Electronic Copy Selection Controls for a Document Reproduction Machine

The present invention relates to document reproduction machines and particularly to electronic copy selection and related controls for a convenience copier type of document reproduction machine.

Xerographic and other forms of document reproduction machines have been used for years as convenience copiers, as well as for higher throughput of copy production, such as found in printing or publication centers. There has been a trend from the original relay and cam-operated machines to electronic controls, as well as program controls of such document reproduction machines. Adoption of electronic controls generally has provided a greater flexibility in controlling document reproduction machines. A further change is the adoption of keyboard input for selecting the number of copies to be made of a given original document. Such keyboard entry usually results in a serial transmission of digits to a shift register in a manner similar to that of entry into an adding machine or a pocket electronic calculator. Once the copy number has been inserted into the shift register, a clear button enables the shift register to be cleared for permitting insertion of a new number, a machine reset clears the number, or a powder down clears the number. Hence, to change the selection of the number of copies to be reproduced requires externally actuated clearing action followed by insertion of the new number.

In other machines the copy select register is counted to zero or one, destroying the selection. Such action requires a new selection for each copy run, an operator inconvenience to be arrested.

While the above features permit utilization of electronic circuits in controlling a document reproduction machine, the interaction between the operator and the document reproduction machine requires the operator to clear the selection before inserting a new one. Also, machine reaction to the selection has no affect upon the selection itself. For example, if a number of copies greater than the capacity of the machine is selected, a machine produces copies up to the capacity of the machine, then the machine has been put in a wait state. Upon the operator removing the copies from the collator or other unit, which is filled up, then the machine automatically resumes the copy run.

In summary, it is desired to enhance the convenience of the operator using a convenience copier while facilitating throughput with minimal attention of the operator.

It is an object of the invention to provide an electronic document reproduction machine having enhanced electronic control data entry controls for tending to minimize operator attention to details while controlling or limiting the operator selections to predetermined functions and copy quantities in accordance with design goals of the machine.

A feature of the invention is to keep a copy selection in a control register until a new selection is made or a timer has timed out upon non-use of the machine. Further, control circuits in the machine facilitate inserting new selections into the control register.

A document reproduction machine using the present invention preferably includes a multidigit position control register which receives control or value digit signals from a manually actuatable keyboard or other suitable source. Position means indicate the number of significant digit value signals contained in the control register. When the position means is in a nonreference state and the machine is operating, further entries into the register are inhibited. However, upon completion of a copy run, the position means is reset to a reference state enabling insertion of a new number into the control register. The signal contents of the control register are unchanged.

Further, in another aspect of the invention, register control means jointly respond to the position means indicating that all digit positions of the control register have significant value signals therein and the keyboard was actuated, a new value from the keyboard is inserted into the control register which is substituted for the present signal contents of such control register. The control register and the position means are selectively resettable to a predetermined state in accordance with predetermined machine operational conditions. As an example, when the machine is in a duplex copy production mode (images are impressed upon both sides of the copies being produced), the machine having an interim copy storage means of finite capacity limits the number of copies to be produced in a given run to the capacity of the interim storage means. If an operator selects a number of copies to be produced greater than such capacity, then the machine automatically alters the signal contents of the control register to the maximum capacity of the interim storage means. In a similar manner, a collator may be attached to the document reproduction machine. Such collator may have a limited number of bins, i.e., may accept a limited number of copies to be collated in a given set of copies. For example, a machine may have either a 25-bin collator or a 50-bin collator. In the event the 25-bin collator is attached to the machine, the maximum number of copies to be produced in the collate mode would be limited to 25. Similarly, for a 50-bin collator, the maximum number of copies is 50.

