JPH0210062B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Field of Industrial Application The present invention relates to a sheet stacking device equipped with a sheet sorting section capable of sorting and collecting sheets such as transfer paper, and specifically relates to a sheet stacking device that is equipped with a sheet sorting section that can sort and stack sheets such as transfer paper. Used with a forming device to sort and collect sheets on which images have been formed,
The present invention relates to a sheet stacking device that can perform multiple functions such as forming images on both sides of a sheet and forming multiple images on one side of a sheet.

(b) Prior art In recent years, image forming devices such as copying machines (hereinafter referred to as copying machines) have a sheet sorting function for sorting and collecting copied sheets, a duplex function for forming images on both sides of sheets, and a duplex function for forming images on one side of sheets. There is a demand for multi-functions such as multiple functions for multiple copying, as well as systemization. Conventionally, these multi-functions have been built into the main body of the copying machine in advance, or separately from the main body of the copying machine, such as a sorting device, duplex device, etc. is attached to support multi-functionality.

For example, as shown in FIG. 6, the copying apparatus 1 includes a document table 2 that can slide back and forth with a document M placed thereon;
Lens system fixed to support member S of the main body of the device
LE, and two cassettes C ₁ and C ₂ on which a large number of sheets can be placed and which can be attached to and removed from the main body of the apparatus, and a cylindrical photoreceptor having a central axis extending perpendicular to the sheet surface. 3, and a developing device 5, a cleaner 6, and a charger 7 arranged near the periphery thereof are integrally arranged in a frame 9, and these photoreceptor 3, developer 5, cleaner 6, and charger 7 are connected to the main body. A unit 10 that can be freely inserted and removed from the support member S
It consists of Furthermore, a conveyance device 13 having a transfer charger 11, a separation roller 12, etc. is disposed below the unit 10, and a conveyance device 13 is provided below the unit 10.
A paper feed roller 15 and a registration roller 16 for feeding the sheets on the cassettes C ₁ and C ₂ are disposed at 3.
A fixing device 17 to which the transferred sheet is fed from the conveyance device 13 is also provided. And fuser 1
A flapper 19 for changing the sheet feeding direction is disposed at the exit portion of the copying machine 7, and the flapper 19 transfers the sheets to a sheet sorting device 2 separate from the main body 1 of the copying machine.
0 or an intermediate tray 22 disposed within the device main body 1
It is selected and fed to the conveyor belt 23 that leads to. The sheet sorting device 20 has a large number of sheet storage bin trays 25.
..., and these trays 25 can be transported up and down by a conveyor 26, and sheets are discharged and collected on a predetermined tray 25 by a paper feed roller 27. On the other hand, the intermediate tray 22 is installed at a lower position of the apparatus main body 1 and inclined to ensure sheet stacking and refeeding performance. A feed roller 29 and a feed roller 30 are provided.

Based on the above configuration, when the document table 2 moves, the document M placed on the document table 2 is irradiated by the light source L, and the reflected light passes through the lens system LE and is uniformly charged by the charger 7 in advance. An electrostatic latent image is formed on the surface of the photoreceptor 3, and then, based on the rotation of the photoreceptor 3 in the direction of the arrow, the electrostatic latent image forms a toner image at the position of the developing device 5. Meanwhile, cassette C ₁
Or, the sheets loaded on C ₂ are loaded on paper feed roller 1.
5, and is aligned with the toner image on the surface of the photoreceptor by a registration roller 16, and further transferred to the sheet surface by a transfer charger 11. Furthermore, the sheet carrying the toner image is separated from the photoreceptor 3 by a separation roller 12,
The image is sent to the fixing device 17 by the conveyance device 13, and is fixed therein. In the case of single-sided copying, the flapper 19 is switched to the sheet sorting device side, and the copied sheet is ejected to a predetermined tray 25 by the paper feed roller 27, and
are moved by a conveyor 26 according to a prespecified sorting method, and the sheets are sorted in a predetermined pattern. On the other hand, in the case of double-sided copying, the flapper 19
is switched to the intermediate tray side. Therefore, the sheets copied on one side are guided to the intermediate tray 22 by the conveyor belt 23, and a predetermined number of sheets are stacked and accumulated on the tray 22. When the one-sided copying is completed, the sheet on the intermediate tray 22 is transferred to the feed roller 29.
The sheet is switched back and fed from the rear end surface by the feed roller 30, and is copied onto both sides of the photoreceptor 3 and the transfer charger 11 with the uncopied side facing upward, and then transferred to the fixing device 17 as described above. The sheets are then sent by the flapper 19 to the sheet sorting device 20, where they are sorted in a predetermined pattern.

