JP2001139169A - Automatic document feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic document feeder preventing the transport accuracy from lowering when a document is a small size, avoiding the unnecessary high-speed transport, and reducing the noise. SOLUTION: This automatic document feeder is provided with a paper feed part detecting the size of the document stacked on a document load means and feeding the paper sheet to an image readout part, a paper transport delivery part stopping the fed document at the image readout part, transporting it again after the readout of the image, and delivering the paper sheet, and a control means actuating and controlling the paper transport delivery part and the paper feed part. The control means can set the transport speed at least between a general transport speed V1 and a transport speed V2 slower than the general speed and, when the detected document size is smaller than a specific size, and when the transport order of the document is the first or it is a mixed stack mode, the continuous paper feed is possible at the transport speed V2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic document feeder mounted on a copying machine, a facsimile, a scanner, and the like, and more particularly, to a technique for controlling a document conveying speed.

[0002]

2. Description of the Related Art An automatic document feeder mounted on an image forming apparatus such as a copying machine can exhibit 100% of the capacity of the image forming apparatus unless the document exchange operation can follow the continuous copying speed of the copying machine. Can not do. For this reason, conventionally,
With an emphasis on shortening the document exchange time, the transport speed of the automatic document feeder has been set to be very high.
In addition, the separation operation from separation of the stacked originals one by one to sending to a pull-out roller is performed at a low speed commensurate with the separation in order to improve the separability of the originals, and then the paper is conveyed at a high speed. It is common. Therefore, as the speed of the automatic document feeder increases, the difference between the separation speed and the transport speed increases.

[0003]

However, due to the effect of increasing the transport speed, not only the problem of noise but also a problem that the transport accuracy of the original is reduced in some cases has occurred. In particular, when a document is skewed by separation in an apparatus having a large difference between the separation speed and the conveyance speed, the skew tends to increase as the subsequent conveyance speed increases. This is more remarkable as the document size is smaller.

FIG. 55 shows how the skew of a small-size document is increased. As shown in the drawing, for example, when a small-size document P such as B6 size is slightly skewed when separated, the separation operation ends when the leading end of the document P reaches the pull-out roller 8. After the separation, the width of the document P is small, so that a plurality of transport rollers 8a constituting the pull-out roller 8 are applied to only about half the width of the document P, and only one side in the traveling direction is strongly driven. For this reason, when the separation is completed and the sheet is pulled by the pull-out roller 8 and fed at a high speed, a rotational force acts as shown by an arrow, thereby increasing the skew.

In a mixed document mode in which originals of different sizes are set at the same time and copying is performed, the main body of the copier adjusts a paper feed tray or the like in accordance with the original size detected each time each original is fed. Perform the control to change and copy. For this reason, the copy productivity becomes lower than the normal copy processing speed, so that in this mixed mode, there is no need to convey the second and subsequent sheets at a high speed. It is desirable to work.

Further, when performing double-sided copying, generally, the transfer paper set in the double-sided tray of the copying machine body is re-fed after the front side copying, and the back side copying is performed. Due to the time required for this refeeding operation, there is no need to transport the document at a high reverse speed when reversing the document as in the case of feeding and transporting. It is desirable to aim at.

Accordingly, the present invention has been made in view of the above circumstances, and an object of the present invention is to prevent a reduction in conveyance accuracy when a document is small in size and to avoid unnecessary high-speed conveyance to reduce noise. An object of the present invention is to provide an automatic document feeder capable of performing possible transport control.

[0008]

In order to achieve the above object, an automatic document feeder according to the present invention detects a document stacked on document placing means, separates the documents one by one, and sends the separated documents to an image reading section. A paper feed unit for feeding paper, a paper discharge unit for stopping the document fed from the paper feed unit to the image reading unit, re-transporting and discharging the image after reading the image, the transport paper discharge unit and the paper feed And a control means for controlling the driving of the image forming section and setting two or more document feeding speeds having different speeds so that these can be arbitrarily switched. The document size is detected based on a detection signal sent from the copy unit, and when the detected document size is a specific size, the document is continuously fed at a lower transport speed.

The control means according to the present invention may be configured so that the specific size is equal to or smaller than a predetermined size.

The control means specifies the document feed order based on a detection signal of a document setting operation sent from a paper feeding unit, and switches the transport speed of the second and subsequent sheets to either low speed or high speed. It is possible that, when the size of the first document is the specific size, it is desirable to set the transport speed of the second and subsequent documents to a low speed.

It is preferable that the control means sets a slower transport speed when it determines that the document on the document placing means is in the mixed loading mode including two or more sizes.

Further, the control means may be configured to set the low transport speed set for the second and subsequent sheets to the same speed as the transport speed of the first sheet.

In the double-sided mode, the transport / discharge unit has a reversing discharge unit capable of reversing and transporting the original of the image reading unit. It is desirable that the configuration be set to.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. First, an outline of an automatic document feeder according to an embodiment of the present invention will be described. FIG. 1 shows the overall configuration of the automatic document feeder 1 according to the present embodiment. FIG. 2 is a control block diagram of the automatic document feeder 1 of the present embodiment.

As shown in FIG. 1, this automatic document feeder 1 is installed on an image recording apparatus such as a copying machine main body. The left side in the figure is a paper feeder, the center is a document feeder, and the right is a document invertor. It is the paper discharge section. The transport discharge unit referred to in the present application is a transport unit,
And a reversing sheet discharging unit.

As shown in FIG. 2, a main control unit for controlling the conveyance of the automatic document feeder is a microcomputer including a single-chip CPU including an input / output function and a memory. It executes a program stored in a ROM or the like. An interface (I / F) between the CPU and the copying machine exchanges signals with a serial interface. As shown in the figure, the load controlled by the CPU is a roller lift motor M
5, two stepping motors used as a bottom plate raising motor M4, three DC servo motors used as a sheet feeding motor M1, a conveying motor M2, and a sheet discharging motor M3,
There is one electromagnetic clutch means including a separation clutch, two solenoids for driving the discharge switching claw 18 and two solenoids for driving the discharge inversion switching claw 22. The output of each sensor such as the paper feed roller position sensor 6, the pull-out sensor 9, the registration sensor 11, the paper discharge entrance sensor 16 and the reversing sensor 20 is taken into the CPU. The transport control is performed according to the operation command.

In the apparatus of this embodiment, as independent driving means driven and controlled by the CPU, a paper feeding motor M1 for driving a paper feeding section and a transport motor M for driving a transporting section are provided.
2. It has a discharge motor M3 for driving the reverse discharge section. The feed motor M1 drives the pickup roller 5, the feed belt 7, the reverse roller 26, and the pull-out roller 8, the transport motor M2 drives the transport belt 14, and
The paper discharge motor M3 drives the paper discharge unit entrance roller 17, the single-sided paper discharge roller 18, and the double-sided paper discharge roller 23.
Hereinafter, the configuration and operation of the apparatus will be described in detail with reference to FIGS.

The automatic document feeder 1 has a one-sided paper discharge tray 4 attached to the right side of the main body of the copying machine in FIG. 1 and a two-sided paper discharge provided below a document table 29 as a document placing means. It has two discharge trays including a tray 3. The single-sided discharge tray 4 is a discharge tray used in a single-sided discharge mode for copying one side of a document, and the double-sided discharge tray 3 is a discharge tray used in a double-sided discharge mode for copying both sides of a document. . The original before copying is set on an original table 29 including the bottom plate 2 with its original surface facing upward. When the original bundle is set on the original table 29, the original set filler 27 is pushed by the leading end of the original and separated from the original set sensor 28, which is an optical interrupter, to detect the setting state of the original.

The bottom plate 2 is rotatably supported about a rotation fulcrum 30, and its rotation position is controlled by a bottom plate lifting motor M4. In this way, the originals stacked on the original table 29 are driven and controlled such that the leading end of the bundle placed on the bottom plate 2 moves up and down. Pickup roller 5 is a roller lift motor M
When the original is not set by the lever driven by the rotation of the cam 5, the original is lifted in the ascending direction.