In another aspect of the invention, the keyboard entry produces value signals which are detected in accordance with a scanning counter and a comparison circuit. A closure counter integrator determines whether or not a sufficient actuation of the key occurs before a value signal is inserted into the control register. Similarly, the closure counter integrator measures contact break time for indicating that a key has been released. These counts gate the digit value selected by the scanning counter for insertion into the control register. Provisions are made for selecting one and only one digit value signal for each depression of the keyboard; i.e., a plurality of keys may be simultaneously depressed, but only one value signal will be transferred. Further, means are provided for ignoring insignificant zero digits, i.e., zeroes to the left of the first nonzero value signal.

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

FIG. 1 is a diagrammatic and block diagram showing of a document reproduction machine incorporating the teachings of the present invention.

FIG. 2 is an idealized set of timing signals usuable to time the operation of the electronic circuits shown in FIG. 1.

FIG. 3 is a combined block and signal flow diagram showing a digit value selector and a copy select controller usable with the FIG. 1 illustrated document reproduction machine.

FIG. 4 is a simplified combined block and signal flow diagram of a limit control usable with the FIG. 1 illustrated document reproduction machine.

Referring now more particularly to the drawings, like numerals indicate like parts and structural features in the various diagrams. Overview of an illustrative embodiment of the invention is best seen by referring to FIG. 1. A document reproduction machine has an original image portion 10 controlled by a set of imaging controls 11. The image is obtained from an original document (not shown) placed on a platen (not shown) in the usual manner, and then projected upon an image area of a photoconductor member (not shown) or other document reproducing unit (not shown), all contained within a document reproduction portion 12 of the machine. Portion 12 is controlled by a set of process controls 13, all constructed using known techniques and in a known manner. The copies produced by the document reproduction portion 12 are transferred along a paper path (not shown) to a copy output portion 14 for accumulation or collation, as the case may be. Portion 14, in turn, is controlled by output controls 15. It is to be understood that the three controls 11, 13, and 15 have interconnections and interactions for coordinating and synchronizing the operations of all the portions 10, 12, and 14 with the movement of a photoconductor member (not shown) in document reproduction portion 12. A document reproduction machine of the type controllable by the circuits of the present invention include that shown in U.S. Pat. No. 3,834,807. It is also to be understood that other document reproduction machines may be similarly controlled, such as the so-called Copier II manufactured and sold by International Business Machines Corporation, Armonk, New York. Those machines do not have complete electronic controls. Rather, a timing shaft having cams thereon actuate switches (circuit breakers -- CB's) to produce control signals called CB signals. Such CB signals synchronize the operation of all portions of the document reproduction machine. As an example, a CB1 signal is supplied by process controls 13 over line 16 for interrogating circuitry added to the document reproduction machine 10-15 for incorporating the present invention into such a machine. Such machines also have a turn-off signal, i.e., an indication that the number of copies to be made have been actually made. Such turn-off signal, as supplied over line 17 to process controls 13 initiate a shut-down of the document reproduction machine as is well known in the art and is not described for that reason. Exchanging signals between electronic circuits and relay circuits is well known and not described for that reason.

The present invention provides enhanced keyboard control 20 of the document reproduction machine 10-15 as well as enhancing control based upon signals received from communication circuits (not shown) and other automatic (not shown) or semiautomatic (not shown) control inputs. Such a keyboard 20 is usually mounted in a console 21 for the document reproduction machine 10-15. In addition to keyboard 20, the console includes operator station display and selection switches 22, as well as a timer 23 which deselects certain operator selections if the document reproduction machine 10-15 has not been used for a predetermined time. Such predetermined time will vary upon selection parameters of the document reproduction machine. In one machine 10-15, timer 23 had a time-out of 30 seconds. In another, 90 seconds timed out all of the selections. The timer 23 is reset by a signal traveling over line 24 from station 22 each time the machine is turned off. Of course, when the machine is running, a second signal on line 24 inhibits operation of tomer 23. When timer 23 has timed out, it supplies an actuating signal over line 25 for resetting the selections, as well as providing certain control functions in connection with the present invention, as will be later described.

