Collation Controls

Co-pending commonly assigned U.S. application Ser. No. 636,252 filed Nov. 28, 1975 in the name of Ralph J. LeClere now U.S. Pat. No. 4,026,543 is incorporated for its showing of collator control circuits.

Co-pending commonly assigned U.S. application Ser. No. 729,453, filed Oct. 4, 1976 in the name of Wallace L. Hubert and entitled "Copy Production Machine Having a Duplex Mode" shows microprocessor construction with which the microcode in this disclosure can be executed.

U.S. Pat. No. 4,003,569 shows detection of a last copy.

The present invention relates to copy production machines having collation apparatus and particularly into a control aspect of a collator in a copy production machine having document feeding means.

Copy production machines, including convenience copiers, often have a semiautomatic document feed (SADF) or an automatic document feed (ADF) which semi-automatically or automatically supplies original documents to be copied to an imaging area. A copy production portion (CPP) responds to the image presented by the original document in the imaging position to produce copies. The copies often can be supplied to a simple exit tray or to an automatic collation apparatus. In the latter, sets of documents can be conveniently reproduced.

It is also highly desirable that the copy production rate be maximized under certain conditions; i.e., reduce the total time required to make a set of documents. In this regard, most collators have a preferred direction of collation. That is, for jam control purposes and jam avoidance it is desired that the collator operates from a so-called home position and collate when the relative movement is away from the home position. Upon completion of one collating run the collator moves back to the home position in preparation of the next run. While reliable operation may be enhanced by this type of function, throughput is penalized in that the copy production machine must wait for the collator to reset to the home position.

Collators come in various forms and shapes. For example, a travelling vane copy distributor may travel along an open side of a stack of collator bins and supply a copy to the bins in accordance with a sequence or a program of instructions. Alternatively, a document distributor may be fixed so that a stack of movable bins will move in front of the distributor for receiving the copies to be collated. In either event, collators of this type have a home position and a preferred direction of collation; i.e., a relative movement between the copy distributor and the collator bins.

It is an object of the present invention to provide a copy production machine with a collator having a maximal throughput while maintaining high reliability of operation whenever possible.

A copy production machine constructed in accordance with the teachings of the present invention includes a collator having a preferred direction of collation along a first direction, plus a second direction of motion opposite to the first direction for recovering to a home position for collation in the first direction. The copy production machine has means for indicating that copies for more than one image will be simultaneously in the copy production machine in a so-called overlap mode. When the overlap mode is active the copy production machine actuates the collator to collate copies in both of said directions, and in the absence of the overlap mode collate copies only in the first direction, the collator recovering to a home position intermediate successive runs in all runs other than the overlap mode runs.

In a specific form of the invention, a semi-automatic document feed has a preentry sensor which indicates an original document in position to be moved to an imaging position. Whenever such a document is detected at the preentry position while copies are being produced from a different document, an add run indication is provided, placing the machine in an overlap mode such that copies bearing images from a plurality of different image sources, i.e., original documents or electronic sources, require the collator to collate in both directions. In the absence of an original document at the preentry position, collation only occurs in a first direction. Various means for indicating the end of a copy run for determining the overlap mode is included within the present invention. Also, electronic means may contain image-indicating signals and when such image-indicating signals have a predetermined state, the overlap mode is employed. In an automatic document feed any document in a stack of documents for being moved to an imaging position imposes an overlap mode on the copy production machine for requiring bidirectional collation of copies being produced.

The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of a preferred embodiment of the invention, as illustrated in the accompanying drawings.

FIG. 1 is a diagrammatic showing of a machine incorporating the teachings of the present invention.

FIG. 2 is a simplified flow chart showing the operation of the FIG. 1 machine when operating in accordance with the present invention.

FIG. 3 is a partial simplified diagrammatic showing of the FIG. 1 machine when computer controlled.

FIG. 4 is a diagrammatic showing similar to FIG. 3 but for hardware logic circuit controls.

