JP2607539B2 - Document feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a document feeder provided in, for example, an electronic copying machine and automatically feeding a document to an exposure position on a document table.

(Prior Art) In general, this type of document feeder is provided to be freely openable and closable on a document table of a copying machine main body. Conveys the supplied document to the exposure position on the platen,
And a transport unit for discharging the document from the document table after the exposure is completed.

Conventionally, such a document feeder is in a standby state when the copying operation is interrupted, and when the document feeder is opened and closed at this time, if a document remains, a jam occurs. The release of the jam is performed by removing all remaining documents and opening and closing the document feeder again. Further, after the jam state is released, the document can be restarted by setting the document again on the paper feed tray.

As described above, in the conventional document feeder, in the standby state after the interruption of the copying operation, when the document is opened and closed as it is, a jam occurs, and in order to release the jam, all the remaining documents are removed, and Since it has to be opened and closed, there is a problem that the operation is troublesome. In addition, when restarting after clearing the jam state, there is a problem that the document must be re-set on the paper feed tray without fail.

(Problems to be Solved by the Invention) As described above, in the standby state after the interruption of the copying operation, if the original is opened and closed as it is, a jam state occurs. All documents must be removed and opened and closed again, which is troublesome for operation, and restarting after clearing the jam condition requires that documents be re-set in the paper tray. In the standby state after the copying operation was interrupted, even if the original is opened and closed as it is, if the original is still set correctly, the jam will not occur and the conveyance will be resumed from that state. An object of the present invention is to provide a document feeder that can be started, eliminates the trouble of resetting a document, and saves labor for operation.

[Configuration of the Invention] (Means for Solving the Problems) A document feeder according to the present invention includes a pickup roller that picks up and feeds documents set in a document receiving unit one by one,
A registration roller that further conveys after aligning the leading end of the document taken out by the pickup roller in the conveyance direction,
A feed roller for receiving and further transporting the document transported by the registration roller, a transport belt for receiving the document transported by the feed roller and transporting the document to a predetermined position on a document table; When at a predetermined position on the table, a document following the preceding document is
The pickup roller and the registration roller are controlled such that the pickup roller and the registration roller are caused to stand by at an advance position located between the feed roller and the registration roller in a document conveyance path formed by the pickup roller, the registration roller, the feed roller, and the conveyance belt. Advance means to
A plurality of sensors provided along the document transport path for detecting the presence or absence of a document in the document transport path; and detecting a document jam in the document transport path by referring to detection results of the plurality of sensors. Jam detection means, and when the jam detection means detects a document jam in the document conveyance path, stopping the drive of the pickup roller, registration roller, feed roller, and conveyance belt to stop document conveyance. Means, after the document jam detected by the jam detecting means is released, referring to each output of the plurality of sensors at the time when the restart of conveyance of the stopped document is instructed by the stopping means, When a sensor located upstream of the advance position in the document conveyance path among the sensors detects the presence of a document, the jam detecting unit detects that a document jam has occurred. Driving the rollers and the conveyance belt to convey the document waiting at the advance position to the predetermined position without causing the document to move downstream of the advance position in the document conveyance path among the plurality of sensors. When the disposed sensor detects the presence of a document, the control unit includes a control unit that causes the jam detection unit to detect a document jam and prohibits the driving of each roller and the conveyance belt.

(Operation) At the restart after the interruption of the copying operation, it is detected whether or not there is a document at the advance position. It is determined whether or not there is a document. When it is detected that there is no document, supply of the document from the document receiving unit is selected. When it is detected that there is a document, supply of the document from the advance position is selected. Thus, when the original is opened and closed in the standby state after the interruption of the copying operation, if the original is still set at the leading-out position or the original receiving portion, the original is not jammed and the copying operation is performed again. Is started, the document transporting operation can be continued (restartable) from that state. Therefore, for example, the trouble of setting the original at the first-out position in the original receiving portion again is eliminated, and the operation time is saved.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 4 shows a schematic configuration of, for example, an electronic copying machine provided with the document feeder according to the present invention. The electronic copying machine includes a copying machine main body 1, a document conveying device 2 which is provided on the upper surface of the copying machine body 1 to open and close, and automatically supplies a document D, and a mounting table on which the copying machine main body 1 is mounted. The sheet P discharged from the discharge section of the copying machine main body 1 is received as necessary, and the copying machine main body 1 is left as it is or turned upside down in order to perform multiple or double-sided copying on the paper P. And a direction changing conveyance device 3 for guiding the sheet to a sheet feeding section.

