; a transfer nip between a transfer member and the surface of the image carrier; a driving-force exerting unit exerting a driving force on any one of the image carrier and a first drive transmission member on a drive transmission path, and a specific drive transmission member imparting weakest spring characteristics among drive transmission members to a drive transmission system; a detecting unit detecting an estimation parameter used in estimating a driving-load-torque variation amount of the image carrier; a torque-variation-amount estimation unit; and a driving-force control unit controlling the driving force to cancel the driving-load-torque variation.

主权项

1. An image formation apparatus for forming an image on a recording medium, the image formation apparatus comprising:
an image carrier having an angular velocity; a driving source configured to generate a driving force based on a driving current provided thereto, the driving force for driving the image carrier; a drive transmission unit configured to transmit, via a driving roller having an angular velocity, the driving force generated by the driving source to the image carrier; a driving control unit configured to control the driving source to cause the image carrier to be driven at any one of a target driving angular velocity and a target velocity; an image formation unit configured to form an image on a surface of the image carrier, the surface being moved by the driving force transmitted from the drive transmission unit; a transfer member configured to form, between the transfer member and the surface of the image carrier, a transfer nip, which the recording medium enters to transfer the image formed on the surface of the image carrier onto the recording medium; a driving-force exerting unit configured to exert, via a driven roller which is a different roller from the driving roller, an additional driving force on any one of the image carrier and a first drive transmission member among drive transmission members provided on a drive transmission path ranging from the driving source to the image carrier, the additional driving force configured to selectively vary between a driving torque provided in a same direction as the driving force provided by the driving source and a load torque provided in a opposite direction as the driving force provided by the driving source, the first drive transmission member being on a side of the image carrier with reference to a specific drive transmission member, and the specific drive transmission member imparting weakest spring characteristics among the drive transmission members to a drive transmission system formed by the drive transmission members; a detecting unit configured to detect estimation parameters used in estimating a driving-load-torque variation amount of the image carrier, the estimation parameters including at least (i) the driving current of the driving source, (ii) an angular velocity of the driving source and (iii) the angular velocity of the driving roller; a torque-variation-amount estimation unit configured to sample the estimation parameters detected by the detecting unit continually at a predetermined sampling interval and estimate the driving-load-torque variation amount based on the sampled estimation parameters; and a driving-force control unit configured to control the additional driving force such that the additional driving force exerted by the driven roller cancels the driving-load-torque variation amount estimated by the torque-variation-amount estimation unit by applying the additional driving force, if the driving-load-torque variation amount indicates a variation in the angular velocity of the image carrier, the applied additional driving force being the driving torque if the angular velocity of the image carrier has decreased and the applied additional driving force being the load torque if the angular velocity of the image carrier has increased.