Keyboard 20 can be of any design. However, it is preferred that the keying arrangement be as shown in FIG. 1. The numeral 1 is selected by the left-hand button 30, number 2 by button 32, etc., through button 32 which selects zero. An operator selects the number of copies to be produced by a succession of key depressions. For example, if 156 copies are to be produced, the operator depresses key 30 (selects 1), then the 5-indicating key 33, and then the 6-indicating key 34. The number 156 is then automatically inserted into control register 35 and suitably displayed in station 22 by signals supplied over cable 36 from control register 35. Such signals from register 35 are also applied to the controls 11, 13, and 15. Additionally, station 22 supplies selection control signals over cable 37 to the circuits of the present invention, as later described, as well as to the controls 11, 13, and 15, the latter in accordance with known design techniques.

The electronic circuits 41-62 illustrated in FIG. 1 are electrically interposed between keyboard 20 and control register 35 provide the enhanced functions of the invention as well as operator convenience and a more automatic control of copier 10-15.

Keyboard 20 key closure signals travel over cable 40 (having 10 circuits, one for each key) actuating digit value selector circuit 41 to detect the value of the key depressed, as well as integrating the closures and openings for eliminating noise and bounce caused noise signals. Selector 41 is described later in detail with respect to FIG. 3. Its functions include supplying a digit received signal over line 42 to actuate copy select controller 43 to insert a new data value into control register 35. The data values are supplied in binary coded decimal, or other coded form, over cable 44 to copy select controller 43 and to control register 35. Controller 43 examines the data signals on cable 44 for determining whether or not a significant value signal is being received. If no significant value signal is being received, then the data value signals are not inserted into control register 35.

A timing signal generator 45 synchronizes the operation of a portion of the illustrated electronic circuit 41-62. It provides a high-frequency signal A (see FIG. 2), a submultiple frequency B, and a set of four distributor pulses 1-4 for sequencing copy select controller 43.

Control register 35 is the same as a copy select register used in the Copier II, supra, and in other convenience copiers. That is, the signal content of control register 35 signifies the number of copies to be made in a copy set, i.e., how many times the original image is to be reproduced in a set of copies in a given copy run. A second register 50 receives signals over cable 51 from process controls 13 signifying the number of copies actually produced in a given set of copies. When the signal contents of register 50 equals the signal contents of register 35, the copy set is complete and the document reproduction machine is turned off by a signal supplied over line 17. To this end, compare circuit 52 responds to signals from control register 35 and from copy count register 50 to supply an RC (run complete) signal through OR circuit 53, thence to line 17 for turning the document reproduction machine 10-15 off. The RC signal is also supplied to copy select controller 43 for enabling a later described override input feature for control register 35.

Copy select controller 43 includes a register position select control 55 which detects the data on cable 44 for significant value and simultaneously controls register position selector 59. Register position selector 59 in turn controls register controller 56 for selectively inserting cable 44 signals into control register 35 and shift signal contents thereof to more significant digit positions. Register controller 56 includes reset means 57 which resets certain digit positions of register 35, as well as gating means 58 which selectively actuates control register 35 to receive the cable 44 data signals. Register position selector 59 indicates the number of significant digits in control register 35 and controls the gating means 58 and the reset means 57 for employing an override function and data value insertion principles of the present invention. Limit control 60 limits the number of copies in a copy set by selectively altering the signal contents of control register 35 in accordance with functional capabilities of the document reproduction machine 10-15, as described in detail with respect to the showing in FIG. 4. Limit control 60 and the select modulus signals received over cable 61 provide additional controls on automatically limiting the number of copies in a given copy set in accordance with selections beyond the control of the operator.

Decode circuit 62 examines the signal contents of control register 35 and register 50 for illegal signal patterns and for detecting when the signal contents of register 50 has a numerical value greater than the numerical value contained in control register 35. In the latter case, a stop signal is supplied over line 63 through OR circuit 53 to turn off the document reproduction machine 10-15. Additionally, an alarm may be sounded, or a suitable indicator (not shown) is illuminated within station 22. Decode 62 also supplies control register 35 decoded signals indicating the magnitude of the value signals in that register. Limit control 60 responds to those signals for determining whether or not the signal contents of register 35 should be altered to coincide with the functional capabilities of document reproduction machine 10-15.

