JP2672672B2 - Paper transport mechanism of image forming apparatus - Google Patents

Description

TECHNICAL FIELD The present invention relates to an image forming apparatus in which a sorter for sorting recording sheets is attached to an image forming main body.

[Related Art] In various image forming apparatuses such as a copying machine, a printer, and a facsimile, a sorter for recording paper sorting is often attached to an image forming main body. A general image forming main body is usually configured as a side operation type for handling recording paper in a side region of the image forming main body. Corresponding to this, inside the image forming main body portion, there is provided an image forming conveyance path for conveying the recording paper from one side to the other side, and the sorter is used for image forming. The main body is arranged and connected so as to be juxtaposed at an exit portion of the image forming conveyance path, that is, a side portion of the image forming main body.

[Problems to be Solved by the Invention] However, in such a conventional image forming apparatus,
Since the image forming main body is configured as a side operation type as described above, the entire apparatus is elongated in the left-right direction, and
It is necessary to perform various operations on both sides of the image forming apparatus, such as mounting a paper feed cassette storing the unrecorded paper, which is obtained by taking the recorded paper on which an image has been formed from the tray, on both sides of the image forming apparatus. Therefore, an operating space is required on both sides of the image forming apparatus. Further, on both sides, a space is needed to allow a pedestrian to not hit a projection such as a tray, and the space actually required for installing the image forming apparatus is very small. It is getting bigger. On the other hand, if the image forming apparatus is installed in a relatively narrow space, there is a problem that various operations on the side as described above become inconvenient.

Therefore, according to the present invention, the apparatus itself can be downsized, and it is not necessary to provide a large operation space around the apparatus, the apparatus can be installed in a small space, and high-speed and efficient paper conveyance can be performed. It is an object of the present invention to provide a paper transport mechanism for an image forming apparatus.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the means according to the present invention provides a recording paper on which an image is formed and discharged at a predetermined process speed in a predetermined direction toward the front side and the rear side. A front operation type image forming main body provided with an image forming conveying path for conveying at a paper feeding speed, a sorter for sorting recording sheets arranged side by side on the image forming main body, and the image forming described above. Image forming including a sorting discharge transport path that is connected to the image forming transport path so as to receive the recording sheet discharged from the transport path for transporting in a substantially right angle direction and feed the recording sheet to the sorter. In the paper transport mechanism of the apparatus, the paper feed speed in the image forming transport path has a constant relationship with the process speed so that the distance between the preceding recording paper and the succeeding recording paper is equal to or more than a constant value. The paper feed means in the image forming conveyance path is provided with a paper conveyance speed that is increased in a fixed relationship with the process speed, and the paper feed speed between the preceding recording paper and the succeeding recording paper is increased. It has a configuration in which it is driven via a one-way clutch so that the interval becomes a certain value or more.

[Operation] In the means having such a configuration, first, the image forming main body portion is configured to be the front operation type, so that the recorded sheet on which the image is formed is taken out from the tray or the unrecorded sheet is stored. All operations such as mounting the paper feed cassette in the image forming main unit are performed from the front side of the image forming apparatus, so that there is no need for operating space and space for both sides of the apparatus. The three sides except the front side of the device can be brought close to the wall surface. Also, for a sorter arranged side by side on the image forming main body, the paper recorded from the sorting discharge path of the image forming main body in a direction substantially perpendicular to the feeding direction of the image forming conveyance path changes its direction. And the sorting operation is performed. Then, the sorted recording paper is also taken out from the near side. Therefore, even in the sorter, neither space for operation nor space for margin is required on both sides of the device, and the three sides except the front side of the device can be brought close to the wall surface.

Further, in such a right angle discharging operation for the sorter, the paper feeding speed in the image forming conveyance path is increased in a constant relationship with the process speed. At this time, the paper feeding means in the image forming conveyance path is driven through the one-way clutch, so that the recording paper fed at the low process speed can be smoothly transferred to the high speed feeding state. There is.

Thus, the distance between the preceding recording sheet and the succeeding recording sheet in the image forming conveyance path is set to a certain value or more,
After the preceding transfer paper is received at the entrance of the right-angled transport path and sent out from it, the subsequent transfer paper enters the entrance of the right-angled transport path. A wrapping interference state between the recording sheet and the succeeding recording sheet is surely prevented, and a favorable discharging operation is performed.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

First, the structure of the image forming main body according to the present invention will be described with reference to the embodiment of the copying machine shown in FIG. The image forming main body includes a copier main body C, a multi-stage paper feeder (PB) 400 installed below the copier main body C, and an automatic reversing original device ( ARDF) 100.

