Bind processing method, bind processing device, and binder cartridge

A bind processing method in which sheets of loose leaf paper are bound with a binder, the sheets of loose leaf paper having a plurality of punch holes formed along one side of the sheets of paper and the binder comprising a continuous rectangular bar-like spine portion and a plurality of hinged first and second division ring portions arranged at regular intervals along both long sides of the continuous rectangular bar-like spine portion, the spine portion being interposed between the first and second division ring portions, the method comprising:

• symmetrically driving pairs of first and second pushers so as to close the first and second division ring portions of the binder;
• engaging forward end portions of the first division ring portions with forward end portions of the second division ring portions within the punch holes formed on the sheets of loose leaf paper;
• and
• separating one binder from a stack of a plurality binders, wherein the one binder which is separated is used as said binder for binding the sheets of papers.