JPH0114587Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic document feeder for a diazo copying machine or an electronic copying machine.

In recent years, diazo copying machines are required to be more compact and automated at high speed. Therefore, we have developed a small automatic document feeder (hereinafter referred to as ADF) that is attached to a diazo copying machine equipped with an automatic document repeat mechanism and an automatic paper feeder for photosensitive paper. A system has already been proposed in which manuscripts are fed out one after another at regular intervals while working in conjunction with
No. = Japanese Patent Application Publication No. 56-140336).

However, one of the problems with configuring the ADF in this way is that the ADF document feeding operation cannot be stopped.
The question is whether or not it can be performed immediately when the stop switch is pressed. Normally, it is completely unpredictable when the user presses the stop switch on the ADF, and therefore, the stop switch is turned on while the originals fed from the original cassette are still in the ADF's document transport path. The probability of this happening is very high. In such a situation, for example, if a certain user
This problem occurs when you are copying multiple copies of a large number of originals using the ADF, and you want to give priority to copying another user's original in a separate cassette (interrupt copying). . Therefore, when configuring the ADF so that the document feeding operation stops immediately when the stop switch is turned on,
There is a drawback that the ADF stops when the original remains in the middle of the original transport path of the ADF.

SUMMARY OF THE INVENTION An object of the present invention is to provide an automatic document feeder that does not have the above drawbacks.

The illustrated embodiment will be described in detail below.

Figure 1 shows the automatic document feeder (ADF) of this invention.
is shown combined with a diazo copying machine 1.

First, in order to facilitate understanding of the present invention, the copying machine 1 will be briefly explained.

The lower roller of the pair of document receiving rollers 3 provided near the document receiving opening 2 and the lower roller of the pair of feed rollers 4 provided in front of the confluence point A where the document and photosensitive paper are superimposed are used for inserting documents. A transport belt 5 is wrapped around the document, thereby forming a document insertion path. Further, a conveyor belt 7 is provided between the photosensitive paper feed tray 6 and the confluence point A, thereby forming a photosensitive paper insertion path. Continuing from the merging point A is a conveyor belt 13 wound around the roller 8, the printing cylinder 9, and the rollers 10, 11, and 12 provided at the merging point A. Separation tanks 14 and 15 suck and separate the polymers of the photosensitive paper and the original. The belt 13 passes over this separation tank 14 between rollers 10 and 11, and for the other separation tank 15 it passes over rollers 16 and 17.
A conveyor belt 18 wound between the two passes through. A developing section 19 is located behind the roller 11 (on the upper side in FIG. 1), and a conveyor belt 20 continues behind the roller 16 (on the left side in FIG. 1).

This conveyor belt 20 is wound between a roller 21 located near the roller 16 and an upper roller of the feed roller pair 4, and is maintained in a V-shape by rollers 22 and 23. The area between 2 and 3 runs parallel to the conveyor belt 5 for inserting the document. Therefore, the area of the rollers 21 and 22 of the conveyance belt 20 can also function as a document return path for returning the document to the middle of the document insertion path of the conveyance belt 5. That is, by the conveyor belt 20,
A repeat path for the original document is formed by the conveyor belts 20, 13, and 15. However, a repeat release pawl 24 is provided in the middle between the rollers 21 and 22 of the conveyor belt 20, and when this pawl 24 is in the release position where it protrudes as shown in the figure, the original is not moved by the guide plate 25 and the rollers. The paper is discharged outside the machine through the pair 26.