Further, as another example of the conventional copying apparatus 1', there is one shown in FIG. The copying device 1' also includes:
Similar to the copying apparatus 1, a document table 2, a cassette
C ₁ , C ₂ , lens system LE, photoreceptor 3, developer 5,
The unit 10 includes a cleaner 6, a charger 7, a transport device 13, a fixing device 17, and the like.
Then, it branches to a path 31 from the fixing device 17,
A reversing guide path 32 having a paper feed roller 34 is provided, and a flapper 33 connects the reversing guide path 32 to the path 3 to the sheet sorting device 20'.
It can be switched to 5. Furthermore, a path 37 is installed which is guided from the reversing guide path 32 via a flapper 36, and this path 37 has a large number of discharge ports 37a.
... According to the sheet size, the intermediate tray 22'
guided by. On the other hand, the sheet sorting device 20' is constructed separately from the main body of the copying apparatus 1', and is fixed to the main body of the apparatus with screws or the like. Further, the sorting device 20' has a large number of trays 25' fixed thereto, and flappers 41... and paper feed roller 42
...is arranged.

Based on the above configuration, the sheet transferred by the photoreceptor 3 and fixed by the fixing device 17 is transferred to the path 31.
guided by. In the case of one-sided copying, the flapper 33 is switched to the path 35 side, and the ejection roller 39
from there to the sheet sorting device 20'. and,
Flapper 41 and paper feed roller 4 of sorting device 20'
2, sheets are stacked on a predetermined tray 25' according to a predetermined sorting method. On the other hand, in the case of double-sided copying, the flapper 33 is switched to the reversing guide path 32 side, the single-sided copied sheet sent from the path 31 is guided to the guide path 32, and then the sheet feeding roller 34
Switch the sheet by flipping the . Then, the reversed sheet is discharged by the flapper 36 to the intermediate tray 22' through the path 37,
A predetermined number of single-sided copy sheets are stored in the tray 22'. Further, the sheet on the intermediate tray 22' is sent to the photoreceptor 3 portion with the non-copied side facing up by the feeding roller 29 and the sending roller 30, and is transferred to the upper surface of the sheet at this portion. The sheets that have been double-sided copied are then sent to the sheet sorting device 20' and sorted into each tray 25'.

(c) Problems to be solved by the invention Therefore, in the main body of the copying machine 1 (or a special double-sided copying machine), the special intermediate trays 22, 22'
Furthermore, it is necessary to install the intermediate tray 22 at an angle to ensure sheet loading performance, or to install a reversing mechanism such as a reversing guide path 32 outside the intermediate tray. A large dead space is created, and the double-sided copying device becomes quite large, so that the entire unit including the sheet sorting devices 20, 20' becomes a fairly large device. Furthermore, as shown in FIGS. 10 and 11, when a double-sided copying device part is incorporated into the main body of the copying device 1,
As the main body of the device becomes larger, it is necessary to have a fairly robust structure in terms of strength, which also causes an increase in weight.

Furthermore, when troubleshooting problems such as paper jams, paper jams can occur over a wide range of locations because the main body of the copying machine, the double-sided copying section, the sheet sorting device, and the sheet conveyance path are long and complicated.
It takes time to find the location where paper jams occur, and because the intermediate tray and conveyance section of the duplex copying device are built inside the device, the location of the paper jam cannot be seen from the outside, making it difficult to open the cover, etc. This requires a lot of work, and troubleshooting has become extremely troublesome. Furthermore, as shown in the above-mentioned conventional example, the intermediate trays 22, 22' are generally installed in the lower part of the apparatus, that is, near the floor, and the user must bend down to clear paper jams, making it extremely inconvenient to use. It's getting worse.

In addition, single-sided copied sheets are stacked on the intermediate trays 22 and 22', but these sheets often curl due to the pressure and heat received during the fixing process, so the curled sheets are When refeeding from the tray, feeding errors such as double feeding are likely to occur, which, together with the increasing size and complexity of the copying apparatus, is a factor that reduces the reliability of the entire apparatus.

Furthermore, in addition to multi-functionality and systemization of copying devices as mentioned above, there has recently been a trend toward personalization, but copying devices that meet this trend are limited by limitations such as size, weight, price, etc. They are not equipped with many functions; for example, even paper feeding devices are generally equipped with a single paper feeding device or devices that only have a manual feed function. Therefore, although mini-sorters, optional cassettes, document feeders, etc. can be added to such personal copying machines according to the user's requests, these mini-sorters and other devices only have individual functions. If these devices are installed one after another in the main unit of the device, the unit device as a whole becomes quite large and expensive, even though the main unit is small and low-priced. The benefits of this are not being taken advantage of.

Therefore, the present applicant has developed a sheet stacking device that utilizes the bin tray in a sheet sorting device as an intermediate tray and returns the sheets on the bin tray to the copying machine main body by a sheet refeeding means, which has multiple functions such as double-sided copying. proposed.

However, even in this sheet stacking device, when performing multiple copying in which multiple images are overlapped and copied on one side of a sheet, the sheet on which the first image has been copied is stacked on the bin tray used as an intermediate tray. It is necessary to first invert the sheets and stack them face down. Therefore, it is necessary to provide a sheet inversion path in the apparatus main body or the like for inverting the sheets. For this reason, with the sheet stacking device proposed by the applicant, double-sided copying can be performed in a small space by using a sheet sorting device, but in order to perform multiple copies, it is still difficult to perform multiple copies due to the sheet reversing path. It has the problems mentioned above.