The copying machine body 1 is configured as follows. That is, a document table (transparent glass) 5 is provided on the upper surface of the housing 4, and the document feeder 2 is provided on the document table 5 so as to cover the upper surface thereof, and can be opened and closed. The document D is automatically conveyed to the exposure position on the document table 5 by the conveyance device 2.

Paper feed cassettes 6 and 7 are detachably mounted on the right side of the housing 4, respectively, and a large-capacity paper feeder 8 is provided corresponding to the right side of the direction change transport device 3. The cassette cover of the upper paper feed cassette 6 is provided with a manual paper feed table 9 for feeding paper P by hand.
It has become.

A drum-shaped photoconductor 10 is disposed substantially at the center of the housing 4. Around the photoreceptor 10, a charging charger 11, an exposure optical system 12, a developing device 13, a transfer charging device 14, a peeling charging device
15, a cleaner 16, and a static elimination lamp 17 are sequentially arranged.

Paper P supplied from the paper cassettes 6 and 7 and the large-capacity paper feeder 8 via the paper feeding means 18 and the paper P manually supplied from the manual paper feed table 9 are provided in a lower portion of the housing 4. , And the paper P guided from the direction changing transport device 3
The housing 4 passes through an image transfer section between the photoreceptor 10 and the transfer charger 14.
Paper transport path leading to the paper output tray 19 provided on the left side of the printer
20 are formed. An aligning roller pair 21 is disposed upstream of the image transfer section of the paper transport path 20, and a fixing device (heat roller) 22 and a paper discharge roller pair 23 are disposed downstream.

The exposure optical system 12 includes an exposure lamp 25 whose back portion is surrounded by a reflector 24 and irradiates the original D on the original table 5 with light, and a first mirror that reflects light reflected from the original D on the original table 5 in a predetermined direction. 26, a first optical unit 27 that can reciprocate along the document table 5, and, in synchronization with the first optical unit 27, move in the same direction at half the speed of the first optical unit 27; A second optical unit 31 having a second mirror 29 and a third mirror 30 for reflecting the light reflected by the first mirror 26 toward the zoom lens unit 28 is provided.
Further, the lens unit 28
A fourth mirror 32 that reflects light output from 28 in a predetermined direction.
And a third optical unit 34 having a fifth mirror 33, the position of which is moved according to the set magnification, and the third optical unit.
A sixth mirror 35 that reflects the light reflected by 34 toward the photoreceptor 10
And a configuration including

Reference numeral 36 denotes a document stopper for stopping the document D conveyed by the document conveyance device 2 at a predetermined position (exposure position) on the document table 5, provided at the left end of the document table 5 with respect to the drawing. I have. The document stopper 36 is moved up and down by a stopper solenoid (not shown).

Thus, the photoreceptor 10 rotates in the direction of the arrow in the figure, and the surface is first uniformly charged by the charging charger 11. on the other hand,
The first optical unit 27 moves along the document table 5 with the exposure lamp 25 turned on, and the second optical unit 31 moves in the same direction at half the speed in synchronization with this movement. The document D set on the document table 5 is optically scanned, and the image of the document D is
The electrostatic latent image is formed thereon.

