JP4116153B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention ,mark The present invention relates to an image forming apparatus such as a printing machine or a copying machine.
[0002]
[Prior art]
As a paper discharge sorting apparatus in a conventional image forming apparatus such as a printing machine or a copier, for example, there is a “paper discharge stacker device” described in JP-A-7-101615. This paper discharge stacker reciprocates in the paper width direction every time a set number of sheets are discharged, so that the discharged paper is stacked for each set number of sheets. In this way, the printed matter is sorted into sorting groups. Furthermore, there is a paper discharge sorting device that aims at the same effect as described above, in which the paper discharge position is changed every time a set number of papers are discharged, instead of moving the paper discharge table.
[0003]
Further, in the case of an effect similar to that of the paper discharge stacker described above, the paper is not reciprocated in the width direction, but the paper is not like the “sorting device” described in Japanese Patent Publication No. 6-78151. Some stacking trays rotate 90 degrees each time a set number of sheets are ejected. In this case, by changing the direction of the paper discharge tray, the sheets stacked on the paper discharge tray are alternately stacked for each set number of sheets.
[0004]
Also, in general office printing machines such as stencil printing machines, jump plates are provided on both sides of the paper transport unit to raise the side edges of the paper, and these jump plates cause the center of the paper to face the side edges. The paper is bent so that it bends downward in a U-shape, and the paper is seated. Both sides of the discharged paper are supported by two side fences, and the paper is bent and stored in a U-shape. There is a loading device. Such a paper stacking device cannot be used as described above, in which the paper is shifted in the width direction and stacked, so when sorting, the printing machine is stopped for each set number of sheets, and the operator The work of placing the mark tape on the paper is repeated.
[0005]
Alternatively, there is a “tape launching device for a printing press” described in Japanese Patent Application Laid-Open No. 7-1722 which automates the sorting operation using the tape. In this method, a tape on which sorting status information and the like have been launched is sent each time a set number of sheets are ejected, and is swallowed for each set number of sheets.
[0006]
In addition, there is a sorter device that feeds sheets discharged from the image forming apparatus to a plurality of discharge trays for each set number of sheets, and sorts the sheets for each discharge tray.
[0007]
When the paper stacking device such as the above “Paper stacker” is stacked in the width direction, the overlapped paper moves by inertia when the paper delivery platform is moved and stopped, so the boundary between the papers is clear. It may not be. In addition, a device that rotates the paper discharge table by 90 degrees, such as the above-described “sorting device”, requires that the length of any side of the paper discharge table is equal to or longer than the length in the longitudinal direction of the predetermined paper. Increases in size and weight. Further, since the paper discharge table is rotated, the configuration becomes complicated and expensive. In addition, these devices cannot be used for a U-shaped stack that guides both sides of a sheet so that the sheet to be ejected has a waist.
[0008]
In the case of stacking sheets of paper in a U shape, not only the work of placing a mark tape on the paper but also the work of removing it is necessary, which is inefficient. Moreover, since the tape may come off, the sorting becomes incomplete. Furthermore, tape is uneconomical because it is difficult to reuse. The above-mentioned “tape ejecting device for printing presses” that automatically sorts by tape may not always realize smooth and reliable sorting because the timing of tape delivery and paper discharge may not match. It is scarce. And it is necessary to remove the tape, which is also inefficient.
[0009]
In addition, instead of the above-described mark tape, one sheet of blank paper is ejected in a state where printing is paused, and used as a mark at the boundary of the sorting group. In the case of a solid image, it is easy to discriminate because the contrast difference is clear, but in the case of printed matter with a small image area, it is difficult to discriminate because the contrast difference is small.
[0010]
Sorter apparatuses that sort into a plurality of paper discharge trays are large and expensive, and are often separated from image forming apparatuses and treated as options. Furthermore, it requires an area as large as an image forming apparatus and is not widely adopted for general office use.