When a document is set on the bottom plate 2 and a copy start button of a copying machine main body (not shown) is pressed, the lifting force of the pickup roller 5 is released by the roller lifting motor M5, and the weight of the pickup roller 5 is released. The pickup roller 5 descends. Next, the bottom plate 2 is raised by the drive of the bottom plate raising motor M4, and the pickup roller 5 is pushed by the upper surface of the document and lifted again. At this time, the height of the pickup roller 5 is detected by a sheet feeding roller position sensor 6 which is a means for detecting an appropriate sheet feeding position, and the position of the bottom plate 2 is determined. That is, when the top sheet height of the document bundle is detected via the sheet feed roller position sensor 6 and the bottom plate raising motor M4 is stopped and controlled by this detection signal, the top document is conveyed to the sheet feeding port. Is determined.

In a state where the pickup roller 5 is lifted on the original surface, the pickup roller 5 is driven to rotate by the sheet feeding motor M1. This rotation direction is the paper feed direction in which the uppermost document moves, and the paper feed belt 7 is similarly driven in the forward direction. The paper feed belt 7 and the reverse roller 26 are configured such that the drive of the paper feed motor M1 is transmitted to each of the paper feed belt 7 and the separation clutch formed by an electromagnetic clutch. Among them, the reverse roller 26 is driven to rotate in the direction opposite to the sheet feeding by the sheet feeding motor M1 and performs a separating operation. That is, even if the original located below the uppermost original is sent along with the uppermost original, this is reversed by the reverse roller 26 so that only the uppermost original is fed. A pull-out roller 8 is a relay roller that transports the document separated by the paper feed belt 7 to the transport roller 10.

When the pull-out sensor 9 detects the leading end of the document, the power to the separation clutch is turned off to terminate the separation operation, and the document is conveyed onto the contact glass 15 via the conveyance roller 10. OFF of this separation clutch
As a result, the drive to the pickup roller 5 and the paper feed belt 7 is not transmitted, and the roller is rotated in the document transport direction, and the reverse roller 26 is driven in the direction opposite to the transport direction.
At this time, the pickup roller 5 is driven by a roller lift motor M.
Since the document is conveyed by the pull-out roller 8 and the conveyance roller 10, it is possible to prevent the pickup roller 5 from separating the next document one after another.

The registration sensor 11 is an optical reflection type sensor for detecting a document conveyed by the conveyance roller 10, and serves as a timing sensor for stopping the document on the contact glass 15.

In the paper feeder having the above-described configuration, a detection signal for specifying the size of the original is taken out by the following means. If you want to detect the original size when feeding the original,
A pull-out sensor 9 composed of an optical reflective sensor detects the original conveyed by the pull-out roller 8 and reads the leading and trailing end positions of the original. That is, the document is being passed (when the pull-out sensor 9 is ON).
Then, an output pulse from an encoder sensor (not shown) for detecting the rotation of the driven roller of the pull-out roller 8 is measured, and the measured value is taken into the CPU and converted into a distance based on the speed data. Thus, the length of the document can be detected. In the following description of the control flow, a method of setting a size detection start flag during the paper feeding operation shown in FIG. 14 and performing the above-described detection operation is described.

As another detection method at the time of feeding the paper, the encoder pulse is measured during the period from when the registration sensor 11 is turned on to when the pull-out sensor 9 is turned off. May be added to the transport span between the sensors to detect the length of the document.

The present invention is not limited to the case where the original is detected at the time of conveyance, and is supplied by a plurality of original sensor groups arranged on the original table 29 so as to vary the combination of the detection signals according to the original size. It is also possible to detect the size of the original before the paper. As described above, if the size can be determined while the original is placed, good conveyance control based on the original size can be performed for the first sheet feeding speed.

The transport belt 14 of the document transport section is driven by a driving roller.
An endless belt made of rubber, cloth, or the like is wound between the roller 13 and a plurality of stretching rollers. When the drive roller 13 is driven by the transfer motor M2, the transfer belt 14 wound therearound is rotated. Configuration. The transport belt 14 is positioned so as to be substantially in contact with the original scale 12 and the contact glass 15 of the image reading unit, and the original fed between the contact glass 15 and the transport belt 14 is formed of the contact glass 15 and the transport belt 14. Due to the difference in friction coefficient between them, they move in accordance with the rotation of the transport belt 14 and are transported on the contact glass 15.

The end of the original scale 12 is slightly higher than the upper surface of the contact glass 15 and is set with the end of the original abutting against the end of the original scale 12, so that an image with a registered registration can be read. Can be.
This abutment of the document is performed by reversing the transport belt 14 after passing through the document scale 12 once. If the original is skewed by this abutment, skew correction is also performed.

Inside the image reading section composed of a scanner unit, there is a scanner 25 which moves under the contact glass 15 and scans the original, and a scanning line from the scanner 25 is detected by an optical element such as a CCD (not shown). It is configured to read image data. The scanner 25 is driven by a scanner motor (not shown) located in the copying apparatus, and performs scanning and horizontal movement of a document.

On the opposite side of the paper feed unit with respect to the transport belt 14 of the transport unit, a paper discharge unit entrance roller 17, a single-side paper discharge roller 18, and a double-side paper discharge roller 23 There is a reversing sheet discharge unit provided with. These rollers are driven by the same discharge motor M3. In this transport path, there are a paper discharge unit entrance sensor 16 and a reversing sensor 20, and at a branch point of the transport path, there are a paper discharge switching claw 19 and a paper discharge inversion switching claw 22. A paper discharge unit entrance sensor 16 composed of an optical reflection type sensor is used as a trigger for switching control of the paper discharge switching claw 19 during document reversal and double-sided paper discharge, and control of a paper discharge reversal switching claw 22 during double-sided paper discharge. Used as a trigger or the like.

To discharge a single-sided original for reading a single-sided image, the discharge switching claw 19 is rotated clockwise to the discharge direction, and the discharge section entrance roller 17 and the single-side discharge roller 1 are rotated.
8 is guided in a direction to be discharged onto the single-sided paper discharge tray 4.

In the case of reversing and conveying a double-sided document on which reading of an image on the front side has been completed in the double-sided mode, the discharge switching claw 19 is rotated counterclockwise by the discharge reversal switching solenoid to switch to the reversing direction. In this state, the original is discharged from the discharge unit entrance roller 1.
The sheet 7 is conveyed while being guided in the reverse direction, and is returned onto the contact glass 15 again. If the double-sided document is discharged to the single-sided paper discharge tray 4 after reading the back side, the page order of the document bundle is reversed and the usability is deteriorated. At this time, the two-sided original
9 is rotated in the reverse direction, and the paper discharge reversal switching claw 22 is rotated clockwise to switch to the paper discharge direction, and the paper is discharged to the double-sided paper discharge tray 3.

Next, the conveyance control performed by the automatic document feeder having the above configuration will be described. FIGS. 3 and 4 are timing charts in the single-sided copy mode, and FIGS. 5 and 6 are timing charts in the double-sided copy mode. Also, FIGS. 7 to 43 and FIG.
5 to 54 are flowcharts for explaining the control of this embodiment. FIG. 44 is a schematic diagram showing the transport path length at the time of reversing. Hereinafter, the transport control of this embodiment will be described in detail with reference to the drawings. The control of the automatic document feeder is performed by calling each subroutine in the main routine. Note that the description of the main routine that controls the entire apparatus is made up of the description of the configuration and operation described above and FIGS.
The illustration is omitted as a substitute for the timing chart of FIG. 6, and a description will be given focusing on a subroutine relating to the features of the present invention.

FIG. 7 is a flow chart of the control processing for setting the transport speed. This subroutine is a process for setting speed data V used as a transport speed after separation under predetermined conditions. The speed data V is the transport speed after separation, that is, as shown in the charts of FIGS. 3 to 6, the paper feed transport of the paper feed motor M1, the forward rotation transport of the transport motor M2, and the paper discharge of the paper discharge motor M3. This is the speed set for transport. Here, the normal transport speed is set to V1, and the slower speed is set to V1.
2 and V1> V2.

