# Patent

## Title
Electrophotographic copying process and apparatus having means for

## Abstract

A control device for operation of a copying machine includes a timer capable of counting a predetermined unit of time and being activated upon completion of a copying operation. The copying machine can be stopped upon the elapse of the predetermined unit of time. Paper detection sensors are provided for determining the presence of copy paper in the transportation paper supply passageway, and upon such detecting the copying machine continues to ensure that any paper in the paper transportation system of the copying machine will be removed. If after a second elapse of time, copy paper is still detected, a jam signal can then be provided to the operator.

## Background
The present invention generally relates to a control system for a copying machine.

Generally, in a photoelectronic copying machine, a so-called, automatic shutoff mechanism is employed for automatically stopping a main motor for a predetermined period of time after the completion of a series of copying operations. This automatic shutoff mechanism comprises a predetermined automatic timer adapted to be driven subsequent to the completion of post-processes following the copying operation, such as interruption of high voltage electrical power from a power source, and to interrupt the main motor after the lapse of the predetermined period of time.

In this type of copying machine, a jam detecting mechanism including a sensor for monitoring the passage of a copying paper through a predetermined path is also employed for generating a jam signal indicative of the occurrence of the jamming of a copying paper in the path, which jam signal is generated when the copying paper is not in a properly supplied condition at the elapsed time of a predetermined time period after the initiation of the supply of such copying paper.

In view of the recent trend that the control of the copying machine be diversified, the use has been proposed or suggested either of a paper supply failure detecting mechanism for detecting a failure in the supply of the copying paper at a paper supply unit in the copying machine so that, in the event of the occurrence of the paper supply failure, the jam detection to be performed subsequent to the detection of the paper supply failure can be interrupted to effect a control different from that effected when the occurrence of the paper jam would have been detected, or of a function mode enabling the copying machine to continue its copying operation, while the jam detection is interrupted, for the purpose of enabling the machine to be checked during the fabrication thereof at a factory and/or a service man to check the sequence of operation of the copying machine.

In the copying machine of the type wherein the jam detecting operation can be interrupted as hereinabove discussed, there has been found the possibility that, during the execution of the function mode an erroneous operation can take place, for example, in detecting a paper supply failure and the copying paper is left remaining in the transport path at the time of termination of the copier operation with no jam signal being generated. In such a case, the copying paper to be subsequently supplied is likely to result in the occurrence of a paper jam, requiring the operator to remove the copying papers remaining in the path in a jammed condition.

This problem may be removed by using an automatic timer having a relatively long preset time, but the use of such a timer may result in the necessity of the main motor being driven for a prolonged period of time. Accordingly, when one considers the efficiency during the trial run at the factory, the period is desired to be as small as possible.

Accordingly, the present invention has been developed with a view to substantially solve the above discussed problems and has for its essential object to provide an improved control system wherein the automatic termination time period can be prolonged only when one or more copying papers remain jammed in the copying machine.

In accomplishing these and other objects, a control device for a copying machine comprises, in combination, an automatic timer capable of starting upon completion of a copying operation and continuing for a predetermined time, means for interrupting the drive of the copying machine when the automatic timer reaches a predetermined time period, a paper detecting means for detecting the presence or absence of a copying paper in a paper supplying passage in the copying machine, and means for disabling the interrupting means, when the paper detecting means detects the presence of the copying paper in the paper supply passage at the expiration of the predetermined time period, to allow the drive motor to continue for a predetermined time.

These and other objects and features of the present invention will become apparent from the following detailed description taken in conjunction with a preferred embodiment thereof with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view showing the outer appearance of a copying machine embodying the present invention;

FIG. 2 is a front elevational view of a portion of the copying machine, showing the details of a control panel;

FIG. 3 is a schematic side view of the copying machine, showing internal mechanisms thereof;

FIG. 4 is a schematic circuit diagram showing the connection between a microcomputer used to effect the sequence control of the copying machine and the display unit for displaying the number of copies to be made;

FIG. 5 is a time chart showing the sequence of operation of the copying machine;

FIG. 6 is a flow chart showing the sequence of control to be effected to the copying machine;

FIGS. 7, 7a, 7b, 7c comprise a flow chart showing the details of the control effected at the step #4 shown in FIG. 6;

FIG. 8 is a flow chart showing the details of the control effected during the unit digit display at the step #8 shown in FIG. 6;

FIG. 9 is a flow chart showing the details of the control during the tenth digit display at the step #16 shown in FIG. 6;

FIGS. 10, 10a, 10b comprise a flow chart showing the details of the control during the copying operation at the step #9 shown in FIG. 6;

FIGS. 11, 12, 13, 14, 15, 15a, 15b, 16, 17, 18, 19, 20 are flow charts showing the conditions 5, 6, 7, 8, 9, A, C, D, E and F shown in FIG. 10, respectively;

FIG. 21 is a flow chart showing the details of the control during the total counter setting process at the step #12 shown in FIG. 6;

FIG. 22 is a flow chart showing the details of the control during the jam detection and total counter processing at the step #17 shown in FIG. 6;

FIG. 23 is a flow chart showing the details of the control during the C/S key processing at the step #18 shown in FIG. 6;

FIG. 24 is a flow chart showing the details of the control during the stop processing at the step #20;

FIG. 25 is a flow chart showing the details of the control during the print processing at the step #21 shown in FIG. 6;

FIG. 26 is a flow chart showing the details of the control during the trouble shooting at the step #22 shown in FIG. 6; and

FIG. 27 is a flow chart showing the details of the control of the trouble routine.

Before the description of the present invention proceeds, it is to be noted that like parts are designated by like reference numerals throughout the accompanying drawings.

Referring first to FIGS. 1 to 3, an electrophotographic copying machine embodying the present invention comprises a cabinet 10 of a generally rectangular box-like configuration including a generally rectangular movable transparent support 11 made of, for example, a clear glass plate, and supported on the top of the cabinet 10 for reciprocal movement between a start position, as shown in FIG. 3, and a scanned position in a direction parallel to, for example, the longitudinal axis of the cabinet 10 together with a hingedly supported flexible or foldable cover 12. The transparent support 11 is for the support thereon of an original bearing one or more images to be copied, which original is, after having been placed on the transparent support 11 with the image facing downwards, i.e., in a direction opposite to the cover 12, covered by the cover 12 to make the original flat against the support 11. The image of the original so placed on the support 11 is adapted to be relatively scanned by an optical system, as will be described later, so that it can be optically projected onto a photoreceptor drum 13 as will be described later.

The copying machine so far shown also includes a function switch 40 for effecting a changeover between normal and function modes of operation and a trouble counter 41 for displaying the location of a problem occurring in the copying machine. Both the switch 40 and the counter 41 are arranged on a front panel of the cabinet 10.