[0011]
[Problems to be solved by the invention]
For this reason, when stacking sheets for each sorting group on the paper output tray, the edge of the uppermost sheet in the sorting group is held by the pickup and shifted horizontally, and the sorting group uses the shifted sheet. There has been considered a paper discharge sorting device which is used as a partition mark.
[0012]
However, when the top layer paper of the sorting group is shifted, the ink of the next layer paper is rubbed by the top layer paper, so the image of the next layer paper is distorted, and the back side of the top layer paper is There is a problem that ink adheres and gets dirty. This is because when the amount of image is large, such as a solid image, in a low-temperature environment where the fluidity of ink is poor, when the drying of the ink is delayed because the printing speed is fast, the printing speed is slow and the amount of transferred ink is low. In many cases, this is particularly likely to occur when using paper with poor ink absorbency, such as high-quality paper with high smoothness.
[0013]
Conversely, when the amount of image is small, in a high temperature environment, the printing speed is slow, and it is determined that the ink on the already printed paper is dry. If the amount of ink used is low, such as when using paper with high ink absorption, such as loose paper, the time from when the paper to be sorted is discharged until the sorting operation cannot be shortened, the print cycle There is a problem that becomes longer.
[0014]
[Means for Solving the Problems]
[0016]
Claim 1 The image forming apparatus described is A paper discharge stand for sequentially stacking printed sheets that are discharged from the image forming apparatus, and driven by a pickup driving unit when a sheet to be sorted is discharged from the image forming apparatus when the sorting print mode is set. A pickup for shifting the paper to be sorted in the sorting direction, and a time changing unit for changing a waiting time from when the paper to be sorted from the image forming apparatus is discharged to when the pickup driving unit is driven. Equipped with a paper output sorting device, Printing unit and image amount detecting means for detecting the amount of image printed on paper And A time changing unit of the paper discharge sorting device issues an instruction to change the waiting time from the time when the paper to be sorted according to the amount of the outputted paper is discharged to the paper discharge stand until the pickup driving unit is driven. Output means for outputting to the output.
[0017]
Therefore, the waiting time from when the paper to be sorted is discharged to the paper discharge stand to when the pickup driving unit is driven is determined according to the image amount. As a result, it is possible to shift the paper to be sorted in the sorting direction at a time that matches the dry state of the printed images of the sheets that overlap below the paper to be sorted.
[0018]
Claim 2 The image forming apparatus described is A paper discharge stand for sequentially stacking printed sheets that are discharged from the image forming apparatus, and driven by a pickup driving unit when a sheet to be sorted is discharged from the image forming apparatus when the sorting print mode is set. A pickup for shifting the paper to be sorted in the sorting direction, and a time changing unit for changing a waiting time from when the paper to be sorted from the image forming apparatus is discharged to when the pickup driving unit is driven. Equipped with a paper output sorting device, Paper setting means to specify printing section and paper type And finger An instruction to change the waiting time from the time when the paper to be sorted according to the specified paper type is ejected to the paper ejection tray until the pickup driving unit is driven is the time of the paper ejection sorting device. Output means for outputting to the changing means.
[0019]
Therefore, the waiting time from when the paper to be sorted is discharged to the paper discharge stand to when the pickup driving unit is driven is determined according to the designated paper type. As a result, it is possible to shift the paper to be sorted in the sorting direction at a time that matches the dry state of the printed images of the sheets that overlap below the paper to be sorted.
[0020]
Claim 3 The image forming apparatus of A paper discharge stand for sequentially stacking printed sheets that are discharged from the image forming apparatus, and driven by a pickup driving unit when a sheet to be sorted is discharged from the image forming apparatus when the sorting print mode is set. A pickup for shifting the paper to be sorted in the sorting direction, and a time changing unit for changing a waiting time from when the paper to be sorted from the image forming apparatus is discharged to when the pickup driving unit is driven. Equipped with a paper output sorting device, Printing section and temperature detection means for detecting temperature And A time changing unit of the paper discharge sorting device issues a command to change the waiting time from the time when the paper to be sorted according to the discharged temperature is discharged to the paper discharge tray until the pickup driving unit is driven. Output means for outputting to the output.
