Abstract:
A sophisticated collator having a general purpose microprocessor with a stored program is capable of intercommunicating with a sophisticated photocopier. In most operations, the collator functions as a slave to the photocopier. It processes a collator task by receiving and processing signals from several sensors positioned about the collator. A manual insertion assembly allows entry of sheets into the collator from a source other than the photocopier. Proofed pages can be re-fed for collating, or jobs from a second source may be processed. Thus the collator need not be a slave only to the photocopier. A second vacuum belt reduces problems of transporting wide paper. Diverting fingers may contact the conveyor system to allow sheets to pass over a bin into additional bin units attached to the sophisticated collator.

Description:
DESCRIPTION 
     TECHNICAL FIELD 
     This invention relates to a sophisticated collator capable of intercommunication with a computer-controlled photocopier. The collator has a logic control means having a stored program which responds to job commands of the photocopier. Information from various sensors aids collating of sheets from the photocopier. 
     BACKGROUND ART 
     Collator technology has improved steadily. Demand has arisen for fast collating with expanded capabilities. With this demand has also come correlative problems in the collator mechanics. The art of microprocessor control has allowed many of these problems to be reduced or eliminated. This invention relates to use of a sophisticated logic control means which will allow the collator to perform tasks more quickly with fewer problems. The collator functions as a slave to a sophisticated, computer-controlled photocopier. Through a computer link, the two devices can operate together to better achieve desired results. 
     There are far too many collator patents to describe them all in this introductory section. However, a few should be mentioned. U.S. Pat. No. 3,905,594 (Davis) discloses a randomly programmed, sequential sheetsorting machine for filling trays with differing numbers of sheets. A computer memory stores input on the number of sheets desired in a particular tray. When operating, the collator counts the sheets for each tray. Each job must be individually programmed. Because most collating jobs require sorting a consistent number of sheets to each tray, the program capability, which is the essence of the Davis invention, has limited use. 
     U.S. Pat. No. 3,772,970 (Snellman et al.) discloses another collator which may be programmed to distribute selected numbers of sheets to selected sheet receivers. This collator uses relays and contacts to perform its desired sorting. This electromechanical control system requires manual programming before each sorting job. 
     Yet another collator for placing an unequal number of sheets into separate trays is disclosed in U.S. Pat. No. 3,572,685 (Snellman). A dispatcher assembly controls the operation of a distributor in accordance with sequentially recorded information advanced through an information-sensing or &#34;readout&#34; section of the assembly. Magnetic tape at each tray is read to determine how many sheets should be placed in that tray. Alternatively, a punch card reader may be used. A memory stores the information on sheets and trays and controls the sheet deflector assembly. 
     U.S. Pat. No. 3,618,936 (Ziehm) discloses an improved jam detection system for sorting apparatus. The system comprises program means to actuate individual deflector members to route documents into a selected tray in a predetermined sequence, sensing means disposed along the feed path for the document, and a timing circuit with an output to control the feed path. 
     U.S. Pat. No. 3,709,485 (Acquaviva, Jr.) discloses a control circuit for a sorting system. A jam detection circuit times signals received. The circuit is coupled to the motor drive of the conveyor. When sheets jam, the conveyor will be shut down. Relays and phototransistors along the conveyor collect information. Comparison circuits count the numbers of sheets reaching trays. 
     Although some of these patents disclose limited aspects of microprocessor control, none discloses the intercommunication and cooperation with a sophisticated, computer-controlled photocopier. Much of the utility of this invention relates to its flexibility in responding to tasks ordered by the photocopier. Its ability to store functions for later use, to detect errors, and to converse with its overlord photocopier makes this invention a valuable and much desired improvement over other machines. 
     DISCLOSURE OF THE INVENTION 
     A novel feature of this invention relates to a sophisticated collator&#39;s ability to intercommunicate with and to respond to a computer-controlled photocopier. A logic control means on the collator of this invention has a programmable computer with a stored program. Unlike electromechanical relays or random logic control, this computer is readily adaptable through reprogramming. Its function is not necessarily fixed, although during any particular collator operation, its function is predetermined. The logic control means converses with the photocopier to receive job commands and information on the running of a particular job in the photocopier. It acts upon these job commands to sort sheets, principally in three modes: proof, stack or collate. To aid its completion of a job, the logic control means receives and processes signals from several sensors around the collator. Thus the job is completed more efficiently, or notification as to a particular problem is more detailed. 
