Two-up automatic document feeder for simplex to duplex copying

Claim 1

A document feeder adapted for use with a reproduction machine, for successively advancing to sequential copying positions on a copying platen of a reproduction machine two simplex documents to be copied to both sides of a single duplex copy sheet, said document feeder comprising: a document input for receiving documents to be copied; a document input feeder for feeding successive documents to be copied from said document input; first and second selectably controllable document transport means, said first document transport means for advancing documents fed from said document input, along a document input path, said second document transport document means for advancing documents from said document input path across a copying platen to selected copying positions and to an output means; sensor means for sensing the passage of documents in said document input path; control means for sequentially controlling said first and second document transport means to advance a first document to a first registration position a selected distance past said sensor member, said first document transport means to advance a second document to a registration position with respect to said first document position, said second document transport means to advance said first and second documents simultaneously to sequential, closely adjacent copying positions on a copying platen, and said second document transport means to advance said first and second document simultaneously to said output means.

Claim 12

A method for advancing two simplex documents to copying positions for sequential copying in a reproduction machine, for making a desired number of duplex copies therefrom, comprising the steps; advancing a first simplex document to a selected registration position; advancing a second simplex document to a selected registration position closely adjacent to said first document; and advancing first and second documents simultaneously to a selected copying position for sequential copying thereof.

Claim 13

A method for advancing two simplex documents to copying positions for sequential copying in a reproduction machine, for making a desired number of duplex copies therefrom, comprising the steps; advancing a first simplex document to a selected registration position; advancing a second simplex document to a selected registration position closely adjacent to said first document; and advancing first and second documents simultaneously to a selected copying position for sequential copying thereof.

Claim 16

A method of operating a document feeder for advancing first and second simplex documents from an input stack to sequential copying positions on an reproduction machine to produce duplex copies therefrom, said document feeder including input stack feeder means for feeding documents out from said input stack, first and second selectably operable document transport means, sensor means for sensing passage of documents thereby, and a document output means, said method comprising: operating said input stack feeder means to feed a first document from said stack to said first document transport means; driving said first and second document transport means for a selected time, whereby a trail edge of said first document is advanced to a predetermined position past said sensor; operating said input stack feeder means to feed a second document from said stack to said first document transport means; driving said first document transport means for a second selected time, whereby a lead edge of said second document is advanced to a position closely adjacent to said trail edge of said first document; driving said second document transport means for a third selected time, whereby said first and second documents are advanced to predetermined sequential copying positions for sequential copying thereof; driving said second document transport means to drive said documents to said output means.

Claim 17

A method of operating a document feeder for advancing first and second simplex documents from an input stack to sequential copying positions on an reproduction machine to produce duplex copies therefrom, said document feeder including input stack feeder means for feeding documents out from said input stack, first and second selectably operable document transport means, sensor means for sensing passage of documents thereby, and a document output means, said method comprising: operating said input stack feeder means to feed a first document from said stack to said first document transport means; driving said first and second document transport means for a selected time, whereby a trail edge of said first document is advanced to a predetermined position past said sensor; operating said input stack feeder means to feed a second document from said stack to said first document transport means; driving said first document transport means for a second selected time, whereby a lead edge of said second document is advanced to a position closely adjacent to said trail edge of said first document; driving said second document transport means for a third selected time, whereby said first and second documents are advanced to predetermined sequential copying positions for sequential copying thereof; driving said second document transport means to drive said documents to said output means.

Claim 18

A method of operating a document feeder for advancing first and second simplex documents from an input stack to sequential copying positions on an reproduction machine to produce duplex copies therefrom, said document feeder including input stack feeder means for feeding documents out from said input stack, first and second selectably operable document transport means, at least said second transport means having known acceleration time for accelerating documents from a stop position to a constant velocity, sensor means for sensing passage of documents thereby, and a document output means, said method comprising: operating said input stack feeder means to feed a first document from said stack to said first document transport means; driving said first and second document transport means for a selected time, whereby a trail edge of said first document is advanced to a predetermined stop position past said sensor; operating said input stack feeder means to feed a second document from said stack to said first document transport means; driving said first document transport means for a second selected time, whereby a lead edge of said second document is advanced at a constant velocity toward a position closely adjacent to said trail edge of said first document; accelerating said second document transport means for a third selected time, to accelerate said first document from said stop position to said constant velocity whereby said second document reaches said position closely adjacent to said trail edge of said first document when said first document has substantially attained said constant velocity, whereupon both documents are advanced at said constant velocity to predetermined sequential copying positions for sequential copying thereof; driving said second document transport means to drive said documents to said output means.

Claim 19

A method of operating a document feeder for advancing first and second simplex documents from an input stack to sequential copying positions on an reproduction machine to produce duplex copies therefrom, said document feeder including input stack feeder means for feeding documents out from said input stack, first and second selectably operable document transport means, at least said second transport means having known acceleration time for accelerating documents from a stop position to a constant velocity, sensor means for sensing passage of documents thereby, and a document output means, said method comprising: operating said input stack feeder means to feed a first document from said stack to said first document transport means; driving said first and second document transport means for a selected time, whereby a trail edge of said first document is advanced to a predetermined stop position past said sensor; operating said input stack feeder means to feed a second document from said stack to said first document transport means; driving said first document transport means for a second selected time, whereby a lead edge of said second document is advanced at a constant velocity toward a position closely adjacent to said trail edge of said first document; accelerating said second document transport means for a third selected time, to accelerate said first document from said stop position to said constant velocity whereby said second document reaches said position closely adjacent to said trail edge of said first document when said first document has substantially attained said constant velocity, whereupon both documents are advanced at said constant velocity to predetermined sequential copying positions for sequential copying thereof; driving said second document transport means to drive said documents to said output means.