[0021]
Therefore, the waiting time from when the paper to be sorted is discharged to the paper discharge stand to when the pickup driving unit is driven is determined according to the detected temperature. As a result, it is possible to shift the paper to be sorted in the sorting direction at a time that matches the dry state of the printed images of the sheets that overlap below the paper to be sorted.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of the present invention will be described with reference to FIGS. First, an example of an image forming apparatus in which the sorting apparatus of the present invention is mounted will be schematically described with reference to FIG. The image forming apparatus in this example is a stencil printing apparatus, but is not limited thereto.
[0025]
A plate cylinder 2 around which the master 1 that has been subjected to plate making is wound is rotatably provided. Around the plate cylinder 2, the master 1 is heated and punched to make a plate, and a plate making section 3 for feeding the master 1 to the plate cylinder 2 and a sheet S fed from a sheet feeding section (not shown) are provided. A pair of registration rollers 4 that convey the master 1 wound around the plate cylinder 2 in time with the progress of the master 1, and a press roller 5 that presses the sheet S fed from the registration rollers 4 against the plate cylinder 2 via the master 1. A peeling claw 6 for peeling the printed paper S from the plate cylinder 2 and a paper discharge table 7 for loading the paper S peeled by the peeling claw 6 are arranged.
[0026]
The plate making unit 3 includes a platen 9 that is rotationally driven along the conveyance path 8 of the master 1, a thermal head 10 that is supported so as to be able to contact with and separate from the platen 9, a fixed blade 11 that cuts the master 1, and a movable blade 12, a pair of conveying rollers 13 and 14, a guide plate 15 that supports the master 1 from below, and the like are sequentially arranged. The roll core 1a, the platen 9, the transport rollers 13, 14 and the like of the master 1 are rotatably supported by side plates (not shown) of the main body case of the stencil printing apparatus.
[0027]
The plate cylinder 2 is formed with a non-opening 2a and an opening 2b. A mesh screen formed of a resin or metal net is provided in the opening 2b. A flange (not shown) fixed to both ends of the plate cylinder 2 is rotatably supported by an ink pipe 16 fixedly supported on a side plate of the stencil printing apparatus, and is driven clockwise. An ink roller 17 and a doctor roller 18 that are in contact with the inner peripheral surface of the plate cylinder 2 are provided inside the plate cylinder 2 so as to be rotatable with a slight gap therebetween. The ink roller 17 and the doctor roller An ink reservoir 20 that receives ink dropped from a supply hole 19 formed at the lower end of the ink pipe 16 is formed in a wedge-shaped space between the ink pipe 16 and the ink reservoir 16. Ink is supplied to the ink pipe 16 from an ink pack (not shown) provided outside the plate cylinder 2. Further, a stage 21 and a clamper 22 are attached to the outer peripheral surface of the plate cylinder 2 so as to sandwich the tip of the master 1 at the non-opening portion 2a. The stage 21 is formed of a magnetic material and has a length along the axial direction of the plate cylinder 2. The clamper 22 is supported rotatably about a clamper shaft 23 disposed along the longitudinal direction of the stage 21.
[0028]
Here, the plate cylinder 2, the press roller 5, the ink roller 17 incorporated in the plate cylinder 2, and the doctor roller 18 constitute a printing unit P.
[0029]
Next, the operation of the stencil printing apparatus will be described. When a document is set in a document reading unit (not shown) and a start signal is output by pressing a start button or the like, an image of the document is read by the document reading unit and the plate cylinder 2 is driven counterclockwise by a motor (not shown). Is done. In this process, the master 1 that has been wound around the plate cylinder 2 is peeled off and discarded by a plate discharging device (not shown), and the plate cylinder 2 is stopped when the clamper 22 reaches almost directly above. . At the time of this stop, the clamper 22 rotates around the clamper shaft 23 in the opening direction and is maintained in the plate feed standby state.