Specifically, in FIGS. 3 and 4 showing the one-sided mode, the separation speed of the original is the same under all conditions and a low speed suitable for the separation performance is set. The paper speeds are all the same and V2. Either V1 or V2 is selected as the paper feed and discharge speed for the second and subsequent sheets according to the conditions shown in FIG. 7 (V2 is indicated by a broken line).

In FIGS. 5 and 6 showing the duplex mode, the relationship between the speeds when the front side is fed is as follows.
This is the same as the one-sided mode. In this embodiment, speed data V3 is used as the speed at which the document is reversed.
The speed data V3 is lower than V1 and can be set within a range that does not reduce the productivity of the copying system. Therefore, if there is no particular problem, V3 may be set equal to V2. If at least V1> V3, the noise at the time of reverse conveyance can be reduced.

In the subroutine of FIG. 7, it is first determined whether or not a first sheet flag indicating that the sheet feeding order is the first sheet is set (S101-1). If YES, the sheet feeding motor M1 is determined. The speed data V for driving the transport motor M2 and the discharge motor M3 is set to a speed V2 lower than the normal transport speed (S101-4 to S101-6). The first sheet flag is set in a sheet preparation subroutine (FIG. 8) described later.
), And is cleared once the sheet feeding operation is performed in the sheet feeding JOB routine (see FIG. 18).

Furthermore, setting the slow speed V2 only for the transport speed of the first sheet is based on the document size signal from the automatic copy document feeder for the first page and the set copy mode (magnification, presence or absence of staples, etc.). ), A paper feed tray is selected and various settings are made. Therefore, after the first document is set on the contact glass 15, there is a waiting time in comparison with the second and subsequent sheets until an image is scanned,
It is not necessary to transport the first document at a high speed. Therefore, in the present embodiment, the first sheet is always conveyed at a low speed to reduce noise.

If the first sheet flag is not set in S101-1, it is determined whether or not the small size flag is set (S101-2).
As in the case of setting the first sheet flag, the speed is set to a speed V2 that is slower than the normal conveyance speed (S101-4 to S101-).
6). This small size flag is set when the document size data is equal to or smaller than a predetermined size (B6 size in this embodiment) during a feeding JOB routine described later (see FIG. 18).

In this embodiment, since the size of the original is detected at the time of transporting the first sheet, the small size flag is not set at the time of transporting the first sheet.
The sheet feeding speed of the sheet has time to be set for various setting processes such as a sheet feeding tray selection process, so it is preferable that the sheet feeding speed is set to be lower in the first place. There is no particular problem. of course,
It is also possible to change the speed data from the first sheet. In this case, as described above, for example, a configuration including a plurality of document sensors arranged on the document table 29 or a configuration in which the user inputs a document size may be used, and the size of the placed document may be detected in advance. .

If the small size flag is not set in S101-2, it is determined whether or not the mode is the mixed mode (S10).
101-3). This mixed loading mode is performed, for example, when a selection key of the mixed loading mode is pressed on an operation unit (not shown).
This is based on a control signal sent from the copying machine body.
That is, usually, the "document set"
When the user presses the print key of the copier after sending the signal of (1) to the copier main unit, the signal of the “mixed mode” specified when setting the original of different size か ら from the copier and copying is transmitted. Will be. Such a mixed mode signal is not sent in the normal copy mode.

As described above, S101-1 to S1 in FIG.
If NO in all of 01-3, it is determined that there is no adverse effect such as a decrease in transport accuracy even when driving at high speed V1, and the normal transport speed V1 is set as speed data V for all transport speeds. (S101-7 to S10
1-9).

FIG. 8 is a flowchart of the paper feed preparation control. When the document set filler 27 is pressed at the leading edge of the document and the document set sensor 28 is turned on, the setting state of the document is detected,
On the condition that the "document set" has not been transmitted, the "document set" is transmitted to the main body control unit of the copier after a predetermined time (500 sec in the present apparatus) by a timer counter called a set timer counter (S102-1 to S102). −
4). A first sheet flag for indicating the order of the "first sheet" to be fed for the first time after entering the original set state after transmitting the "original set" is set (S102).
-5).

The set timer counter is incremented every predetermined time in a timer interrupt routine inside the CPU, and the time after the document set sensor 28 is turned on is checked. Here, the counting of 500 sec is performed when the “document set” is transmitted immediately after the document is set, and the document conveyance command comes immediately after this,
Even if the original is not set properly, the user's usability deteriorates when paper feeding starts.
If NO in S102-1, the flag called the set sensor edge flag is set, the set timer counter is cleared, and the original is not set (S102-9 to S102-9).
S102-11).

The set sensor edge flag detects an edge when the document set sensor 28 changes from the OFF state to the ON state. That is, the document set sensor 28
When the set sensor edge flag is set by turning OFF the flag, the process proceeds to the appropriate position processing of the subsequent document (S
102-6). In this process, it is confirmed that the pickup roller 5 has been lowered (S102-7, 8), and the roller is raised by the bottom plate raising motor M4 (S102-12, S102-12).
13). Raise bottom plate 2 and feed roller position sensor 6 turns ON
At this point, the bottom plate lifting motor M4 is stopped (S102).
-14, 15), the document is set at a position where paper can be fed.
In this process, the set sensor edge flag is cleared (S102-16). Thereafter, a command signal "next document set" for causing the apparatus to set a document on the contact glass 15 is sent from the copying machine body.

As shown in FIG. 9, in the next original set start subroutine, when "next original set" is received, it is determined whether or not the original is stopped on the contact glass 15 (S103-1). When the original is stopped (the previous original is set on the contact glass 15), the previous original is discharged. However, since the information of the paper discharge tray is sent from the copying machine in advance, According to this, it is possible to change the paper discharge control described later.

In FIG. 9, when the paper is to be discharged to the single-sided paper discharge tray 4, YES is determined in S103-3, and one of the two job counters, one of the single-sided paper discharge JOB2 and the one-sided paper discharge JOB2, is operated. When the one-sided discharge job 1 is 0 (YES), 1 is set to the one-sided discharge job 1 and the one-sided discharge job 1 is set.
Is used (S103-4, 5). Here is the single-sided output job
If 1 is not 0 (NO), it means that the document two pages before is being discharged, so 1 is set to one-sided discharge JOB2, which is another JOB counter, and this one-sided discharge JOB2 is used (S103). -4, 6). Then, the “document stopped flag”
Is cleared (S103-7), the sheet feeding job of the job counter for advancing the sheet feeding job is set to 1 (S103-8), and the next document set reception flag indicating the reception state of the next document set is cleared (S103). -9) Exit from this subroutine.
It should be noted that the subroutine of the single-sided discharge job JOB1 and the single-sided discharge JOB2 is a routine for performing the same control except for using separate job counters.

On the other hand, when the paper is discharged to the two-sided paper discharge tray 3 in the two-sided copy mode, the two-sided paper discharge JOB is operated.
“1” is set to the double-sided discharge job, which is a double-sided discharge job counter (S103-10). Thereafter, the document suspension flag is cleared (S103-11), and the paper feed standby flag is set (S103-12). In the duplex mode, the paper feed standby flag is used to delay the next paper feed until the previous document enters the drive system of the discharge motor M3 to prevent two documents from being lined up on the contact glass 15. This is a flag. This flag is cleared in the double-sided discharge job 3 (see FIG. 51). That is, in the two-sided copy mode, the fed document is turned over next, but in order to prevent the problem that the previous document will be turned over during ejection, The job counter is not set (S103-13).

FIGS. 10 to 18 are flow charts of the sheet feeding operation control. As shown in FIG. 10, the control of the sheet feeding job proceeds according to the value of the sheet feeding job counter. Paper feed JO
When B is 0, nothing is performed and a return (RTE) is made (FIG. 11). When 1 is set in the paper feed JOB in the above-described next original set start subroutine, the process proceeds to paper feed JOB 1 (FIG. 12), and it is first checked whether the advance original is already set (S106-1). If the first original is set, the process jumps to A of the sheet feeding job 4 (FIG. 14) (S106-2). When the first original is not set, the separation clutch for transmitting the drive of the paper feed motor M1 to the pickup roller 5 and the paper feed belt 7 is turned on in order to separately feed the original on the document table 29 (S106-).
3). At the same time, after setting 0 in the start timer counter, 2 is set in the paper feed JOB and the process exits (S106-
5).