Claim 20

A method for recirculatively precollatively copying a set of plural original documents onto both sides of copy sheets to produce a desired number of precollated duplex copy sheets using a document handler means for advancing first and second simplex documents from an input stack to sequential copying positions on an reproduction machine, and returning said documents therefrom to said input stack, said document handler including input stack feeder means for feeding documents out from said input stack in an N-1 order, first and second selectably operable document transport means, at least said second transport means having known acceleration time for accelerating documents from a stop position to a constant velocity, sensor means for sensing passage of documents thereby, and a document output means returning said documents to the input stack, said method comprising; operating said input stack feeder means to feed a first document from said stack to said first document transport means; driving said first and second document transport means for a selected time, whereby a trail edge of said first document is advanced to a predetermined stop position past said sensor; operating said input stack feeder means to feed a second document from said stack to said first document transport means; driving said first document transport means for a second selected time, whereby a lead edge of said second document is advanced at a constant velocity toward a position closely adjacent to said trail edge of said first document; accelerating said second document transport means for a third selected time, to accelerate said first document from said stop position to said constant velocity whereby said second document reaches said position closely adjacent to said trail edge of said first document when said first document has substantially attained said constant velocity, whereupon both documents are advanced at said constant velocity to predetermined sequential copying positions for sequential copying thereof; driving said second document transport means to drive said documents to said output means, whereby said documents are returned to said input tray.

Claim 21

A method for recirculatively precollatively copying a set of plural original documents onto both sides of copy sheets to produce a desired number of precollated duplex copy sheets using a document handler means for advancing first and second simplex documents from an input stack to sequential copying positions on an reproduction machine, and returning said documents therefrom to said input stack, said document handler including input stack feeder means for feeding documents out from said input stack in an N-1 order, first and second selectably operable document transport means, at least said second transport means having known acceleration time for accelerating documents from a stop position to a constant velocity, sensor means for sensing passage of documents thereby, and a document output means returning said documents to the input stack, said method comprising; operating said input stack feeder means to feed a first document from said stack to said first document transport means; driving said first and second document transport means for a selected time, whereby a trail edge of said first document is advanced to a predetermined stop position past said sensor; operating said input stack feeder means to feed a second document from said stack to said first document transport means; driving said first document transport means for a second selected time, whereby a lead edge of said second document is advanced at a constant velocity toward a position closely adjacent to said trail edge of said first document; accelerating said second document transport means for a third selected time, to accelerate said first document from said stop position to said constant velocity whereby said second document reaches said position closely adjacent to said trail edge of said first document when said first document has substantially attained said constant velocity, whereupon both documents are advanced at said constant velocity to predetermined sequential copying positions for sequential copying thereof; driving said second document transport means to drive said documents to said output means, whereby said documents are returned to said input tray.

Claim 22

A method for recirculatively precollatively copying a set of plural original documents onto both sides of copy sheets to produce a desired number of precollated duplex copy sheets using a document handler means for advancing first and second simplex documents from an input stack to sequential copying positions on an reproduction machine, and returning said documents therefrom to said input stack, said document handler including input stack feeder means for feeding documents out from said input stack in an N-1 order, first and second selectably operable document transport means, at least said second transport means having known acceleration time for accelerating documents from a stop position to a constant velocity, sensor means for sensing passage of documents thereby, and a document output means returning said documents to the input stack, said method comprising: operating said input stack feeder means to feed a first document from said stack to said first document transport means; driving said first and second document transport means for a selected time, whereby a trail edge of said first document is advanced to a predetermined stop position past said sensor; operating said input stack feeder means to feed a second document from said stack to said first document transport means; driving said first document transport means for a second selected time, whereby a lead edge of said second document is advanced at a constant velocity toward a position closely adjacent to said trail edge of said first document; accelerating said second document transport means for a third selected time, to accelerate said first document from said stop position to said constant velocity whereby said second document reaches said position closely adjacent to said trail edge of said first document when said first document has substantially attained said constant velocity, whereupon both documents are advanced at said constant velocity to predetermined sequential copying positions for sequential copying thereof; driving said second document transport means to advance said first and second documents to said output means.

Claim 23

A method for recirculatively precollatively copying a set of plural original documents onto both sides of copy sheets to produce a desired number of precollated duplex copy sheets using a document handler means for advancing first and second simplex documents from an input stack to sequential copying positions on an reproduction machine, and returning said documents therefrom to said input stack, said document handler including input stack feeder means for feeding documents out from said input stack in an N-1 order, first and second selectably operable document transport means, at least said second transport means having known acceleration time for accelerating documents from a stop position to a constant velocity, sensor means for sensing passage of documents thereby, and a document output means returning said documents to the input stack, said method comprising: operating said input stack feeder means to feed a first document from said stack to said first document transport means; driving said first and second document transport means for a selected time, whereby a trail edge of said first document is advanced to a predetermined stop position past said sensor; operating said input stack feeder means to feed a second document from said stack to said first document transport means; driving said first document transport means for a second selected time, whereby a lead edge of said second document is advanced at a constant velocity toward a position closely adjacent to said trail edge of said first document; accelerating said second document transport means for a third selected time, to accelerate said first document from said stop position to said constant velocity whereby said second document reaches said position closely adjacent to said trail edge of said first document when said first document has substantially attained said constant velocity, whereupon both documents are advanced at said constant velocity to predetermined sequential copying positions for sequential copying thereof; driving said second document transport means to advance said first and second documents to said output means.