FIG. 5 is a simplified diagrammatic showing of indicating a last copy of a copy production run. de

Referring now more particularly to the drawings, like numerals indicate like parts and structural features in the various diagrams. An early copy production machine 10 employing the present invention includes a semiautomatic document feed (SADF) 11 for feeding manually inserted original documents to be copied. The document glass 11A (FIGS. 3, 4) in SADF 11 is scanned by known optical scanners in original input optics 12, as indicated by dashed line 12B, to provide an illuminated image over path 23 to a later described copy production portion CPP 13. CPP 13 transfers the line 23 indicated optical image to a copy sheet as will be later described, and supplies the produced copies to output portion 14 for pick up by an operator or for automatic transfer to other utilization apparatus (not shown). In a constructed version of the invention, output portion 14 includes a copy output tray 14A which receives all produced copies in a so-called noncollate mode. When the copy production machine 10 is to be used in an environment requiring automatic collation, a collator 14B is included in output portion 14. When the number of copies to be collated becomes relatively large, a second collator 14C is connected to the first collator 14B in tandem for receiving copies to be collated.

In accordance with the present invention, control means are provided in copy production machine 10 for automatically controlling the mode of operation of collators 14B, 14C in accordance with the status of SADF 11 and particularly in accordance with whether or not CPP 13 is operating in the so-called overlap mode. It is preferred that collators 14B, 14C collate from an upper or home position 15B, 15C, respectively, downwardly to a bottom position at the last collator bins 16B and 16C, respectively. Upon reaching the lowest bin the travelling vane copy distributors 16B, 16C return to the home position. Because of the construction of the collators 14B, 14C, collating from the home positions 15B, 15C toward the respective bottom or remote positions 16B, 16C provides best collation; i.e., most reliable. For jam recovery purposes it is preferred that the collations always occur from top to bottom. The return of the copy distributors 16B and 16C to the home positions 15B, 15C requires time detracting from the throughput of CPP 13. Because of the efficiencies of SADF 11 CPP 13 can operate continuously without missing any image areas as documents are successively supplied to SADF 11 from input tray 11B, as is presently done in the convenience copiers termed Copier II and Copier Series III manufactured by International Business Machines Corporation, Armonk, N.Y. When an original document to be copied is placed on tray 11B such that preentry sensor 60 is activated while copies are being produced by CPP 13, an overlap mode is defined for CPP 13. That is, copies in copy path 17 contain images from more than one original document, i.e., the runs are overlapped within document production machine 10. In this instance, it is desired not to wait for the copy distributors 16B, 16C to return to the home or upper positions 15B, 15C. Accordingly, control 53 responds to sensor 60 during a copy production run to activate collators 14B, 14C to collate in both directions so long as an original document is placed in tray 11B before the end of the current copy production run. At all other times control 53 actuates collators 14B, 14C to return to the home position for unidirectional collation.

FIG. 2 is a simplified flow chart showing the sequence of operations of control 53 for actuating copy production machine 10 as above described. Flow chart represents operations of control 53 either in a programmed computer embodiment shown in FIG. 3 or the harware logic sequence embodiment shown in FIG. 4. It is preferred that the programmed computer embodiment be employed in practicing the present invention. Both embodiments operate the copy production machine 10 in an identical manner.

Referring to FIG. 2, the first step in practicing the invention is determining when there is to be an image change (new original document to be copied) in copy production, as at step 45. In a preferred embodiment an image change or impending image change is indicated by an end of run signal supplied by CPP 13 to control 53. From control 53 the end of run signal is signified as an image change signal on line 46 (FIG. 4) and identified by numeral 46A in FIG. 2.

Next, the controls 53 must determine the location of collator carriages 16B or 16C. If a single collator 16B is being used, then the vertical location of carriage 16B determines whether or not the appropriate carriage is at home. If so, the collating operation will always proceed from the home position 15B downwardly toward the ultimate position 16L. In the event both collators are used, then the computer must determine the number of images made in each run. If the number of images, i.e., copies, being made is equal to or less than the number of receiving bins in collator 14B then the location of carriage 16B determines whether or not the carriage is "at home." On the other hand, if more than one collator is being used and the number of copies being produced in a run is greater than the bins in collator 14B then the location of carriage 16C in collator 14C is determinative of whether or not the collator is at home. In any event, if the collator is away from the home positions 15B, 15C then the next step in FIG. 2 is to determine whether or not an original document 62 has been inserted in the document receiving tray 11B for adding another run to the collator sequence. This determination is made in step 50 which when zero indicates no original document 62 is in receiving tray 11B. Then the collator carriages 16B, 16C are automatically returned to the home position in the step "collator go home" 51. On the other hand, if there is a document 62 in receiving tray 11B then the next run must be collated up as at step 52. Accordingly, the collator direction of collation is selected in accordance with the location of the collator carriages as well as whether or not a copy producing run is ready to be started in the copy production machine, the latter being signified by a document 62 being sensed by preentry sensor 60 as shown in FIGS. 3 and 4.