(d) Means for Solving the Problems The present invention aims to solve the above-mentioned problems, and provides an image forming section and a sheet for discharging a sheet on which an image has been formed in the image forming section. An image forming apparatus comprising a discharging means and a sheet introducing means for introducing a sheet and guiding the sheet to the image forming section, the image forming apparatus comprising a unit separate from the image forming apparatus and aligned with the sheet discharging means. A sheet loading device is provided having a sheet inlet for and a sheet outlet aligned with said sheet introducing means.

Further, the sheet stacking device has the sheet entrance on one side, and has a large number of movable bin trays that can move up and down and a fixed bin tray arranged in line at the bottom of these movable bin trays on the other side. a sheet classification section consisting of a vertically long member installed;
a sheet conveying section having the sheet outlet above and conveying the sheets from the sheet sorting section to the sheet introducing section via the sheet outlet, and a sheet discharging rotary body at a predetermined position facing the movable bin tray. The sheet discharging rotor is connected to a forward/reverse drive means to reverse and convey the sheets guided to the movable bin tray. further comprising a first switching means for guiding the sheet directly toward the sheet conveyance unit on a conveyance path that guides the sheet to the sheet discharge rotary body, and facing the fixed bin tray; A re-feeding means capable of re-feeding the sheets collected in the bin tray is provided, and the sheet is directly guided in the direction of the sheet conveying section through a conveying path that leads the sheet to the re-feeding means. A second switching means is provided to perform the operation.

The sheet sorting section is movably connected to the sheet conveyance section by a guide member, and a guide plate is provided which constitutes a conveyance path facing the sheet entrance, the first switching means, and the second switching means. It is characterized by being configured so that it can be opened.

(E) Operation Based on the above configuration, the sheet sorting section sorts and collects sheets into each bin tray according to a predetermined pattern. Further, when double-sided images are formed on a plurality of sheets, the sheet with an image formed on one side by the image forming apparatus is introduced from the sheet discharging means to the sheet sorting section via the sheet inlet, and then the first switching means and A predetermined number of sheets are discharged to a fixed bin tray via the second switching means and accumulated on the bin tray. Thereafter, the sheet on the fixed bin tray is re-fed by the re-feeding means, the sheet is conveyed through the sheet conveying section, from the sheet outlet through the sheet introducing means, again to the image forming section, and then the sheet is conveyed to the image forming section again. An image is formed on the back surface of the sheet at the sheet sorting section, and the sheet is sorted and stored in each movable bin tray again at the sheet sorting section. Also, when forming multiple images on multiple sheets,
A sheet with an image formed on one side is discharged toward a movable bin tray by a sheet discharge rotary body of a sheet sorting section, and the discharge rotary body is reversed with the rear end of the sheet being bitten by the discharge rotary body, Switch the sheet back and forth. Then, the sheet is discharged to a fixed bin tray by the second switching means and accumulated on the bin tray with the image side facing down. After that, in the same manner as the double-sided image formation described above, the sheet on the fixed bin tray is re-fed by the re-feeding means, an image is formed on the surface on which the image is formed in the image forming section, and the sheet is classified. Sort and collect into departments.

If a jam occurs in the sheet stacking device, the sheet sorting section is moved away from the image forming apparatus and the sheet conveyance section by the guide member. In this state, by opening the guide plate, the sheet entrance, the first switching means, and the second switching means are opened, and since a jam normally occurs in these parts, it is not possible to easily remove the jammed sheet from the open position. can.

(f) Examples Examples of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the copying device 50 includes a document table 2, a light source L, a lens system LE, two cassettes C ₁ ,
C ₂ , and a cylindrical photoreceptor 3 is disposed within the device main body. Further, near the periphery of the photoreceptor 3, two developing devices 5 and 5' each containing toner of a different color, a cleaner 6 and a primary charger 7 are installed at the tip of the conveying device 13. A transfer charger 11 and a separation roller 12 are provided. Further, paper feed rollers 15, 15 are disposed in the cassettes C ₁ and C ₂ and are guided to a pair of registration rollers 16 via paths 51 and 52, respectively. It is guided from the guide port 53 to the registration roller pair 16 via a path 55. In addition, the transport device 1
A fixing device 17 is disposed at the rear end portion of 3.
Further, the fixing device 17 is provided with a pair of discharge rollers 56 for discharging the sheet to the outside of the machine, and a sensor _S0 for detecting the passage of the sheet.

