GB1603332A - Document feeding method and apparatus - Google Patents

Description

PATENT SPECIFICATION

( 11) 1 603 332 ( 21) Application No 33518/80 ( 22) Filed 14 Feb 1978 ( 62) Divided out of No 1 603 331 ( 19) ( 31) Convention Application Nos.

768 665 ( 32) Filed 14 Feb 1977 in 768 666 ( 33) United States of America (US) ( 44) Complete Specification published 25 Nov 1981 ( 51) INT CL ' B 65 H 9/00 ( 52) Index at acceptance B 8 R 402472 601 611 671 681 TC ( 72) ALPHONSE BENJAMIN DIFRANCESCO CHARLES THOMAS HAGE ( 54) DOCUMENT FEEDING METHOD AND APPARATUS ( 71) We, EASTMAN KODAK COMPANY, a Company organized under the Laws of the State of New Jersey, United States of America of 343 State Street, Rochester, New York 14650, United States of America do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statements:

The present invention relates to document feeding methods and apparatus More specifically, the invention relates to document feeding methods and apparatus that circulate original document sheets automatically in a manner suitable for the production of copies in page sequential order without the use of a sorter.

According to the present invention there is provided a recirculating document feeder comprising a hopper for holding a plurality of document sheets in an initial orientation, first feed means for feeding a document sheet to an exposure platen along a first path to present one side thereof for exposure, second feed means for feeding the document sheet from and back to the exposure platen along an intermediate path having a sheet inverter to present the other side for exposure, third feed means for returning the document sheet to the hopper along a second path, the first andlor the second path including a further inverter, so that the document sheet is returned to the hopper in its initial orientation.

According to the present invention there is further provided a method of circulating orientated document sheets from and back to a hopper for copying comprising the steps of removing a document sheet from the hopper, feeding the document sheet to an exposure platen along a first path to present one side thereof for exposure, feeding the document sheet away from and back to the exposure platen along an intermediate inverting path to present the other side for exposure, feeding the document sheet from the exposure platen back to the hopper along a second path, and inverting the document sheet whilst travelling along the first andlor second path so that the document sheet is returned to the hopper in its initial orientation.

The present invention will now be 55 described, by way of example, with reference to the accompanying drawings in which:Figure 1 is a schematic representation of a document copier having a document feeder 60 in accordance with the present invention; Figure 2 is a block diagram of the logic and control unit depicted in Figure 1; Figure 3 is a schematic illustration of the document feeding mechanism depicted in 65 Figure 1, but showing additional structural features thereof; Figure 4 is a schematic view depicting the document path in the duplex to duplex mode of operation of the document feeding 70 mechanism.

Referring now to the drawings and particularly to Figures 1 and 2, an electrophotographic apparatus 10, referred to herein as a copier, is schematically illus 75 trated as comprising an image processing mechanism 3, a document feeding mechanism 5, a copy processing mechanism 7, and a logic and control unit 9 The image processing mechanism 3 includes an imaging 80 device 10 and a processor l 1 for establishing visible representations of original document sheets, typically as an image-wise distribution of electroscopic marking particles.

The document feeding mechanism 5 pres 85 ents the original sheets to the image processing mechanism 3 for establishing the visible representations, while the copy processing mechanism 7, in synchronism with the document feeding mechanism 5, presents 90 the copy sheets to the image processing mechanism 3 for receiving the visible representations forming the final copies The logic and control unit 9 coordinates the operation of the three sections as required 95 The document feeding mechanism 5 includes a hopper 31, a sheet presenting section 33 and a sheet returning section 35.

The hopper 31 is adapted to receive a set of original document sheets S face up in their 100 m 1 603 332 normal page-sequential order, to deliver the sheets S one after another, last sheet first, from the bottom of the document set, and to receive the sheets S, each sheet on top of the previously delivered sheet, at the top of the document set The sheet presenting section 33 removes the sheets S sequentially from the bottom of the hopper 31 The sheet presenting section 33 includes first feed means which feeds the sheets along a first path to present a removed sheet with one face engaging an exposure platen 14 for copying, and second feed means which, in the duplex to duplex mode of operation feeds the sheet along an intermediate path having a sheet inverter to re-present the sheet with its other face engaging the platen 14 The sheet returning section 35 removes the sheet from the platen 14 after one or both its faces have been copied and third feed means is provided to return the sheets to the top of the ho pper 31 along a second path.

Referring now more specifically to the structural details of the document feeding mechanism 5, and to Figure 3 in particular, the hopper 31 is located above and spaced from the platen 14 where it is rapidly accessible for receiving and supporting the set of original document sheets S Of conventional design, the hopper 31 includes a sloping hopper tray 37 for assisting in aligning the document sheets S against a forward wall 38, suitable side guides and joggers (not shown) and a set-completed detector 39 for determining, without counting, when (each time) the set of original sheets S has been copied.