Before proceeding further with the detailed description of the invention, the operation of copy production portion (CPP) 13 and SADF 11 are described as a constructed embodiment of a so-called xerographic copy production machine 10, no limitation thereto intended. Photoconductor drum member 20 rotates in the direction of the arrow past a plurality of xerographic processing stations. The first station 21 imposes either a positive or negative electrostatic charge on the surface of photoconductor member 20. It is preferred that this charge be a uniform electrostatic charge over a uniform photoconductor surface. Such charging is done in the absence of light such that projected optical images, indicated by dash line arrow 23, alter the electrostatic charge on the photoconductor member in preparation for image developing and transferring. The projected optical image from original input optics 12 exposes the photoconductor surface in area 22. Light in the projected image electrically discharges the surface areas of photoconductor member 20 in accordance with lightness. With minimal light reflected from the dark or printed areas of an original document, for example, there is no corresponding remains in those areas of the photoconductive surface of member 20 corresponding to the dark of printed areas of an original document in SADF 11 (semiautomatic document feed). This charge pattern is termed a "latent" image on the photoconductor surface. Interimage erase lamp 30E discharges photoconductor member 20 outside defined image areas.

The next xerographic station is developer 24 which receives toner (ink) from toner supply 25 for being deposited and retained on the photoconductive surface still having an electrical charge. The developer station receives the toner with an electrostatic charge of polarity opposite to that of the charged areas of the photoconductive surface. Accordingly, the toner particles adhere electrostatically to the charged areas, but do not adhere to the discharged areas. Hence, the photoconductive surface, after leaving station 24, has a toned image corresponding to the dark and light areas of an original document in SADF 11.

Next, the latent image is transferred to copy paper (not shown) in transfer station 26. The paper is brought to the station 26 from an input paper path portion 27 via synchronizing input gate 28. In station 26, the copy paper (not shown) is brought into contact with the toned image on the photoconductive surface resulting in a transfer of the toner to the copy paper. After such transfer, the sheet of image bearing copy paper is stripped from the photoconductive surface for transport carried image fused thereon in fusing station 31 for creating a permanent image on the copy paper.

Returning now to the photoconductor member 20, after the image area on member 20 leaves transfer station 26, there is a certain amount of residual toner on the photoconductive surface. Accordingly, cleaner station 30 has a rotating cleaning brush (not shown) to remove the residual toner for cleaning the image area in preparation for receiving the next image projected by original input optics 12. The cycle then repeats by charging the just-cleaned image area by charging station 21.

The production of simplex copies or the first side of duplexing copies by portion 13 includes transferring a blank sheet of paper from blank paper supply 35, thence to transfer station 26, fuser 31, and, when in the simplex mode, directly to the output copy portion 14. Blank paper supply 35 has an empty sensing switch (not shown) which inhibits operation of CPP 13 in a known manner whenever supply 35 is out of paper.

When in the duplex mode, duplex diversion gate 42 is actuated by connective 53 to the upward position for deflecting single-image copies to travel to interim storage unit 40 to reside as partially produced duplex copies (image on one side only) waiting for the next subsequent single-image copy producing run in which the copies receive the second image. In the next successive single-image run in the duplex mode, initiated by inserting a document into SADF 11, the copies are removed one at a time from the interim storage unit 40, transported over path 44, thence to input path 27 for receiving a second image, as previously described. The two-image duplex copies are then transferred into output portion 14. Gate 42 is a diagrammatic showing representative of any one of a large plurality of sheet deflecting or directing apparatus usable for the stated purposes.