Referring now more particularly to FIG. 3, digit value selector 41 is detailed. Selector 41 is enabled only when process controls 13 are supplying a not copy run signal over line 70 which enables compare circuit 71, decade or 10's counter 72, and AND circuit 73. 10's counter 72 scans the key selections received by compare circuit 71. The scan is operated at the rate by A pulses poking through AND circuit 73 to continually increment counter 72. When compare circuit 71 detects a coincidence between the numerical content of counter 72 and the decoded value of a key closure activated line in cable 40, compare circuit 71 latches the comparison and supplies an active signal over line 74 for initiating a determination of whether or not a sufficient contact closure is occurring. At all other times, compare circuit 71 supplies a noncompare indicating signal over line 75 which partially enables AND circuit 73 to pass the A pulses. Digit received indicating latch 76 being reset supplies a no-digit received signal over line 77 for completing control of AND circuit 73. Accordingly, counter 72 counts the A pulses until compare circuit 71 removes the line 75 signal, at which time the value signals are generated in counter 72 in correspondence with closure of a key in keyboard 20. The signal contents of counter 72, which is preferably in binary coded decimal, but may be in straight binary or other number notational system, supplies the resultant value signals over cable 44 as mentioned with respect to FIG. 1.

Digit value selector 41 also selects one and only one set keyboard 20 selected value signals. If two keys are simultaneously actuated, selector 41 supplies value signals corresponding to but one key. Such action is achieved by the ten's counter 72 scan. The scan is interrupted upon compare circuit 71 detecting a comparison with any key. The first successful comparison stops the scan and initiates inserting a value signal into control register 35. All other selections are excluded. Hence, which key is received is a random function of the scan position (count in counter 72) and time of keyboard actuation.

Closure counter 80 determines a satisfactory closure or opening of a keyboard 20 key. A pair of AND/OR (AO) circuits 81 and 84 control closure counter 80. To detect a closure, the A1 input portion of AO (AND/OR) 81 is enabled to pass B pulses to increment closure counter 80 from a reference state, such as all 0's. When closure counter 80 is counted to a predetermined number, for example, 78, counter 80 then supplies an activating signal over line 82 enabling AND circuit 83 to pass a distributor 1 pulse for setting digit latch 76. Hence, 78 B pulses define a satisfactory closure of a keyboard 20 key. Circuitwise, the A1 portion of AO 81 is enabled to pass the B pulses when digit latch 76 is reset and when compare 71 is supplying a successful compare signal over line 74.

In a similar manner, a contact opening is detected by closure counter 80 counting to 73 "B" pulses. To this end, the A2 input portion of AO 81 receives the B pulses whenever compare circuit 71 is supplying a noncompare active signal over line 75 and digit latch 76 has been set; i.e., a digit has been successfully received from keyboard 20. Now, closure counter 80 has to detect release of the key by counting to decimal 73. When closure counter 80 reaches count 73, it supplies an active signal over line 85 enabling AND circuit 86 to reset digit latch 76.

Intermediate the above-described counting activity, counter 80 is reset by AO 84. The AO 84 input portion responds to digit latch 76 being in the reset state, as indicated by the active signal on line 77 and to compare circuit 71 supplied active signal over line 75 to reset closure counter 80. That is, when digit latch 76 indicates no digit has been received and compare circuit 71 signifies no key is closed, i.e., all keys are open, then closure counter 80 can be reset for detecting the next closure; i.e., count to decimal 78. In a similar manner, the A2 input portion of AO 84 responds to digit latch 76 set indicating signal on line 42 and the compare 71 comparison signal received over line 74 to reset counter 80. This detection signifies that compare circuit 71 has detected a contact closure and that counter 80 already has counted to 78 and set digit latch 76. Accordingly, counter 80 should be reset for conditioning the circuits to detect a contact opening. In summary, in accordance with the above detection processes, selector 41 supplies a digit received indication signal on line 42 and the corresponding detected value signals over cable 44.