The total length of the above-mentioned repeat path is determined to be such that three A4-sized originals can be circulated at the same time in landscape orientation. Therefore, for B4 size originals, two sheets can be circulated at the same time in portrait orientation. In this specification, the operation of circulating the document in this manner is referred to as "repeat mode," and the operation of ejecting the document outside the machine with only one exposure process without returning it from the document return path to the document insertion path is referred to as "one-two mode." We will call it "One Mode". Therefore, the number of originals that can be circulated through the repeat path at the same time in repeat mode is determined by the size of the original, and if the number of originals exceeds this number, the number of originals that can be circulated through the repeat path at the same time is
When these originals are continuously fed into the copying machine 1 from the ADF, these originals are sent to the exposure section through the original return path, overlapping the originals that are already circulating. Therefore, when the number of originals that can be circulated simultaneously within the repeat path is about to be sent out from the ADF, the insertion of the originals is temporarily stopped, and the number of originals that can be circulated at the same time within the repeat path is paused. It is necessary to restart the feeding of the originals once all the originals have been discharged outside the repeat path. For this purpose, a repeat number counting cam 27 (FIG. 2) that rotates in synchronization with the conveyor belt is provided at an appropriate location within the copying machine 1. As shown in FIG. 2, this cam is a disc cam having a protrusion 27a at one location on its periphery, and a detection switch SW installed near the document receiving opening.
1 or detection switch SW installed at the entrance of the document return path
When the solenoid SOL3 is turned on, the solenoid SOL3 is energized for a very short period of time, and when the plunger is pulled momentarily, it starts rotating and stops after one rotation, making it a so-called one-rotation cam. The time for one rotation is set to be slightly shorter than the time required for the original to circulate once through the repeat path within the copying machine 1. There are two micro switches around the cam 27.
SW5 and SW6 are provided, and these switches are operated by the protrusion 27a. switch
SW6 is a switch that generates a signal to temporarily stop the feeding of originals when the number of originals that can be simultaneously inserted into the original repeat path in the copying machine 1 is fed into the copying machine 1, and the switch SW5 is a switch that generates a signal to temporarily stop feeding the originals. This is a switch that generates a signal to restart document feeding after the document that has been repeated a preset number of times is ejected from the repeat path.

The repeat operation is performed as follows. In this case, for convenience of explanation, only one original is inserted.

When a document is fed into the copying machine 1, the leading edge of the document first turns on the switch SW1. As a result, the solenoid SOL1 of the repeat canceling pawl 24 is energized, and the repeat canceling pawl 24 is displaced to close the document return path, and at the same time, the clutch MC1' of the automatic photosensitive paper feeder is turned on for a certain period of time. As a result, the paper feed roller 28 rotates for a certain period of time, and feeds out the topmost sheet of photosensitive paper S placed on the paper feed tray 6. When the leading edge of the first sheet of photosensitive paper S turns on a detection switch SW2 provided midway through the photosensitive paper insertion path, a solenoid SOL2 for aligning the leading edge is turned on. As a result, the tip alignment pawl 29 provided in the middle of the overlapping area of the conveyor belts 5 and 20 in the document insertion path descends to block the document insertion path, and the document is blocked by this and temporarily stopped. When the tip of the photosensitive paper S turns on the second detection switch SW3 installed in the middle of the photosensitive paper insertion path, the solenoid
SOL2 is turned off, the leading edge alignment claw 29 is raised, and the document moves forward again. Tip alignment claw 29 and switch
The distances from each SW3 to the merging point A are set to be exactly the same. Original O and photosensitive paper S
The tips of the polymers are completely aligned and polymerized at point A, and then sent to the cylinder 9 by the conveyor belt 13. The polymer is sandwiched between the cylinder 9 and the belt 13, and as it is conveyed, it is printed by a light source inside the cylinder. . The polymer that has been baked is sent to a separation tank 14,
15, the photosensitive paper S is sent to a developing section 19, developed, and then discharged to a copy receiver. On the other hand, the original O is transferred to the conveyor belt 20, and the switch SW4 at the entrance of the original return path is activated. This causes the clutch MC1' of the photosensitive paper automatic paper feeder to
A second sheet of photosensitive paper is fed out, the tips thereof are aligned and polymerized using the method described above, and the paper is fed into the exposure section. In this way, the original is repeatedly circulated within the repeat path, and each time it is automatically superimposed on the next photosensitive paper to make a copy.

Now, in FIG. 2, the repeat number counting cam 27 rotates once when the original turns on switch SW1, and then the original turns on switch SW4.
The second rotation is performed by rotating the switch, and the cam protrusion 27a rotates the switch every time one rotation is completed.
SW5 is activated to send a count signal to the repeat counter circuit 30. The time required for one rotation of the cam 27 is set to be slightly shorter than the time required for the document to circulate once through the repeat path.
After the cam 29 rotates once and stops, it starts rotating again by switch SW4 after a short interval.
You can reliably count the number of repeats. Note that when three originals circulate through the repeat path at the same time, switches SW1 and SW4 are actuated each time by the leading edges of the three originals, but even if the solenoid SOL3 is momentarily pulled while the cam 27 is rotating, the switches SW1 and SW4 are activated each time. Since it does not affect the rotation, only one count signal is sent to the repeat counter circuit 30 every time three originals are repeated once.