Preentry switch 60 senses when an original document has been placed in input tray 11B for entry into SADF 11. This condition is defined as "ORGATDF". The condition is signalled to logical control 53 which in turn then actuates SADF 11 to transport the inserted original document onto the document glass 11A. As the original document is being transported onto the document glass 11A, entry sensor 61 senses that the original document is moving onto the document glass 11A. During normal operation trailing edge of the document will be first sensed by sensor 60 indicating the document is no longer at the preentry position. Lastly, it will be sensed by entry sensor 61 as it leaves the entry area and is completely placed on the imaging area of document glass 11A.

CPP 13 also has second or alternate copy paper supply 54 which supplies copy paper to input path 27 via paper path 55. Selection of paper supply 35 or 54 as a copy paper source is controlled from panel 52 by actuation of switches 56. Selection is mutually exclusive. Logical connective 53 responds to switches 56 to actuate paper picker (not shown) in the respective copy paper supplies 35, 54 in a usual manner.

FIGS. 3 and 4 identically illustrate the SADF 11 and its essential connections to logical control 53 for practicing the present invention. The operation will be described with respect to FIG. 3, then the FIG. 4 control will be described. As shown, original document 62 has been placed on input tray 11B, entry gate 63 has not yet been opened, however, entry aligner roll 64 has aligned original document 62 against entry gate 63. Accordingly, both preentry sensor 60 and entry sensor 61 are active (sense original document 62). These conditions are signalled by the two sensors 60, 61 respectively over lines 65 and 66 to input register 173A, bit positions 0 and 1 (not shown). A copy microprocessor 170 periodically scans input register 173A or can be actuated by an interrupt (not described) for sensing that original document 62 is at the illustrated position. In response to sensing the above conditions and assuming that predetermined copy production status of the copy production machine 10 are satisfied, copy microprocessor 170 supplies control signals to output register 174A for opening gate 63. This action is achieved by setting bit position 1 (not shown) of register 174A to the active state. As a result, an activating signal supplied from bit position 1, register 174A to gate solenoid 67 pulls the gate down and allows the original document 62 to be picked up by the SADF transport belt 68. Belt 68 was activated by copy microprocessor 170 at the same time as gate 63 was opened by setting bit position 2 (not shown) of register 174A to the active state for activating driver 70 to actuate SADF motor 71 for moving belt over rollers 72 and 73. As belt 68 engages original document 62, the document moves over the top of document glass 11A against exit gate 74 at the left hand side of document glass 11A. As soon as the document 62 is on the document glass copy production can ensue. Copy microprocessor 170 then actuates CPP 13 and optics 12 in a known manner via output registers 174C and 174B, whereupon input optics 12 scans the document on document glass 11A and causes a transfer of image to copy paper as previously described. Of course, belt 68 is stopped by copy microprocessor 170 deactivating motor 71.

When original document 62 moved onto document glass 11A, preentry sensor 60 first indicated paper left and then entry sensor 61 indicated the document 62 left that position. When both sensors indicate the above sequence, the copy microprocessor 170 reacts to initiate a copy production cycle.

Upon completion of the copy production cycle, exit gate 74 is opened by microprocessor 170 actuating bit position 3 (not shown) of output register 174A to actuate solenoid 76 which frees original document 62 to be exited past exit sensor 77 into an original document exit tray (not shown). When exit sensor 77 senses the leading edge of original document 62 it supplies a signal to input register 173A signifying same. At this time copy microprocessor 170 knows that the original document 62 is being successfully exited to the original document exit tray (not shown). At this time a second original document on input tray 11B may be entered onto document glass 11A. When sensor 77 senses an exit while sensor 61 senses an original document, copy microprocessor 170 should actuate collators 14B, 14C to collate bidirectionally, as will become apparent. The control 53 actuates such bidirectional collator control in response to an end of run signal, later described, occurring when sensor 61 indicates a document is to be entered. Collator control is exercised via output register 174D.

Input aligners 64 are rotated by motor 78 as actuated by bit position 0 (not shown) of output register 174A. These aligners are activated whenever input sensor 60 senses document 62 being inserted on input tray 11B and other copy production prerequisites are met. The rollers 64 are maintained in the active position until entry sensor 61 senses the alignment of original document 62 or a timer (not shown) times out and a document feed error is called.