The electrostatic latent image formed on the photoreceptor 10 is developed by attaching toner by facing the developing device 13, and thereafter,
The image is transferred to the image transfer section facing the transfer
The upper toner image is transferred onto the sheet P supplied through the aligning roller pair 21. Then, the sheet P to which the toner image has been transferred is separated from the surface of the photoreceptor 10 by the separating charger 15 and guided to the fixing device 22 through the sheet conveying path 20, where the toner image is fixed. After that, the sheet is discharged to the sheet discharge tray 19 via the sheet discharge roller pair 23.

On the other hand, the surface of the photoreceptor 10 after the transfer of the toner image onto the sheet P is opposed to the cleaner 16 so that the residual toner is cleaned, and further, the charge is removed by the charge removing lamp 17 to prepare for the next copying operation. I have.

When performing multiplex or double-sided copying, by switching the distribution gate 37 provided in front of the paper discharge roller pair 23, the fixed paper P is temporarily discharged to the paper discharge tray 19 without being discharged. It is guided to the conversion / conveyance device 3 and guided again to the aligning roller pair 21 as it is, or in an inverted state.

Next, the document feeder 2 is configured as shown in FIG. The document feeder 2 includes a supply unit 41 for sequentially separating and setting the set documents D one by one, a reversing unit 42 for reversing the document D as necessary, and a document supplied from the supply unit 41. The transport unit 43 transports the document D to the exposure position on the document table 5 and discharges the document D from the document table 5 after the exposure is completed. The transport unit 43 includes the document table 5
It is provided to be able to open and close according to the document, and also serves as a document cover.

The supply unit 41 includes a paper feed tray (document receiving unit) 44 for setting a plurality of documents D in a stacked state, a pickup roller 45 for taking out the documents D set on the paper feed tray 44 one by one,
A paper feed roller (sending roller) 46 for sending out the original D picked up by the pickup roller 45, a separation roller 47 that comes into contact with the paper feeding roller 46, and the original D sent out by the paper feeding roller 46.
Roller pair 48 for transporting while aligning the document, receiving the document D transported by the pair of registration rollers 48, and
And a guide path 50 provided between the feed roller pair 49 and the registration roller pair 48. The guide path 50 is located at a leading position 51.
It has become. An empty switch for detecting the presence or absence of the document D is provided on the paper feed roller 46 side of the paper feed tray 44.
52, a first jam switch 53 in front of the pair of registration rollers 48, a size switch 54 for detecting the size of the document D behind the pair of registration rollers 48, and a post-registration in front of the pair of feed rollers 49. Switches 55 are provided.

The reversing unit 42 receives the document D reversely fed from the transporting unit 43, reverses the original D, and guides the original D to the middle of the guide path 50 of the supply unit 41 from the pair of reverse rollers 56, 57, 58 and the guide paths 59,. Become
The junction with the guide path 50 is the reverse stop position 60. In front of the reversing roller pair 57, a reversing switch 61 is provided.
Is provided.

Reference numeral 62 denotes an openable / closable reversing unit cover, which covers a portion of the reversing unit 42 and the supply unit 41 other than the sheet feeding tray 44. 63
Is a cover switch for detecting opening and closing of the reversing unit cover 62. 74 is a gate guide, the supply unit 41 and the inversion 42
Provided between the feeding unit 41 and the feeding unit 41 to guide the document D from the feeding unit 41 to the feeding unit 43, and guide the document D sent backward from the feeding unit 43 to the reversing unit 42. Is the supply unit 41
Is set in a horizontal state so as to guide the original D from the printer to the transport unit 43, and is driven by a gate solenoid (not shown).

The transport unit 43 includes an endless transport belt 66 that transports the original D, which is suspended and supplied between the transport rollers 64 and 65, along the original table 5, and a pressing roller that presses the transport belt 66 onto the original table 5. 67,..., A pair of paper ejection reversing rollers 68, a guide path 69 and a pair of paper ejection rollers 70 for ejecting the original D sent out from the original table 5 while reversing them, and a paper output tray for receiving the ejected original D. Consists of 71. A second jam switch 72 is provided at the rear of the sheet discharge reversing roller pair 68. Reference numeral 73 denotes a set switch for detecting whether the transport unit 43 is open or closed.