When the number of count signals matches the number of repeats stored in advance in the repeat counter circuit 30 by the preset dial 31, a match signal is generated in the counter circuit 30, causing the flip-flop F/F to be set. In addition, this coincidence signal turns off the solenoid SOL1, and the repeat release claw 24 blocks the return path and opens the discharge path outside the machine, so that the original is discharged to the document holder outside the machine. Before the document is ejected, the leading edge of the document activates switch SW4, but the completion of the repeat count has been detected by the repeat counter circuit 30 immediately before that, so in this case, regardless of the activation of switch SW4, MC1 is activated. ' is not operated to prevent the photosensitive paper from being sent out unnecessarily. The solenoid SOL3 is energized by the operation of the switch SW4 mentioned above, and the cam 27 starts to rotate. However, the purpose of the rotation of the cam 27 in this case is not to count the number of repeats, but to wait until the document is completely ejected from the repeat path. It's about taking time for. When the cam 27 rotates once and stops by turning on the switch SW5, the flip-flop F/F that was previously set becomes High due to the turning on of the switch SW5.
An output is generated at the AND gate 32 in cooperation with the Q output in the state, and a document re-insertion start signal is input to the control circuit 40 of the automatic document feeder (ADF).

The above-mentioned contents have already been mentioned in the above-mentioned patent application filed in 1982.
This is described in No. 042803.

FIG. 3 shows the structure of an automatic document feeder ADF docked in the diazo copying machine. Inside the ADF housing 41 (Fig. 1),
A cassette-type document feed tray 42 that is replaceable for each document size is provided on the side opposite to the document delivery port connected to the document reception port 2 of the copying machine. The manuscript should be landscape or B4
The original size is placed vertically. A paper feed fan 43 is arranged above the paper feed table 42 for sucking the original document on the paper feed table 42 upward. Between the paper feed tray 42 and the paper feed fan 43, on the area side of the paper feed tray 42, there is one rear paper feed roller 44 and two front paper feed rollers 45, 46.
are arranged one after the other in the paper feeding direction. A paper feed tray 42 is located closer to the document delivery port than the front paper feed roller 46.
A normal rotating roller 47 is located near the copying machine 1, and a pinch roller 48 is located near the document sending port and is rotating in synchronization with the conveyance speed of the copying machine 1. On the other hand, the rear paper feed roller 44 is rotationally driven via the first electromagnetic clutch MC1, and the front paper feed rollers 45, 46 and forward rotation roller 47 are rotationally driven via the second electromagnetic clutch MC2. Ru.

The rear paper feed roller 44 and front paper feed rollers 45 and 46 are provided one after the other in the paper feed section in order to increase the conveying force and to be able to feed long objects, and also to avoid conveyance caused by dirt on the rollers. This is to postpone the period of power decline. A stop roller 47' made of a rubber roller is in contact with the normal rotation roller 47. Further, this pair of rollers 47, 47' prevents double feeding of documents when the normal rotation roller rotates. Reference numeral 49 denotes a metal guide plate for preventing the leading edge of the document from hitting the stop roller 47' first and making feeding impossible or inaccurate when the document is curled downward.

Between the normal rotation roller 47 and the pinch roller 48, first and second document detectors S1 and S2 are arranged in sequence when viewed in the document feeding direction, and the pinch roller 48 is arranged in sequence when viewed in the document feeding direction. immediately after the third
A document detector S3 is arranged. These detectors are, for example, photoelectric reflection detectors. 1st
The detector S1 is from the rear paper feed roller 44 to approximately A4
The third detector S3 is located at a distance corresponding to the short side of the A4 size paper, and the third detector S3 is located at a distance from the front paper feed roller 46 by a distance corresponding to the short side of the A4 size sheet. Conversely, the normal rotation roller 47 and the pinch roller 48 are arranged at such a narrow interval with respect to the paper feed rollers 44, 45, 46,
The aim is to downsize the entire ADF.