On the other hand, the sheet sorting section 57 and the sheet conveying section 59
A sheet stacking device 60 consisting of a sheet stacking device 60 is arranged facing the copying device 50. The sorting section 57 of the sheet stacking device 60 is made of a vertically elongated member, with an opening for a path 62 serving as a sheet entrance formed on one side, and n-1 movable sheet storage movable bin trays 61 ₁ , 61 ₂ on the other side. . . 61 _o-1 is supported so as to be movable up and down, and one fixed bin tray 61 _o is disposed at the lowest stage. Furthermore, a path 62 is formed in the sorting section 57 at a position that can be aligned with the ejection roller pair 56 of the copying apparatus main body 50, and the movable trays 61 ₁ to 61 Can feed sheets to _o-1 .
The movable trays 61 ₁ to 61 _o-1 are moved up and down by a known drive mechanism (for example, see Japanese Patent Application Laid-open No. 78769/1983) comprising a forward/reverse motor and a grooved cam.
Further, a path 65 is formed by being branched and selected by the first flapper 63, and furthermore, the path 65 is connected to a fixed tray 65 _o which is selected by the second flapper 66.
The route is branched into a route 67 to the transport section 59 or a route 68 to the transport section 59. Further, a second ejection roller pair 69 for ejecting to the fixed tray 61 _o is disposed on the path 67, and the ejection roller pair 69 and the fixed tray 61 _o are further provided.
A refeed roller 70 is disposed between the two.
Further, the sheet conveying section 59 is composed of an oblong base-like member having a pair of conveying rollers ₇₁₃ at the upper side serving as a sheet outlet, and the copying device 50 is placed on the base-like member and constitutes a lower frame thereof. Three pairs of conveyor rollers 71 ₁ , 71 ₂ , 71 ₃ are mounted on both side plates (not shown).
is pivotally supported, and an adjustment roller pair 72 consisting of upper and lower biting rollers, which will be described later, is disposed between the second and third conveyance roller pairs 71 ₂ and 71 ₃ . Furthermore, guide plates 73 ₁ , 7 are provided between each roller.
3 ₂ , 73 ₃ , 73 ₄ are installed, and the 3rd
The transport roller pair 71 ₃ is arranged to align with the guide port 53 of the main body of the copying device 50 . In addition,
As shown in FIG. 2, a guide rail G is fixed to both side plates constituting the lower frame of the sheet conveying section 59, and a rod R guided by the guide rail G is fixed to the sheet sorting section 57. A pair of conveying rollers 71 constitutes a guiding member when moving/separating the sheet sorting section 57 in the direction of arrow A.
₃ is aligned with the guide port 53 and the path 62 is aligned with the discharge roller pair 56. When the sheet sorting section 57 is moved in the direction of arrow A, the guide plates T forming the paths 62 and 65 can be separated.
7 can be opened.

Further, as shown in FIG. 3, an upper guide plate 62a and a lower guide plate 62b constituting the path 62 are fixedly installed between both side plates 75 of the sheet stacking device 60, and between these upper and lower guide plates 62a and 62b. A shaft 63a to which the first flapper 63 is fixed is disposed, and the shaft 63a is pivotally supported by a side plate 75. Furthermore, an arm 76 is fixed to one end of the arm 76, and a spring 77 is tensioned at one end of the arm 76, urging the flapper 63 to the solid line position, that is, the position where the path 62 is communicated with the pair of discharge rollers 64. and a solenoid 79 is connected to the other end to move the flapper 63 to the chain line position, that is, the path 65.
It can be switched to a position communicating with. Further, a large number of auxiliary guide members 81 are disposed in the upper part of the upper guide plate 62a in the shape of a comb so as to be rotatable around a shaft 80 extending between the side plates 75. The upper guide plate 62
protrudes into the path 62 through the notch hole a,
A path 65 allows the sheet to flow toward the pair of discharge rollers 64 and transports the sheet returned from the discharge roller 64.
lead to. Further, a micro switch SW ₁ is disposed facing one of the auxiliary guide members 81, and the switch SW ₁ is turned on by the upward rotation of the auxiliary guide member 81 based on the passage of the sheet along the path 62. , to detect the passage of the sheet. Further, the first discharge roller pair 64 includes an upper roller 64a and a lower roller 64.
b, which fixes the lower roller 64b and has a side plate 7.
A forward/reverse DC motor 82 is attached to the shaft supported by 5.
are connected to each other, and the shaft fixing the upper roller 64a is interlocked with the lower roller shaft via a gear.

Note that, like the first flapper 63, the second flapper 66 is also connected to the second ejection roller pair 69 by a spring.
and is configured to be switched to path 68 by a solenoid.

Further, as shown in FIG. 4, the second discharge roller 69 consists of an upper roller 69a and a lower roller 69b, a shaft 83 fixing the lower roller 69b is supported by a side plate, and a conveyance roller 71 ₁ ~71 ₃
At the same time, the lower roller 69b is driven counterclockwise in FIG. 1, and the lower transport roller is driven clockwise by a timing belt 85 and a gear 84 so that the rotation directions are reversed. Also, a shaft 86 fixing the upper roller 69a
is interlocked with a lower roller shaft 83 via a spring clutch 87 and a gear train 87a, and a spring clutch 88 and a gear train 88a. is driven in the forward and reverse directions based on the Furthermore, an arm 89 is attached to the upper roller shaft 86.
A bell crank 89 having arms 89a and 89b is rotatably supported, and the arms 89 of the bell crank 89 are rotatably supported.
A refeed roller 70 is rotatably supported at the tip of 9a via a shaft 90. Further, the shaft 90 is interlocked with the upper roller shaft 86 via a timing belt 91, and the refeed roller 70 is connected to the upper roller 69a.
rotated in sync with and in the same direction. On the other hand, a spring 92 is tensioned at the tip of the other arm 89b of the bell crank 89, and a solenoid 95 is connected via a link arm 93 in a direction opposite to the spring biasing direction. Further, a back up link 97 is rotatably supported on a shaft 96 passed between the side plates, and an arm 97a formed at one end of the link 97 is connected to the solenoid link arm 93 together with the arm 89b through a long hole or the like.
is connected to. Furthermore, the back up link arm 97 extends to the fixed tray 61 _o below the refeed roller 70 and contacts the lower part of the auxiliary plate 100 which is pivotally supported by a pin 99 at the base of the fixed tray 61 _o . Therefore, in synchronization with the refeed roller 70, that is, as the refeed roller 70 descends, the auxiliary plate 100 is rotated in the upward direction based on the back up link arm 97, and the sheet on the auxiliary plate 100 is refeeded. do.

