Paper feed apparatus capable of feeding of common use papers and specifically processed papers

A paper feeding apparatus comprising:

• means for holding a stack of a large number of paper sheets;
• a first roller means for sheetwise feeding out paper sheets in paper feeding direction from the stack held by said holding means;
• a regular rotation roller means for further feeding each of the paper sheets and rotatably mounted at a position downstream from said first roller means in the paper feeding direction;
• a paging roller means mounted in opposition to and pressed against said regular rotation roller means;
• a drive source for driving said regular rotation roller means and said paging roller means;
• a torque limiter for transmitting the drive force from said drive source to said paging roller means within a predetermined range of torque;
• and
• wherein the following formulae is satisfied:
• .mu.i.multidot.Ns >.mu.t.multidot.Ns>Ts/R>.mu.p.multidot.Ns>.mu.o.multidot.Ns .mu.r.multidot.Ns>Ts/R
• Where,
• Ts:
• torque value at torque limiter, gr.multidot.cm;
• Ns:
• pressure force at paging roller means, gr;
• R:
• radius of paging roller means, cm;
• .mu.i:
• friction coefficient between regular rotation means and sheet;
• .mu.t:
• friction coefficient between paging roller means and special class sheet;
• .mu.p:
• friction coefficient between paging roller means and common class sheet;
• .mu.o:
• friction coefficient between sheets;
• and
• .mu.r:
• friction coefficient between regular rotation roller means and paging roller means.