The sheet presenting section 33 includes a first portion defined by an oscillating vacuum pick-off device 41, a driving nip formed between a ring 43 and a back-roller 45, and a sheet diverter 47; a second portion including a temporary sheet storage device of the snail shell type 49 and two driving rollers 51 and 53 defining a non-inverting sheet path 61; and a third portion including a guide part 54 and rollers 63 and 65 defining the first sheet inverting path 55 and the intermediate inverting path 57, respectively.

The first portion of the sheet presenting section 33 removes the sheets S from an exit 59 located at one end of the hopper tray 37 and directs a removed sheet into a selected one of the inverting or non-inverting paths 55 and 61, respectively, depending on the position of the diverter 47 The sheets are removed at first by vacuum pick-off device 41, which draws one end of the sheet out of the exit 59, and then by the driving nip, which propels the sheet into the selected path In the duplex to duplex mode of operation of the document feeder the sheets are directed by the diverter 47 into the noninverting sheet path 61 In the simplex to simplex or simplex to duplex mode of operation the sheets are directed by the diverter 47 into the inverting sheet path 55 and onto the platen 14.

As noted above, in the duplex to duplex mode of operation, the second portion of 70 the sheet presenting section 33 directs a removed sheet to the platen 14 without inverting the sheet, i e with the lower face (or even page) of the sheet engaging the exposure platen 14 In one sense, as men 75 tioned above, this arrangement defines the non-inverting sheet path 61 leading from the hopper 31 to the platen 14 In another sense, however, it is a disabling device which renders the inverting sheet path 55 ineffec 80 tive to divert the sheets In operation, a sheet entering the non-inverting sheet path 61 from the diverter 41 will be curled into the snail shell device 49 under the motive force of rollers 51 and 53 until the trailing 85 end of the sheet clears the diverter 47 The rollers 51 and 53 are then reversed to drive the sheet from the snail shell device 49 around the guide part 54 and, with the assistance of the roller 63, onto the platen 14 90 The third portion of the sheet presenting section 33, which is operative only in the duplex to duplex mode of operation, removes a sheet from the platen, after its first face has been copied, and inverts the 95 sheet for copying its other face This is accomplished by the intermediate inverting path 57 and the driving rollers 63 and 65, which propel the sheet through 3600 and back onto the platen 14 100 The platen 14 itself defines a sheet registration and exposure station including rollers 67 and a registration gate 69 On entering the exposure station, a document sheet is driven by the rollers 67 into a registered 105 position against the gate 69 After the first face of the sheet is copied, the rollers 67 are reversed, once to drive the sheet into the intermediate inverting path 57, and again to re-register the sheet for copying the second 110 face Then, after the second face has been copied, the gate 69 is removed from the sheet path by a solenoid 71 and the rollers 67 drive the sheet to the third section of the feeder 115 The sheet returning section 35 includes a sheet inverting path 73 and two drive rollers and 79 for returning the document sheet to the top of the set from which it was originally removed 120 The non-inverting path 61, as described above, maintains the original orientation of the sheet faces while moving from the hopper 31 to the platen 14 in the sense that the sheet, while it may be curled in the snail 25 shell device 49, is never turned over entirely It should be apparent to those skled in the art, however, that an even number of sheet inversions would also present the sheet to the platen with the same side down 130 1 603 332 for copying Thus, the snail shell device 49 could be eliminated and the intermediate inverting path 57 could then be used twice (i.e an even number of times, before copying) This would present the original document sheet faces in the same order as the structure described above In similar respect, the inverting paths 55, 57 and 73 could have one or another odd number of inversions and still operate for the purpose described The document feeder is sometimes referred to as a circulating or recirculating feeder because the sheets S move in the feeder repeatedly from the hopper 31 to the exposure platen 14 and back to the hopp er in a manner which simulates a closedloop or circuitous path It is a collating feeder because it is capable of feeding sheets in an appropriate sequence which enables an associated copier to produce collated copies without a sorter It is also a duplexing feeder in the sense that it is capable of feeding original duplex document sheets in a manner suitable for generating duplex copies.

Referring now to the overall operation of the document feeder, a document or other original comprising a set of individual sheets in circulated and recirculated one sheet after another from the hopper 31 to the exposure platen 14 and back to the hopper 31 Using the example of a six page duplex original, the sheet defining pages 5 and 6 is circulated first, for copying page 6 and then page 5, followed by the sheet defining pages 4 and 3 and finally the sheet defining pages 2 and 1.