Further, as shown in FIG. 5, a pair of adjustment rollers 72
consists of a lower driving roller 72a and an upper driven roller 72b, and a biasing spring applies a gripping force to clamp the sheet between the two rollers. Furthermore, the lower roller 72 is splined to a shaft 101 provided across both side plates, and the shaft 101 is interlocked with a drive chain 103 via an electromagnetic clutch 102. Further, two circular guide plates 105 are supported on the lower roller shaft 101 so as to be able to slide together with the lower roller 72a.
A pin 107 fixed on the circumference of the disk 106 is located between
is engaged. Further, a servo motor 109 is fixed to the frame side plate, and the motor 1
The disc 106 is fixed to the output shaft of the motor 109, and the lower roller 72a is driven by the motor 109.
01 can be slid on. On the other hand, the driven upper roller 72b
is slidably supported by the upper roller shaft 110, and a disk 111 is fixed to one end of the upper roller 72b. The disc 111 is engaged with the guide plate 105, and therefore the upper roller 72b
can slide in the axial direction together with the lower roller 72a.
Further, a micro switch SW ₂ is disposed above the guide plate 73 ₃ on the slightly upstream side of the pair of adjustment rollers 72 , and the switch SW ₂ is connected to the guide plate 73 ₃ .
The actuator is pushed up by the sheet passing through the actuator, and the passage of the sheet is detected. Further, a guide plate 73 ₄ on the slightly downstream side of the adjustment roller pair 72
A photo interrupter PI is disposed on the side surface of the notch, and the photo interrupter PI detects the side end surface of the sheet by blocking the transmitted light.

The lower rollers of the conveyance rollers 71 ₁ , 71 ₂ , 71 ₃ are driven by the main drive source of the sheet conveyance unit 59 by a drive chain 103 or the like, and the upper rollers are interlocked with the lower rollers by gears. ing.

Next, the operation of this embodiment will be explained.

First, a so-called sheet sorting (sorter) function will be described in which the sheet stacking device 60 of this embodiment is used to sort a plurality of copies n of sheets in a predetermined pattern by single-sided copying.

The sheet, one side of which has been copied in the main body of the copying device 50, is discharged from the pair of discharge rollers 56 to a path 62 in the sheet stacking device 60. At this time, the first flapper ₆₃ is set to the position shown by _the solid line in FIG _. It is initially set to . In this state, the first sheet from the path 62 is discharged and collected onto the first movable tray 611 by the pair of discharge rollers ₆₄ , and n copies and sorting of documents in a predetermined pattern, for example, pages a to z, are performed. In this case, after the first sheet of page a is stacked on the first movable tray 61 ₁ , the movable tray is immediately raised and placed on the second movable tray 61.
₂ is aligned with the discharge roller pair 64. This results in
The second copy sheet is stacked on the second movable tray ₆₁₂ , and similarly, the n-1th copy sheet is stacked on the movable tray 61o _-1 . For the nth seat, the solenoid 79 is energized and the first flapper 63 is activated.
is switched so that it leads to the path 65 and the second flapper 66 leads to the fixed tray _61o ,
The n-th sheet of the page is stacked on the fixed tray 61 _o by a pair of discharge rollers 69 . At this time, the refeed roller 70 is in the raised position as shown by the solid line in FIG. 1, and does not interfere with the discharge of the sheet to the fixed tray _61o . Similarly, n copies of the b-th page are stacked on each of the trays 61 ₁ to 61 _o , and similarly, copy sheets up to the z-th page are stacked on each tray one after another.

Next, a case will be described in which double-sided copying is performed in which copies are made on both sides of a sheet.