Reference numeral 50 denotes a manual document feeding section for feeding documents of sizes other than A4 size and B4 size when the ADF is not used. 48, and a guide plate 53 extending in the middle of the document conveyance path.

FIG. 4 shows details of the control circuit 40 of the ADF, SWa is a start switch,
SWb is a stop switch, and SWc is a size switch that is automatically switched depending on the type of paper feed cassette, that is, whether the size of the document set on the paper feed tray 42 is A4 or B4. Reference numeral 54 denotes an input terminal for switching the document feeding interval, to which a positive voltage is applied from the copying machine side in the case of repeat mode. S1,S
2 and S3 are the above-mentioned document detectors, each of which includes a comparator here. FF1~FF
5 are flip-flops, FF1 is for size command, FF2 is for start, FF3 is for driving paper feed fan 43, FF4 is for driving first electromagnetic clutch MC1, and FF5 is for driving second electromagnetic clutch MC2. It is for driving.

In order to cause the detector S2 to participate in sheet feeding control only in the repeat mode, a 3-input AND gate 59 is provided, and the first input terminal of the gate is connected to the detector S2.
The second input terminal is an input terminal 54 for switching paper feed interval.
And the third input terminal is connected to the output terminal of an inverter 58 connected to the Q output terminal of the size FF1. The output terminal of this AND gate 59 is connected to the second input terminal of an OR gate 60 whose first input terminal is connected to the detector S1. Therefore, at the output terminal of the OR gate 60, the combination of the outputs of the detectors S1 and S2 appears when the size is A4 and the repeat mode is selected, and the output of the detector S1 appears otherwise. This OR gate 6
The output terminal of 0 is connected to the first input terminal of an AND gate 62 placed in front of the trigger input terminal of the monostable multi-MM1, and is also connected to the trigger input terminal of the monostable multi-MM2. Therefore, when the output of the OR gate 60 rises, MM2 is triggered, and when it falls, MM1 is triggered. The output terminal of MM1 is OR
It is connected through gate 63 to the second input terminal of an AND gate 64 preceding the set input terminal of FF5 for MC2, and the output of gate 64 is connected to both the set input terminals of FF4 and FF5.
Further, the output terminal of MM2 is connected to the second input terminal of an AND gate 66 whose first input terminal is connected to the Q output terminal of FF1 for size, and the output terminal of the AND gate 66 is connected to the reset terminal of FF4 through an OR gate 67. Connected to the input terminal.

The start switch SWa is connected through an AND gate 55 to the set input terminal of the start FF 2, and the stop switch SWb is connected through an OR gate 56 to the reset input terminal of the start FF 2. The Q output terminal of this FF2 is connected via an inverter 57 to the set input terminal of the fan FF3. The Q output terminal of FF3 is connected to the first input terminal of AND gate 64, and is also connected to the second input terminal of AND gate 62 via inverter 61.

The detector S3 is connected to the trigger input terminal of the monostable multi-MM3, and the output terminal of the MM3 is
It is connected to the reset input terminal of FF4 through OR gates 65 and 67, and to the reset input terminal of FF5 through OR gate 65 and inverter 68.

First, let's explain the operation in one-to-one mode. It is assumed that the original cassette is set for A4 size.

In the case of A4 size, the size switch SWc is in the position shown in the figure, so the size FF1 is in the reset state. Therefore, one input of the AND gate 66 connected to the Q output terminal of FF1 becomes active. Conversely, the output of inverter 58 becomes H level, and the output of inverter 58 is input to the third input terminal of three-input AND gate 59 connected to detector S2. This AND gate 59 does not become active unless a positive signal is inputted to its second input terminal from the paper feed interval switching input terminal 54.
The signal input to the paper feeding interval switching input terminal 54 is switched so that it is positive in the repeat mode and negative in the one-to-one mode.
Therefore, in the one-to-one mode, the AND gate 59 is inhibited and the detector S2 does not participate in the operation of the ADF. Also, FF for electromagnetic clutch MC1
4 has its reset input terminal connected to the output terminal of the AND gate 66 via an OR gate 67. Therefore, FF4 and therefore MC1 receive not only the signal from OR gate 65 that is applied to the second input terminal of OR gate 67, but also the signal that is applied to the first input terminal of OR gate 67 only when the document is A4 size. It can be reset depending on the output of the preceding AND gate 66, that is, the presence or absence of the output signal of the monostable multi-MM2 input to the second input terminal of the gate.

