Recirculating document handler

Claim 2

A recirculating document handler (10) for plurally recirculating duplex original document sheets (12) to and from a stack (13) thereof and to and from the imaging station (18) of a copier for providing duplex document precollation copying, characterised by a plural-mode document recirculation loop path (38, 40) means providing selected ones of different document recirculation looped paths, depending on the copying mode selected, and movable path selector means (58, 62) in said plural-mode document recirculation loop path means for, in one selected mode, returning a document sheet in a selected said loop path directly but inverted to said imaging station for copying the opposite side thereof after copying one side thereof and before returning the document sheet to said stack (13), and alternatively, in another mode selected by movement of said selector means (58, 62), returning a document sheet to said stack (13) inverted after copying one side thereof, so that said recirculating document handler provides, selectably, both an immediate duplex document precollation copying mode and a common side duplex document precollation copying mode, respectively.

Claim 3

A recirculating document handler according to claim 1 in which said document recirculating loop path means (38, 40) provides a completed single inversion document recirculation loop path (42, 40, 44) from and back to and over said imaging station (18) in said immediate duplex copying mode, and provides a single inversion path (42, 46) from said imaging station back to said stack (13) in said common side duplex precollation copying mode.

Claim 4

A recirculating document handler according to claim 1 or 2, in which in both said duplex document precollation copying modes the duplex document sheets (12) are fed separately from the bottom of the stack (13) of sheets in a stack support (16) adjacent the side of said imaging station (18), fed by the same constant velocity transport means (28) over a narrow scanning slit at- said imaging station (18) without inversion; and thereafter in said immediate duplex copying mode the duplex documents are then inverted once' in a first inversion path (42, 40, 44) and refed to said imaging station for copying the opposite side of the same sheet, and then fed back to the top of the stack (13) of sheets in said stack support with one additional inversion in a second inversion path (42, 46) so that the sheet (12) returns to the same stack in its same, original, orientation in said stack and may be refed to recopy both sides of the same sheet in the same page sequence; and wherein in said common side duplex document copying mode the duplex document sheets are. returned from the same imaging station (18) inverted once through a return inversion path (42, 46) to the top of the stack in said stack support, so that the document sheets (12) are inverted from their previous orientation in the stack (13) and may be refed to the imaging station (18) to recopy the opposite sides of the sheets in a different page sequence.

Claim 5

A recirculating document handler according to claim 3, in which the return path for a document sheet from said imaging station (18) back to the top of the stack (13) including said return inversion path (42, 46) in said common side duplex copying mode is the same as that for a document sheet in said immediate duplex copying mode after the second side has been copied, including said second inversion path (42, 46).

Claim 6

A recirculating document handler according to claim 1, in which said plural-mode document recirculation loop path means (38, 40) and said path selector means (58, 62) therefor provide selected different, but integral document recirculation loop paths, depending on a selected copying mode, and includes an oval loop recirculation path (38) over said imaging station, and includes means for selectably feeding document sheet into and out of said oval loop recirculation path after at least partial circulation therein, and wherein said integral plural-mode document recirculation loop path means (38, 40) further includes an additional S-shaped document recirculation path (42, 40, 44), which S-shaped path is within said oval loop recirculation path (38) and partially in common therewith and returns documents to said imaging station (18) for copying the opposite sides thereof.

Claim 7

A recirculating document handler according to claim 5 in which said integral plural-mode document recirculation loop path means (38, 40) includes an integral inverter/return loop document path (42) common to both said oval loop path (38) and said S-shaped path (42, 40, 44) which inverter/ return loop path (42) provides a document sheet reversing and non-inverting temporary storage chute in at least one said copying mode and provides a non-reversing and inverting document return path therethrough in at least one other said copying mode.

Claim 8

A recirculating document handler according to claim 6, in which said inverter/return loop document path (42) is an integral one side of said oval document recirculation loop (38) and includes selectively reversible sheet feed means (30); and in which said document recirculation loop path means (38, 40) further includes an alternative transverse loop-intersecting bypass path (40) communicating with the entrance of said inverter/return loop path (42), said bypass path (40) forming a central portion of said S-shaped path (42, 40, 44), and wherein a document sheet may be selectively unidirectionally fed through said inverter/return loop path (42) or reversed in said inverter/ return loop path by said reversible sheet feed means (30) and fed into said bypass path (40).