In the copying machine main body C, the document to be copied is inserted from the position shown by the arrow A, and is stopped at a predetermined position on the contact glass 203. The operation of the original set will be described in detail in the section of the automatic reversing original feeder (ARDF) described later.

Next, an exposure step is performed by the optical system 200. The optical system 200 is arranged so that the original image can be operated below the contact glass 203, and includes an original illumination light source 201, movable mirrors 204, 205, 206, a zoom lens 207, and a fixed mirror 20.
8,209,210. The document illumination light source 2
01, the reflector 202, and the movable mirror 204 constitute a first scanner 220. The first scanner 220 has a relative velocity (V) of the photosensitive drum 601 (V / m; m is a copy magnification). Is moved rightward at the speed of at the same time, and at the same time, the second scanner 230 composed of the movable mirrors 205 and 206 is (V / 2m)
It is rotationally driven by a drive motor (not shown) so as to be moved rightward in the drawing at the speed shown in FIG. The peripheral speed of the photosensitive drum 601 is constant irrespective of the same magnification or variable magnification.

The copy magnification is changed by driving a lens driving motor (not shown) to change the position of the zoom lens 207 on the optical path. In the figure, when the position of the zoom lens 207 is G, m = 0.5 (50% reduction), when it is H, m = 1.0 (equal magnification), and when I, m = 2.0 (20).
0% magnification).

At a slightly right side of the center of the copying machine main body 1, an image forming system 600 is provided around the photosensitive drum 601. That is, a charging charger 602 for uniformly charging the photosensitive drum 601 around the photosensitive drum 601, an eraser 603 for erasing unnecessary charges, and a first development for visualizing the toner powder on the electrostatic latent image by a magnetic brush. Device 502, a second developing device 501, a belt transfer device 630 for transferring a toner image on the photosensitive drum 601 to recording paper, and a photosensitive drum 601 without being transferred to recording paper
A cleaning device 608 and the like for cleaning the toner image remaining thereon are provided.

In the belt transfer device 630, an endless belt 613 stretched by a plurality of rollers 614 and the like is lightly pressed against the photosensitive drum 601, and a corona discharge for transfer is performed by a charger 609 from the back. Charger 612
Is for charging the endless belt 613 and electrostatically attracting the recording paper. The charger 610 is a charger for removing static electricity from the endless belt 613. The rubber blade 615 is for cleaning the residue of the endless belt 613 after the paper is conveyed.

There are roughly two recording paper feeding units, one is a multi-manual paper feeding device 300 attached to the main body side, and the other is a multi-stage paper feeding device having a plurality of paper feeding trays ( PB)
400. Paper guide 301 of multi-purpose feeder 300
Is normally closed, and is opened as shown in the figure when used, whereby the recording paper is set.
The set recording paper is pulled in by the call roller 302 and is fed by the paper feed roller 303 and the separation roller 304. After being temporarily stopped by the pair of registration rollers 305, the sheet is fed while being synchronized with the leading end of the image on the photosensitive drum 601. Meanwhile, the multi-stage paper feeder
In the sheet feeding operation by 400, first, the sheet feeding device 410 is moved up and down toward the sheet tray of the selected sheet feeding stage. When the selected paper tray is approached, a signal from a sensor (not shown) is received to stop the elevation drive of the paper feeding device 410, and then the paper tray is moved to the paper feeding device side. The paper feeding method is basically the same as the multi-manual paper feeding device. That is, the paper is fed by the feeding roller 411
And then feed roller 412 and separation roller 4
The sheets are separated into one sheet by 13 and fed. The fed paper reaches the registration roller pair 305 via the transport roller 306 and is stopped. The sheet on which the toner image has been transferred while being held by the endless belt 613 after passing through the registration roller pair 305 is fused with the toner image by the heat roller pair (the fixing roller 701 and the pressure roller 702). The recorded paper after fixing (hereinafter referred to as transfer paper) passes through a pair of fixing discharge rollers, and travels to the main body discharge tray 809, the re-feeding device 900, and the sorter transport unit 950.

In the case of performing double-sided copying, two different transport paths are roughly used for A4 (or LT) size or smaller and other sizes.