[0030]
When the image data is output to the thermal head 10, dots by perforation are formed on the master 1 based on the image data. The master 1 is conveyed to the plate cylinder 2 side by the rotation of the platen 9 and the conveying rollers 13 and 14. At this time, if it is determined that the tip of the master 1 has reached the clamper 22 by counting the number of steps of the stepping motor that drives the platen 9 and the conveying rollers 13 and 14, the clamper 22 is closed by an unillustrated opening / closing device. The tip of the master 1 is held between the clamper 22 and the stage 21 on the plate cylinder 2. Subsequently, the plate cylinder 2 is driven clockwise at a circumferential speed substantially equal to the conveying speed of the master 1, and the master 1 is wound around the outer periphery of the plate cylinder 2. When it is determined that the plate making is completed based on the number of steps of the stepping motor, the movable blade 12 is actuated to cut the master 1 and the platen 9 and the conveying rollers 13 and 14 are stopped. Then, when the plate cylinder 2 further rotates, the winding of the master 1 around the plate cylinder 2 is completed.
[0031]
As described above, when the winding of the master 1 around the plate cylinder 2 is completed, the paper S stacked on a paper supply tray (not shown) is fed by a separation paper feeding device (not shown), and the paper S is transferred to the plate cylinder. 2 is conveyed between the plate cylinder 2 and the press roller 5 by a registration roller 4 that rotates in synchronization with the rotational movement of the plate 2. In printing, the press roller 5 presses the paper S against the outer periphery of the plate cylinder 2. As a result, the ink oozes out from the perforations of the master 1 and is transferred to the paper S. That is, printing is performed.
[0032]
Next, the configuration of the paper discharge sorting apparatus A that sorts the sheets S printed by the stencil printing apparatus will be described. The paper discharge tray 7 has an end plate 7a on the discharge direction side and a partition plate 7b on the opposite discharge side, and the distance between the end plate 7a and the partition plate 7b is slightly larger than the size of the paper S to be used. A paper transport unit 24 transports the printed paper S toward the paper discharge table 7. A pickup 25 is provided below the paper transport unit 24. The pickup 25 includes a swing arm 26 that is rotatably supported and a roller 27 that is rotatably supported at a free end of the swing arm 26. The swing arm 26 is driven by an arm drive motor 29 that can be rotated forward and backward together with a shaft 28 fixed to the lower end thereof, and the roller 27 is a roller drive motor 30 (pickup drive unit) fixed to the free end of the swing arm 26. (Refer to FIG. 2).
[0033]
Accordingly, the swing arm 26 is rotated by driving the arm drive motor 29 counterclockwise to an area within the projection area of the paper discharge tray 7 and is driven by driving the arm drive motor 29 clockwise. It rotates from the area within the projected area of the paper table 7 toward the outside of the paper discharge table 7. For this purpose, an opening (not shown) that allows passage of the swing arm 26, the roller drive motor 30, and the roller 27 is formed in the partition plate 7 b of the paper discharge tray 7.
[0034]
Next, an electrical block diagram of the paper discharge sorting apparatus A is shown in FIG. A CPU 31, a ROM 32 storing fixed data such as programs executed by the CPU 31, a RAM 33 for storing variable data such as work data in an updatable manner, an interface 34 for inputting / outputting signals with the stencil printing apparatus, and the like. Connected by system bus. The I / O port 35 connected to the CPU 31 includes an HP (home position) sensor 36 that detects a state in which the swing arm 26 has returned to the initial position outside the paper discharge table 7, and a printing unit P (see FIG. 1). A paper discharge sensor 37 that detects the paper S to be discharged, a paper sensor 38 that detects a state in which the roller 27 of the pickup 25 is in contact with the paper S on the paper discharge tray 7, a driver 39 that drives the arm drive motor 29, and rollers A driver 40 for driving the drive motor 30 is connected.
[0035]
Here, the stencil printing apparatus can set the sorting printing mode. When the sorting print mode is set, the number of sheets to be printed at one time can be set in order to sort the printed matter for each sorting group. The set number of sheets is stored in a sheet counter (not shown). For example, the count value of the number counter is decremented every time one sheet is printed, so that the end of printing a set number of sheets can be recognized when the count value becomes zero. .