Claim 9

A recirculating document handler according to claim 7, in which said inverter/return loop path (42) also includes automatic one-way deflection gate means (58) for allowing document sheets to feed in one direction from said imaging station (18) into said inverter/return loop path (42) but automatically causing reverse movement document sheets fed from said inverter/return loop path (42) back towards said imaging station (18) to be deflected into said bypass path (40), said automatic one-way deflection gate means (58) preferably being normally closed by gravity and deflectable by the lead edge of a document sheet.

Claim 10

A recirculating document handler according to claim 7 or 8, in which said bypass path (40) connects at one end thereof with one end of said inverter/return loop path (42), and connects at the opposite end with both a further return loop path (44) for returning document sheets directly to said imaging station and with an output path (46) for returning documents to said stack, and wherein said selector means (62) are provided for selecting between said further return loop path (44) and said output path (46) by guiding a document sheet from said bypass path (40) into a selected one of said other paths.

Claim 11

A recirculating document handler according to any preceding claim, in which said copier imaging station (18) is a narrow optical scanning slit underlying only a minor portion of said document recirculation loop path means (38) adjacent one end thereof, and document feeding means (28) are provided therein for feeding document sheets over said imaging station at a constant speed for imaging same.

Claim 12

A recirculating document handling method for plurally recirculating original document sheets to and from a stack (13) thereof and to and from the imaging station (18) of a copier in a selected one of at least two different document recirculation looped paths, depending on the copying mode selected, for providing precollation copying, in a single document recirculating apparatus, characterised by duplex document precollation copying comprising the steps of: feeding duplex document sheets seriatim from the stack (13) to the imaging station (18); and in one selected mode returning a document sheet on a selected loop path (42, 40, 44) directly, but inverted once, to said copying station after copying one side thereof and before returning the document sheet to the stack (13) and then returning the document sheet to the stack (13) in its original orientation in the stack; and in an alternative selectable mode returning a document sheet to said stack (13) inverted once after copying one side thereof so that the document sheets are inverted from their previous orientation in the stack and may be refed to the imaging station to recopy the opposite sides of the sheets in a different sequence to provide, selectably, an immediate duplex document copying mode and a common side duplex precollation copying mode with the same recirculating document apparatus.

Claim 13

A recirculating document handling method for plurally recirculating original document sheets to and from a stack (13) thereof and to and from the imaging station (18) of a copier in a selected one of at least two different document recirculation looped paths, depending on the copying mode selected, for providing precollation copying, in a single document recirculating apparatus, characterised by duplex document precollation copying comprising the steps of: feeding duplex document sheets seriatim from the stack (13) to the imaging station (18); and in one selected mode returning a document sheet on a selected loop path (42, 40, 44) directly, but inverted once, to said copying station after copying one side thereof and before returning the document sheet to the stack (13) and then returning the document sheet to the stack (13) in its original orientation in the stack; and in an alternative selectable mode returning a document sheet to said stack (13) inverted once after copying one side thereof so that the document sheets are inverted from their previous orientation in the stack and may be refed to the imaging station to recopy the opposite sides of the sheets in a different sequence to provide, selectably, an immediate duplex document copying mode and a common side duplex precollation copying mode with the same recirculating document apparatus.

Claim 14

A recirculating document handling method according to claim 11, in which in said immediate duplex copying mode duplex each document sheet is ' fed separately from the bottom of the stack (13) of sheets from adjacent the side of said imaging station (18), then fed with a constant velocity through a narrow scanning slit at said imaging station without inversion, then reversed and inverted through a first single inversion path (42, 40, 44) and refed through said scanning slit for copying the opposite side of the same sheet, and then fed back to the top of the stack of sheets with one additional inversion through a different inversion path (42, 46) so that the sheet returns to the same stack (13) in its same, original, orientation in said stack and may be refed to recopy both sides of the same sheet in the same sequence on the next recirculation of the document stack.

Claim 15

A recirculating document handling method according to claimll or 12, wherein the return path (42, 46) from the imaging station back to the top of the stack is the same for a document sheet in said common side duplex copying mode after the first side has been copied as it is for a document sheet in said immediate duplex copying mode after the second side has been copied.