First, if the size is smaller than A4 (or LT),
When the trailing edge of the copy paper passes through 700, a signal from the signal of the sensor 801 is received and immediately after passing through the gate 803, the roller pair 8
02 is reversed, and the transfer paper goes to the conveyance path 821. After passing through the roller pair 901, the call roller 908 is lowered and rotated, and the transfer paper is conveyed immediately below the paper feed roller 909. Except during paper feeding, the pressure plate 911 is below, and is raised during paper feeding to apply paper feeding pressure to the paper feeding roller 909. The separation roller 910 is given a counterclockwise rotation at a certain torque or less, but is rotated with the paper feed roller 909 when a larger torque is applied. Are supplied one by one. The re-fed transfer paper is conveyed until a predetermined slack is given by the pair of registration rollers 305, then stopped, and restarted in synchronization with the leading edge of the image on the photoconductor. Subsequent operations are the same as those for one-sided copying.

In the case of paper having a size larger than A4 (or LT), the transfer paper passes through the fixing device, passes through the pair of rollers 802 and 804, passes through the gate 811, and when the trailing edge is detected by the sensor 810, the pair of rollers 806 Is reversed, and the transfer paper is
Will be sent to At this time, the gate 814 has been displaced to the position indicated by the broken line, and the transfer paper is sent to the roller pair 902. When the size of the transfer paper is A3 (or 17 ″), the gate 905 takes the position indicated by the broken line and is discharged onto the re-feeding device immediately after passing through the roller pair 902. The size of the transfer paper is B4 (or 1 ″).
In the case of 4 ″), the gate 905 assumes the position indicated by the solid line and the gate 906 assumes the position indicated by the broken line, so that the transfer sheet passing through the roller pair 903 is discharged onto the re-feeding device.
When the transfer paper size is A4 portrait or B5 portrait (or 11 ″), the gates 905 and 906 take the position of the solid line, the gate 907 takes the position of the broken line, and the transfer paper passing through the roller pair 904 is placed on the re-feeding device. The subsequent operations are the same as those described above for A4 and below.

In the case of multiple (synthetic) copying, regardless of the size, the gate 805 is first displaced to the position indicated by the broken line and the fixed transfer paper is sent to the transport path 823. Next, the gate 814 is displaced to the position indicated by the broken line, and the transfer paper is sent to the roller pair 902.
When the transfer paper size is A3 (or 17 ″), the gate 905 assumes the position indicated by the broken line and is discharged onto the re-feeding device immediately after passing through the roller pair 902. The transfer paper size is B4 (or 14 ″).
In this case, the gate 905 takes the position indicated by the solid line, and the gate 906 takes the position indicated by the broken line. When the transfer paper size is A4 portrait or B5 portrait (or 11 ″), the gates 905 and 906 take the position of the solid line, the gate 907 takes the position of the broken line, and the roller pair 904
Is discharged onto the re-feeding device. The operation up to this point is the same as the above-described operation on both sides of paper having a size larger than A4 (or LT). When the transfer paper size is A4 landscape (or LT or less), the gates 905, 906, and 907 assume the positions indicated by solid lines, and are discharged onto the re-feeding device after passing above the gate 907. In order to align the discharged transfer paper, a pair of call rollers 908 is operated. Subsequent operations are the same as in the above-described duplex copying.

First configuration and operation of automatic reversing manuscript device (ARDF) 100
It will be described with reference to FIGS. 1 and 12.

First, in the case of a single-sided original, the original to be copied is set on the tray 101 in the direction of arrow A with the image side up. The set document is fed by a feeding mechanism similar to that of the multi-manual feeding device. That is, the original is pulled in the left direction by the calling roller 102, and then only the uppermost original is directed to the roller pair 106 by the paper feed roller 103 which is rotated clockwise and the separation roller 104 which is also rotated clockwise. Be fed. In this automatic document feeder, documents are fed in page order. The roller pair 106 is stopped until the document is sent, and starts rotating a little after the leading end of the document is reached. Thus, the skew (skew) of the document is corrected. After passing through the roller pair 107, it is guided by the guide plate 123 and is fed between the contact glass 203 and the transport belt 118. The transport belt 118 is a drive roller 115, a roller
It is stretched by 116 and a tension roller 117. The stop position of the document on the contact glass 203 is determined by the number of pulses starting from when the rear end of the document passes the sensor 127.

When scanning of the document is completed, the transport belt drive roller
Reference numeral 115 denotes a document which is rotated clockwise and fed back to the left in the form of switchback. The first gate 111, which was initially at the position indicated by the solid line, is displaced to the position indicated by the broken line in FIG. That is, the state shown by the solid line in FIG. Roller 11 at the top of the manuscript
The paper passes between the roller 2 and the roller 113 and is discharged onto the tray 119. In this state, since the image surface of the original is on the upper surface, if the paper is continuously discharged as it is, the page order will be reversed. In order to avoid this, the device is again inverted. That is, at the same time when the rear end of the original is detected by the sensor 128, the rollers 108 and 1
13 is reversed counterclockwise. At the same time, the second gate 110 is switched to the position indicated by the solid line in FIG. 12 (b) based on this inverted signal, and the first gate 111 is also changed to the lower position indicated by the solid line. In this way, as shown in FIG. 12 (c), the originals pass between the rollers 113 and 114 and are stacked on the tray 119 with the image surface facing downward. The same operation is repeated sequentially, and the originals are stacked in the same page order as when they were first set.