FIG. 2 shows the overall control system of the electronic copying machine constructed as described above. That is, 81 is a main processor which mainly controls the copier main body 1, and 82 is a sub-processor which mainly controls the document feeder 2, and these are mutually different interface signals (to be described in detail later). It gives and receives.

The main processor 81 includes an input switch 84 such as various keys on an operation panel (not shown) via an input interface 83 such as a data selector, and various detectors (switches, sensors, etc.) 85 necessary for control. Connected. The main processor 81 includes a driver 87 for driving a display unit 86 such as various displays on an operation panel, a lamp 4 control unit 88 for controlling the exposure lamp 25, and various driving systems (main motor, clutch, solenoid, etc.). A) a driver 90 for driving the 89; a high-voltage power supply 92 for driving the various chargers 91; a driver 94 for driving a stopper solenoid 93 for driving the original stopper 36;

The sub-processor 82 receives an empty switch 52, a first jam switch 53, a size switch 54, a post-registration switch 55, an inversion switch 61, a cover switch 63, and a second jam switch 72 via an input interface 95 such as a data selector. And the set switch 73 are connected. The sub-processor 82 includes a paper discharge solenoid 96 for moving the pickup roller 45 up and down, a paper feed motor 97 for driving various rollers of the supply unit 41 and the reversing unit 42, and a conveyance unit 43 for conveying the conveyance unit 43. A transport motor 98 for driving the belt 66 and various rollers, and drivers 100, 101, 102, and 103 for driving a gate solenoid 99 for driving the gate guide 74, respectively, are connected. Further, a first pulse generator 104 and a second pulse generator 105 are connected to the sub-processor 82. The first pulse generator 104 generates a clock pulse by a rotary encoder attached to the paper feed motor 97. 2nd pulse generator
A clock pulse 105 is generated by a rotary encoder attached to the transport motor 98.

Here, an interface signal exchanged between the main processor 81 and the sub-processor 82 will be described. There are six interface signals from the main processor 81 to the sub-processor 82, which are output when setting and changing the double-sided copy mode or single-sided copy mode, or setting and changing the stacked original automatic supply mode or the single-sheet original automatic supply mode. Mode set signal (MOD-SE
T), original supply signal (O-IN), original discharge signal (O-OU)
T), an original direction display signal (S-SET), a copying in-progress signal (D-RUN) output during the copying operation of the copying machine body 1, and a manual, automatic magnification, automatic cassette, and initialization when outputting a mode set signal. There is a feeder set signal (F-SET) that outputs a signal according to the selection.

There are 12 interface signals (signals indicating the state of the document feeder 2) from the sub-processor 82 to the main processor 81, and a document set signal (O-RDY) indicating whether or not the document D is set, a jam A feeder jam signal (D-JAM) indicating the status, a feeder busy signal (D-BUSY) indicating that the document is being conveyed, and a feeder switch signal (D) indicating the open / closed state of the conveyance unit 43 and the reversing unit cover 62.
-SW), a document size signal (SIZE0, SIZE1, SIZE2, SIZE3) for indicating the document size with a 4-bit code, a feeder mode 0 indicating one of a manual, an automatic magnification, and an automatic cassette mode, and a feeder mode 1 Signal (D-MO
DE0, D-MODE1), a semi-auto signal (ASDF) indicating whether the automatic document feeding mode is a stacked original feeding mode or a single-sheet original automatic feeding mode, and a connection signal (DF-) indicating whether or not the original feeder 2 is connected.
CNT).

Next, the operation of such a configuration will be described with reference to the flowchart shown in FIG. First, when a power switch (not shown) is turned on, the copier body 1 enters a ready state (copyable state) after a predetermined time has elapsed. At this time, the main processor 81 is in a state where it can receive a copy key provided on the operation panel, and the sub-processor 82 is in a state where it can receive an interface signal from the main processor 81.

