Automatic document feeder

Claim 1

An automatic document feeder for an electrophotographic copying apparatus having a feeding tray for receiving a stack of document sheets with the first document sheet in a series to be copies being initially the lowermost sheet of the stack, feeding means for feeding to an exposing station one document sheet after another from the stack on the feeding tray starting with the lowermost document sheet, and returning means for returning the document sheets to the feeding tray and replacing the same as the uppermost document sheet on the feeding tray after they have been eposed at the exposing station, wherein the improvement comprises: a job sheet placed beneath the initial lowermost document sheet of the stack on the feeding tray and being the same size as the document sheets and having a sensed indicia portion thereon for distinguishing the job sheet from the document sheets and a control indicia portion for controlling a further operation of the document feeder and the copying apparatus; sensing means located in a lower part of the feeding tray on which the stack of document sheets and the job sheet are placed for sensing the indicia portion of the job sheet; and reading means located between the feeding means and the returning means for reading the control indicia portion on the job sheet; whereby said sensed indicia portion of said job sheet is sensed by said sensing means when it has been returned to the feeding tray and becomes located beneath the lowermost document sheet on the lower part of the feeding tray to thereby indicate completion of one series of copying, and said control indicia portion is read by said reading means to control a further operation of said document feeder and copying apparatus only when said sensed indicia portion is sensed by said sensing means.