For double-sided documents, the first side should be
The operation is the same as in the single-sided mode up to the stop on the upper side. When scanning of the document is completed, the transport belt driving roller 115
Is rotated clockwise and the document is sent out to the left in the form of being switched back. At this time, the first gate 111 is displaced upward as in the case of a one-sided original, and
The position of the gate 109 is also changed upward. The state is the 12th
This is shown in FIG. The head of the original to be inverted is guided by guides 121 and 122 and is sent again onto the contact glass 203. The stop position of the document on the contact glass 203 is determined by the number of pulses from the time when the rear end of the document has passed the sensor 128.

When the scanning of the document on the second side is completed, the transport belt driving roller 115 is rotated clockwise to switch back, and the document is fed leftward. At this time, the third gate 109 is displaced downward, and the original is placed on the roller 112 and the roller 113 in the state as shown in FIG. 12 (c).
And is stacked on the tray 119. Thus, the operation of feeding and discharging the two-sided document is completed. Thereafter, the same operation is sequentially repeated, and the originals are stacked in the same page order as when they were first set.

Sorters 1000 as shown in FIG. 6 are arranged side by side on the side of such an image forming main body. To this sorter 1000, the recording paper is sent in such a manner that the direction of the recording paper is changed in a substantially right angle direction from the double-sided copying refeeding device constituting the image forming conveyance path in the image forming main body. . That is, as shown in FIG. 2, a sorting discharge transport path is provided for transporting the transfer sheet, which is moved to the near side in the re-feeding device 900 of the image forming apparatus main body, by changing the transport direction by 90 °, as described later. The paper that has been sent in the lengthwise direction such as A3 and B4 is shortened and sent, so it has excellent transport efficiency.

Although the sorter 1000 can switch between the front and back sides of the transfer paper to be discharged, a case where the sorter does not switch first will be described. When copying in page order, the copied paper must be stacked with the image side down, or if the image side is up, it must be inserted under the previous transfer paper to make it the same as the original. Must. The latter method is not so general, and the former method is more general, and this is called backside discharge.

The operation of turning the transfer paper upside down is performed on the image forming main body side shown in FIG. That is, as in the case of multiple (composite) copying, the transfer paper is sent to the roller pair 922 through the transport paths 823 and 826 by switching to the position of the broken line of the gate 805, and as shown in FIG. Vertical transport rollers 923, 924, 925 as forward transport rollers feed the sorter transport path 921 with the image surface facing downward. At this time, the pinch roller 926a as the pressure contact roller which constitutes the right angle transport roller 926 is retracted so as to be separated upward. The transfer paper from the vertical transport roller 925 is
The leading end is detected by the photo sensor 927, and is stopped after being sent for a predetermined time. Then, vertical conveyance rollers 923,924,
Pinch roller 923 as a pressure contact roller constituting 925
a, 924a, 925a are retracted so as to be separated upward, and instead, the pinch roller 926 of the right-angled conveyance roller 926 is replaced.
a is lowered, and the transfer paper is pinched and conveyed to the front side.

In this embodiment, A4 size paper is 40 cpm (copy per minute,
(40 copies per minute), B4 longitudinal feed 27cpm, A3 longitudinal feed 23cpm machine.After the trailing edge of the largest size paper passes the fixing roller 701, The leading end of the paper is caught by the upstream vertical transport roller 923.

First, FIG. 3 (a), FIG. 4 (a) and FIG. 5 (a).
In the case of the A3 vertical feed (longitudinal feed) shown in (1), the transfer sheet is transferred with the toner image on the drum 601 and passes through the fixing device 700, where the toner image is fixed. After that, it passes through the fixing paper discharge roller pair 704 and reaches the sensor 801. The transfer paper conveyance speed at this time is about the same as the process speed.
250 mm / sec, and the distance between the transfer sheets is about 233 mm as shown in FIG. 3 (a). The transfer paper advances through the roller pair 802, and after passing the roller pair 804, the transport path 823.
Proceed to. At this time, the gate 805 has been displaced to the upper position shown by the broken line.

