In an ink storing container, movable members are properly constructed by molding sheet material into a convex form and are properly welded to a frame. At a distance from the rear part, part of the profiling protrudes from the plane to one side only. With this structure, the playback apparatus plays the content data on the basis of the relationships between the provision date information and the playback-permitted period information. The hollow shaft socket includes discharge ports that are aligned with the hollow brace members which extend away radially. A manipulated variable computer computes a roll gap instruction value based on the top and bottom side variation components of the rolling load identified by the load topbottom variation identification mechanism, and the top side variation component and the bottom side variation component of the load in a kiss-roll condition stored in the topbottom identified load variation storage.