The cabinet 10 has a control panel 30 disposed on the top of the cabinet alongside the transparent support 11 and above the switch 40 and the counter 41 and at a position convenient to the access of an operator or user of the machine thereto. The control panel 30 includes a keyboard, comprised of a tenth digit key 31 and a unit digit key 32 for entering the desired number of copies to be made, a print key 34, a clear-and-stop key (hereinafter referred to as a "C/S key") 35, an adjustment knob 36 for adjusting the shade of the image to be reproduced on a copying paper, a display window 37 having respective display areas for indicating the occurrence of a paper jamming in the machine, the consumption of any one of the copying papers and the toner below a respective critical value and the necessity of calling a servicing person, a digit display window 38 for displaying the number of the copies desired to be made which has been entered by manipulating one or both of the digit keys 31 and 32, and a power-on indicating lamp 39 for, when lit, indicating that electrical power is being supplied to the machine.

As best shown in FIG. 3, the copying machine comprises, in addition to the photoreceptor drum 13 supported within the cabinet 10 for rotation in one direction shown by the arrow, an electrostatic charger 14, an optical system 15 comprised of an array of bundled light transmitting fibers, a sub-eraser lamp 42, a developing unit 16, a transfer charger 17, an A.C. charge eraser 18, a cleaning unit 14, and an eraser lamp 20, all disposed around the photoreceptor drum 13 in the order given above with respect to the direction of rotation of the drum 13, the function and construction of each of these component parts being well known to those skilled in the art.

The machine includes a start position detecting switch 43 and an overrun detecting switch 44 which are so installed on the cabinet 10 and so positioned below the path of movement of the transparent support 11 that, when the transparent support 11 is in the start position, the start position detecting switch 43 can be activated by a magnet 45 carried by the support 11 to generate an electrical signal indicative of the positioning of the support 11 to the start position, but when the support 11, being moved, arrives at the scanned position, the overrrun detecting switch 44 can be activated by the magnet 45 to generate an electrical signal necessary to cause the support 11 to return from the scanned position towards the start position. The cabinet 10 carries a paper feed control switch 46 disposed along the path of the movement of the transparent support 11 and adapted to be activated by a cam member 47, secured to the support 11, as the latter moves from the start position towards the scanned position, to generate an electrical signal necessary to cause a paper feed roller assembly 24 to rotate in a predetermined direction for initiating the feed of copying papers 22, one at a time, from a paper supply unit 23 towards an image transfer station in synchronism with the rotation of the photoreceptor drum 13.

The transparent support 11 is, when and so long as it is not at the start position as shown in FIG. 3, but at a home position as shown in FIG. 1 which is generally intermediately between the start and scanned positions, moved towards the start position as shown in FIG. 3 upon initiation of the copying operation. During the movement of the support 11 from the home position towards the start position, an illuminator lamp 21 is preliminarily lit, but is lit on a full scale simultaneously with the start of movement of the support 11 towards the scanned position which takes place subsequent to the arrival of the support 11 at the start position. The image of the original on the support 11 is consecutively scanned by generally ribbon-shaped rays of light from the illuminator lamp 21 as the support 11 moves from the start position towards the scanned position, which rays of light are, after having been reflected from the original, projected onto the photoreceptor drum 13 to form on the drum surface an electrostatic latent image corresponding to the image of the original.

A stack of copying papers 22 accommodated in the supply unit 23 are fed one at a time by the feed roller assembly 24 driven in synchronism with the movement of the support 11 from the start position towards the scanned position and is then fed towards the transfer station after having been synchronized by a timing roller assembly 25 with the arrival of the electrostatic latent image on the drum 13 at the transfer station. At the transfer station, a powder image formed on the drum 13 by the application of toner particles to the electrostatic latent image as the drum 13 has passed through the developer unit 16 is transferred onto the copying paper 22, the copying paper 22 with the powder image thereon being in turn supplied to a fixing unit 27 past the charge eraser 18 by means of an endless belt 26. The powder image on the copying paper so fed to the fixing unit 27 is fixed thereon as it passes through the unit 27, and the copying paper with the powder image fixed thereon is subsequently delivered onto a tray 29 by means of a delivery roller assembly 28. The photoreceptor drum 13, after the powder image has been transferred from the drum 13 onto the copying paper, continues to rotate sequentially past a cleaning station, at which time the residual toner particles on the drum surface are removed by the cleaning unit 18, and an erasing station at which the residual electrostatic charge on the drum surface is removed by the illumination of the eraser lamp 20 in readiness for the next succeeding copying operation.

Disposed above the paper supply unit 23 and in alignment with the path of feed of the copying papers 22 is an empty detecting switch 48 for detecting the presence or absence of the papers in the supply unit 23, which switch 48 is operable to interrupt the copying operation in the event that the supply unit 23 becomes empty of any copying paper. Whether or not the copying paper 22 has been supplied can be detected by a detecting switch 49 which may be constituted by a photo interrupter and which is operable to detect the passage therethrough of the trailing end of the copying paper with respect to the direction of feed towards the transfer station and to generate, when it so detects, an electrical signal necessary to cause the transparent support 11 to return towards the start position. Whether or not the copying paper bearing the fixed powder image thereon has been delivered onto the tray 29 can be detected by an ejection detecting switch 50.

The number of copying operations repeated can be counted by a total counter 51 which may be a general purpose counter if it can perform a counting operation per pulse.

The total counter is used for counting the frequency of use of the copying machine and is usually maintained and serviced by a service man. Accordingly, the total counter should not be of a construction that the number indicated thereby can without difficulty be falsified and must show a zero reading at the time of shipment of the copying machine to a particular user. On the other hand, before the shipment, but after the complication of the fabrication of the copying machine, the latter is usually subjected to a trial run at the factory for the purpose of inspection and, at this time, the total counter built therein performs its counting operation. In view of this, it is a general customary practice to employ a total counter of a type wherein the reading can automatically return to zero after the count has reached "9" on the one hand and to carry out the trial run, on the other hand, in such a way that, at the end of the trial run of the machine the total counter reads zero. In this case, the frequency of use of the machine during the trial run is limited as a matter of course, or the trial run must, even though the inspection has completed before the total counter returns to the zero reading, be continued until the total counter reading becomes zero.

However, in general, it has been experienced that every copying machine is not trial-run always through, an equal number of times, and in this case the total counters in some of the machines often show a reading other than zero. In order to reset the total counter to the zero reading, it has been a conventional practice to remove the total counter for adjustment before the machine is packaged, and accordingly, it is a tiresome and time-consuming work which would result in the increased manufacturing cost of the copying machine.

Accordingly, as will become clear from the subsequent description, the present invention is featured in the employment of a particular function mode under which a control device built in the copying machine for controlling the operation of the machine can operate. Specifically, the copying machine can be switched over to the function mode by a switch, which can not be used after the shipment of such a machine, so that the total counter can be advanced a predetermined number of counts equal to the desired frequency of use of the machine during the trial run and can be reset to the zero reading by releasing the machine from the function mode. Therefore, according to the present invention, no total counter is required to be removed from the machine for adjustment.

However, the counter 51 should not be of a type in which the count value can easily be falsified or counted down.