In this state, the operation in the one-sided original mode will be described first. When the document D is set on the paper feed tray 44, the empty switch 52 is turned on, and the presence of the document is detected. Then, the sub-processor 82 outputs an O-RDY signal to the main processor 81. Here, when the copy key is turned on, the main processor 81 outputs an O-IN signal. The sub-processor 82 receives this O-IN signal and starts the document transport operation of the document transport device 2. That is, first, the stopper solenoid 93 is turned on, the original stopper 36 is lowered, and the paper feed motor 97 and the paper feed solenoid 96 are turned on. As a result, the pickup roller 45 rotates and descends to come into contact with the set original D, so that one original D is taken out and sent to the paper feed roller 46. Next, by rotating the transport motor 98 in the forward direction, the transport belt 66, the pair of paper discharge reversing rollers 68, and the pair of paper discharge rollers 70 are rotated in the discharge direction, and a document discharge operation is performed. This takes into consideration the case where a residual document exists. If there is a remaining original, a discharge completion check is performed by a signal from the second jam switch 72, and then the stopper solenoid 93 is turned off, and the original stopper 36 is raised.
If there is no remaining document, stop solenoid after a certain time
Turn off 93 and raise document stopper 36.

The original D sent to the paper feed roller 46 is separated by a separation roller.
47 is rotated in the opposite direction to the paper feed roller 46 to be separated and conveyed, and the first jam switch 53 is turned on to be sent to the registration roller pair 48 stopped at this time. The motor 97 is turned off and the conveyance of the document D is stopped. After a certain time, the paper feed motor 97 is rotated in the reverse direction to drive the pair of registration rollers 48 and the pair of reversing rollers 56, 57, 58 to start feeding the original D, turn on the size switch 54 and the post-registration switch 55, and After passing through the roller pair 49, it is fed to the conveyor belt 66 from above the gate guide 74 which is in a horizontal state at this time. The conveyance motor 98 is turned on a predetermined time before this, and the conveyance belt 66 is already rotating in the conveyance direction when the document D is sent to the conveyance belt 66. The document D is transported by the transport belt 66 to the document stopper 36, where the transport motor 98 is turned off and the transport belt 66 stops. The stop timing of the transport belt 66 is set by counting the number of clock pulses generated by the second pulse generator 105 after detecting the leading end of the document D by the post-registration switch 55.

(1) The sub-processor 82 turns off the D-BUSY signal a predetermined time before the document D stops at the document stopper 36, and notifies the main processor 81 of the end of document conveyance. After a certain period of time, the main processor 81 outputs a D-RUN signal,
The copying operation of the copying machine body 1 is started.

While the copying machine body 1 is performing a copying operation, the document D
Exists, the sub-processor 82 performs the advance operation of the next original D. That is, the pickup roller 45 is lowered to take out and transport the next original D. After that, until the switch 55 is turned on after the registration, it is the same as when the first original is transported. After a certain period of time from when the leading edge of the second document D has turned on the post-registration switch 55, the conveyance thereof is stopped. The second document D is in a standby state at the advance position 51 at the time of stopping.

After a lapse of a predetermined time from the end of the copying operation, the main processor 81 outputs the O-IN signal again. Sub processor 82
Receives the O-IN signal, outputs a D-BUSY signal, and starts the document transport operation again. That is, first, the stopper solenoid 93 is turned on to lower the document stopper 36, and the transport belt 66, the pair of paper discharge reversing rollers 68, and the pair of paper discharge rollers 70 are rotated in the discharge direction, and the document discharge operation is performed. And the second
When the jam switch 72 detects the rear end of the document D, the document stopper 36 is raised. Next, a predetermined time delay from the timing of rotating the transport belt 66 in the transport direction,
Is performed to feed the second original D to the conveyor belt 66. In the subsequent operations, the operations from (1) to the above are repeated.