First, when the power is turned on, all flip-flops except FF1 for size command are reset by the power-on reset signal.

When the start switch SWa is turned on, the AND gate 55 immediately becomes active and the start FF2 is set. The reason is that there is no document leaving the normal rotation roller 47 yet, so the detectors S1 to S3 are all
OFF, and therefore the signal connected between the detector S3 and the other input terminal of the AND gate 55
This is because the output of NOR gate 71 is also at H level. When FF2 for starting is set, FF
The fan FF3 connected to the Q output terminal of No. 2 is also set. The paper feed fan 43 begins to rotate, and the operation of sucking the original document on the paper feed table 42 upward is started.

The Q output of the fan FF 3 is input to one input terminal of an AND gate 64 and is also sent to a second input terminal of an AND gate 62 through an inverter 61 . The first input terminal of this AND gate 62 is at L level since the detector S1 is still in a non-detecting state. Therefore, the AND gate 62 becomes active and triggers the monostable multi-MM1. M.M.
An output appears at 1 and is applied through an OR gate 63 to the other input terminal of the AND gate 64 mentioned above. Therefore, AND gate 64 becomes active,
Connected to the AND gate 64 are two flip-flops for electromagnetic clutches MC1 and MC2.
FF4 and FF5 are set. As a result, MC1
turns on and the rear paper feed roller 44 rotates, while
When the MC2 is turned on, the front paper feed rollers 45, 46 and the forward rotation roller 47 begin to rotate, and feeding of an A4 size document is started.

When the leading edge of the fed document reaches the detector S1, the detector S1 is turned on. Therefore, the positive signal
Trigger monostable multi-MM2 through OR gate 60. By the output of monostable multi MM2
AND gate 66 becomes active, and FF4 of electromagnetic clutch MC1 is reset via OR gate 67. The reason for doing this is that, as already mentioned, the point at which the leading edge of an A4-sized document is detected by the detector S1 is the point at which the trailing edge of the document exits the rear paper feed roller 44; If the rotation of the rear paper feed roller 44 is not interrupted at this point, an inconvenience will occur in which the original immediately below the original is likely to be fed out by the rear paper feed roller 44.

Next, when the leading edge of the document leaves the pinch roller 48 and is detected by the detector S3, the document can then be transported by the pinch roller. Therefore, when the detector S3 is turned ON, the electromagnetic clutch is activated as follows.
MC2 is turned off. That is, the monostable multi-MM3 is triggered by the ON of the detector S3, and the Q output of the MM3 is sent to the inverter 68 through the OR gate 65.
is input to MC2 via inverter 68.
FF5 is reset. Furthermore, this OR gate 65
The output of FF4 is also input to OR gate 67.
has already been reset, so it has no effect.

Further, the document is fed until the leading edge enters the copying machine 1 and the trailing edge exits the detector S1. Detector S1
is turned OFF, the output of the OR gate 60, that is, the first input of the AND gate 62 becomes L level, and the AND gate 62 becomes active. Therefore monostable multi-MM
1 is triggered and the output of MM1 is applied to the second input terminal of AND gate 64 via OR gate 63. Therefore, AND gate 64 becomes active and FF4 and FF5 are set again. Therefore, the electromagnetic clutches MC1 and MC2 are engaged, and the rear and front paper feed rollers 44 to 46 and the normal rotation roller 47 are engaged.
starts rotating again, and the second document is fed.

Thus, in one-to-one mode, A4
Documents of various sizes are automatically fed sequentially by the detectors S1 and S3 at intervals of, for example, 35 mm.

The operation in the one-to-one mode when the document is B4 size is the same, except that the AND gate 66 is not activated because FF1 is set. That is, in the case of a B4 size document, the only difference is that when the leading edge of the document is detected by the detector S3, the output of the OR gate 65 resets FF4 and FF5 simultaneously via the OR gate 67 and the inverter 68. FF at the same time when the original passes through detector S1
The point that 4 and FF5 are set again is the same as in the case of an A4 size document.