When the feed job counter is 2, feed job 2
Proceed to (FIG. 13) and the start timer counter is set to 40 seconds.
If it is larger, the paper feed motor M1 is driven at a low speed corresponding to the separation speed (S107-1, 2), and 3 is set in the paper feed JOB (S107-3). The reason for setting the delay time in the start timer counter in this way is to allow for the time during which the separation clutch is engaged.

When the feed job counter is 3, the feed job 3
The process proceeds to (FIG. 14), and waits for the document to reach the pull-out sensor 9 (S108-1). If the paper does not arrive within the predetermined time, the paper is determined to be a paper jam in the JAM detection processing (S10).
8-2). When the pull-out sensor 9 is turned on within a predetermined time, the roller raising motor is driven to rise (S108-3),
The pickup roller 5 is lifted and separated from the upper surface of the document, and the separation clutch is turned off so that the next document is not conveyed (S108-4). Thereafter, a size detection start flag for starting the subroutine for detecting the document size is set (S108-5), the start timer counter is set to 0, and the paper feed JOB is set to 4 (S108-6). 7). Note that the document size detection subroutine started by the size detection start flag is omitted, but for the means of size detection, refer to the above description.

When the feed job counter is 4, the flow advances to feed job 4 (FIG. 15), and when the start timer counter is longer than 40 seconds (S109-1), or the advance original has been set (FIG. 12, S106-1). When the paper feed motor M1 is separated from the low speed at the time of separation,
The drive is switched to the drive using the speed data V set in (see S109-2). Almost simultaneously with this, the transport motor M
2 is also driven in the normal rotation direction (the flow direction of the original) at the speed V (S109-3). Thus, the pull-out roller 8,
The document feed and transport based on the speed data V are performed by the transport rollers 10 and the transport belt 14. After starting the drive, feed JOB
Is set to 5 and the process exits (S109-4). In this flow, in the apparatus according to the present embodiment, the speed V is set to V2 when the first sheet flag is set (see the flow of FIG. 7), so that at least when the first document is conveyed, the speed V2 is low. On the other hand, the conveyance speed of the second and subsequent sheets is different from that of the first sheet based on other conditions, such as “small size” and “mixing mode” as in this example. One of the same low speed V2 and high speed V2 can be selected.

When the paper feed job counter is 5, the flow advances to paper feed job 5 (FIG. 16), and waits for the document to reach the registration sensor 11 (S110-1). Registration sensor 1 at a predetermined time
If 1 is not ON, it is determined that a jam has occurred in the JAM detection process (S110-2). When the registration sensor 11 is turned on, 6 is set in the sheet feeding job and the process exits (S110-
3).

When the feed job counter is 6, the feed job 6
The process proceeds to (FIG. 17), and waits for the document to pass through the registration sensor 11 (S111-1). If the registration sensor 11 is not turned off within a predetermined time, it is determined that a jam has occurred in the JAM detection processing (S111-2). OFF of registration sensor 11
Drives the roller raising motor M5 to lower the pickup roller 5 to the upper surface of the original (S111-3), and prepares for feeding of the next original. At about the same time, the paper feeding motor M1 is stopped (S111-4). The transport motor M2 starts deceleration control for accurately stopping the document at a predetermined position on the contact glass 15 (S111-5). Thereafter, 7 is set in the paper feed JOB and the process exits (S111-6).

Regarding the control for stopping the original, there is a method in which the transport motor M2 is gradually decelerated and stopped at a position where the rear end of the original comes into contact with the original scale 12 on the contact glass 15, and There is a method in which after the edge is once transported to a position away from the original scale 12, the transport motor M2 is rotated in the reverse direction to stop the rear edge of the original while making contact with the original scale 12. If the former method is called a non-colliding method and the latter method is called a collating method, the abutting method is stopped while being in contact with the original scale 12, so that the registration accuracy is good. However,
In the case of a thin original, there is a problem that a wrinkle or the like occurs in the original at the time of abutting. Therefore, in this case, it is preferable that the non-abutting method can be selected. In the present embodiment, as is apparent from the timing charts of FIGS. 3 to 6, the “butting method” in which the sheet feeding operation of the transport motor M2 stops after the reverse rotation.

When the paper feed JOB counter is 7, the flow advances to paper feed JOB 7 (FIG. 18), and waits for the completion of the deceleration stop processing of the transport motor M2. "Document stop signal" (S112-1,
2). After that, the first sheet flag is cleared (S112-
3) Then, the document size detected by the document size detection subroutine is determined (S112-4). Where CP
The original size data read to U is a predetermined size (B6
If it is smaller than (size), the small size flag is set (S1).
12-5) If the document size is other than that, the small size flag is cleared (S112-6). Next, when the advance mode is set, the job to advance the advance control
After setting 1 in the advance job that is the counter,
Is set to 9 and the sheet feeding job is completed (S112).
-7 to 9).

The advance mode in S112-7 is based on information previously sent from the copying machine main body. In the advance mode, the feeding of the previous original is terminated so as to prepare for the next original exchange. At the time, the next document is separated and fed, and is conveyed to the vicinity of the registration sensor 11, thereby shortening the document replacement time. This advance mode is performed while the original is stopped on the contact glass 15 and the scanner 25 is scanned to read the image of the original.

FIGS. 19 to 25 are flow charts for controlling the advance operation of the original. As shown in FIG. 19, the advance job is J
The control proceeds according to the value of the advance job which is the OB counter. When the advance job is 0, the process returns without performing anything (FIG. 20). When 1 is set in the advance job at the end of the paper feed job subroutine (FIG. 18),
The process proceeds to advance job 1 (FIG. 21), and the separation clutch is turned on (S115-1). At the same time, 0 is set in the start timer counter, and 2 is set in the advance job, and the process exits (S115-2, 3).

When the advance job counter is 2, the advance job
Proceed to 2 (FIG. 22) and the start timer counter
If it is larger than c (S116-1), the sheet feeding motor M1 is driven at a low speed corresponding to the separation speed (S116-2), and 3 is set to the first-out job and the process exits (S116-3).

When the advance job counter is 3, the advance job
3 (FIG. 23), and waits for the document to reach the pull-out sensor 9 (S117-1). If it does not arrive within the predetermined time, it is determined that a jam has occurred in the JAM detection processing (S117-
2) If the pull-out sensor 9 is turned on within the time, the roller lifting motor M5 is driven (S117-3), and the pickup roller 5 is raised and lifted away from the upper surface of the document. Almost simultaneously with this, the separation clutch is turned off (S117-4),
Do not transport the next and subsequent documents. Thereafter, the sheet feeding motor M1 is switched from the low speed at the time of separation to the speed data V2, and the document is conveyed by the sheet feeding motor M1 (S11).
7-5). After that, a size detection start flag for starting a subroutine for detecting a document size is set (S117-6), a start timer counter is set to 0 (S117-7), and a 4 is set to the advance job to exit. (S117-8).

When the advance job counter is 4, the advance job
4 (FIG. 24), and waits for the registration sensor 11 to detect a document.
It is determined that a jam has occurred in the detection processing (S118-1,
2). When the registration sensor 11 detects the original, the deceleration stop process of the paper feeding motor M1 is started (S118-3).
5 is set in the advance job and the process exits (S118-4).
The stop control is performed by the deceleration stop process of the sheet feeding motor M1 so that the leading end of the first-out original is located near the original scale 12.

When the advance job counter is 5, advance job 5
Proceeding to FIG. 25, when the deceleration stop process of the paper feeding motor M1 is completed and the paper feeding motor M1 is stopped, an "advance original set signal" is transmitted to the copying machine body (S119-1,
2) The first job is set to 0 (S119-3), and the first job is completed.

After the "document stop signal" is transmitted to the copying machine main body by the above-described paper feed subroutine, the scanner 25 is driven to read the document surface. When the image reading is completed, a "next document set signal" is transmitted from the copying machine body. As described above, the next sheet feeding job and the following sheet discharging job are started by the next original set start subroutine (FIG. 9).