When the operator instructs double-sided copying of the number n of sheets and operates the start switch of the copying device 50, the sheet sorting section 57 is set to the initial state as necessary, and the first flapper 63 is activated to excite the solenoid 79. , and the second flapper is set to the solid line condition so as to lead to the dashed line condition or path 65.
Then, when a sheet copied on one side by the copying device 50 is introduced from the discharge roller pair 56 into the path 62 of the sheet stacking device 60, the sheet is guided by the first flapper 63 and led to the path 65, and then further It is guided by the second flapper 66 and led to a path 67. At this time, the spring clutch 87 is not connected, and the spring clutch 88 is connected, and the lower roller 69b and the upper roller 6 are connected via the gear train 88a.
Both rollers 9a are rotated in the forward rotation direction, that is, in the direction in which both rollers work together to discharge the sheet to the fixed tray 61 _o , and the solenoid 95 is not energized, and the refeed roller 70 is rotated by the spring 92. in a raised position. Therefore, the sheet guided to the path 67 is transferred to the fixed tray 6 by the second discharge roller pair 69.
Emitted and collected at 1 _o . Such an operation is repeated n times, and n sheets with one-sided copies are stacked and accumulated on the fixed tray _61o with the copy side facing up.
When the last n-th sheet passes through the detection sensor _S0 of the copying machine main body 50 and its trailing edge is detected, a sufficient time has elapsed for the sheet to be stacked on the fixed tray _61o . , one-sided copying is automatically completed and preparations are made to copy the other side of the sheet, and the rotation of the discharge roller pair 69 of the sheet stacking device 60 is also stopped. Next, the copying device main body 5
0, a signal to start copying on the other side of the sheet (double-sided copy signal) is energized, the solenoid 95 is energized, the bell crank 69 is rotated clockwise, and the refeed roller 70 is moved downward. Rotate the back up link 97 counterclockwise to lift up the auxiliary plate 100. Furthermore, the timing belt 85
etc., the lower roller shaft 83 is rotated in the normal rotation direction, and the spring clutch 87 is connected and the spring clutch 8
8 is cut, and the upper roller shaft 8 is connected via the gear train 87a.
6 is given rotation in the reverse direction. This causes the upper roller 69a to move in the reverse direction, that is, to move the sheet to the fixed tray 6.
1 _o to the path 62, the lower roller 69b also rotates, and the re-feed roller 70 is further rotated in the same direction via the timing belt 91. Therefore, the single-sided copied sheets stacked on the fixed tray 61 _o and the auxiliary plate 100 are sent by the refeed roller 70 to the ejection roller pair 69, further sent to the path 67 by the upper roller 69a, The sheet is then guided by the second flapper 66 to a path 68, and further sent to the conveying roller 71 ₁ of the sheet conveying section 59. At this time, even if multiple sheets are fed, they are separated based on the normal rotation of the lower roller 69b, and only the sheet in contact with the upper roller 69a is fed to the conveying roller pair ₇₁₁ . After a sufficient period of time has elapsed for the sheet to reach the position where it is bitten by the pair of transport rollers ₇₁₁ , the solenoid 95 is de-energized and the re-feed roller 70 is raised, and the spring clutch 87 is disconnected and the spring clutch 88 is As a result, the upper roller 69a is also rotated in the normal rotation direction by the gear train 88a, thereby stopping the refeeding of the second sheet. On the other hand, the re-fed first sheet reaches the detection switch SW ₂ by the pair of transport rollers 71 ₁ and 71 ₂ and turns on the switch. Then, the electromagnetic clutch 102 is disengaged,
The pair of adjustment rollers 72 is temporarily stopped just before biting the sheet, and the sheet forms a loop on the guide plate 73 ₃ between the pair of transport rollers 71 ₂ and the pair of adjustment rollers 72 . After a predetermined period of time, the drive clutch 102 is restarted and the adjustment roller pair 72 is rotated, thereby correcting the inclination of the sheet relative to the guide plate caused by refeeding from the tray _61o . Next, with the adjustment roller pair 72 biting the sheet, the servo motor 10 is rotated until the side edge of the sheet is detected by the photo interrupter PI.
9 is driven to move the adjustment roller pair 72 in its axial direction, thereby adjusting the lateral position (lateral registration) with respect to the sheet traveling direction. At this time, if the photo interrupter PI does not detect the sheet even after a predetermined period of time has elapsed after restarting the adjustment roller pair 72, it is determined that the sheet is closer to the back side (right side in Figure 5) and the adjustment is made. When the roller pair 72 is moved to the front side (left side in Figure 5) until the interrupter PI detects the sheet, and the interrupter PI detects the sheet before a predetermined time elapses after restarting the adjustment roller pair 72. ,
It is determined that the sheet is closer to the front side, and the adjustment roller pair 72 is once moved to the back side to remove the sheet from the interrupter PI, and then the adjustment roller pair 72 is moved to the front side in the same manner as described above. In this way, after a predetermined period of time has elapsed since the adjustment roller pair 72 was restarted with the skew and lateral registration of the re-fed sheet adjusted, the drive to the sheet conveying section 59 is cut off, sheet conveyance is stopped, and copying is performed. Waits for a paper feed signal from the apparatus main body 50. Then, after the operator performs an operation such as replacing the original on the document table 2, when the start switch of the copying apparatus main body 50 is operated again, the drive motor of the sheet conveying section 59 is activated in time with the apparatus main body 50. The adjustment roller pair 72 and the conveyance roller pair ₇₁₃ rotate again to move the sheet to the guide port 5.
3 into the path 55 of the device main body 50. Then, the toner image is transferred to the back side (the side that is not copied) of the sheet by the photoreceptor 3, the transfer charger 11, etc., and further fixed by the fixing device 70, and then the sheet copied on both sides is transferred to the discharge roller. The sheets are discharged to the sheet stacking device 60 by the pair 56. Then, based on the sheet sorting function of the sheet sorting section 57 described above, the double-sided copy sheets are sorted into each of the bin trays 61 ₁ to 61 _o according to a predetermined pattern as necessary.