Next, let's explain the operation of repeat mode for A4 size paper.

A positive voltage is applied to the input terminal for switching the paper feed interval, and this causes the number of A4 size documents that can be inserted into the repeat path of the copying machine 1 to be prevented from overlapping each other while circulating through the repeat path. Specifies document spacing with a margin that is not exceeded. That is, in order to obtain this document spacing of, for example, 59 mm, the detector S2 becomes able to participate in the operation of the ADF through the 3-input AND gate 59.

When the leading edge of the A4 size document reaches detector S1, electromagnetic clutch MC1 turns OFF, and then when the leading edge of the document reaches detector S3, electromagnetic clutch MC1 turns OFF.
The fact that 2 is turned off is the same as described above. However, after that, the monostable multi MM1 is triggered only when the trailing edge of the original passes through the detector S2 and an output is generated at the AND gate 59, and is applied to the first input terminal of the AND gate 62 through the OR gate 60. Electromagnetic clutch depending on output
Both MC1 and MC2 flip-flops FF4 and
FF5 is set. Because OR gate 60
The output of the OR gate 60 is a combination of the detectors S1 and S2, and even if the trailing edge of the document passes through the detector S1, the output of the detector S2 still exists, so the output of the OR gate 60 causes the detector S2 to This is because it falls only when the rear end comes out.

When the rear edge of the third document passes the detector S2, the switch SW belonging to the cam 27
6 (Fig. 2) is turned ON, and a document insertion stop signal is input from . Although this signal is not shown in FIG. 4, it is held within the control circuit until the document restart signal is input to the terminal. The cam 27 for counting the number of repeats starts rotating when SOL3 is momentarily excited by SW1.
The rotation is a little shorter than around repeat path 1, and after repeating once, it stops once and immediately switches to SW4.
It is now possible to restart.
When the original insertion stop signal is input to the ADF, the electromagnetic clutches MC1 and MC2 are turned OFF in the following manner. That is, the stop signal becomes one input of the AND gate 75 via the inverter 73 and the OR gate 74. The other input terminal of the gate 75 is connected to the OR gate 60 via an inverter 72, and is therefore opened by the inverter 72 while there is no document on the detectors S1, S2. accordingly
AND gate 75 becomes active and FF4 and FF5 are reset through OR gate 65. This will temporarily stop re-inserting the original.

In this state, when the copying machine repeats a predetermined number of times, the repeat counter 30 outputs a signal that matches the preset number of times. With this coincidence signal, as explained in Fig. 1,
Turn off SOL1 and bring out the repeat release claw 24.
Also, by turning on SOL3 for a certain period of time, the cam 27 is started again. Three originals are ejected to the original tray. The position of the protrusion 27a of the cam 27 after three sheets have been ejected is such that SW5 is turned on, and when SW5 is turned on, a document restart signal is issued.
It is output to the NAND gate 32.

When the document restart signal is input from the terminal, the signal activates the AND gate 64 via the OR gate 63, so that FF4 and FF5 are set and feeding of the document is restarted. The ADF feeds three originals again, pauses, and repeats copying. This process is repeated until there are no more originals left.

By the way, in the one-to-one mode or repeat mode as described above, if the operator wishes to stop the feeding operation of the ADF, he or she must turn on the stop switch SWb. There is no problem if this stop switch SWb is turned on when there is no document on the detector S1 and/or S2, but if the stop switch SWb is
When a document is passing over the sensor S1 or S2, it is necessary to wait for the ADF to stop feeding until the rear end of the document passes over the detector S1 or S2, that is, until it passes through the normal rotation roller 47. be. you should do,
A state in which the leading end is not yet gripped by the pinch roller 48 after passing through both detectors S1 and S2, or a state in which the trailing end is caught between the normal rotation and stop rollers 47 and 47' even if the leading end is gripped by the pinch roller 48. So, the manuscript
This is because they remain in the conveyance path of the ADF. On the other hand, if the trailing edge has already passed through the detectors S1 and/or S2, even if the document is in the ADF, the trailing edge will not be pinched between the rollers 47 and 47', and will definitely pass through the pinch roller 48. Since the paper is inserted into the mouth of the copying machine and is quickly brought out of the ADF and into the copying machine by the pinch roller 48, there is no need to wait for the feeding of the ADF to stop.