FIG. 26 to FIG. 33 are flow charts of the discharge operation control in the single-sided mode. As shown in FIG. 9, single-sided discharge JO
Although two counters are used as the B counter, since both controls are exactly the same, the single-sided discharge job 1 will be described simply as [single-sided discharge job], and the description of the single-sided discharge job 1 will be omitted. As shown in FIG. 26, this sheet ejection control is also performed on one-sided sheet ejection job
The control proceeds according to the value of the counter. When the single-sided ejection JOB is 0, the process returns without performing anything (FIG. 27).

When 1 is set in the single-sided discharge job in the next original set start subroutine (see FIG. 9), the single-sided discharge J
Proceeding to OB1 (FIG. 28), the transfer motor M2
The driving is started so as to be (S122-1). At the same time, a timing calculation for driving the paper discharge motor M3 is performed using the document size data detected at the time of paper supply (S122-2), and 2 is set in the single-sided paper discharge JOB to exit (S122-3). ).

When the one-sided discharge job counter is 2, the process proceeds to the one-sided discharge job 2 (FIG. 29), and waits for the drive timing of the discharge motor M3 calculated by the one-sided discharge job 1 (S12).
3-1). According to this drive timing, the discharge unit entrance roller 17 must rise at least at the same speed as or higher than the speed of the transport belt 14 before the leading end of the document reaches the discharge unit entrance roller 17. Therefore, the drive timing of the discharge motor M3 is defined as the contact glass 1
The original set at the registration position on the transfer belt 5
After the conveyance is started by step 4, the timing is obtained by subtracting the rise time of the paper discharge unit entrance roller 17 from the predetermined time until the leading edge of the document reaches the paper discharge unit entrance roller 17. Therefore, the drive start timing of the discharge motor M3 that satisfies this differs depending on the length of the document to be conveyed.
Specifically, the span to the paper discharge unit entrance roller 17 is corrected by the original size data in the feed direction, and the number of encoder pulses of the transport motor M2 for this length is measured from the start of the transport motor M2 to start the drive. Get the timing. When the drive timing comes, the discharge motor M3
Is started so that the speed becomes the set speed data V (S1).
23-2). However, usually, for a document having a short length in the conveyance direction, the feeding of the next document is completed before this timing comes, and the document is stopped on the contact glass 15 together. Therefore, the single-sided discharge job waits for the drive timing of the discharge motor M3 in the single-sided discharge job 2 until the discharge of the document fed later is started. When the drive timing of the discharge motor M3 comes, the drive is performed based on the speed data V, and 3 is set in the single-side discharge job (S123-3). Note that the discharge switching claw 1
Reference numeral 9 denotes an OFF state of the discharge switching solenoid, and the conveyance path is in the direction of the single-sided discharge tray 4.

When the one-sided paper discharge job counter is 3, the process proceeds to one-sided paper discharge job 3 (FIG. 30), and the paper discharge unit entrance sensor 16 is set to O.
N (S124-1). During this time, the next original is fed before the paper output unit entrance sensor 16 is turned on. If the original is stopped (S124-2), the paper discharge motor M3 is turned off. The job is stopped (S124-3), and 6 is set in the single-sided sheet ejection job (S124-4). Normally, the single-sided discharge described above
At the time of JOB2, it is the timing to stop feeding the next document. However, if the timing is shifted due to a delay in feeding or the like, the discharged document is sent to the drive system of the transport belt 14 before the discharge unit entrance sensor 16 is turned on. Therefore, the discharge motor M3 is stopped here and the next discharge start is awaited. When the next original is not stopped, the paper exit unit entrance sensor 16 is set within a predetermined time.
Is not ON, it is determined that a jam has occurred by the JAM detection processing (S124-4, 5). When the paper discharge unit entrance sensor 16 is turned on, 4 is set in the single-sided paper discharge JOB (S124-
6). After 6 is set in the single-sided discharge job in S124-4, the process proceeds to the single-sided discharge job 6 (FIG. 33).
When the document stop flag is cleared by the start of discharge of the next document, the drive of the transport motor M2 and the discharge motor M3 is started at a high speed V, 3 is set in the single-side discharge job, and the discharge job is restarted. (S127-1 to S127-4).

If the one-sided discharge job counter is 4 in S124-6, the process proceeds to the one-sided discharge job 4 (FIG. 31), and waits until the discharge unit entrance sensor 16 is turned off (S125-).
1). If the paper discharge unit entrance sensor 16 is not turned off within the predetermined time, it is determined that a jam has occurred by the JAM detection process (S12).
5-2). When the paper discharge unit entrance sensor 16 is turned off, the deceleration processing of the paper discharge motor M3 is started (S125-3).
This is because, when the document is discharged onto the single-sided paper discharge tray 4, if the document is ejected with the high-speed conveyance, the document jumps out, and the discharge speed needs to be reduced to an appropriate low speed. is there. As shown in the timing chart of FIG. 4, at the time of deceleration, due to a circuit configuration (not shown), the vehicle is temporarily stopped, brakes are applied, and then the speed is switched to low speed. After the start of the deceleration process of the discharge motor M3, if the feeding and discharge job of the next document is not in operation, the transport motor M2 is stopped (S125-5). Thereafter, 5 is set in the single-sided paper discharge job (S125-6).

When the one-sided discharge JOB counter is 5, the process proceeds to the one-sided discharge JOB 5 (FIG. 32), where a predetermined number of pulses (encoder pulses of the discharge motor M3) or a predetermined time required for discharging the original are set. At the time when the time has elapsed (S126-1), it is determined whether or not the discharge job of the next original is in operation (S126-2).
If the discharge job is not in operation, the discharge motor M3 is stopped (S126-3). If the discharge job of the next original is in operation, the discharge motor M3 is switched to the set speed data V. (S126-4), preparing for the discharge of the next original. Thereafter, a "document discharge signal" is transmitted to the copying machine to notify that one document has been discharged. Thereafter, 0 is set in the single-sided paper discharge JOB, and the single-sided paper discharge JOB counter is completed (S126-5, 6).

Next, the operation in the double-sided copy mode will be described.
In the case of the duplex mode, as shown in FIG. 5, when the image reading of the fed "front side" of the fed document is completed, a "reverse signal" is transmitted from the copier body to the automatic document feeder to reverse the document. Is done. FIG. 34 shows a subroutine of the reverse receiving process started by the "reverse receiving".
FIG. 43 is a flowchart of the inversion operation control.

In FIG. 34, when the "reverse signal" sent from the copying machine main body is received (S128-1), 1 is set to the reverse job which is the job counter of the subroutine for performing the reverse control (S128-2). The document stop flag and the reverse reception flag are cleared (S128-3, 4).

FIG. 35 shows an inversion start subroutine, in which the control is advanced by the value of the inversion JOB counter in the inversion control subroutine. When the job counter in FIG. 35 is 0, nothing is performed and the process returns (FIG. 36). When 1 is set in the inversion job counter in the inversion start subroutine of FIG. 35, the process proceeds to inversion job 1 (FIG. 37). In the reversing job 1, the driving of the transport motor M2 is started so that the speed data becomes V3 (S131-1), and at the same time, the timing for starting the driving of the discharge motor M3 is calculated based on the document size determined at the time of feeding (S131-). 2). It has been described that the speed data V3 in this embodiment satisfies V1> V3.

Thereafter, the switching timing of the registration control pulse input is calculated (S131-3). This calculation process will be described in detail with reference to FIG. 44, which shows the relationship of the transport distance at the time of reversal, and FIG. 45, which shows a flow. First, flip the original to the registration position (the leading edge of the original is the original scale 1
2), the motor is controlled to decelerate by a pulse count from the time when the original reaches the reversing sensor 20 by the encoder pulse input of the motor for conveying the original, and the speed is gradually decreased. The document is stopped accurately at the registration position without damaging the document. During this reversal drive, the driving direction of the motor changes from the transport motor M2 to the discharge motor M3 to the transport motor M2 depending on the position of the document. Therefore, the reversing sensor 2
When the value reaches 0, the original is mainly conveyed by the drive of the discharge motor M3. After returning to the conveying belt 14, the original is conveyed again by the conveying motor M2. Therefore, it is necessary to control the switching of the registration control pulse input on the way.