[0036]
Although not shown, the stencil printing apparatus includes an image amount detecting means for detecting the amount of image to be printed on the paper S, a paper setting means for specifying the type of the paper S to be printed, a temperature detecting means for detecting the ambient temperature, and a printing speed. Is provided with a printing speed setting means. For example, the image amount is configured to be detected by data stored in the page memory, and the printing speed is configured to be set by key input from the operation panel.
[0037]
These settings on the stencil printing machine side, that is, the state in which the sorting printing mode is set, the number of prints for each sorting group, the amount of images to be printed on the paper S, the type of paper S to be used, the detected temperature, are set. The waiting time value corresponding to the printing speed or the like is stored in the RAM 33 via the interface 34 of the paper output sorting apparatus A from an interface (not shown) as output means of the stencil printing apparatus. . The waiting time is the time from when the paper Sa to be sorted is discharged to the paper discharge stand 7 until the arm drive motor 29 is driven.
[0038]
Hereinafter, the printing operation will be described. The stencil printing apparatus executes printing in the order of the processes shown in FIG. As described above, this printing process includes a document image reading process (S5-1), a plate removing process (S5-2) for removing the used master 1 from the plate cylinder 2, and a master plate making process (S5-2). S5-3) and print processing (S5-4). In this printing, when sorting printing, the stencil printing apparatus sets the sorting mode, the number of printed sheets for each sorting group, and sorting as described above. The Set the number of groups.
[0039]
As shown in FIG. 6, the paper discharge sorting apparatus A first determines whether or not the sorting printing mode is set in the stencil printing apparatus (S6-1). When it is determined that the sorting print mode is set (Y in S6-1), the set value of the waiting time is recognized (S6-2).
[0040]
Next, it is determined whether or not the paper Sa to be sorted has been discharged (S6-3). As described above, since the number of printed sheets is counted on the stencil printing apparatus side as described above, based on the count value received via the interface 34, the sheet S to be discharged next is the sheet Sa to be sorted. The CPU 31 determines whether or not this is the case, and the CPU 31 recognizes whether or not the corresponding paper Sa has been detected by the paper discharge sensor 37.
[0041]
In order to distinguish the paper to be sorted out from the other sheets S among the papers S that have been ejected to the paper ejection tray 7, a description will be given with the symbol Sa, but the paper Sa to be sorted has been ejected. Is recognized (Y in S6-3), the arm drive motor 29 is driven counterclockwise, and the swing arm 26 is rotated counterclockwise from the initial position to advance inside the paper discharge tray 7. (S6-4) When the state where the roller 27 is in contact with the paper Sa on the paper discharge tray 7 is recognized by the on output of the paper sensor 38 (Y in S6-5), the arm drive motor 29 is stopped (S6). -6). The position of the swing arm 26 at this time is shown by a virtual line in FIG.
[0042]
Then, when it is recognized that the set waiting time has elapsed (S6-7), the sorting is executed. This sorting is performed by driving the roller drive motor 30 and rotating the roller 27 counterclockwise (S6-8). As a result, the paper Sa on the paper discharge tray 7 is shifted toward the partition plate 7 b of the paper discharge tray 7. Since the shift amount of the sheet Sa at this time is set in advance by the number of pulses for driving the roller drive motor 30, the sheet Sa is shifted to the sorting position when the roller drive motor 30 is driven by the set number of pulses. The roller drive motor 30 is stopped and the roller 27 is stopped (S6-10).
[0043]
Subsequently, the arm drive motor 29 is driven clockwise, and the swing arm 26 is rotated clockwise. That is, the swing arm 26 is retracted to the outside of the paper discharge tray 7 (S6-11), and when it is recognized that the swing arm 26 has returned to the initial position by the detection signal of the HP sensor 36 (S6-12). Then, the arm drive motor 29 is stopped, and the swing arm 26 is stopped (S6-13).