Next, a case will be described in which multiple copying is performed in which two types of images are overlapped and copied on one side of a sheet.

When the operator instructs the main body 50 of the copying machine to perform multiple copying of the number n of sheets and activates the start switch, the first ejection roller pair 64 is rotated in the normal direction, and the first flapper 63 and the second flapper 66 are set to the solid line state. The force is maintained and the movable trays 61 ₁ to 61 _o-1 are all lowered to set the sheet sorting section 57 to its initial state. Then, when the sheet on which the first image has been copied in the copying device 50 is introduced from the ejection roller pair 56 into the path 62 of the sheet stacking device 60, the sheet is guided by the first flapper 63 and transferred to the first ejection roller. The roller pair 64 rotates normally, and the roller pair 64 sends it onto the movable tray ₆₁₁ . Further, when the sheet passes through the path 62, the leading edge of the sheet pushes up the auxiliary guide member 81, and further, based on the rotation of the guide member 81, the detection switch _SW1 is turned on to detect the passage of the leading edge of the sheet, Further, when the rear end of the sheet passes through the auxiliary guide member 81, the guide member 8
1 returns due to its own weight and the detection switch
SW ₁ is turned off at the position where the rear end of the sheet is held between the discharge roller pair 64. Then, forward/reverse DC
The motor 82 is reversed, and the first discharge roller pair 64 is now fed from the tray side toward the flapper 63, but at this time, the leading edge of the sheet (the trailing edge until the sheet is fed backwards) is aligned with the leading edge of the auxiliary guide member 81. vertical part 8
1a and is guided to the path 65. At this time, the time during which the detection switch _SW1 is on is measured by a clock counter, and the size (length) of the sheet is detected. At the same time, from the start of reversal of the first ejection roller pair 64, a value (T+a) obtained by adding the margin a to the counter measurement value T is subtracted by the same clock counter, so that the ejection roller pair of the sheet during reversal and reverse feeding is subtracted. After detecting the separation from the sheet 64, the forward/reverse DC motor 82 is rotated in the normal direction again to prepare for the next sheet. on the other hand,
The first sheet led to the path 65 is guided by the second flapper 66 and sent to the second pair of discharge rollers 69. At this time, the second pair of discharge rollers 69 is connected to the upper and lower rollers 69a and 69b by the spring clutch 88. Since both are in the forward rotation state and the refeed roller 70 is in the raised position, the sheet is transferred to the discharge roller pair 69.
is discharged onto the fixed tray _61o . Therefore,
In the multiple copying state, the sheet is reversed once by the first ejection roller pair 64 (switchback).
Therefore, the sheets are stacked on the fixed tray 61 _o with their copy side facing down. After the above operation is repeated n times and n sheets are stacked and accumulated on the fixed tray 61 _o , the sheet conveying section 59 is driven in the same way as in the case of double-sided copying, and the copying apparatus main body 50 is further driven. , the second image is superimposed on the surface that has been copied once. Then, based on the sheet classification function of the sheet classification section 57 described above, the multiple copy sheets are sorted into each bin tray 6 as needed.
1 ₁ to 61 _o according to a predetermined pattern.

In addition, when the operator instructs only one copy of multiple copies, that is, when one copy of multiple copies without a sort mode is required, the solenoid 79 is energized and the first
While switching the flapper 63 to the chain line position,
The flapper 66 is also switched and held at the chain line position. In this state, when the sheet on which the first image has been copied is guided to the path 62 by the discharge roller pair 56,
The sheet is guided by a flapper 63 to a path 65, and further guided by a flapper 66 to a path 68.
guided by. The sheet is then transported by the sheet transport section 59, skew correction and lateral registration adjustment are performed by the adjustment roller 72, and then a second image is superimposed and copied. And solenoid 79
is turned off, the first flapper 63 is returned to the solid line position, and the multiple copied sheets are transferred to the uppermost movable tray 61.
It is discharged and collected on ₁ .

Note that when a problem such as a paper jam occurs in the sheet stacking device 60, the sheet sorting section 57 is moved in the direction of arrow A, as shown in FIG. 2, and the sheet sorting section 57 and the copying device 50 are separated. do. Then, the guide plate T is removed and the route 62,
By opening 65, troubles such as paper jams can be easily solved.