The copying machine of the construction and function as hereinbefore described is so designed that, by manipulating one or both of the digit keys 31 and 32 on the control panel 30 prior to the initiation of the copying operation, the desired number of copies to be made can be preset to the machine on the one hand and displayed through the display window 38 on the other hand. Therefore, the copying machine can repeat its copying operation for a number of times equal to the desired number of copies to be made which has been preset and displayed.

In the illustrated example, the desired number of copies to be made can be set in such a way that, each time a single push is applied to the unit digit key 31, the unit digit displayed by the display window 38 increases by one. Where the tenth digit key 32 is depressed the tenth digit displayed by the display window 38 can be increased by one for every push applied thereto.

The sequence of operations of the copying machine including the presetting of the desired number of copies to be made and the control of repetition of the cycle of the copying operation can be controlled by, for example, a microcomputer MC shown in FIG. 4.

Although not shown, the microcomputer MC comprises, as its internal devices, a central processing unit (CPU), a read-only memory (ROM), a random access memory (RAM) and an accumulator (ACC), all being well known to those skilled in the art. As shown in FIG. 4, the microcomputer MC is adapted to receive input signals from one or both of the digit keys 31 and 32, the function switch 40, the print key 34, a transistor 52 adapted to be operated by an electric signal indicative of the detected failure of a high voltage transformer, a transistor 53 adapted to be operated by an electrical signal indicative of the detected failure of the illuminator lamp, a transistor 54 for detecting the failure of a main eraser, a transistor 55 adapted to be operated by a wait signal, the start position detecting switch 43, the paper feed control switch 46, the C/S key 35, an F5 switch 56, the ejection detecting switch 50, the paper end detecting switch 49, the empty detecting switch 48, a toner detecting switch 57, and the overrun detecting switch 44, respectively, and to generate in response, in accordance with a predetermined program, a control signal necessary to control the digit display at the display window 38, a signal necessary to effect increment of the count of the total counter 51 and another control signal necessary to control the copying machine in such a way as to cause the copying operation to be repeated a number of times equal to the number displayed through the display window 38.

The "F5" switch 56 is a switch for setting in a function mode "II" and can be manipulatable only during the assembly of the copying machine at a factory. This switch 56 can not be manipulatable by any person including a servicing person, nor should any person be taught how to manipulate this switch 56. In practice, this switch 56 is installed on a printed circuit board to be set at a position where, after the fabrication it, is not accessible. By way of example, it is better to provide terminals (connectors) on a substrate and then to shortcircuit these terminals so that an extra function mode "5" (total counter setting) can be provided in addition to the function which can normally select "1" to "4". Accordingly, if these terminals are left open after the shipment, no function mode "5" for the total counter setting can be used.

Hereinafter, the details of the operation of the copying machine embodying the present invention will be described with reference to the time chart shown in FIG. 5 and also to the flow charts shown respectively in FIGS. 6 to 22.

FIG. 6 illustrates the sequence of entire control of the copying machine embodying the present invention.

Assuming that electrical power has been supplied to the machine, initialization takes place at the first step #1. This initialization includes execution of such procedures required to be done subsequent to the supply of the electrical power to the copying machine and includes the setting of a heater failure timer T-HT, the manipulation of the keyboard to enter digits representative of the number of copies desired to be made, the setting of a single copy to a keyboard saving memory, the clearing of the memories and others.

Subsequently, although at the steps #2, #7 and #14, internal timers t1, t2 and t3 are respectively set, the internal timers t2 and t3 determine the respective times during which the unit and tenth digits composing the number of copies to be made are displayed. Since a cycle of the process from the step #2 to the step #25 is repeatedly executed in a predetermined period of time, this predetermined period of time for each cycle provides a reference time at which timers other than the internal timers (for example, timers T-M5, T-M6 and others, which are adapted to be counted up per routine) are driven to perform their counting operation.

At the subsequent step #2, the internal timer t1 is set. Timer t1 represents the time that it takes from the initial setting of the internal timer until the display of the unit digit and which is set longer than the time required to perform the keyboard input (at the step #4) and the switch input (at the step #5), thereby fixing the processing time during this period. When the termination of the internal timer t1 is detected at the step #6, the internal timer t2 is set to be slightly longer than the time required until the tenth digit is displayed with the display time for the unit digit consequently determined.

When the termination of the internal timer t2 is detected at the step #3, the internal timer t3 is newly set and this timer t3 is set to be slightly longer than the time required to perform the processing until the output step #25 with the display time for the tenth digit being consequently determined.

When the termination of the internal timer t3 is detected at the step #23 during the tenth digit display, the tenth digit display disappears at the step #24 and the contents of a load output RAM in a memory are outputed to an output port at the step #25 and are controlled.

Since the processing time at the output is fixed, the time, or loop time, required to perform each loop from the setting of the internal timers to the completion of the outputing, (the processing time required to perform each routine), becomes fixed from [Input], [Unit Digit Display], [Tenth Digit Display]and [Output].

Since the time required for the input processing is 3.78 ms, the display times t2 and t3 for the display of the unit and tenth digits are 6.3 ms, respectively, and the time required for the output processing is about 0.6 ms, the loop time (the processing time required to perform each routine) is about 17 ms.

The details of the keyboard input (the step #4) are shown in and will be described with reference to FIG. 7.

Before the supply of inputs from the keyboard, whether or not they can be acceptable is judged. The keys (the digit keys, the function key and the print key) are not accepted during the execution of the machine operation (such as copying operation and function operation).

If the inputs from the keyboard are acceptable, a keyboard input processing is performed. At the step #401, it is determined whether or not a timer KS has terminated. The timer KS is a timer for determining an entered digit increment interval time so long as the digit keys 31 and 32 continue to be depressed and, when the timer KS terminates, a key flag is reset at the step #402 to a condition similar to the condition which is established when the digit keys once depressed are again depressed.

When the unit and tenth keys 31 and 32 are successively depressed at the respective steps #403 and #404, the step #415 starts at which the timer KS is reset to prevent the increment of the next succeeding digit entered, followed by the step #460 at which the key flag is reset and an auto-clear timer T-N, as will be described later, is subsequently set at the step #461, thereby completing the entry of the inputs from the keyboard.

If the unit and tenth keys 32 and 31 are on and off, respectively, the step #403 is followed by the step #404 and then by the step #405 at which the determination is made as to the key flag. In the event that any of the unit and tenth keys are switched from the non-depressed conditions over to depressed conditions (the step #405 Y), the step #405 is followed by the step #406, or otherwise the step #405 is followed by the step #460 to set the key flag.

At the step #406, the function mode is determined. If it is a function mode (the step #406 Y), the entered digit permits the increment of "1" to "4" or "5" (In the case of the function mode "II", the "F5" switch is on.) whereas, if it is a normal mode (not the function mode) (the step #407 Y), a digit from "1" to "9" and "0" can be entered.