For this reason, the stop switch SWb
is connected to one input terminal of an AND gate 75 via an OR gate 74, and the other input terminal of the gate is connected to an output terminal of an OR gate 60 via an inverter 72. Incidentally, the output terminal of the AND gate 75 is connected to the flip-flop FF4 and
It is connected to the third input terminal of a three-input OR gate 65 for commonly resetting FF5.

Now, the stop switch SWb is activated when there is no document on the detector S1 and/or S2.
If it is turned on, the start FF2 is reset via the OR gate 56, its Q output becomes L level, and the signal connected to the Q output terminal is reset.
It becomes one input of AND gate 69. This AND
The other input terminal of gate 69 is the OR of detector S1.
It is connected to the gate 60, and the OR gate 60
Since the output is at L level when there is "no original", the AND gate 69 becomes active. Therefore this
The fan FF 3 is reset by the AND gate 69 via the OR gate 70, and the document feeding fan 43 is stopped.

On the other hand, the output of the inverter 72 applied to the other input terminal of the AND gate 75 is "no original".
In this case, it is H level, so the stop switch
When SWb is turned on and a positive voltage is applied to OR gate 74, AND gate 75 is also activated by the gate, and flip-flops FF4 and FF5 are reset via OR gate 65. That is,
ADF feeding operation stops immediately.

Switch SWb is turned ON when the original is already sent onto the detector S1 and/or S2.
When this happens, fan FF3 is reset in the same way as above, but the output of inverter 72 becomes L level and AND gate 75 is inhibited, so FF4 and FF5 are not reset immediately and the original is reset when it leaves the detector S1 and/or S2. In other words, this document is directly transferred from the ADF to the copying machine 1 by the pinch roller 48.
handed over to.

Since the automatic document feeder of the present invention is configured as described above, for example, when there is an original that you want to copy preferentially than the original that is being copied and you want to replace the cassette with a different size original, you can at the time
Even when the ADF stop switch is turned on, no original remains in the original transport path of the stopped ADF.
Therefore, after stopping, the document cassette can be replaced and subsequent document feeding operations can be performed normally.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing a specific example of a copying machine to which the automatic document feeder of the present invention can be applied, Fig. 2 is an explanatory diagram of the operation of the copying machine, and Fig. 3 is a cross section showing the configuration of the automatic document feeder. FIG. 4 is a control circuit diagram thereof. 42...Document feed table, 43...Paper feed fan, 4
4...Rear paper feed roller, 45, 46...Front paper feed roller, 47...Normal rotation roller, 48...Pinch roller pair, 50...Manual document feed section, 51...Manual feed slot, FF1...Size Flip-flop for FF2
...Flip-flop for start, FF3...Flip-flop for fan, FF4...Clutch
Flip-flop for MC1, FF5...Flip-flop for clutch MC2, S1, S2, S
3...Document detector, MM1, MM2, MM3...
Monostable multi, SWa...start switch,
SWb...Stop switch, SWc...Size switch.

Claims (1)

[Scope of claim for utility model registration] A front paper feed roller for feeding documents from the document feed table, and double-feed prevention rollers provided sequentially in the document conveyance path from the front paper feed roller to the document delivery port. a first document detector provided between the double-feed prevention roller pair and the pinch roller pair; and a second document detector provided immediately after the pinch roller pair when viewed in the document conveyance direction. The electromagnetic clutch for rotationally driving the front paper feed roller and the pair of double-feed prevention rollers is controlled on and off by both the first and second document detectors, so that documents can be fed at regular intervals. The automatic document feeder includes a manual stop switch that generates a stop signal to instruct the stop of the document feed operation in response to manual operation, and an electromagnetic clutch that turns on the electromagnetic clutch when set.
A flip-flop which turns off the electromagnetic clutch at the time of reset, an output terminal connected to the reset terminal of the flip-flop, and further includes an output signal from the manual stop switch and an output signal from the first document detector.
It has an AND element as an input, and a stop signal is sent from the manual stop switch,
An automatic document feeder characterized in that, when a signal indicating that there is no document is sent from the first document detector at the same time, the flip-flop is reset by the AND element.