Document feeder

A document feeder, comprising:

• a transfer path for allowing a document to pass therethrough,
• a reading section situated near the transfer path for reading an image of the document,
• transferring means situated along the transfer path for transferring the document read by the reading section along the transfer path,
• stamping means situated near the transfer path for impressing a mark on a surface of the document transferred by the transferring means,
• document detecting means provided in the transfer path,
• setting means connected to the stamping means for setting a density of the mark on the document impressed by the stamping means so that the mark impressed on the document becomes substantially constant when it is used, said setting means including at least one of a setting panel for setting a desired density of the mark on the document, and counter means for counting a number of usage of the stamping means, said setting panel setting in advance at least one of an impressing force and an impressing duration of the stamping means relative to the document, said counter means automatically setting at least one of the impressing force and the impressing duration of the stamping means relative to the document based on the number of usage of the stamping means, and
• driving means connected to the transferring means for changing a transferring speed of the document from a first transferring speed to a second transferring speed by a detected signal of the document detecting means, said driving means controlling the second transferring speed in accordance with density information by the setting means.