If it is the function mode, but not the total counter setting mode (#407 N), whether or not the digit has been entered is checked. The condition in which the digit has not yet been entered is the condition in which, although the function mode has been established by depressing the function switch 40, the function number has not yet been set, and this condition is displayed  F    as will be described later.

In the event that the unit and tenth keys 32 and 31 are off and on at the respective steps #403 and #416, after the key set-up (resetting of the key flag) has been determined at the step #417, the total counter setting mode is determined at the step #418 and, if it is one of the function modes excluding the total counter setting mode (the step #419 Y), the keyboard input is terminated with the tenth key 31 being no longer accepted. If it is a key set-up (the step #417 Y), the unit digit entered is forcibly zeroed at the step #420 and the increment is effected to the tenth digit at the step #421. Since the unit digit reads zero when the tenth digit reads zero (the step #422 Y), the tenth digit is set to read 1 at the step #423 thereby to avoid any display of "00".

When the keyboard is manipulated (that is, when one or both of the unit and tenth keys 32 and 31 are depressed) and is accepted as a key set-up, the step #456 is initiated with the entered digit retracted and, at the step #457, the timer KS (for the entered digit increment interval) can be set.

If it is the total counter setting mode (the step #458 Y), the digit "5" is entered at the step #459 as a function number being executed, or otherwise it is cleared at the step #462 and, subsequently, the both proceed to the step #460.

At the step #424 Y at which the function switch 40 is depressed and at the step #425, whether or not it can be acceptable is determined. The time during which it can be accepted is the time which appears to affect the previous function such as the copying operation or the execution of the function.

When and after the function switch 40 has been accepted accompanied by the key set-up (the step #426 Y), whether or not the time at which the function switch 40 has been depressed is during the function mode determined at the step #427. By this determination, the function mode or the normal mode is established respectively.

When the function mode step #431 is established, the tenth digit place is displayed "F" at the step #432 and it is determined at the step #433 that no digit is entered, and at the step #444, the function number is cleared.

At the time of return to the normal mode (the step #428), the entered digit reads 1 at the step #429.

In the event that the print key 34 is depressed (at the step #445 Y), the key is set up (at the step #446 Y) and the digit is entered (at the step #449 Y) during the function mode (the step #448 Y), the unit digit figure is set to the function number being executed at the step #450. Subsequently, a print demand flag is set at the step #451 and a stop demand flag is reset at the step #451.

Should any key be depressed (the step #445 N), a key flag for the purpose of determination of the key set-up is reset at the step #453 and the timer KS is then reset at the step #454.

Since the auto-clear timer T-N to be set at the step #461 is always set whenever any one of the keys has been depressed, the timer T-N starts its counting operation when the key is released and a condition necessary to start the counting operation is established. The timer T-N is a timer used to set an input condition to a standard condition, that is, the same condition as the initialization at the step #1, when it has reached a predetermind time. In other words any manipulation is effected to the copying machine during a predetermined period of time, the input condition is initialized.

The details of the unit digit display (the step #8) will now be described with reference to FIG. 8.

For the unit digit display, subsequent to the termination (the step #6 of FIG. 6) of the internal timer which has been set before the keyboard input and, then, subsequent to the termination of t1, the internal timer t2 for the display time for the unit digit is newly set at the step #7.

If not the function mode (the step #801 N), a converted output of the entered unit digit is generated at the step #803, but if the function mode (the step #801 N), it is determined at the step #802 that the digit has been entered.

The converted output referred to above means an output representative of binary digit data which have been converted into respective elements of the 7-segment display device 38 for the purpose of enabling the CPU to directly drive the display device 38.

The condition in which the digit has not yet been entered (the step #802 N) is a condition established when the C/S key 35 is depressed when the function mode is established by function switch 40 or when the function is not executed and, during this condition, the unit digit place is not displayed, but  F    is displayed.

The tenth digit display (the step #16) will now be described in detail with reference to FIG. 9.

Even the tenth digit display is similar to the unit digit display. However, during the function mode (the step #1601 Y), the tenth digit is with no fault displayed at the step #1603, whereas during the normal mode (the step #1601 Y), no tenth digit is displayed if it is zero (the step #1602 Y).

Even the tenth digit entered is converted and outputed, there is a symbol display of  F  other than the display of a digit from "0" to "9" in the case of the tenth digit (In the actual programme, if the value of "A" ("10" according to the decimal system) is included in the tenth digit, the F  display is effected.). Subsequent to the emergence of outputs from ports Co to C3 and Do to D3 after having been converted, a port E1 is outputed for effecting the display of the tenth digit and the tenth digit display is then lit.

The details of the copying process (the step #9) will now be described with reference to FIG. 10.

The copying process is performed depending on the operative condition. With respect to the copying operation, conditions (5) and (6) are preliminary processes, conditions (7) to (A) are scanning operations, a condition (C) is a return operation and conditions (D) to (F) are post-processes. In case of a single copy, the condition starts from (5) and terminates at (F), but in case of a multi-copy, the condition is transferred from (C) onto (7).

The conditions (D) to (8) are, in practice, used for a preliminary rotation and the function operation (functions "2", "3" and "4").

The condition (4) is a stand-by condition. Upon completion of the copying operation, the condition shifts from (F) to (4), returning to the stand-by condition. The condition (B) is empty.

A timer associated mainly with the copying operation is constituted by a main timer and a sub-timer. The main timer is operable to shift one condition to the next succeeding condition upon termination of the timer. The sub-timer is used as a control timer during the condition except for T-SD.

The copying condition (5) shown in FIG. 10 will be described with reference to FIG. 11.

When the first copy is being made subsequent to the depression of the print key 34, the condition is shifted to (5). At the set-up (the step #9-501) at which the condition has become (5), a timer T-M5 operable to determine the length of the condition (5) at the step #9-502 is set. T-M5 is the timer for the determination of the stand-by time for delaying the time, at which the next succeeding load is to be invested, for a period of time required for the main motor to be set up.

At the step #9-503, the main motor is turned on and, at the step #9-504, the acceptance of the function switch 40 is inhibited.

When the timer T-M5 terminates (at the step #901), the increment is effected to the condition at the step #902 to shift the condition from (5) to (6).

By the switching on of the main motor (at the step 9-503), a return drive is mechanically transmitted to the transparent support to return the latter to the start position if the transparent support is not in the start position and continues until the start position switch is turned on (at the step #9-701) during the condition (7).

The copying condition (6) shown in FIG. 10 will be described with reference to FIG. 12.

At the set-up of the condition (6) (the step 9-601), a main timer T-M6 is set (at the step #9-602). This T-M6 is a timer for the determination of the preliminary processing time of the copying operation and has a preset time effective to utilize the surface area, where a transfer charge is applied, always within the area where the image has been formed. At the succeeding steps #9-603, 9-604 and #9-605, the sub-eraser, the high voltage and the preliminary lighting are turned on, respectively.

The copying condition (7) shown in FIG. 10 will now be described with reference to FIG. 13.