When the document D on the paper feed tray 44 runs out, the empty switch 52 is turned off, and the sub-processor 82 turns off the O-RDY signal (there is no document). As a result, the sub-processor 82 performs only the operation of discharging the final document after the copying operation of the final document in the copying machine body 1, but does not perform the advance operation. After finishing the copying operation of the last original, the main processor 81 turns off the D-RUN signal and ends the operation in the one-sided original mode.

Next, the operation in the double-sided document mode will be described. 1
Until the sheet D is conveyed to the document stopper 36, the operation is the same as in the one-sided original mode.

(2) When the document D is stopped by the document stopper 36, after a certain period of time, the gate solenoid 99 is turned on to switch the gate guide 74 to the reversing section 42 side, drive the reversing roller pair 56, 57, 58, and further transport. By reversely rotating the motor 98, the transport belt 66 is rotated in a direction opposite to the transport direction. As a result, the original D on the original platen 5 is sent backward and sent to the pair of reversing rollers 56 via the gate guide 74, where the reversing switch 61
Is turned on, passes through the pair of reversing rollers 57 and 58, and is stopped at the reversal stop position 60. The stop timing is a certain time after the leading edge of the document D turns on the reversing switch 61.

At the same time when the document D is stopped at the reversal stop position 60, the gate solenoid 99 is turned off to make the gate guide 74 horizontal, the transport belt 66 is rotated again in the transport direction, and after a certain period of time, the reverse roller pair 56, 57, 58 Drive. As a result, the original D is moved to the original stopper 36 in the same manner as in the single-sided original mode.
And the conveyor belt 66 is stopped. After a certain period of time, the main processor 81 starts the copying operation of the copying machine body 1. After the copying operation is completed, the sub-processor 82 receives the O-IN signal and outputs
-Output the BUSY signal. Next, the operation after (2) is repeated again. Then, similarly to the one-sided original mode, the original discharging operation → the original advance operation → the conveyance to the original stopper 36 are executed.

From this point, the operations from (2) to the above are repeatedly executed, and when the original D on the paper feed tray 44 is exhausted, only the original discharge operation is performed after the end of the copying operation of the final original as in the one-sided original mode. No advance operation is performed. After the second copy operation of the last original is completed, the main processor 81 turns off the D-RUN signal and ends the operation in the duplex original mode.

Next, abnormality detection when an abnormality occurs during the operation of the document feeder 2 will be described. When the following phenomenon occurs, the sub-processor 82 determines that there is an abnormality, outputs a D-JAM signal to the main processor 81, and turns off the sheet feeding solenoid 96, the sheet feeding mode 97, the transport motor 98, and the gate solenoid 99. .

A. During the supply operation, the first
Jam switch 53 does not turn on.

B. During the feeding operation, the leading edge of the document D does not reach the post-registration switch 55 from the pair of registration rollers 48 within a predetermined time.

C. During the supply operation, the rear end of the document D does not pass through the post-registration switch 55 within a predetermined time after the post-registration switch 55 is turned on.

D. After the advance operation is completed, the post-registration switch 55 is not turned on within a predetermined time after the supply is started from the advance position 51 by the O-IN signal.

E. The conveyance of the document D is started from the feed roller pair 49, and the post-registration switch 55 is not turned off when the conveyance to the document stopper 36 is completed.

F. During the discharging operation, the second jam switch 72 does not turn on within a certain period of time after turning on the transport motor 98.

G. During the discharging operation, the second jam switch 72 does not turn off after a certain period of time after the second jam switch 72 turns on.

H. At the time of the reversing operation, the reversing switch 61 does not turn on within a certain time after the conveying motor 98 is turned on in order to convey the document D at the exposure position to the reversing unit 42.

I. During the inversion operation, the post-registration switch 55 does not turn on within a certain time after the inversion switch 61 turns on.

J. During the feeding and discharging operation of the advanced original D, the second jam switch 72 does not turn on within a predetermined time after the post-registration switch 55 turns on.

K. No clock pulse is output from the first and second pulse generators 104 and 105 even after a certain period of time when the paper feed motor 97 and the transport motor 98 are started.

