An electrostatic latent image on an image-bearing member is developed with a two-component developer comprising a toner and a carrier stored in a developer vessel while supplying as required a replenishing developer to the developer vessel. A direction determining unit recognizes an edge direction of a remarked pixel and outputs it with information on its position to a reliability ranking unit and a directional distribution generating unit. The present invention also provides for the periodic placement of slideable supports under a bundle as it is pushed onto a trailer. 2 \u03bcm or less, the diameter D2 of the maximum inscribed circle of the Sn covering layer is 1. A resisting block extends from the sliding pole. A first step part is formed by swelling the shaft tooth part toward the hub tooth part from a point horizontally moved from the center point of the shaft tooth part to a shaft shank side.