After the lapse of the preliminary processing time of the copying operation, a check is made as to whether or not the transparent support is held at the start position (the step #9-701). If it is at the start position, the next succeeding scanning operation starts.

The copying condition (8) shown in FIG. 10 will now be described with reference to FIG. 14.

Although the next succeeding scanning operation starts when the transparent support 11 has returned to the start position, since there is a time lag from the moment the start position detecting switch 43 is turned on to the moment the mechanical drive to the transparent support 11 is interrupted in the case where the transparent support 11 is returned, the time at which the scanning is to be initiated is delayed by a timer T-M8 at the step #9-802 for a period of time corresponding to such time lag.

The copying condition (9) shown in FIG. 10 will now be described with reference to FIG. 15.

At the set-up of the copying condition (9), a scan solenoid (the step #9-904) and the illuminator lamp 21 (the step #9-903) are lit on full scale and, at the same time, a sub-timer T-S9 is also set (the step #9-902). This is for switching off the sub-eraser 42 to initiate the image formation. A drive failure timer T-ST (the step #9-906) is a timer for regulating the time during which detection is made as to whether or not the transparent support 11 has departed from the start position detecting switch 43 subsequent to the transparent support 11 being driven and has a preset time which may terminate at the time of the set-down of the paper feed control switch 46 (the step #9-918) so as to process during the condition (9).

Although a paper feed solenoid is turned on during the on state of the paper feed control switch 46, an AND logic between an on output of the paper feed control switch 46 and an turning on output of the microcomputer MC, is connected to the solenoid is in practice utilized to effect a fine adjustment because the microcomputer MC receives inputs and generates outputs for each routine and, if the paper feed solenoid is controlled solely by the output from the microcomputer MC, and it would be continually turned on and off by step.

At the set-up of the paper feed control switch 46, the failure of a high voltage transformer is detected (the step #9-912) and, during a time in which a new paper feed is not initiated, the failure detection is done.

At the start of the paper feed, a check is made as to whether or not the paper supply unit has become empty (the step #9-914) and, in the event that is has become empty, the copying operation is terminated (the step #9-916) and proceeds to the post-processes.

When the paper feed control switch 46 shuts down (the step #9-918 Y), the paper supply is terminated (the step #9-919) and the next succeeding condition is initiated (the step #9-920) to set a leading end jam detection timer T-X (the step #9-921).

Upon this termination of the paper feed, the timing roller assembly is driven to effect the supply of the copying paper towards the transfer station and, therefore, leading ends of the copying papers of different sizes can be detected by the same timer.

Although at the step #9-904, the scan solenoid is switched on in response to the setup of the condition (9), the scan time is cleared at the step #9-905 because the counting of the scan time is also performed at the same time.

The error occurring in the copying paper supply is judged in the following manner.

In the event that the trailing end detecting switch 49 fails to detect the paper at the timing (the step #9-918 Y) of the set-down of the paper feed control switch 46 (the step #9-918' N), it is determined as a paper supply error and, consequently, the condition is shifted to (D) at the step #9-918".

Since the jam detection timers T-X and T-Y have not yet been set at this time, the operation associated with the jam detection is not executed.

When the paper supply error has been detected by the erroneous operation of the trailing end detecting switch 49, the paper is supplied while the jam detection is cancelled and, since the condition (D) shifts to (E) and (F) with an auto-shut being effected, the paper may remain at the time of termination of the auto-shut.

Although not specifically shown, a similar phenomenon will take place when the paper 22 is fed during the function mode while the jam detection is cancelled.

The copying condition (A) shown in FIG. 10 will now be described with reference to FIG. 16.

When the condition (A) is initiated upon the termination of the paper supply (the step #9-920), a check is made as to whether or not the copying paper 22 has moved past the trailing end detecting switch 49 (the step #9-A01). If it has moved, the condition shifts to condition (C) (the step #9-A05) and the scanning operation terminates (the step #9-C05). This is true even when the overrun detecting switch 44 is turned on (the step #9-A02 Y).

In the illustrated copying machine, a return signal for the transparent support 11 can be obtained when the trailing end of the copying paper 22 moves past a photo sensor 49 positioned on the leading side of the paper 22 feed roller assembly 24 (a so-called random return type). Accordingly, there is provided the overrun detecting switch 44 for forcibly returning the transparent support 11 when the length of the copying paper 22 is of a value greater than a predetermined length.

Before the condition shifts to (C), the trailing end jam detection timer T-Y is set (the step #9-A04).

At the time of termination of the scanning at which the overrun detecting switch 44 is turned on, the drive failure timer T-ST is set at the step #9-A03 and monitors until the overrun detecting switch 44 is turned off.

In other words, the timer T-ST for the detection of the drive failure has a preset time somewhat longer than the length of time from the switching on of the overrun detecting switch 44 to the switching off thereof incident to the return, and is adapted to be set (the step #9-A02 and the step #9-A03) in response to the switching on of the switch 44 and to be reset (cleared) (the steps #9-C12 and #9-C13) in response to the switching off of the switch 44. Accordingly, unless it is reset within the preset time, the drive failure is determined as occurring (Refer to #2209 of the step #22.).

The copying condition (C) shown in FIG. 10 will now be described with reference to FIG. 17.

In response to the set-up, the scanning operation is terminated (the step #9-C05) and, also, an entered digit flag is reset (the step #9-C07).

Upon termination of the scanning operation, decrement is effected to the entered digit (the step #9-C08) and, if the result is found to be zero (the step #9-C08 Y), the entered digit once retracted is restored (the step #9-C10) with the preset copy number being displayed and the execution flag is then reset (the step #9-C11), thereby transferring to the post-processes (the conditions (D) to (F)) to be done subsequent to the copying operation (the step #9-C21).

If the result of the decrement is not zero (the step #9-C09 N), the execution flag will not be reset and the copying operation continues (the steps #9-C18 Y, #9-C19 and #9-C20).

When the sub-timer T-SC terminates at the step #9-C14, the sub-eraser (inter-image eraser) is turned on (the step #9-C15) and a sub timer T-SD is set (the step #9-C16). This timer is a timer for the high voltage switching off and, since during the multi-copying operation there is no judgement as to the termination of this sub-timer under the conditions (7) and (8), the high voltage is not switched off. However, during the execution of the terminating process of the copying operation, the high voltage is switched off under the condition (D) upon completion of this timer (the steps #9-D08 #9-E04).

When the paper feed control switch 46 is turned on incident to the return of the transparent support 11 (the step #9-C17 Y), the execution flag is determined (the step #9-C18) and, if it is set (the step #9-C18 Y), the condition is transferred to (7) (the step #9-C19) and the preliminary point is turned on (the step#9-C20) to effect the multi-copying operation. If the execution flag is reset (the step #9-C18 N), the condition is transferred to (D) (the step #9-C21) to effect the post-processes.