Before entering the value signals on cable 44 into control register 35, position select control 55 determines whether or not a new significant data value has been received. Decode 90 detects for an all-0's indication of a cable 44 signal. If a zero is detected, it supplies an activating signal over line 91 to NAND circuit 92. If the register position selector counter 59 is already in the later described KO state, i.e., there are no value signals in register 35 or an override, as later described, is enabled, an active signal on line 93 completes actuation of NAND 92. NAND 92 then supplies an activating signal over line 94 to activate AND circuit 95. AND circuit 95 only passes an incrementing signal over line 96 for incrementing the position selector counter 59, as later described, when digit latch 76 is set, as indicated by the line 42 signal, and closure counter 80 has detected a key opening, as indicated by the line 85 signal being active. These conditions indicate significant digit value signals in cable 44. Incrementing counter 59 only under those conditions also suppresses entry of nonsignificant zeroes, i.e., the all zeroes to the left of the first non-zeroes digit. Hence, for all nonsigificant zeroes, the line 96 signal remains quiescent. It should be remembered that for significant zeroes, i.e., zeroes to the right of nonzero digits, this action results in an activation of line 96 in that counter 59 is in a nonzero count state.

Position select control 55 also resets position counter 59 to the zero or reference state KO via OR circuit 100. OR circuit 100 passes all resetting and clearing signals received from station 22 and process controls 13 to reset register position counter 59. The reset signals include a reset signal from line 101. Reset is a key in station 22 which resets all electronic circuits within the machine, including those circuits and relays in controls 11, 13, and 15. Additionally, the timer 23 signal on line 25 time-out signal (TO) resets counter 59. A power-on reset signal (POR), received over line 102 from station 22, resets counter 59, as well as control register 35. For control register 35 override, counter 59 is reset by the RC signal on line 17 without resetting control register 35. This override enables the operator to insert a new set of value signals or control signals into register 35 without depressing either a reset button or a clear button. That is, at the end of a copy run, the present invention enables the operator to select a new number of copies to be produced without manually resetting control register 35.

The override facility mentioned above is best understood by understanding the functions of the register position selector counter 59. Counter 59 has a number of count states equal to the number of digit positions in control register 35. Counter 59 can either be a shift register counter or a three-state binary counter. The First state, K0, is a reference state signifying that the first received digit signal from keyboard 20 is to be assigned to the units digit position of control register 35 and the more significant digit positions, 10's and 100's, contain nonsignificant zeroes. The second signal state, K1, signifies there is a value signal in the unit digit position and that the next received signal from keyboard 20 should be put in the units digit position, and that the significant value signal contents of the units digit position should be shifted to the 10's digit position. The 100's digit position has a nonsignificant zero. Similarly, the K2 state, the third state, signifies that the units and 10's digit positions contain signals and that the next received signal from keyboard 20 signifies that those two signals should be shifted to a more significant digit position and the newly received signal be inserted in the units digit position. When control register 35 is cleared to its reference state, counter 59 is always in the K0 state. Upon override, control register 35 contains value signals and still the next received value signal from keyboard 20 will replace all of the signal contents of control register 35. That is, the copy number selection contained in register 35 can be overridden by actuation of the keyboard without any intervening action by the operator.

Gating means 58 respond to the K0, K1, K2 counter states of counter 59 to achieve the shifting and data insertion into control register 35. Control register 35 includes a decimal shift register 105 having the units, tens, and one hundreds digit positions. It is preferred that register 105 contain signals in the binary coded decimal notation, no limitation thereto intended. Cable 44 is connected to all of the unit digit positions and may consist of four D-type flip-flops wherein the data signals on cable 44 are attached to the data input of the respective D-type latches while the gating means 58 control signals are connected to the clock inputs. To this end, AND circuit 106 of gating means 58 controls insertion of data signals from cable 44 into the units digit position.