The sheets are presented for copying in sequential order, from page 6 to page 1, and each page is exposed only once during each respective circulation, for collating the copies without a sorter Multiple copies are generated by circulating and recirculating the sheets a number of times equal to the number of copies desired.

As the pages are sequentially presented for copying, a succession of images representing the presented pages are established in frames on a photoconductor 15 of the copier, one following another, in the same sequential order as the pages were presented i e, page 6, page 5, page 4, page 3, page 2, and page 1.

hen making simplex collated copies from simplex originals, the document feeding mechanisms could operate generally as described in U K Patent 1,492,466 The same would be true for making duplex copies from simplex originals in so far as the feeder is concerned, but the copy processing section of the copier would present both faces of the copy sheets S' to the photoconductor 15 for receiving toner images on both faces.

Turning now to Figure 2, a block diagram of a typical logic and control unit (LCU) 9 is shown which interfaces with the copier 10 and the document feeder 5 The LCU 9 consists of a temporary data storage memory 123, central processing unit 125, timing and cycle control unit 127 and stored program 70 control 129 Data input and output is performed sequentially under program control.

Input data is applied to the central processing unit 125 through either an input signal buffer 131 which is coupled to a multiplexer 75 133 or through an interrupt signal processor 134 which is coupled to an incremental encoder 114 The encoder 114 is connected to the drive means of a photoconductor drum 16 to provide information required to 80 relate the position of the moving photoconductor to the positions of the fixed process stations.

The output data and control signals are applied to storage latches 135 which provide 85 inputs to suitable output drivers 137 which are connected to the copier work stations.

More specifically, the output signals from the LCU 9 are logic level digital signals which are buffered and amplified to provide 90 drive signals to various clutches, brakes, solenoids, power switches, and numeric displays in the various copier work stations and the document feeding mechanism 5 The LCU 9 processing functions can be prog 95 rammed by changing the instructions stored in the computer memory.

The program is located in stored program control 129 which may be provided by a conventional Read Only Memory (ROM) 100 The ROM contains the operational program in the form of instructions and fixed binary numbers corresponding to numeric constants These programs are permanently stored in the ROM(s) and cannot be altered 105 by the computer operation.

It should be understood that the present invention contemplates modes of operation that will account for the usual variations in originals A duplex original that ends on the 110 first face of the last sheet, need not be copied on the blank face In similar respect, it should be recognized that all of the capabilities that are available in accordance with the present invention need not be used 115 in every mode Thus, if desired, the document feeder could provide a noncollating mode in which each page could be presented to the platen area regardless of the number of copies to be made 120

Claims (1)

1. WHAT WE CLAIM IS:

   1 A recirculating document feeder comprising a hopper for holding a plurality of document sheets in an initial orientation, first feed means for feeding a document 125 sheet to an exposure platen along a first path to present one side thereof for exposure, second feed means for feeding the document sheet from and back to the exposure platen along an intermediate path 130 1 603 332 having a sheet inverter to present the other side for exposure, third feed means for returning the document sheet to the hopper along a second path, the first andlor the second path including a further inverter, so that the document sheet is returned to the hopper in its initial orientation.

   2 A recirculating document feeder according to Claim 1 wherein the first and second paths each comprise a respective further inverter and control means is provided to inhibit the passage of the document sheet along the intermediate path when only one side of the document sheet is to be copied.

   3 A recirculating document feeder according to Claim 2 wherein the control means controls a diverter adjacent one of the further inverters for diverting the document sheet into a temporary sheet storage device, effectively preventing inversion by that further inverter when both sides of the document sheet are to be presented for exposure at the exposure platen.

   4 A recirculating document feeder substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.

   A method of circulating orientated document sheets from and back to a hopper 30 for copying comprising the steps of removing a document sheet from the hopper, feeding the document sheet to an exposure platen along a first path to present one side thereof for exposure, feeding the document 35 sheet away from and back to the exposure platen along an intermediate inverting path to present the other side for exposure, feeding the document sheet from the exposure platen back to the hopper along a second 40 path, and inverting the document sheet whilst travelling along the first and/or second path so that the document sheet is returned to the hopper in its initial orientation 45 6 A method according to Claim 5 wherein the document sheet is inverted during passage along the second path.

   7 A method according to Claim 6 where, for simplex copying, the document 50 sheet is inverted during passage along the first and second paths but is not fed along the intermediate inverting path.

   8 A method substantially as hereinbefore described with reference to the accom 55 panying drawings.

   L A TRANGMAR B Sc, C P A.

   Agent for the Applicants Printed for Her Majesty's Stationery Office by The Tweeddale Press Ltd, Berwick-upon-Tweed, 1981 Published at the Patent Office, 25 Southampton Buildings, London, WC 2 A l AY, from which copies may be obtained.