In the event that at the time of a final copying operation, even though the execution flag is reset (the step #9-C11) in response to the set-up of the condition (C), the execution flag is set by the continued depression of the print key until this paper feed control switch 46 is turned on during the return of the transparent support 11 (See #2109 of the step #21), no post-process takes place do to the multi-copying operation.

The copying condition (D) shown in FIG. 10 will be described with reference to FIG. 18.

Under the condition (E), the high voltage is turned off (the step #9-E04). Inhibition to accept the function switch 40 is also released (the step #9-E07). The acceptance of the function switch 40 has been inhibited to avoid any possible erroneous operation.

The condition (F) shown in FIG. 10 will be described with reference to FIG. 20.

The condition (F) is a condition in which a timer for the auto-shut is operated and in which only the main motor is turned on. When the sub-timer T-SF terminates (the step #9-F04 Y), whether or not the copying paper is present at the ejection detecting switch 50 is checked at the step #9-F05 and, if it is not present (the step #9-F05 Y), the main motor is turned off at the step #9-F06 and the condition is returned to (4) at the step #9-F07 thereby establishing the stand-by condition.

On the other hand, if the copying paper is present at the ejection detecting switch 50 (the step #9-F05 N), and if it is the first time, the sub-timer T-SF' is further set and the stand-by condition continues without the main motor being turned off until the copying paper is completely ejected. If there still remains copying paper even when T-SF' has terminated (the step #9-F09 N), the copying paper will be determined as not ejected and the occurrence of the paper jam is judged at the step #9-F13.

The total counter setting process (the step #12) will now be described with reference to FIG. 21.

If the function under execution is "5" (the step #1201 Y), a decision is made at the step #1202 as to whether or not it is in the total counter setting mode. (Even if the display is merely  F   , the total counter setting mode will not be set.)

When the print demand is made (the step #1203) because of the print key 34 having been depressed while not in the total counter setting mode (the step #1202 N), the machine is set in the total counter setting mode (the step #1204) with the entered digits cleared (the step #1205) and, consequently,  0 0  is displayed to permit the print demand to be accepted, the print demand so accepted being released at the step #1206.

By reason of the setting in the total counter setting mode, two digits can be entered through the keyboard input arrangement (See the step #4.).

When the print demand is further made (the step #1207 Y) during the total counter setting mode (the step #1202 Y), a timer TC for driving the total counter is set at the step #1208 and the total counter 51 undergoes its counting operation during the jam detection and total counter processing (the step #17). Simultaneously therewith, the execution flag is set (the step #1209) to indicate the execution and the print demand is released (the step #1210).

During the counting operation of the total counter (the step #1210), a check is made as to whether or not the entered digit becomes zero (the step #1212). When the entered digit becomes zero and the counting operation is completed (the step #1212 Y), the setting mode is released (the step #1213) and, since the entered digit returns to the display of  F 5  at the step #1214, re-execution is possible. Incident to the termination, the stop demand execution flag is released (the steps #1215 and #1216) and, at the same time, the counting timer T-TC is reset at the step #1217.

If it is during the continuance of the counting operation (the step #1212 N), the stop demand is accepted only during the period in which the solenoid of the total counter 51 is deenergized (the step #1218 Y), and simultaneously with the termination the stop demand execution flag is released (the steps #1215 and #1216) and, consequently, the timer T-TC is reset (the step #1217) to inhibit the counting operation, but the setting mode is not released and accordingly, the display displays the count value obtained at that time while the continued counting operation is possible by depressing the print key 34.

During the following process, the selection of the function mode can be carried out.

If it is found to be in the function mode at the step #1210, the step #1221 follows to determine the "F5" switch 56. The "F5" switch 56 is a switch capable of performing the function "5" (the total counter setting) and, if this switch is turned off, the key input is accepted only from "1" to "4". However, when the switch 56 is turned on, the function mode "II" is set at the step #1222 with "1" to "5" being acceptable.

The jam detection and total counter processing (the step #17) will be described with reference to FIG. 22.

When the leading end jam detecting timer T-X terminates (the step #1701 Y), a check is made at the step #1702 as to whether or not the copying paper is present at the eject switch 50. If no copying paper is present, it is determined at the step #1703 that the jamming has occurred. This occurrence of the jamming is detected during the trouble shooting (the step #22) and trouble resolving is carried out. When the leading end check is done at the step #1704, a check is made at the step #1705 as to whether or not the total counter 51 should perform its counting operation. Under the function mode, the total counter 51 does not perform its counting operation.

Upon termination of the trailing end detection timer T-Y the step #1707 Y), it is determined at the step #1708 whether or not the checking of the trailing end of the copying paper 22 has been completed. If it is found that the checking has not yet been completed, it is deemed that the copying paper has not yet moved past the ejection detecting switch 50 indicating the occurrence of the paper jam.

In the event that the copying paper is not present at the ejection detecting switch 50 (the step #1710 Y) and the checking of the leading end of the copying paper has been completed (the step #1711 Y), it is deemed that the copying paper has moved therepast and the checking of the trailing end has been completed. Should the total counter be ready to count at the time the copying paper has moved past the ejection detecting switch 50 (the step #1713 Y), the total counter 51 is turned on at the step #1714 and, subsequently, an on-time timer T-TC is set at the step #1715.

Upon termination of the timer T-TC (the step #1716 Y), the drive of the total counter 51 is interrupted if it is not in the total counter setting mode (the steps #1717 .fwdarw. #1721), and the next succeeding count will not be initiated with the counter having performed only one count (normal counting operation).

On the other hand, if it is in the total counter setting mode (the step #1717 Y), the timer T-TC is again set at the step #1718 upon termination of the timer T-TC. In the event that the total counter is turned off (the step #1719 N) at the time the timer T-TC has terminated (the step #1716 Y), it is turned on but it is turned off at the step #1722 upon termination of the timer T-TC. Simultaneously with the switching-off, the increment is effected to the entered digit of the total counter 51 with the current count value being displayed as the number of the copying papers.

(In this example, the same timer T-TC is used for both the on-time and the off-time of the total counter 51.)

The C/S key processing (the step #18) will now be described with reference to FIG. 23.

When the C/S key 35 is turned on at the step #1801, the key flag is set at the step #1801 so that the other keys (the digit keys 31 and 32, the function switch 40 and the print key 34) cannot be accepted. At the set-up of the C/S key 35 (the step #1803 Y), the timer T-KS for the entered digits is reset at the step #1805, thereby avoiding the increment of the next succeeding digit to be entered. During the copying operation or the execution of the function (the counting operation when in the total counter setting mode ) (the step #1806 N), the stop demand is set at the step #1812 and this stop demand is determined during the stop processing at the step #20 (In the case during the total counter setting mode, the total counter setting). If it is not during the execution (the step #1807 N), both the entered digit and the entered digit saving memory are rendered 1 (the steps #1808 and #1809) and the entered digit flag is reset (the step #1810).

Under the total counter setting mode (the condition in which the two digits can be entered) (the steps #1807 Y and #1813 Y), the total counter setting mode is released at the step #1814 so as to subsequently render the function switch 40 to be acceptable at the step #1815 with the consequence that  F 5  is displayed.