The sequence of inserting signals into register 105 is best understood by referring to the distributor pulses 1-4. Distributor pulse 1 detects receipt of a digit value by sampling circuits 83 and 86 of digit value selector 41. The circuits are then conditioned for detecting the action required for inserting the received value signals or for inhibiting the received value signals. In the event signals reside in the units and tens digit positions of register 105, AND circuit 107 responds to the 2 distributor pulse and to the K2 indicating state of counter 59, as well as the line 42 active signal to shift the signal contents of the tens digit position to the hundreds digit position, all as indicated by line 108. Such shifting is achieved by circuitry (not shown) contained within register 105 as is well known in the arts. Then, at distributor time 3, AND circuit 109 responds to the 3 pulse, line 42 pulse, and to OR circuit 110 to shift the signal contents of the units digit position to the tens digit position, as indicated by the line 111. This action is identical to the shift from the tens to the hundreds digit position. OR circuit 110 passes the activating signals indicating the K1 or the K2 state; that is, the units digit position signals are supplied to the tens digit position whenever any value signal is in the units digit position. Finally, AND circuit 106 responds to the 4 distributor pulse and to the line 42 pulse to activate the C inputs of the D latches (not shown) to the units digit position 105 as indicated by line 112.

Reset means 57 cooperates with counter 59 and the other previously indicated reset control signals for resetting and conditioning control register 35 to reflect the desired number of copies to be produced. The override feature enabled by counter 59 being reset to the K0 state by the RC line 17 signal includes activating AND circuit 120 whenever the digit latch 76, line 42, signal occurs simultaneously with the counter 59 K0 state. AND circuit 120 supplies its activating signal through OR circuit 121 for resetting the tens and hundreds digit positions of register 105 as signified by the small circles 122, 123. Then, in the next distributor 4 time, AND circuit 106 inserts the received value signal from cable 44 into the units digit position. The tens and hundreds digit positions of register 105 are also reset by OR circuit 121 in response to a line 101 reset signal and whenever OR circuit 124 receives either the POR signal on line 102 or the TO signal on line 25. OR circuit 124 supplies its signal over line 125 for also setting the units digit position to a 1 signal state. This is done in coincidence with a 4 distributor signal pulse via AND circuit 126. The line 101 reset signal also supplied over line 127 resetting the units digit position of register 105 to zeroes.

Another feature of the illustrated document reproduction machine is that whenever the control register 105 indicates all 0's, the document reproduction machine produces one copy per copy run. In certain prior art machines, an all-0's in the copy select register or dial resulted in no copies being produced. To make it more convenient for the operator, i.e., not requiring the operator to insert a 1 in the copy select register, a decode circuit 130 responds to an all-0's condition in register 105 to generate an active signal on line 131. OR circuit 132 combines the line 131 signal from the 1 indicating line from the units digit position of register 105 to supply a 1 signal over line 134. The line 134 signal not only signifies to the document reproduction 10-15 to produce one copy, but also is the best significant bit of register 105 copy select control signals for a copy run of more than one copy.

Referring now more particularly to FIG. 4, limit control 60 and its interaction with the remaining portions of the machine is detailed. In some constructed embodiments of the document reproduction machine 10-15, copy handling facilities may be limited. For example, in a duplex mode wherein images are printed on both sides of copy paper, an interim storage unit (not shown) is provided within document reproduction portion 12. This interim storage unit (not shown) may have a capacity of storing 125 copy sheets, for example. In the event that the copy select or control register 35 signifies in the duplex mode that 200 copies are to be produced, the capacity of the interim storage unit will be exceeded. As a result, paper jams or error conditions may result. A similar situation may occur when a collator is included in copy output portion 14. That is, the number of copies in the copy set should not exceed the number of bins in the attached collator. FIG. 4 illustrated circuits obviate these problems by limiting the content of register 105 to the maximum capacity of the critical element in the document reproduction machine involved in a particular copy run.