     Another novel feature of this invention relates to a manual insertion means which interconnects with the customary sheet conveyor system of the collator. While attached to a photocopier, this means allows entry of sheets from a second source. The manual insertion means allows dual functioning for the collator. The preferred collator need not only function as a slave to the sophisticated photocopier, but it can collate other jobs through this secondary input. The manual insertion means is particularly useful for refeeding sheets displaced in a collator jam or for running small collating jobs in which prior photocopying is unnecessary. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the collator of this invention connected to a photocopier. 
     FIG. 2 shows an assembly drawing of the collator of FIG. 1, illustrating access means to the mechanical works. 
     FIG. 3 is an isometric view illustrating the preferred manual insertion means and proof tray of this invention. 
     FIG. 4 is an isometric view illustrating the entry for sheets into the proof tray. 
     FIG. 5 is an isometric view illustrating the sheet conveyor system over the top of the collator. 
     FIG. 6, a section along line 6--6 of FIG. 3, shows the preferred drive means for the conveyor system. 
     FIG. 7, a section along line 7--7 of FIG. 8, shows details of the conveyor system and deflector assembly of the collator. 
     FIG. 8 shows a detail of the drive means for the collator, illustrating the means for identifying the individual trays of a bin. 
     FIG. 9 is a simplified flow chart of the control system. 
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     The collator 10 of this invention responds to commands of a sophisticated photocopier 11 to process sheets. To receive information and to process it so that the job commands may be executed, this sophisticated collator features a logic control means 100 (see FIGS. 6 and 7) having a digital computer with a stored program. Zilog Z80 chips have proven satisfactory for this application. Upon command from the photocopier 11, which also has a computer to aid its operation, the collator of this invention operates quickly and efficiently to sort incoming sheets. It records and processes the order, knowing the number of sheets in the job and their desired disposition to the trays. Using sensed information from several sensors mounted along the path of the conveyor system of the collator, the collator processes the sheets in three modes: to proof, to stack, or to collate. In proof mode, the sheets which enter from the photocopier are routed to an accessible bin 12 on the top of the collator. Dog 53 (see FIG. 7) lowers plate 54 to contact the common conveyor system and to deflect incoming sheets into the proof tray. In stack mode, sheets are routed to the first open tray 13 in a bin and subsequent sheets continue to this tray until it is filled. Then the deflector assembly moves to the next tray, which is filled by subsequent sheets. In collate mode, the sheets proceed to a series of trays, the collator accomplishing the sorting of the various sheets. 
     Means for communicating 60 (see FIG. 6) with the photocopier, such as direct wiring, interconnect the photocopier and collator so that information may be interchanged between the two logic control means. Initially, the photocopier 11 signals the mode of operation and the size of the job. The collator&#39;s logic control means 100 surveys its sensors to prepare for processing. If a problem is detected, it will communicate that fact back to the photocopier. If no problems exist, the collator 10 will prepare to receive sheets. For each sheet passing out of the photocopier, the collator will receive a counting signal. Similarly, a sensor 14 (see FIG. 7) at the entrance to the collator signals the successful arrival of each sheet. The passage of paper over the entrance sensor is timed so that the collator may calculate the anticipated arrival at the desired bin and tray. Either adaptive timing for each sheet or a threshold time failure system may be used to detect jams along the path. As the paper leaves the entrance sensor 14, a clock times its travel to the tray against the prescribed time for travel. If the paper fails to reach the tray entrance sensor 16a and 16b within the prescribed time, notice of a jam is sent to the photocopier. The entrance sensor 14 preferably is a microswitch which is tripped by the paper as it moves along the conveyor. If a jam is detected, the logic control means reduces the power in the collator, signals the jam, and stores the progress of the job. When the jam is successfully overcome, the collator returns to the job command. A jam reset sensor 70 manually signals that jams have been cleared. 
     A second type of jam detection is accomplished at each sensor. When the leading edge of a sheet contacts the sensor, a clock begins to time the passage of paper over the sensor. The clock resets when the trailing edge of a sheet leaves the sensor. If the time of travel exceeds a threshold value (at which point the clock expires), a jam will be signalled for that sensor. 
     A preferred timer capitalizes on the time-sharing capacity of the computer. The job functions are interrupted and stored in a sequence at predetermined intervals. A specific address in the random access memory (RAM) easily serves as a clock for jam detection purposes. The threshold time is determined as a multiple of the time-sharing interrupts. The RAM address is incremented from its elapsed count to the added threshold count. The RAM address and the actual interrupt count are compared for each sheet. If the actual count exceeds the RAM increment, a jam has occurred. 