When it is during the function mode (the step #1807 Y), but not during the total counter setting mode (the step #1818 N), the step #1810 takes place to reset the entered digit flag with the consequence that  F    is displayed.

The stop processing (the step #20) will now be described with reference to FIG. 24.

When the stop demand arises (the step 2001 Y) and if it is in the normal mode (the step #2002 N), whether or not it is acceptable is determined at the step #2003. It cannot be accepted during the scanning operation. In addition, unless the current condition is the condition (C) (from the time of completion of the scanning operation to the time of switching-on of the paper feed switch) (the step #2004 N), the condition is transferred to (D) at the step #2005 to carry out the post-processes. If it is in the condition (D) (the step #2004 Y), the resetting of the execution flag at the step #2006 terminates the condition (C) to initiate the condition (D) so that the post-processes can be performed. When the stop demand is accepted, the stop demand is released at the step #2007.

The printing process (the step #21) will be described with reference to FIG. 25.

Although the print demand is set when the print key is depressed and then accepted, once the print demand arises (the step #2101 Y), it is temporarily released at the step #2102 so that checking from the step #2102 to the step #2107 can be performed, and at the step #2109, the execution flag is set to indicate that the printing process is in execution. If it is not in the function mode, but in the normal mode (the step #2103 N), whether or not a sufficient period of time for the period heater has been elapsed the step #2104) and whether or not the paper supply unit is empty (the step #2105) are minimum necessary requirements for the acceptance of the print demand.

If the conditions are ready by this time, a check is made as to whether or not the condition is (C) (from the termination of the scanning operation to the switching-on of the paper feed control switch 46) (the step #2107). If it is in the condition (C), the preliminary processes are unnecessary and the operation takes place in a manner similar to the operation during the multi-copying and, therefore, the determination of this condition is accepted. If not in the condition (C), the step #2108 is initiated to transfer the condition to (5) thereby initiating the preliminary processes.

If in the condition (C), the step #2109 is initiated to set the execution flag and, therefore, at the time of termination of the condition (C), the execution flag can be checked (the step #9-C18). If it is during the execution, the copying operation is continued at the step #9-C19.

The execution flag is set at the step #2109 and, at the same time, the demand is released at the step #2110 since there may be the possibility that the stop demand is being set.

When the print demand arises during the function mode, the function operation, except for the function number "5", corresponding thereto can be initiated and, therefore, the further details thereof will not be described herein.

The trouble shooting procedure (the step #22) will now be described with reference to FIG. 26.

In the event that the main eraser 20 is in an abnormal condition (the step #2202 N) (with CdS not receiving light) at the time failure of the main eraser can be detected (the step #2201 Y), the trouble routine is initiated from a terminal S6.

Similarly, when the illuminator lamp is in an abnormal condition (the step #2204 N) and when the high voltage transformer is in an abnormal condition (the step #2208 N), the steps proceed respectively to S7 and S5.

If the wait condition is not complete and the heater failure timer (to be set at the time of initialization) terminates (the step #2206 Y) or if a drive failure timer T-ST terminates (the step #2209 Y), the steps proceed respectively to S8 and S4.

If the paper jam occurs during the jam detection and total counter processing (the step #17) or during the copying operation (the step #9) (the condition (F)), the step #2210 of this trouble shooting proceeds to J1.

When the scan solenoid is turned on (the step #2211 Y), the scanning time can be counted at the step #2212 and the count is used for the detection of a failure during the return of the transparent support 11 at the step #2212.

When the start position detecting switch 43 is turned on (the step #2216 Y) while not in the scanning operation (the step #2211 N), the detection of the drive failure during the return movement is inhibited. (The return failure detection during the multi-copying operation is not affected directly since the subsequent drive failure time can be set upon return to the start position.) Simultaneously therewith, the detection of the return time is terminated.

Upon completion of the scanning (the step #9-C01 Y .fwdarw. #9-C05) (including the paper empty and a misfeed at the start of the copying paper supply), the return time can be detected (the step #9-C06) and the scan time counted during the period in which the scan solenoid is turned on (the steps #2211 Y and #2212) can be subtracted (the step #2213 Y and #2214). If the result of subtraction becomes zero, the drive failure is determined in view of the return speed being higher than the scan speed and the next step then proceeds to the trouble routine S4.

Although in this example the scan time is used in the form as it is, it may be adjusted, for example, multiplied by a coefficient, to a proper value.

The trouble routine will now be described with reference to FIG. 27.

In the case where trouble occurs such as a jam or a condition requiring a call of the service man, a count corresponding to the particular trouble is displayed in a trouble counter and no switches are accepted thereafter.

Terminals J0 and S0 represent trouble counters at the time of the supply of the electrical power and, unless the trouble counters are reset at the time of the detection of the resetting, will not proceed thereto and no copying operation is performed.

S1 represents the jam, S4 represents the drive failure, S5 represents the charger failure, S6 represents the eraser failure, S7 represents the illuminator lamp failure, and S8 represents the heater failure.

The jam display and the call for a service man display are respectively lit when the jam has occurred and when the call of the serviceman is required. The copy number display is turned off with the output cleared and also with the load turned off. Thereafter, signals corresponding to the respective troubles are outputed to the trouble counters. When the counting performed by the trouble counters terminates in response to these signals, the copy number display is effected with no input from any key and switch being accepted.

In a copying machine of the type described hereinbefore, the setting of the total counter to a zero reading can be achieved in the following manner.

When and after the function switch 40 is turned on subsequent to the supply of electric power to the copying machine, the function switch can be acceptable during the key board input processing and, unless the other keys are depressed, the function mode supersedes the normal mode with  F consequently displayed. At this time, since the entered digit flag is reset, the depression of the print key 34 does not result in the execution of the function.

When the F5 switch 56 is turned on during the function mode, the function mode II is set during the total counter setting process. When the F5 switch 56 is on and off, "1" to " 4" and "1" to "5", respectively can be executed.

When at this time the unit key 32 is turned on, since the keyboard input process, not the total counter setting mode, is under execution, "1" enters the unit place and  F 1  is consequently displayed.

Although the timer KS is set, this timer is a timer for the determination of the entered digit increment interval time and, when the key is continuously depressed, the key flag is reset to accept the key upon termination of the timer KS. Since the entered digit flag is set when the key is accepted, it is determined that the machine is in the mode II. If it is in the mode II, and if the unit place of the currently entered digit is "5" or larger, the unit place of the entered digit reads "1", but if it is "5" or smaller, the increment is effected. By this method, the mode II transforms in a manner, "1".fwdarw."2".fwdarw."3".fwdarw."4".fwdarw."5".fwdarw."1". Similarly, unless it is in the mode II, it transforms in a manner, "1".fwdarw."2".fwdarw."3".fwdarw."4".fwdarw."1".fwdarw."2". In view of this, unless it is in the mode II, that is, unless the F5 switch 56 is turned on, F5 (the total counter setting) is neither displayed as  F 5 , nor prosecuted.