As shown in the block diagram of FIG. 2, a pulse selection circuit connected to the transport motor M2 and the discharge motor M3 receives a switching signal from the CPU to input a pulse for register control (using an interrupt port). Can be selected from the encoder pulse of the transport motor M2 or the encoder pulse of the paper discharge motor M3. This is for the following reason.

Conventionally, the registration control pulse input mainly uses only the encoder pulse of the conveyance motor M2. In this case, even when the sheet is conveyed by the paper discharge motor M3, anticipation control is performed by the encoder pulse of the conveyance motor M2. Therefore, when the speed of the discharge motor M3 changes due to the temperature or the like, there occurs a problem that the conveyance amount of the document differs. Specifically, when the discharge motor M3 is slower than the transport motor M2, the transport amount is reduced, and the image registration does not reach the original scale 12, causing a problem that the registration of the image goes wrong. Conversely, when the discharge motor M3 is faster than the transport motor M2, the transport amount increases, and the amount of contact with the document scale 12 increases, and the thin document or the like buckles at the leading edge to cause wrinkles and damage the document. Such a problem occurs. In order to solve these problems, the registration control pulse input is switched halfway, but the switching timing differs depending on the document size.

This will be described with reference to the transport route diagram of FIG. When the document is reversed and enters the transport belt 14, the transport force of the reverse transport unit is stronger than the transport force of the transport belt 14, and the document is transported by driving the paper discharge motor M <b> 3. For a document having a relatively short length in the feeding direction, the discharge motor M is used until the rear end passes through the last roller of the reversing conveyance unit shown by B in the figure.
It can be seen that it is following the drive of No. 3. When the leading edge of the inverted document reaches the position indicated by A in FIG.
It has been found through experiments that the conveyance force of the document becomes larger than the conveyance force of the reversing conveyance section, and the document follows the conveyance motor M2.
Since the distance between A and B is the difference between the distances from the reversing sensor 20, it is 359.2-86.7 = 272.5 mm.

Therefore, in this embodiment, for a document whose length in the feed direction is shorter than 272.5 mm, the trailing edge of the document passes through the point B before the leading edge of the document reaches the point A.
The registration control pulse input is switched from the discharge motor M3 to the encoder pulse input of the transport motor M2 when the trailing edge of the document passes through the point B. If the original length is 27
For a document of 2.5 mm or more, the position is switched to the encoder pulse input of the transport motor M2 when the leading end of the document reaches A.

The various items in the switching timing calculation process are shown below, and this process is shown in the flow chart of FIG. Discharge motor transport amount: 0.318 mm / 1 pulse Discharge motor pulse number: N Transport motor transport amount: 0.134 mm / pulse Transport motor pulse number: Y Document length: L Registration correction amount: x

If the original length measured at the time of paper feeding is less than 272.5 mm, the original length L is added to the distance (86.7 mm) from the reversing sensor 20 to the point B, and the rear end of the original becomes The distance to the point is determined, and the distance is divided by the carry amount (0.318 mm) of the discharge motor M3 to obtain the pulse number N (S138-1, S138). Therefore, the pulse number N
Is set to the number of encoder pulses of the discharge motor M3 until the trailing end of the document passes through the point B from the reverse sensor 20. For a document having a document length L of 272.5 mm or more, the distance (359.2 mm) from the reversing sensor 20 to the point A from the reversing sensor 20 is divided by the transport amount (0.134 mm) of the discharge motor M3. The set pulse number N is set (S138-1, 3).

Therefore, the number of pulses Y of the transport motor M2
Is the distance 60 from the reverse sensor 20 to the document stop position.
The resist adjustment value x is added to 4.2 mm (see FIG. 44),
From this sum, the transport distance by the paper discharge motor M3 (N × 0.3
18 mm) is subtracted, and a value obtained by dividing this distance by the carry amount (0.134 mm) of the carry motor M2 is set (S13).
8-4).

Returning to the description of FIG. 37, after the calculation processing of the pulse switching timing (S131-3), the discharge switching solenoid is turned on (S131-4), and the discharge switching claw 1 is turned on.
9 is switched in the reverse direction. Then, 2 is set to the inverted job (S131-5).

When the inverted job counter is 2, the inverted job 2
The flow proceeds to (FIG. 38), and after waiting for the drive timing of the discharge motor M3 (S132-1), the discharge motor M3 is driven by the speed data V3, and the pulse selection circuit shown in FIG. The mode is switched to the encoder pulse input of the paper motor M3 (S132-3). Next, the discharge reversal switching solenoid 22 is turned on to switch the discharge reversal switching claw 22 to the reverse direction (S132-4). Then, 3 is set to the inverted job (S132-5).

When the inverted job counter is 3, the inverted job 3
The process proceeds to (FIG. 39), and waits for the paper discharge unit entrance sensor 16 to be turned on (S133-1). If the paper discharge unit entrance sensor 16 is not turned on within the predetermined time, it is determined that a jam has occurred in the JAM detection processing (S133-2). The paper discharge section entrance sensor 16 is O
If N, 4 is set to the inverted job (S133-3).

When the inverted job counter is 4, the inverted job 4
The process proceeds to (FIG. 40), and waits until the reversing sensor 20 is turned on (S134-1). The reversing sensor 20 is turned on within a predetermined time
If not, it is determined that a jam has occurred in the JAM detection process (S
134-2). When the reverse sensor 20 is turned on, the reverse rotation and deceleration stop processing of the transport motor M2 is started (S134).
-3). In this process, an interrupt process is performed each time a pulse signal selected by the pulse selection circuit in FIG. 2 is input.

FIG. 46 shows the flow of the reverse rotation and deceleration stop processing of the transport motor M2. The pulse input immediately after the document arrives at the reversing sensor 20 is the encoder pulse input of the discharge motor M3. At this time, the pulse number N of the discharge motor M3 set in FIG. 45 is decremented (S139).
-1, 2). If the result of the decrement is not 0, a reverse rotation process of the transport motor M2 is performed (S139-3 to 5).
Although the details of the reverse rotation process of the transport motor M2 are omitted, the speed of the transport motor M2 is gradually reduced every time the pulse interruption process shown in FIG. 46 is performed, and finally, the forward rotation drive is switched to the reverse rotation drive. By changing, it prepares for conveyance of the document after reversal. If the result of decrementing N is 0, it means that the input of the encoder pulse of the discharge motor M3 has been completed, and the pulse selection circuit of FIG. 2 is switched to the input of the encoder pulse of the transport motor M2 (S139-6). .

In the process after switching to the encoder pulse input of the transport motor M2, the pulse number Y of the transport motor M2 set in FIG. 45 is decremented (S1).
39-7), M previously set as the number of deceleration start pulses
A comparison is made with the pulse (S139-8). As shown in FIG. 5, after the M pulse input area, that is, the decremented Y becomes less than M, the deceleration stop timing flag of the discharge motor M3 is set (S139-9).
The deceleration control of the transport motor M2 (S139-10) is performed.
Thus, similarly to the above-described reverse rotation control of the transport motor M2, the speed of the transport motor M2 is gradually reduced every time an interruption process is performed, and accurate stop position accuracy can be obtained. When the result of the decrement of Y becomes 0, this interrupt is prohibited (S139-11, 12), the transport motor M2 is stopped (S139-13), and the deceleration stop process (S1) in FIG.
34-3) is ended. Thereafter, 5 is set to the inverted job in the inverted job 4 in the same figure (S134-4).

When the inverted job counter is 5, the inverted job 5
The process proceeds to (FIG. 41), and waits for the discharge section entrance sensor 16 and the reversing sensor 20 to be turned off (S135-1 and S135-2). Within a predetermined time, the paper discharge inlet sensor 16 and the reversing sensor 20
If the flag F is not set, the deceleration stop timing flag of the discharge motor M3 set during the reverse rotation deceleration process of the transport motor M2 is checked. If the flag is set, the deceleration process of the discharge motor M3 is performed. Is performed (S135-
3, 4). When the paper discharge unit entrance sensor 16 and the reversing sensor 20 are ON for a predetermined time or more, the process returns to the reversing JOB 5 and returns to J.
A jam is determined in the AM detection process (S135-5).