(G) Effects of the Invention As explained above, according to the present invention, the sheet discharging rotary body 64 for discharging sheets to the movable bin trays 61 ₁ to 61 _o-1 of the sheet sorting section 57 is driven in the forward and reverse directions. The discharge rotor and the movable bin tray can be used as a switchback path for sheets, and the fixed bin tray _61o is provided with sheet refeeding means 69, 70, so that the fixed bin tray can be used to collect a plurality of sheets and Since it can be used as an intermediate tray for re-feeding, it has multiple functions such as double-sided copying and multiple copying in addition to sheet sorting, but it does not require the intermediate tray, reversing path, etc. that were previously required. In addition, the dead space caused by these intermediate trays and the reversing path can be reduced, and this makes it possible to achieve significant downsizing, simplify the structure, reduce weight, and reduce the cost. can be manufactured. In addition, the sheet sorting function, double-sided copying function, and multiple copying function are available in the bin tray 61 ₁ ~
Since the 61 _o can be used in common, the flow of sheets can be easily checked from the outside, and troubleshooting work such as sheet jams can be done almost the same for each function, and the handling work itself is also simple. This can improve usability. Furthermore, since sheets are re-fed by the sheet stacking device 60 having the bin trays 61 ₁ to 61 _o ,
The parts where sheet jams are likely to occur, such as the sheet conveyance path, can be placed in a relatively upper position, and the refeeding means can reliably refeed sheets, improving the reliability of the unit itself. It is possible to further improve usability. Further, it can be easily added to a personal type copying apparatus, and a single sheet stacking apparatus 60 according to the present invention can be provided with multiple functions. In particular, in the case of multiple copying, the bin tray of the sheet sorting section 57 is used to invert the sheet that has been copied once, and then the face-down sheet is stacked in another bin tray, and then the bin tray is stacked in the bin tray. Since the sheet is re-fed to the copying device 50, there is no need for a sheet reversing path for reversing the sheet, and even a small sheet stacking device 60 that can be attached to a personal copying device can have a multiple copying function. can. Further, each of the bin trays 61 ₁ to 61 _o of the sheet stacking device 60 can be used as a sheet feeding means (cassette), and multifunctionality can be achieved while taking advantage of the advantages of a personal machine.

Further, the sheet stacking device 60 is connected to the image forming device 50.
Since it is a separate unit, the sheet stacking device 60 can be attached later as an option, and the sheet stacking device 60 has a sheet inlet 62 on one side and a movable bin tray 61 ₁ on the other side.
~61 _o-1 and a fixed bin tray 61 _o-1 and a sheet sorting section 57 consisting of a vertically elongated member, and a sheet outlet 7
1 ₃ and a sheet conveyance section 59 having a shape on which the image forming apparatus 50 can be placed, the structure is compact enough to match the image forming apparatus 50 even when the sheet stacking apparatus 60 is attached. be able to.

Furthermore, the sheet sorting section 57 can be moved using the guide members R and G, and in this state, the guide plate T can be opened to open the sheet entrance 62, the first switching means 63, and the second switching means 66. Therefore, jamming can be easily removed by opening the areas where jamming is likely to occur.

[Brief explanation of drawings]

1 to 5 are diagrams showing a first embodiment of the present invention, in which FIG. 1 is an overall front view, FIG. 2 is a front view showing a separated state of the sheet stacking device and the copying device, and FIG. 3 is a diagram showing a first embodiment of the present invention. 4 is a perspective view showing a sheet path switching portion, FIG. 4 is a perspective view showing a sheet refeeding portion, and FIG. 5 is a perspective view showing an adjustment roller portion. FIGS. 6 and 7 are overall front views showing different conventional examples. 50... Copying device, 53... Sheet introduction means (guide port), 56... Sheet discharge means (discharge roller pair), 5
7... Sheet sorting section, 59... Sheet transport section, 60...
Sheet loading device, 61 ₁ to 61 _o-1 ... Movable bin tray, 61 _o ... Fixed bin tray, 62... Sheet entrance (path), 63... First switching means (flutter),
64... Sheet discharge rotating body (discharge roller pair), 66
...Second switching means (flapper), 69, 70...
Sheet refeeding means, 71 ₃ ...Sheet exit (transport roller pair), 82...Forward and reverse drive means (forward and reverse DC motor), G, R...Guiding member (guide rail, rod), T...Guide plate.

Claims (1)

[Scope of Claims] 1. An image forming section, a sheet discharging means for discharging a sheet on which an image has been formed in the image forming section, and a sheet introducing means for introducing the sheet and guiding the sheet to the image forming section; an image forming apparatus comprising: a sheet stacking apparatus which is a separate unit from the image forming apparatus and has a sheet inlet aligned with the sheet ejecting means and a sheet outlet aligned with the sheet introducing means; The sheet stacking device has the sheet entrance on one side, and has on the other side a number of movable bin trays that can move up and down, and a fixed bin tray that is arranged in line at the bottom of these movable bin trays. a sheet sorting section made up of a member; and a sheet conveying section having the sheet outlet above and conveying sheets from the sheet sorting section to the sheet introduction section via the sheet outlet, and facing the movable bin tray. A sheet discharge rotary body is disposed at a predetermined position so that sheets can be sorted and accumulated in the movable bin tray, and
A forward/reverse drive means is connected to the sheet discharge rotary body to constitute a sheet reversal means capable of reversing and conveying the sheet guided to the movable bin tray, and further includes a conveying path for guiding the sheet to the sheet discharge rotary body; a first guide for directly guiding the sheet toward the sheet conveying section;
a switching means facing the fixed bin tray, a refeeding means capable of refeeding the sheets collected on the bin tray, and a conveying path for guiding the sheets to the refeeding means. a second switching means for directly guiding the sheet toward the sheet conveying section; and the sheet sorting section is movably connected to the sheet conveying section by a guide member; An image forming apparatus characterized in that the guide plate constituting the conveyance path facing the entrance, the first switching means, and the second switching means can be opened.