The trailing edge of the transfer paper passes through the sensor 801 after the leading edge is added to the vertical transport roller 923. Here, each of the vertical transport rollers 923, 924, 925 is configured to have a high transport speed of about 500 mm / sec, which is a transport speed double the process speed, and the leading end of the transfer paper is gripped by the vertical transport rollers 923. From that point, the transfer paper is fed at a transport speed twice as high as usual. On the other hand, the transport rollers 804, 813, 922 arranged on the upstream side of the vertical transport rollers 923, 924, 925 are configured to have a low transport speed of about 250 mm / sec, which is the same as the process speed. At this time, the leading edge of the transfer paper is the vertical transport roller 923.
Even when the transfer paper is gripped, the rear side portion of the transfer paper is still gripped by the transport rollers 804, 813, 922. However, each of these transport rollers 804,81
3,922 is connected to the drive system via a one-way clutch (not shown), and thus when the transfer sheet is switched to the high speed side transfer speed as described above, the transfer rollers 804,813,922 correspond to it. Since it is driven to rotate at a high speed, the recording paper fed at a low process speed can be smoothly transferred to a high-speed feed state.

Further, by connecting each of the transport rollers 804, 813, 922 to the drive system via the one-way clutch as described above,
The transport system can be simplified by, for example, unifying the drive source for transport.

Further, as shown in FIG. 1, the vertical conveying rollers 923, 924, 925 obtain the rotational driving force from the pulleys 931, 932, 933, respectively, and the pinch rollers 923a, 924 pressed against the vertical conveying rollers 923, 924, 925.
The a and 925a are pressed and urged by elastic members 941, 942 and 943 such as springs.

The transfer paper P1 is conveyed at the above-described high speed, and after passing through the vertical conveyance roller 925, the front end of the transfer paper P1 is detected by the sensor 927 approximately 0.45 seconds after the rear end of the transfer paper P1 exits the fixing roller 701 of the fixing device 700. , The signal is stopped so that the tip is aligned with the stop position 928. At the same time, the carrying direction is switched by 90 degrees as follows.

This transfer direction switching operation is performed by the pinch roller 923.
The suction operation is performed by plunger solenoids 961, 962, and 963 connected to a, 924a, and 925a. That is, vertical transport rollers 923,924,925 pinch rollers 923a, 924
At the same time when a and 925a are released, the plunger solenoid 964 connected to the pinch roller 926a of the right-angled transport roller 926 is turned off, and the pinch roller 926a of the right-angled transport roller 926 is elasticized by releasing the suction operation up to that point. The tension of the member 944 is applied to the transfer paper P1 so that the transfer paper P1 is subjected to a right-angled conveyance force. As such a transport direction switching mechanism, other means such as a cam can be adopted. In this way, the transfer paper P1 is 90
It will be conveyed while changing the direction.

The conveying speed of the right-angle conveying roller 926 is always set to about 500 mm / sec. Therefore, when about 6 seconds elapse after the above-mentioned right-angle conveying is started, the conveying is performed for about 310 mm, and at this time, the subsequent transfer is performed. It is placed at a position where it does not interfere with the paper P2 (see FIG. 4 (a)). This is about 1.75 seconds after the rear end of the transfer paper P1 leaves the fixing roller 701, and at this time, the front end of the subsequent transfer paper P2 is a roller pair.
Since it is immediately before 804, the interference between the transfer sheet P1 and the subsequent transfer sheet P2 can be avoided. That is, the high-speed conveyance speed is such that the position of the leading end portion of the succeeding transfer sheet P2 (see FIG. 5 (a) at the time of completion of withdrawal from the vertical conveyance of the trailing edge of the preceding transfer sheet (P1B in FIG. 5 (a)). It is set to a value that does not overlap with P2A).

The conveying force by the right-angle conveying roller 926 is released by releasing the pinch roller 926a at the time when the transfer sheet is gripped by the roller pair 929 located downstream of the roller pair 929, thereby discharging the preceding transfer sheet P1. It will be finished.

As soon as the preceding transfer paper P1 is retracted, the plunger
The suction operation of the solenoids 961, 962, 963 is released, and the pinch rollers 923a, 924a, 925a are pressed and urged by the tension of the elastic member 944. This allows vertical transport rollers 923,924,92
The conveyance force is applied to the sheet 5 again, and the sheet 5 is prepared for the subsequent conveyance of the transfer sheet P2.