Conventionally, only the speed of the conveyor belt 14 is reduced at the time of reversing, and the speed of the discharge motor M3 is not reduced. For this reason, in the case of a long document such as an A3 size document, even when the conveyance motor M2 is decelerated and conveyed at a low speed, the rear end of the document is driven by the drive unit of the paper discharge motor M3 and conveyed at a high speed. I was For this reason, the original may be pressed in the rear, and a buckling may occur near the rear end of the original. This is not so problematic in an automatic document feeder having a relatively low conveying speed, but it is necessary to start deceleration early in a high speed automatic document feeding device having a high conveying speed. In the present embodiment, when the transport motor M2 is decelerated to cope with the high-speed reverse transport, a process of decelerating the paper discharge motor M3 is performed at the same time. For example, a portion indicated by a broken line in the paper discharge timing of FIG. This is a deceleration operation for the A3 size. By the way, in the case of a relatively short document, since the driving system of the discharge motor M3 is left before the conveyance motor M2 starts to decelerate, the discharge motor M3 is stopped before the start of deceleration as shown by the solid line in FIG. This is because the document exits the reversing sensor 20 before the deceleration stop timing flag of the discharge motor M3 is set in FIG.
This is because the process returns without proceeding to the deceleration processing (S135-3, S4). According to such a configuration, it is not necessary to drive the paper discharge motor M3 for a long time in the case of a short document. It has the advantage of becoming. When both sensors are turned off (S135-1, S135), the discharge switching solenoid is turned off, the discharge switching claw 19 is switched to the single-sided discharge tray 4 direction, and 6 is set to the reverse JOB (S13).
5-6, 7).

When the inverted job counter is 6, the inverted job 6
(FIG. 42), the number of pulses (encoder pulses of the discharge motor M3) sufficient for the trailing end of the document to leave the drive system of the discharge motor M3 or the predetermined time has elapsed after the reversing sensor 20 is turned off. Stop the paper motor M3 (S136-
1,2). At the same time, the discharge reversal switching solenoid is turned off (S136-3), and the discharge reversal switching claw 22 is switched to the two-sided discharge tray 3 direction. Thereafter, 7 is set to the inverted job (S136-4).

When the inverted job counter is 7, the inverted job 7
Proceeding to FIG. 43, the process waits for the completion of the deceleration stop processing of the transport motor M2 (S137-1), and when it is completed, transmits a "document stop signal" to the copying machine main body (S137-2).
The inversion JOB is set to 0 (S137-3).
End the OB.

In the double-sided mode, when the reading of the image on the back side of the document is completed after the reversing operation, the document is discharged to the double-sided discharge tray 3. In the next original set start subroutine described with reference to FIG. 9, when the "next original set signal" transmitted from the copying machine main body is received, "1" is set in the double-sided discharge JOB counter. Paper control is performed.

FIGS. 47 to 54 show a control flow of the double-sided paper discharging operation. FIG. 47 shows a start subroutine of the double-sided discharge JOB, in which the control proceeds according to the value of the double-sided discharge JOB counter. As shown in FIG. 48, when the double-sided discharge job counter is 0, the process returns without performing anything. Double-sided output JO
When the B counter 1 is set, the process proceeds to the double-sided discharge job 1.

In the double-sided paper discharge job 1 (FIG. 49), the transport motor M2 starts normal rotation driving with the speed data V set in the transport speed setting process (see FIG. 7) (S142-1), and determines at the time of paper feeding. Based on the size of the original, the timing at which the discharge motor M3 starts to be driven is calculated (S142-2). Almost at the same time, the discharge switching solenoid is turned on, and the transport path is switched in the reverse direction by the discharge switching claw 19 (S142-3). Thereafter, 2 is set in the double-sided discharge job (S142-4).

If 2 is set in the double-sided discharge job counter, the process proceeds to the double-sided discharge job 2 (FIG. 50), and waits for the drive timing of the discharge motor M3 (S143-1). The motor M3 is driven by the speed data V set in the transfer speed setting process (see FIG. 7) (S14).
3-2). After that, 3 is set in the double-sided discharge job (S
143-3).

If 3 is set in the double-sided discharge job counter, the process proceeds to the double-sided discharge job 3 (FIG. 51), and waits until the discharge unit entrance sensor 16 is turned on (S144-1). If the paper discharge unit entrance sensor 16 is not turned on within a predetermined time, JAM
A jam is determined in the detection processing (S144-2). When the paper discharge unit entrance sensor 16 is turned on, the paper supply standby flag for waiting for the paper supply of the next document is cleared (S144-3), and 4 is set in the double-sided paper discharge job (S144).
4). By clearing the paper feed standby flag, 1 is set in the paper feed JOB for feeding the next original (see FIG. 9).

When the double-sided discharge job counter is 4, the process proceeds to the double-sided discharge job 4 (FIG. 52) and waits until the reversing sensor 20 is turned on (S145-1). Reversal sensor 2 within a predetermined time
If 0 is not ON, it is determined that a jam has occurred in the JAM detection process (S145-2). When the reverse sensor 20 is turned on, 5 is set in the reverse job.

When the double-sided discharge job counter is 5, the process proceeds to the double-sided discharge job 5 (FIG. 53), and waits for the discharge unit entrance sensor 16 and the reversing sensor 20 to be turned off (S146-1 and S146-2).
If the paper discharge inlet sensor 16 and the reversing sensor 20 are not turned off within the predetermined time, it is determined that a jam has occurred in the JAM detection processing (S146-3). When both the sensors are turned off, the discharge switching solenoid is turned off (S146-5), and the transport path is switched to the double-sided discharge tray 3 by the discharge switching claw 19. Thereafter, similarly to the single-sided sheet ejection, the deceleration processing of the sheet ejection motor M3 is performed (S146-6), and the conveyance motor M2 is stopped when the control of feeding the next document is not in operation (S146).
7). Thereafter, 6 is set in the double-sided discharge job (S14).
6-8).

If 6 is set in the double-sided discharge JOB counter, the process proceeds to the double-sided discharge JOB 6 (FIG. 54), where a predetermined number of pulses (encoder pulses of the discharge motor M3) required for discharging the original are set. Alternatively, when a predetermined time has elapsed (S14
7-1) If the discharge motor M3 is not operating in the reverse job of the next original, the discharge motor M3 is stopped (S147-2, S147-2).
3). If the discharge motor M3 is operating in the reverse job of the next original in S147-1, the discharge motor M3 is switched to the speed of the speed data V set in the conveyance speed setting process (see FIG. 9) (S147- 4) Prepare for the discharge of the next original. After that, the “document ejection signal” is sent to the copier body and
Notify that sheets have been ejected. Thereafter, 0 is set in the double-sided discharge job, and the double-sided discharge job is completed.

[0099]

As described above, according to the automatic document feeder of the present invention, the control means detects the document size based on the detection signal sent from the paper feed unit, and the detected document size is When the paper is of a specific size, the paper can be continuously fed at the slower transport speed.Therefore, for a specific size that is likely to cause skew during separation and transport, the transport speed is set by setting the slower transport speed. Accuracy can be improved.

In the above-described apparatus, according to the configuration in which the specific size is equal to or smaller than the predetermined size, a skew is more likely to occur at the time of separation and transport compared to a large size with a small original size. By setting the slower transport speed, the transport accuracy can be ensured.

Further, the control means specifies the document feeding order based on the detection signal of the document setting operation sent from the paper feeding unit, and sets the transport speed of at least the second and subsequent sheets to either low speed or high speed. When switching is possible and the size of the first document is the specific size,
According to the configuration in which the conveyance speed of the second and subsequent sheets can be set to a low speed, it is possible to reduce noise and the like by the low-speed conveyance of the first document for which the necessity of high-speed conveyance is small, and at the same time, the second and subsequent sheets As for (2), even in an apparatus that performs high-speed conveyance according to the image forming speed, copy productivity can be improved, and in the case of a specific size, the conveyance accuracy can be ensured by selecting low-speed conveyance.