The arrangement of logical control 53 is that the output registers 174A-D cannot be sensed by copy microprocessor 170. Further, registers 173A-D and 174A-D have the same address except that registers 174A-D are addressed during an output mode of the copy microprocessor 170 while input registers 173A-D are accessed during an input mode. Copy microprocessor 170 must know the signal contents of all output registers 174A-D at all times. Accordingly, it provides an image of the signal content of all output registers 174A-D in main memory 172 at all times. One of the registers within main memory 172 is designated to contain a signal image for one of the respective output registers; that is, numeral 174AI indicates the memory register for the image of the signal content of output register 174A, etc. through 174DI. In this manner, copy microprocessor, by reading register 174AI, can immediately determine the control status being supplied to the SADF 11. Control signals to other portions of the copy production machine 10 from other output registers 174B-D are sensed in memory register 174B-D, respectively. For convenience, the input registers 173A-D are also imaged in memory 172 in registers 173AI-DI. Additionally, certain work registers 172A are assigned to work within memory 172 for the convenience of copy microprocessor 170. Also, other status registers 80 have signal contents useful in operating copy microprocessor 170 in implementing the invention.

In setting up copy production machine 10 to operate, copy microprocessor 170 in response to the end of run signal, as later described, received from copy production portion 13 via input register 173C when a new document 62 is being sensed by sensor 61 actuates collators 14B, 14C to bidirectionally collate by sending appropriate control signals over bidirectional bus I/O to output register 174D. The status of the collator copy distributors 16B and 16C are respectively indicated by home sensors 82, 83. When copy distributors or travelling vanes 16B, 16C are in the home position, sensors 82, 83 supply appropriate signals to copy microprocessor 170 via input register 173D. Additionally, copy microprocessor 170 in other status registers 80 keeps an indication of the physical location of copy distributors 16B, 16C. On comparing the sensor outputs 82, 83 with the stored status in registers 80 copy microprocessor 170 executes steps 47 and 50 as previously described and as shown in the code included in Tables I and II. The microcode in Table I represents the control of SADF 11, while the microcode in Table II represents the control of collators 14B and 14C in accordance with the illustration of FIG. 2. Such programs are resident in main memory 172 as a SADF program at 84, collator program at 85. It is understood, of course, that copy microprocessor 170 in controlling copy production machine 10 includes a multitude of programs collectively denoted as other programs 86. It is to be further understood that the SADF program 84 and the collator program 85 include portions illustrated in Tables I and II which may be physically and logically with other programs for programming ease and copy microprocessor 170 efficiencies, as is well known in the programming arts. It is also to be understood that the total program control of SADF 11 and collators 14B, 14C in conjunction with CPP 13 and input optics 12 will include instructions not shown in Tables I or II which are not necessary to an understanding of the current invention, but are convenient for control of copy production machine 10. ##SPC1## ##SPC2##

FIG. 4 diagrammatically illustrates a second embodiment consisting of hardware logic circuits for performing the same functions as described above and as executed in the microcode program executed by copy microprocessor 170 insofar as practicing the present invention is concerned. Therefore it can be said that this logic representation fairly represents the computer program in a limited sense for better understanding the practice of the present invention. Other control circuits 90 represent those computer programs in copy microprocessor 170 not pertinent to the present invention, as well as those known relay control circuits and logic control circuits as used in prior art in copy production machines such as the Copier II and Copier Series III produced by International Business Machines Corporation, Armonk, N.Y. Additionally, the collator controls 91 for controlling the collators 14B, 14C are those controls shown in the LeClere application, supra. Other control circuits 90 additionally provide a communication path (not shown) between SADF 11 circuits, CPP 13, input optics 12, collator controls 91, and the additional circuits later described for implementing the present invention.