Next, in the case of B4 vertical feeding (longitudinal feeding) shown in FIGS. 3B, 4B, and 5B, the leading end of the transfer paper is fed to the vertical feeding roller 923. At the same time it is gripped, the transfer paper transport speed is about 50 times faster than usual.
It becomes 0 mm / sec (twice the process speed), and the transfer paper P1 is conveyed at this speed. At this time, each transport roller 804,813,92
2 is also switched to high-speed driven rotation by the action of the one-way clutch. After passing through the vertical transport roller 925,
About 0.66 seconds after the rear end of the transfer paper P1 exits the fixing roller 701 of the fixing device 700, the front end is detected by the sensor 927, and the signal causes the front end to be aligned with the stop position 928 to stop. At the same time, the transport direction is switched by 90 degrees.

About 5 seconds after the start of the right-angled conveyance, the conveyance is performed for about 270 mm, and at this time, it is placed at a position where it does not interfere with the following transfer sheet P2 (see FIG. 4 (b)). This is about 1.9 seconds after the trailing edge of the transfer sheet P1 exits the fixing roller 701, and at this time, the leading edge of the following transfer sheet P2 is immediately before the roller pair 804. Interference with will be avoided. The on / off control for roller conveyance is basically the same as in the case of A3 described above. In this way B4
The transverse feed at right angles will be completed.

Furthermore, also in the case of A4 horizontal feeding (short-side feeding) shown in FIGS. 3 (c), 4 (c) and 5 (c), the leading end of the transfer paper is the vertical conveyance roller 923. At the same time, the transfer paper transport speed is about 50 times faster than usual.
It becomes 0 mm / sec (twice the process speed), and the transfer paper P1 is conveyed at this speed. At this time, each transport roller 804,813,92
2 is also switched to high-speed driven rotation by the action of the one-way clutch. After passing through the vertical transport roller 925,
Approximately 1.3 seconds after the rear end of the transfer paper P1 exits the fixing roller 701 of the fixing device 700, the front end is detected by the sensor 927, and the signal causes the front end to be aligned with the stop position 928, and the transfer is stopped. At the same time, the transport direction is switched by 90 degrees.

When about 6 seconds have passed after the start of the right-angled conveyance, the conveyance is carried out for about 310 mm, and at this time, it is placed at a position where it does not interfere with the transfer sheet P2 that follows (see FIG. 4 (c)). This is about 2.6 seconds after the trailing edge of the transfer sheet P1 exits the fixing roller 701, and at this time, the leading edge of the succeeding transfer sheet P2 is immediately before the roller pair 804, whereby the succeeding transfer sheet P2 Interference with will be avoided. The on / off operation for roller conveyance is basically the same as in the case of A3 and B4 described above. In this way, the A4 transverse feed right angle conveyance is completed.

In this way, the right-angled discharging operation with respect to the sorter is performed by the driving rollers 923, 924, 925 which are constantly rotated in the forward-direction conveying roller and the right-angled conveying roller provided in the image forming conveying path and the sorting discharging conveying path, respectively.
On the other hand, the pinch rollers 923a, 924a, 925a are pressed and released at a predetermined timing. That is, with respect to the drive rollers 923, 924, 925 that constitute the forward-direction transport roller of the image-forming transport path,
When the pinch rollers 923a, 924a, 925a as pressure contact rollers are pressed into contact with each other, the recording paper is conveyed from the image forming conveyance path to the sorting discharge conveying path, and when the recording sheet comes to a predetermined position, the image forming conveyance is performed. When the pinch rollers 923a, 924a, 925a as pressure contact rollers are removed from the drive rollers 923, 924, 925 that make up the forward transport rollers of the road, the application of the forward transport force to the recording paper is stopped, and at the same time for sorting. A pinch roller 926a as a pressure contact roller is brought into pressure contact with a drive roller 926 forming a right angle conveyance roller of the discharge conveyance path, so that a right angle conveyance force is applied to the recording sheet. As a result, the recording paper is always constantly changed in direction and quickly changed in direction and sent to the sorter.

In order to obtain the shortest conveyance time for each paper size, the high-speed conveyance speed may be varied for each size, and the high-speed conveyance speed may be controlled by a constant K determined by the paper size and the interval between the paper sheets. . However, in this case, it is necessary to provide a separate drive source or a control clutch.

Further, as described above, in the right-angle discharging operation to the sorter, the paper feeding speed in the image forming conveying path is increased in a constant relationship with the process speed, whereby the preceding recording in the image forming conveying path is performed. The space between the paper and the recording paper in the succeeding line is set to a certain value or more. That is, the preceding transfer paper P1 is received at the entrance of the right-angled conveyance path and is sent out from it, and then the transfer paper P2 of the succeeding part enters the entrance of the right-angled conveyance path. For this reason, at the entrance of the right-angled conveyance path, the wrap interference state between the preceding recording paper and the succeeding recording paper is surely prevented, and a good discharging operation is performed.