L. During the transport operation (when the D-BUSY signal is on), the cover switch 63 and the set switch 73 were turned off (the transport unit 43 and the reversing unit cover 62 were opened).

The document jams A to K can be cleared by opening the transport unit 43 and the reversing unit cover 62, removing the cause of the jam (such as a misfeed document), and then re-conveying the transport unit 43 and the reversing unit cover 62.
This is done by closing. That is, when the cover switch 63 and the set switch 73 change from off to on, D
-The JAM signal is turned off (cleared).

If the stop key is pressed while the copying machine main body 1 is executing the copying operation, the copying machine main body 1 completes the copying operation of the original D at that time, and then waits until the copying key is pressed again. (If there is a subsequent document D before this, the document feeder 2 is performing the advance operation even during the copying operation of the copying machine main body 1. In this case, the original is normally transported to the advance position 51, It is assumed that there is no jam switch in the reversing unit 41, the reversing unit 42, and the conveying unit 43.) At this time, the remaining portions of the document D are divided into the following three parts.

a. Exposure position (position where document D is stopped by document stopper 36), advance position 51 and paper feed tray 44 b. Exposure position and advance position 51 c. Only exposure position When copying machine main body 1 is in the standby state described above. Document transport device 2
Are also in a standby state until an O-IN signal or an O-OUT signal is sent from the copying machine body 1. When the copy key is pressed again in the standby state, if the remaining portion of the original D is a or b, the O-RDY signal is on, so that the copying machine main unit 1 outputs the O-IN signal to feed the original. The apparatus 2 performs a document supply operation. When the remaining portion of the original D is c, the O-RD
Since the Y signal is off, the O-OUT signal is output, and the document feeder 2 performs only the document discharging operation.

When the transport unit 43 and the reversing unit cover 62 are opened in the standby state, the set switch 73 and the cover switch 63 are turned off, and when the transport unit 43 and the reversing unit cover 62 are closed, they are turned on. 82 performs a jam check. It is the post-registration switch 55, the reversing switch 61, and the second jam switch 72 that are arranged downstream of the advance position 51 that determine that the jam has occurred in the ON state by the jam detection switch. The reason why the jam is not determined even in the ON state is that the empty switch 52, the first jam switch 53, and the size switch disposed upstream of the advance position 51 are provided.
54. This is to detect the original document and the original document remaining in the paper feed tray 44, and determine the transport restart position when the copy key is turned on again based on the on / off state of these documents. When only the empty switch 52 is ON, the sheet is conveyed from the paper feed tray 44, and when the size switch 54 is ON, the sheet is conveyed from the advance position 51. Note that a document discharging operation is always performed before these conveyances.

If the result of the jam check indicates that the copy key is turned on again, the sub-processor 82 checks the state of the first jam switch 53 (checks whether or not there is a first original), and turns off (first output). If there is no original, the feed roller pair 49 is turned on for a certain period of time. Thereafter, the sub-processor 82 checks the state of the first jam switch 53 again. If it is off, it checks the state of the empty switch 52, and if it is on, it carries the paper from the paper feed tray 44.
As a result of the re-check of the first jam switch 53, if the switch is on, the sub-processor 82 regards the presence of a document, and checks the state of the size switch 54. Transfer from the position where it was shifted). When carrying from the position of the advance position 51 plus α, the carry amount to the document stopper 36 is a value obtained by subtracting “+ α”. Further, the double check of the first jam switch 53 makes it possible to detect, for example, a perforated document.

If the result of the first check of the first jam switch 53 is on, the sub-processor 82 considers that there is an advanced document, and checks the state of the size switch 54. If it is on, the sub-processor 82 conveys from the advance position 51.

As described above, when the conveyance is restarted after the copy operation is interrupted, the state of the first jam switch 53 is used to detect whether or not the original is located at the advance position 51, and when the presence of the original is detected, the original from the advance position 51 is detected. The feed roller pair 49 is supplied, and when it detects that there is no document, the feed roller pair 49 is driven for a certain period of time.
Again, the state of the first jam switch 53 is used to detect whether or not there is a document at the advance position 51, and when the absence of a document is detected, the supply of the document from the paper feed tray 44 is selected. This selects the supply of the original from the advance position 51.