     The tray entrance sensor is preferably a photocell 16a and light source 16b which is intermittently cut when sheets are deflected into the trays. Each break in the signal serves as a paper count. The signal also resets the clock circuits for retiming. 
     Three sensors help to control the position of the deflector assembly 20. A home sensor 17 (see FIG. 7) indicates that the deflector is at the first tray 13 of a bin. Similarly, an end sensor 18 signals that all trays in a bin have been filled. Both of these sensors are preferably Hall effect sensors. The third sensor 25 (see FIG. 8) counts the position of the deflector assembly between home and end. Two halves of a Hall effect sensor 25b and 25c are arranged so that a means for interrupting 25a can break the sensor&#39;s magnetic field each time the deflector assembly 20 moves one tray. A star wheel positioned to cut across the field with alternate openings and fans functions smoothly as the means for interrupting 25a. This star wheel is easily fitted to the drive means 30 for the deflector assembly 20. Each time the deflector assembly 20 moves one tray 13, the wheel 25a spins to cut and then to restore the field, allowing the logic control means 100 to record the position of the deflector assembly. A photocell/light source combination might also be used. 
     To detect if there is any paper in any tray of a bin unit (i.e., if the bin unit is free of paper in any tray), a photocell 19a and light source 19b (see FIG. 7) are positioned at the top and bottom of the bin unit. Paper in a tray breaks the beam. The logic control means 100 interprets this information. 
     To allow other bin units to be added, the collator may be designed with interconnecting means 80. Keyways 80 on one bin unit receive matching keys on a second bin unit. Sheets pass through a slot 82 in the side of the bin. Sensors 81 detect connection of additional bin units and signal to the logic control means. With the information of the number of bin units, the logic control means can determine if the size of job requested is proper. Also, when a deflector assembly 20 reaches the last tray of a bin unit, the logic control means 100 may signal diverter fingers 40 to allow sheets to pass over the filled bin. These fingers flip to contact the conveyor system of the bin to make a route to the next bin. 
     Another novel feature of this invention is a manual insertion means 50 on the collator to allow entry of sheets from a source other than the photocopier. The preferred means includes a microswitch sensor 15 to detect entry of sheets. The logic control means then powers drive wheels 51 which convey sheets to the usual conveyor system for the collator. The manual insertion means 50 is particularly useful to refeed sheets which are diverted to the proof tray 12 when a jam between the proof tray 12 and the trays 13 of a bin is detected. Also, this feature allows the collator 10 to process jobs from a source other than the photocopier 11. Not only is the collator a slave to the sophisticated, computer-controlled photocopier with which it is designed to intercommunicate, but it can act independently to process other jobs. Most of these other jobs will be small, so manual insertion through a curving reception passage 52 at the top of the collator is ordinarily adequate. More sophisticated entry means could easily be designed into the structure, however. 
     To control wider sheets of paper with less problem, this collator also includes a second vacuum belt 61. With suction at two points, the wider sheets adhere better to the conveyor system. Edges do not curl as frequently. Jams are reduced. The second belt 61 is offset from the common belt 60. It need not be used if the paper does not call for the added suction. 
     A Preferred Control Program 
     As best understood with reference to FIG. 9, the logic control means of this collator is programmed to receive input commands from a photocopier. As a first step, the collator records these commands in a buffer. If the copier is then altered, the job status will be preserved. Reading from the buffer, the collator scans its several sensors to see if the desired task is performable. It checks the size and type of job, looking for problems in the sheet path. If the task is performable, the logic control means powers up the various mechanical means required to perform the task. The deflector assembly is brought home, the vacuum is started, the conveyor motors and associated parts are ready. When sheets are received, the logic control means processes them, checking for jamming. It counts the sheets so that it may know where it is in the desired job. If a jam occurs, it will store its status so that upon resetting, it may proceed from the point at which the jam occurred. Each sensor supplies information on this job status. Running jobs may be interrupted to interject special jobs, and yet the collator can return to the point at which it was interrupted without reentry of the job commands. Sheets in the trays need not be removed when a running job is interrupted, but a signal may be given that all trays have some sheets in them, if it is so desired. When the job is completed and the buffer is cleared, the collator will automatically power down. 
     A preferred program using Z80 assembler language to accomplish the multiple functions generally described to this point is: ##SPC1## ##SPC2## ##SPC3##