Note that FIGS. 13A, 13B, and 13C show the transfer paper feed when the transfer paper is conveyed at a high speed when the rear end of the transfer paper is detected by the paper detection sensor 801. The state is represented. In the case shown in this figure, the paper discharge time is slightly shorter than that in the transport in the above embodiment.
However, in the above-described embodiment, there is no sensor for detecting the paper for switching from the low speed to the high speed, and the transport rollers 923, 924, 925, 926 may be kept rotated in the high-speed transport state.

Further, in the above-described embodiment, the high-speed transport speed is set to twice the low-speed transport speed, so that drive elements such as the sprocket, timing pulley, and gear can be shared.
It can be a minimal drive element. The fixing device 70
Since the conveyance control is performed from 0 onward, the fixing temperature control only needs to be performed only on the transfer paper fed at the process linear velocity, and thus the control of the fixing device can be simplified. .

As shown in FIG. 6, the transferred transfer paper passes through the guide plate 1301 and is guided upward by the gate 1302.
Further, as shown in FIG. 7, the gate 1104a is rotated counterclockwise so that the first transfer sheet is paired with the roller pair 1102a, 112.
After passing through 03a, it is fed to the bin tray 1101a. 2
Gates 1104a are opened for the first transfer sheet, gates 1104c are opened for the third transfer sheet, and so on. Stacked. The gate 1105 for the tenth bin 1101j is fixed at the always open position.

In the front-side discharge with the image side up, first, the transfer sheet is switched back in the image forming main body in the same manner as in double-sided copying, and is sent to the sorter conveyance path. The transfer operation of the transfer sheet from the sorter transfer path to the sorter is the same as in the case of the back side discharge.

As for the operation of switching between front side discharge and back side discharge on the sorter 1000 side, the paper processing on the image forming main body side is stacked on the re-feeding device without switchback as in the case of multiplex (composite) copying. explain. Guide plate 1301
Since the image surface is conveyed to the bottom of the sheet, the above-described operation is performed when the back surface is discharged, that is, the gate 1302.
Is located at the bottom and the transfer paper is guided directly to the upper 10 bin sorters. For the front side discharge, the gate 1302 is located above and the transfer paper is first guided to the lower ten bin sorters. The right side of the transfer paper at this time is the image surface. When the sensor 1210 detects the rear end of the transfer paper, the roller
1307, 1205, 1206, and 1207 are reversed and the transfer paper switches back to the upper 10 bin sorters. The stacking in each bin is the same as that for the back side discharge, but the image side is on the tray.

Further, as shown in FIG. 8, in the lower ten bin sorter, the gate 1302 is displaced upward, and the transfer sheet is guided downward by the guide plate 1301 to pass the roller pair 1307. When the first sheet (the 11th sheet is correct since it is the operation after the 11th bin), the gate 1204a is opened and passes through the rollers 1202a and 1203a, and the bin tray 1
Stacked on 201a. Subsequent gates 1204b, 1204c
Is opened and stacked on the trays 1201b and 1201c.

The operation of switching between front side discharge and back side discharge on the sorter 1000 side will be described. In the case of reverse-sided paper ejection, the gate 1302 located directly above
Head to 10 bottle sorters. In the case of front side discharge, the gate 1302 is located below and after passing through the guide plate 1301,
First, they are sent upward. At this time, the image surface is on the left side of the transfer paper in the figure. When the trailing end of the transfer paper is detected by the sensor 1110, the rollers 1102 and 1103 are inverted, whereby the transfer paper is switched back. The subsequent operation is the same as the other stacking operation, in which the gate 1204 is opened, passes through the pair of rollers 1202, 1203, and is stacked on the tray 1201.

FIG. 9 shows a state in which, in addition to such 20 bottle sorters, 20 bottle sorters are further equipped. The additional 20 bottle sorters have a similar internal configuration. The transfer of the transfer paper to the additional 20-bin sorter is performed by sewing between the 10 bin sorters. At this time, the gate 1302 is set at an intermediate position as shown in FIG. 10 (b).
The transfer paper that has passed through the guide plate 1301 is moved horizontally as it is, and passes through the rollers 1304, 1305, and 1306. The operation after passing through the guide plate 1303 is the same as the operation of the 20 bottle sorters after the guide plate 1301.

According to such a sorter, the following advantages can be obtained.