Thus, in the standby state after the copying operation is interrupted, even if the transport section 43 and the reversing section cover 62 are opened and closed while the original is intact, the original is still correctly set in the advance position 51 or the paper feed tray 44. In this case, the jam state is not set, and even if the copy operation is started again, the original sheet conveyance operation can be continued from that state (conveyance restart is possible). Therefore, for example, the trouble of setting the original at the advance position 51 on the paper feed tray 44 again is eliminated, and the operation time is saved. In addition, the double-checking of the first jam switch 53 enables accurate detection of the advanced document, and the accurate determination of the transport restart position (the advanced position 51 or the paper feed tray 44) is expected to reduce the transport jam. it can.

In the above-described embodiment, the description has been made by taking the document conveying device provided in the electronic copying machine as an example, but the present invention is not limited to this. For example, in an electric printer or a printing machine, a document is placed on a document table. The present invention is also applicable to a document feeder that automatically feeds a document to a predetermined position.

[Effects of the Invention] As described in detail above, according to the present invention, in a standby state after a copy operation is interrupted, jamming is performed as long as the original is correctly set even if the original is opened and closed as it is. It is possible to restart the conveyance from that state without changing the state, so that the trouble of resetting the original can be eliminated, and a document conveying apparatus that can save labor in operation can be provided.

[Brief description of the drawings]

1 is a flowchart for explaining an operation of the present invention, FIG. 2 is a block diagram showing an overall control system, and FIG. FIG. 4 is a vertical sectional front view showing a schematic configuration of an electronic copying machine having a document feeder. DESCRIPTION OF SYMBOLS 1 ... Copier main body, 2 ... Document conveying device, 5 ... Document table, 36 ... Document stopper, D ... Document, 41 ... Supply unit,
42 ... Reversing unit, 43 ... Conveying unit, 44 ... Paper feeding tray (document receiving unit), 46 ... Paper feeding roller (sending roller), 49 ... Feed roller pair (supply roller), 51 ... Advance Position, 53 ...
... First jam switch, 81 ... Main processor, 82 ...
... sub processor.

Claims (1)

(57) [Claims] A pickup roller for taking out and transporting the originals set in the original receiving unit one by one, and a registration roller for further transporting the original taken out by the pickup roller after aligning the leading end in the transport direction; A feed roller for receiving and further transporting the document transported by the registration roller; a transport belt for receiving the document transported by the feed roller and transporting the document to a predetermined position on a document table; When in the predetermined position above, the document following the preceding document is positioned between the feed roller and the registration roller in a document conveyance path formed by the pickup roller, the registration roller, the feed roller, and the conveyance belt. The pickup roller and the registration roller are moved so as to wait at the advance position. Advancing means for controlling; a plurality of sensors provided along the document transport path to detect the presence or absence of a document in the document transport path; and a plurality of sensors in the document transport path with reference to respective detection results of the plurality of sensors. Jam detection means for detecting a document jam in the document feeder, when the jam detection means detects a document jam in the document feed path, stops driving of the pickup roller, registration roller, feed roller and feed belt. Stopping means for stopping document conveyance by means of the first and second sensors, and after the document jam detected by the jam detecting means is released, each output of the plurality of sensors is instructed by the stopping means when conveyance of the stopped document is instructed. See
When a sensor disposed upstream of the advance position in the document transport path among the plurality of sensors has detected the presence of an original, the advance detection is performed without causing the jam detection unit to detect an original jam. Driving the rollers and the conveyance belt to convey the document waiting at the position to the predetermined position, and among the plurality of sensors, a sensor disposed downstream of the advance position in the document conveyance path. When the presence of a document is detected, a control means for causing the jam detection means to detect a document jam and prohibiting the driving of the rollers and the conveyance belt is provided.