The connections to SADF 11 are combined into cable 93 and broken out as shown at the top of the figure in the same sense that the connections of input register 173 and output register 174A are made. The lines in the SADF 11 area generally represented by numerals 60-78 are identical to that described for FIG. 3. In any event, at the end of a run copy production portion 13 supplies a suitable end of run signal during collate mode, later described, to other control circuits 90. Other control circuits 90 then supply an image change signal (only during collate mode) over line 46 to AND circuit detector 94. AND circuit detector 94 compares the image change signal from line 46 with the output status of sensor 60 signal supplied over line 65 to set add run latch 95 to the active condition simplifying overlap mode will occur. When the add run latch 95 is set to the active condition bidirectional collation should occur. A variation is present in this embodiment in that rather than using preentry sensor 61 as determining bidirectional collation sensor 60 is used. In any event, add run latch 95 being set supplies a suitable control signal over line 96 to other control circuits 90 indicating bidirectional collation. Additionally, the line 96 add run signal partially enables AND circuit 97 to determine whether or not the collators 14B, 14C should collate in the up direction as by setting latch 98. In this regard, sensors 82, 83 supply the home signal condition through collator controls 91 to other control circuits 90. If both vane copy distributors 16B, 16C are in the home position, AND circuit 97 is inhibited. On the other hand, if the copy distributors 16B, 16C are not in the home position, other control circuits 90 supply an activating signal over line 100 to AND circuit 97 signifying that bidirectional collation is desired; i.e., next collate in the up direction. Finally, other control circuits 90 supply a signal over line 101 indicating that CPP 13 is in fact in the copy overlap mode; i.e., copies bearing images for more than one original document will be or are in the paper path in CPP 13 and the paper path extending to collators 14B, 14C. Finally, collate up latch 98 being set supplies a signal over line 102 to other control circuits 90 as well as to collator controls 91 for actuating the collators 14B, 14C to collate in the up direction.

Go home latch 103 signifies to collator controls 91 that the overlap mode is not present in CPP 13 in that add run latch 95 is reset. Go home latch 103 is set by AND circuit 104 in response to add run latch 95 being reset, the end of run signal during a collate mode on line 101 and last copy signal on line 120. Last copy is indicated as shown in U.S. Pat. No. 4,003,569. The go home latch 103 supplies its control signals over line 105 to collator controls 91 and to other control circuits 90.

In the operation of latches 95, 98 and 103, the add run latch 95 is set during a collate mode copy production run as soon as document 62 is inserted into tray 11B and actuates sensor 60 (sensor 61 in case of FIG. 3 embodiment). This corresponds to copy microprocessor 170 setting a flag bit in status registers 80 for indicating bidirectional collation some time before the end of run signal is received from CPP 13. Communication between other control circuits 90, collator controls 91, CPP 13, and input optics 12 is by cables 106, 107, 108, respectively.

Latches 95, 98, 103 are reset by control circuits 90 via a signal supplied over line 109 corresponding to a start signal for starting a new run, i.e., a new document has been placed on plate and glass 11A to be imaged via input optics 12 as scanned via the image path 12B. Similarly, the line 101 signal is supplied through OR circuit 110 to reset add run run latch 95 in preparation for detection of the next bidirectional collator function as initiated by the operator (not shown) inserting a document 62 onto tray 11B during a present copy production run.

Referring next to FIG. 5, detection of an end of copy run is shown. A copy select register CSR 110 maintains a selection received from panel 52 via cable 111 indicating the number of copies to be produced of each image. A copy count register CC 112 receives a signal generated within CPP 13 in a known manner and supplied over line 113 to increment CC 112 for indicating the number of copies being produced. CC 112 may be actuated at various times within the copy production cycle. One way to actuate CC 112 is by sensing paper picked from supplies 35, 54 or from duplex interim storage unit 40 is approaching aligner gate 28 over path 27 as indicated by a sensor 114 (FIG. 1). When the signal content of CC 112 and CSR 110 are equal, comparator 115 supplies an end of run signal over line 116 to other control circuits 90. During the collate mode, the end of run signal goes over line 101 as previously described.

In a computerized embodiment of FIG. 3, CSR 110, CC 112 are registers within memory 172, such as other status registers 80. Compare 115 is a branch instruction for comparing the signal contents of CSR 110 and CC 112 within status registers 80. Tallying or incrementing counter CC 112 is in response to the signal from sensor 114 actuating programs within copy microprocessor 170 denominated as other program 86.

While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.