When the control means determines that the document on the document placing means is in the mixed mode including two or more sizes, the slower transport speed can be set. The transport speed is also reduced according to low copy productivity,
The transfer accuracy can be ensured and noise can be reduced.

If the control means is configured to set the low transport speed for the second and subsequent sheets to the same speed as the transport speed of the first sheet, the above-described effects can be obtained by relatively simple control. An apparatus can be provided.

The transport / discharge unit has a reverse discharge unit capable of reversing and transporting the original of the image reading unit, and the control means sets the reverse transport speed to a lower transport speed. According to this, it is possible to reduce noise when the original is reversed and conveyed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an overall configuration of an automatic document feeder according to an embodiment.

FIG. 2 is a block diagram illustrating a configuration of a control unit according to the embodiment.

FIG. 3 is a timing chart illustrating conveyance control during single-sided continuous copying.

FIG. 4 is a timing chart following FIG. 3;

FIG. 5 is a timing chart illustrating conveyance control during continuous duplex copying.

FIG. 6 is a timing chart following FIG. 5;

FIG. 7 is a flowchart illustrating a subroutine of a transport speed setting process.

FIG. 8 is a flowchart illustrating a subroutine of paper feed preparation.

FIG. 9 is a flowchart illustrating a subroutine of next original set control.

FIG. 10 is a flowchart showing a routine having a job control job counter.

FIG. 11 is a flowchart showing a subroutine when a sheet feeding job counter is 0.

FIG. 12 is a flowchart showing a subroutine when a sheet feeding job counter is 1;

FIG. 13 is a flowchart showing a subroutine when a sheet feeding job counter is 2.

FIG. 14 is a flowchart illustrating a subroutine when a sheet feeding job counter is 3.

FIG. 15 is a flowchart illustrating a subroutine when a sheet feeding job counter is 4;

FIG. 16 is a flowchart showing a subroutine when a sheet feeding job counter is 5;

FIG. 17 is a flowchart illustrating a subroutine when a sheet feeding job counter is 6;

FIG. 18 is a flowchart illustrating a subroutine when a sheet feeding job counter is 7;

FIG. 19 is a flowchart showing a routine including a job counter for original advance control.

FIG. 20 is a flowchart showing a subroutine when the advance job counter is 0.

FIG. 21 is a flowchart showing a subroutine when the advance job counter is 1;

FIG. 22 is a flowchart showing a subroutine when the advance job counter is 2.

FIG. 23 is a flowchart showing a subroutine when the advance job counter is 3;

FIG. 24 is a flowchart showing a subroutine when the advance job counter is 4;

FIG. 25 is a flowchart showing a subroutine when the advance job counter is 5;

FIG. 26 is a flowchart showing a routine including a JOB counter for one-sided sheet discharge control.

FIG. 27 is a flowchart showing a subroutine when the single-sided paper discharge job counter is 0.

FIG. 28 is a flowchart showing a subroutine when a single-sided paper discharge job counter is 1;

FIG. 29 is a flowchart showing a subroutine when the one-sided paper ejection job counter is 2.

FIG. 30 is a flowchart showing a subroutine when the one-sided paper ejection job counter is 3;

FIG. 31 is a flowchart showing a subroutine when the single-sided paper discharge job counter is 4;

FIG. 32 is a flowchart showing a subroutine when the one-sided paper discharge job counter is 5;

FIG. 33 is a flowchart showing a subroutine when the single-sided paper discharge job counter is 6;

FIG. 34 is a flowchart illustrating a subroutine of inversion start control.

FIG. 35 is a flowchart showing a routine including a job counter for inversion control.

FIG. 36 is a flowchart showing a subroutine when a reverse job counter is 0.

FIG. 37 is a flowchart showing a subroutine when a reverse JOB counter is 1;

FIG. 38 is a flowchart showing a subroutine when the inverted job counter is 2.

FIG. 39 is a flowchart showing a subroutine when a reverse job counter is 3;

FIG. 40 is a flowchart showing a subroutine when a reverse JOB counter is 4;

FIG. 41 is a flowchart showing a subroutine when a reverse JOB counter is 5;

FIG. 42 is a flowchart showing a subroutine when the inverted job counter is 6.

FIG. 43 is a flowchart showing a subroutine when a reverse JOB counter is 7;

FIG. 44 is a schematic diagram of a transport path for explaining reverse transport control.

FIG. 45 is a flowchart showing a subroutine for calculating a pulse switching timing in the inversion control.

FIG. 46 is a flowchart showing a subroutine of reverse rotation and deceleration stop processing of the transport motor.

FIG. 47 is a flowchart showing a routine including a JOB counter for a two-sided paper discharge operation.

FIG. 48 is a flowchart showing a subroutine when the double-sided paper discharge job counter is 0.

FIG. 49 is a flowchart showing a subroutine when a double-sided discharge job counter is 1;

FIG. 50 is a flowchart showing a subroutine when a double-sided discharge job counter is 2.

FIG. 51 is a flowchart showing a subroutine when a double-sided discharge job counter is 3.

FIG. 52 is a flowchart showing a subroutine when a double-sided paper discharge job counter is 4;

FIG. 53 is a flowchart showing a subroutine when a double-sided paper discharge job counter is 5;

FIG. 54 is a flowchart showing a subroutine when a double-sided paper discharge job counter is 6;

FIG. 55 is a schematic diagram showing how the skew of a small-size document is increased.

[Explanation of symbols]

 1 Automatic Document Feeder 29 Document Placement Means (Document Device Board)

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 2H027 DB09 DE07 ED11 EE03 EE04 EE06 JA17 ZA07 2H076 BA57 BA58 BA63 BA65 BA68 BA72 BB04 BB05 3F343 FA03 FB02 FB03 FB04 FC01 FC28 GA03 GB01 GC01 GD01 HA12 HA33 H0301 LC17 JA01 LD10 MA03 MA13 MA14 MA26 MB03 MB13 MB14 MC09 MC21 MC23

Claims (6)

[Claims] A sheet feeder configured to detect a document stacked on a document placing unit, separate the sheets one by one, and feed the separated sheets to an image reading unit; And a paper discharge unit that re-conveys and discharges the paper after reading the image, and drives and controls the paper discharge unit and the paper feed unit, and sets two or more document transport speeds having different speeds. An automatic document feeder comprising: a control unit capable of arbitrarily switching between the document size and a document size based on a detection signal sent from the paper feeding unit; An automatic document feeder that continuously feeds paper at a slower transport speed when is a specific size. 2. The automatic document feeder according to claim 1, wherein the specific size is equal to or smaller than a predetermined size. 3. The control means specifies a document feed order based on a detection signal of a document setting operation sent from a paper feeding unit, and switches a transport speed of the second and subsequent sheets to either low speed or high speed. 3. The apparatus according to claim 1, wherein when the size of the first document is the specific size, the conveying speed of the second and subsequent documents is set to a low speed.
Automatic document feeder as described. 4. The apparatus according to claim 1, wherein said control means sets a slower conveying speed when judging that the document on said document placing means is in the mixed loading mode including two or more sizes. Automatic document feeder. 5. The apparatus according to claim 3, wherein the control means sets the low-speed transport speed set for the second and subsequent sheets to the same speed as the transport speed of the first sheet. Automatic document feeder as described. 6. A sheet feeding unit for detecting documents stacked on a document placing unit, separating the documents one by one and feeding the separated documents to an image reading unit, and reading an image of the documents fed from the sheet feeding unit. And a paper discharge unit that re-conveys and discharges the paper after reading the image, and drives and controls the paper discharge unit and the paper feed unit, and sets two or more document transport speeds having different speeds. An automatic document feeder, comprising: a control unit capable of arbitrarily switching between them; the transport discharge unit includes a reversal discharge unit capable of reversing and transporting the original of the image reading unit; An automatic document feeder, wherein the reverse transport speed is set to a lower transport speed.