If the function number is entered "0" or "5" subsequent to the setting of the timer KS, the function under execution is interrupted.

When the print key 34 is depressed after  F 5  has been displaced by entering the digit in the above described manner, "5" in the unit place is set to the function number and the print demand is accordingly set. This print demand is accepted during the total counter setting process. Since the setting mode has not yet been initiated at this time, the entered digit is cleared by this print demand and  0 0  is consequently displayed with the setting mode initiated. Although zero in the tenth place is not usually displayed, the tenth place will read zero if it is during the function mode. With the total counter setting mode being set, the keyboard input process can be performed by the utilization of the unit and tenth digit keys in a manner similar to the usual entry of the digits.

When the print key 34 is depressed after the value equal to the last two digits read by the total counter has been set, the print demand emerges. Even this print demand can be accepted during the total counter setting process. The print demand generated during the total counter setting mode causes the timer TC to set the execution flag which represents the execution.

The timer TC, since upon termination of the preset time of the timer during the jam detection and total counter processing it is further set because of the execution of the total counter setting mode, is turned on and off when the total counter 51 is turned off and on, respectively. When the timer TC which has been turned on is switched over to an off state, the increment is effected to the entered digit. In other words, the counter is repeatedly turned on and off at the interval of timer TC with the count gradually increasing to the maximum value "99".

The condition in which the digit is entered is monitored at the step #1212 during the total counter setting mode, and, when the contents of the counter 51 read zero, the execution is terminated by performing a process, such as by releasing the setting mode. That is, if the last two digits are at first set in the total counter, the execution is terminated with the display of  F 5  restored when the counter of the counter subsequently reads zero by addition.

When the C/S key 35 is depressed during the counter setting, the setting mode is released with the display of  F 5  restored, unless the counting is performed incident to the C/S key processing. If it is during the execution of the counting, the stop demand is set and is processed during the total counter setting routine. The stop demand is accepted during the switching off of the counter and is suspended by resetting the execution flag and the timer TC. Under this condition, since the setting mode is not released, the continued execution is possible if the print key 34 is depressed. In addition, the re-execution is also possible if the entered digit is changed.

The control to be effected subsequent to the termination of the automatic timer in the copying machine of the type described hereinbefore will be summarized as follows.

At the set-up of the condition (F) shown in Figs. 10 and 20, which illustrates the control to be effected after the termination of the automatic timer, the sub-timer T-SF is set and, when it is determined that the sub-timer T-SF has terminated, a check is made as to the state of the ejection detecting switch 50. If the copying paper is found to be present, the drive is continued without the main motor brought to a halt and another timer T-SF' is set. Upon termination of the timer T-SF', the state of the ejection detecting switch 50 is again checked and, if the copying paper is not found to be present, the motor is turned off to proceed to the condition (4). On the other hand, if the copying paper is found to be present, the jam flag is rendered "1" to execute the jam process.

Accordingly, by lengthening the time of the automatic timer, it is possible to eliminate any possibility that the copying paper remains inside the paper feed passage due to an erroneous operation at the time of termination of the automatic timer.

As hereinbefore fully described, it has now become clear that, in the copying machine of the type having the auto-shut function, the period of time during which the automatic timer works is prolonged, when the copying paper remains jammed in the machine, to prolong the time during which the automatic shutoff feature can be effected. Accordingly, even when unnecessary copying paper is supplied by the erroneous operation of a sensor or others, such paper can assuredly be ejected, thereby avoiding any undesirable accumulation of copying papers inside the machine. In addition, since the preset time of the automatic timer can be reduced during the normal operation, the trial run of the machine can be efficiently carried out.

Although the present invention has fully been described in connection with the preferred embodiment thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are apparent to those skilled in the art. Such changes and modifications are, unless they depart from the true scope of the present invention, to be understood as included therein.

## Claims

1. A control device for a copying machine having a paper supply passage which comprises, in combination: activated upon completion of a copying operation; predetermined unit of time; paper in the paper supply passage in the copying machine; and detects the presence of the copying paper in the paper supply passage when the timer has completed the count of the first predetermined unit of time to allow the copy machine to continue operation for a second predetermined time.

2. A device as claimed in claim 1, wherein said disabling means includes a second timer for regulating the second mentioned predetermined time, and further comprising means for evaluating an output signal from the paper detecting means upon elapse of the second timer and for generating a jam signal when the copying paper is still present at the paper supply passage.

3. A device as claimed in claim 1, wherein said paper detecting means is arranged adjacent and eject opening of the machine through which the copying paper is ejected.

4. A device as claimed in claim 2, wherein said paper detecting means is arranged adjacent an eject opening of the machine through which the copying paper is ejected.

5. A control device for a copying machine having a paper supply passage and a paper feeding mechanism which comprises, in combination: activated upon completion of a copying operation; predetermined unit of time; paper in the paper supply passage in the copying machine; translated through the paper supply passage in a normal manner in reference to both an output from the paper detecting means and the first predetermined timing signal; to allow at least the paper feed mechanism of the copying machine to continue its operation; and detects the presence of the copying paper when the timer has completed the count of the first unit of time while the function of the jam detecting means is cancelled by the cancelling means, to allow the copy machine to continue operation for a second predetermined period of time.

6. A device as claimed in claim 5, wherein said disabling means includes a second timer for regulating the second mentioned predetermined time, and further comprising means for examining an output from the paper detecting means when the second timer has completed the count of the second unit of time and for generating a jam signal when the copying paper is present at the paper supply passage.

7. A device as claimed in claim 6, wherein said paper detecting means is arranged adjacent an eject opening of the machine through which the copying paper is ejected.

8. A device as claimed in claim 5, wherein said paper detecting means is arranged adjacent an eject opening of the machine through which the copying paper is ejected.

9. A control device for operation of a copying machine capable of making paper copies of original documents and having a paper transporation system that is driven wherein copying paper is transported along a paper supply passageway from a paper supply position to an image transfer operation for receiving an image of the original document, the copy paper is subsequently discharged from the copying machine at the termination of a copying operation, comprising: activated upon completion of a copying operation; the predetermined unit of time; transportation paper supply passageway within the copying machine; and detects the presence of copy paper in the transportation paper supply passageway when the timer has completed the count of the predetermined unit of time whereby the copying machine can continue to drive the paper transportation to remove the copy paper from the transportation paper supply passageway.

10. The invention of claim 9 further including a second timer to provide a second predetermined unit of time subsequent to the start of the first unit of time and means for generating a jam signal to the operator when copy paper is still detected in the transporation paper supply passageway at the expiration of the second unit of time.

11. The invention of claim 9 further including counter means for providing a total count of the paper copies made by the copying machine and means for resetting the counter means to zero after an initial trial run.

12. The invention of claim 11 further including means for displaying an indication of a trial run mode of operation.

13. The invention of claim 12 further including means for disabling the means for resetting the counter means.