Station 22 includes a duplex selection switch 140 which, when closed, actuates pulse former 141 to sample AND circuit 142. AND circuit 142 is enabled to pass the pulse former 141 signal whenever process controls 13 indicate that operator selections are ready to be received by a signal on line 143. Line 143 forms a portion of cable 36 in FIG. 1 connecting process control 13, inter alia, to station 22. AND circuit 142 triggers select duplex trigger 145 to the duplex indicating state. Duplex trigger 145 then supplies a duplex indicating signal to process controls 13 and to limit control 60 over line 146. AND circuit 147 in limit control 60 responds to the line 146 signal and to a start signal (later described) received over line 148 and to a decode 62 signal on line 150 signifying register 105 has signal content greater than the capacity of the interim storage means (not shown) to supply an active signal over line 151. The line 151 signal adjusts the signal content of register 105 to the maximum capacity of the interim storage means (not shown), for example, 125. This is achieved via OR circuit 152 supplying a 5 setting signal to the units digit position 10.sup.0 and by the line 151 signal supplying a 2 setting signal to the units digit position 10.sup.1 and a 1 setting signal to the hundreds digit position 10.sup.2. Upon setting register 105 to 125, document reproduction machine 10-15 produces 125 copies in a successful manner without overloading any portion of the machine. Upon completion of the production of 125 copies, the operator then may insert the appropriate number of copies remaining to be made in register 105.

Register 105 is preset as above described by one of several means. As shown in FIG. 4, closure of start switch 155 actuating pulse former 156 passes a pulse through AND circuit 157 whenever the line 143 signal is active. AND circuit 157 then supplies the above-mentioned line 148 signal. In the alternative, process control 13 may supply one of its CB pulses for interrogating AND circuit 157. Yet other sources of interrogation pulses may be used.

A similar situation occurs when the collate mode is selected by closing switch 160. Pulse former 161 supplies the collate select indicating pulse to AND circuit 162 which is enabled by the line 143 signal. Select collate trigger 163 is then triggered to the collate state. The select collate signal supplied over line 164 goes to the output controls 15 for controlling the copy output portion 14. Line 164 signal also samples AND circuits 165, 166 of limit control 60. These AND circuits are selectively further enabled by the setting of single-pole, double-throw switch 167. For example, if there is one collator module of 25 bins, then switch 167 is set to activate AND circuit 165 and deactivate AND circuit 166. On the other hand, if there are two collate modules having a total of 50 collate bins, AND circuit 166 is activated to the exclusion of AND circuit 165. The start signal from AND 157 samples both AND circuits, one of which is enabled during the collate mode for presetting register 105 to either 25 or 50 (AND circuit 165, 166, respectively) whenever decode 62 signifies to the AND circuit 165 and 166 that the signal content of register 105, respectively, exceeds 25 or 50. In the above-described manner, document reproduction machine 10-15 is controlled by electronic circuits for facilitating operator control while imposing facility capability restrictions on operator selections.

The initial condition of the document reproduction machine 10-15 and of the illustrated electronic circuits is determined by the reset signals and the POR signals, respectively, on lines 101 and 102. Resetting station 22 via OR circuit 170 resets the select duplex trigger 145 and the select collate trigger 163 to the nonduplex and noncollate indicating states. Accordingly, the first closure of either switches 140 or 160 will trigger the respective triggers to the duplex or collate indicating modes. Subsequent closures trigger those latches 145 and 163 back to the nonduplex and noncollate states, respectively. The time-out signal TO on line 125 also resets the triggers 145 and 163 for deselecting the operator selections of station 22. It is to be understood that in some document reproduction machines the duplex mode may be the normal mode. Such a situation resets OR circuit 170 connecting it to the set side of trigger 145 and not the reset side.

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