The transfer paper is taken out in the front direction, and the edge of the transfer paper can be brought to the front irrespective of the size of the transfer paper, so that the transfer paper can be easily taken out.

Post-processing such as stapling or punching of the transfer paper edge can be easily performed, and manual operation can be performed.

Even if a jam occurs during sorting, the jammed paper can be easily taken out because the edge of the copy paper is on the front side.

Transfer paper of relatively large size, such as A3 size or B4 size, can be fed in the short direction, so that the transport efficiency is improved and speedy sorting work is possible.

Since the A3 size maximum transfer paper is fed in the short direction and stacked on the bin tray, the width direction of the sorter can be shortened to save space. The width can be further reduced by limiting the number of stacks in the bin and giving the bin a certain angle or more.

Since it can be sequentially added, a large-capacity sorter can be provided that sufficiently satisfies the needs of the user. Even in this case, the transport path of the sorter can be kept short to prevent a decrease in transportability.

As described above, according to the present invention, the sorter is arranged on the side of the front operation type image forming main body, and the direction is changed from the image forming transport path of the image forming main body to a substantially right angle direction. Since the sorting discharge path for sending the recording paper to the sorter is provided in this manner, the overall size of the image forming apparatus including the image forming main body and the sorter can be reduced,
Further, a large operation space around the periphery can be made extremely small, the image forming apparatus can be installed in a small space, and the handling of the transfer paper can be made convenient.

In addition to this, according to the present invention, the paper feed speed in the image forming conveyance path is smoothly increased via the one-way clutch in a constant relationship with the process speed, whereby the preceding recording paper in the image forming conveyance path is increased. Since the gap between the following recording paper and the following recording paper is set to a certain value or more, the lap interference state between the preceding recording paper and the succeeding recording paper at the entrance of the right-angled conveyance path is simple. This is reliably prevented, and good paper conveyance can be stably performed at high speed.

[Brief description of the drawings]

FIG. 1 is an explanatory perspective view showing an example of a paper conveyance switching mechanism for carrying out the present invention, and FIG. 2 is a schematic side explanatory view showing an entire image forming apparatus equipped with a copying machine to which the present invention is applied. 3 (a), (b), (c), 4 (a), (b),
(C) and FIGS. 5 (a), (b), and (c) are explanatory views of the positional relationship showing the transfer state of the transfer paper, and FIG. 6 shows a sorter for the image forming apparatus shown in FIG. FIG. 7 is a schematic front view showing an expanded state, FIG. 7 is an enlarged front view illustrating the configuration and operation of a bin / sorter located above the sorter, and FIG. 8 is a bin / sorter located below the sorter. 9 is a second enlarged view showing the configuration and operation of FIG.
A schematic front view showing a state in which a sorter is further added to the image forming apparatus shown in the figure, and FIGS. 10A and 10B are enlarged front views illustrating the configuration and operation of the sorter inlet section. Fig. 11 shows the automatic reverse document feeder (AR
FIG. 12 (a), (b), (c) and (d) is an enlarged side view of the DF), showing the structure of the document feeding section, reversing section and document feeding section of the automatic reversing document feeder (ARDF). FIGS. 13 (a), 13 (b) and 13 (c) are partial enlarged side views for explaining the operation, and FIGS. 13 (a), 13 (b) and 13 (c) are explanatory views of the positional relationship showing the transfer state of the transfer sheet in another embodiment of the present invention. C: Copier body, 400: Multi-stage paper feeder (PB), 100
… Automatic reversing manuscript device (ARDF), 1000 …… Sorter, 923,
924,925 …… Vertical transport roller, 926 …… Right-angle transport roller, 923a, 924a, 925a, 926a …… Pinch roller.

Claims (1)

(57) [Claims] 1. A front side provided with an image forming conveyance path for conveying a recording sheet, on which an image is formed and discharged at a predetermined process speed, toward a front side and a rear side at a predetermined paper feed speed. An operation type image forming main body section, a sorter for sorting recording papers arranged in parallel on the side of the image forming main body section, and a recording paper discharged from the image forming conveyance path and conveyed in a substantially right angle direction. Then, in the paper transport mechanism of the image forming apparatus, which comprises a sorting discharge transport path continuously provided to the image forming transport path so as to feed the recording paper to the sorter, the paper transporting means in the image transport path. Is provided with a paper conveyance speed increased in a fixed relationship with the process speed, and is driven via a one-way clutch so that the distance between the preceding recording paper and the succeeding recording paper becomes a certain value or more. It Paper transport mechanism of the image forming apparatus characterized by being.