[0044]
Such a sorting operation of the paper discharge sorting apparatus A is performed by the CPU 31 recognizing the setting state of the hole plate printing apparatus and executing a program written in the ROM 32. Therefore, the sorting operation is executed as long as the sort printing is continued in the stencil printing apparatus, and the sort operation is not executed when the sort printing is not performed.
[0045]
At the time of printing, the dry state of the printed image varies depending on the image amount, the type of the paper S, the ambient temperature, the printing speed, and the like. Depending on these conditions, the paper Sa to be sorted is discharged. Since the waiting time until the sorting operation can be changed, the sheet Sa to be sorted can be shifted in the sorting direction after the sheet S of the next layer discharged before the sheet Sa to be sorted is dried to some extent. it can. As a result, even if the next layer paper S is rubbed against the top layer paper Sa to be sorted, the ink of the next layer paper S does not adhere to the back surface of the paper Sa to be sorted.
[0046]
Here, S6-2 to S6-8 correspond to time changing means for changing the waiting time from when the paper Sa to be sorted is discharged to when the pickup driving unit (roller driving motor 30) is driven.
[0047]
As shown in FIG. 3, the swing arm 26 is formed with an inclined surface 26 a for guiding the paper S to the end plate 7 a side. A program relating to the sorting operation is set so that the sheet S of the next sorting group is discharged while being positioned inside, and at this time, the discharged sheet S is guided to the end plate 7a side by the inclined surface 26a. May be.
[0048]
In this way, when the amount of image is small, in the case of a high temperature environment, the printing speed is slow, and it is determined that the ink of the already printed paper S is dry. When the transfer amount is small, or when using paper S having high ink absorbability such as loose paper, the time from when the paper to be sorted is discharged to when the sorting operation is performed can be shortened. Therefore, the printing cycle can be shortened when sorting printing is performed continuously.
[0049]
Furthermore, instead of the roller 27, as shown in FIG. 7A, by using a roller 42 having a large number of protrusions 41 on the outer periphery, the sheet S discharged to the discharge table 7 immediately after printing can be used. The contact area of the roller 42 can be reduced. Accordingly, ink stains caused by rubbing the print image with the roller 42 can be reduced, and dust is less likely to adhere, and hence the stain on the paper S due to dust can be reduced. Further, since the protrusion 41 has a sharp tip, the sheet S can be reliably moved without slipping. Such an effect is obtained by using a roller 44 having a large number of needle-like protrusions 43 on the outer periphery as shown in FIG. 7B, or a sucker made of a soft material such as rubber as shown in FIG. 7C. It can also be obtained by using a roller 46 having a large number of protrusions 45 in the shape of a shape. The suction cup-like protrusion 45 is not pointed like the other protrusions 41 and 43, but the center part is recessed, so that the contact area with the paper S can be reduced. Since the center is concave and the peripheral edge is elastically bent, the adsorbability to the paper S is good, and the paper S can be reliably moved without slipping.
[0050]
According to the present invention, from the time when the paper Sa to be sorted according to various situations in which the ink of the printed image is difficult to dry is discharged to the discharge table 7, the pickup drive unit (roller drive motor 30) is driven. Since the waiting time is changed, the mechanism of the paper discharge sorting device is not limited to the previous embodiment. Another example of the paper discharge sorting apparatus having a different mechanism will be described.
[0051]
First, a second embodiment of the present invention will be described with reference to FIGS. In this embodiment mode and other subsequent embodiment modes, portions having the same structure as those of the previous embodiment mode are denoted by the same reference numerals and description thereof is also omitted. The paper discharge sorting apparatus B according to the present embodiment is formed in a tunnel shape on a lift 48 that is supported by a guide rod 47 that is vertically supported by a support member (not shown) and that can be moved up and down. And a pickup 49 fitted in the opening so as to be movable in the horizontal direction. The pickup 49 includes a pressing plate 51 that is rotatable about the support shaft 50 at an end portion, and further includes a pressing portion 52 that is fixed to the lower surface of the pressing plate 51 on the free end side. The pressing plate 51 is urged counterclockwise (downward) by a spring (not shown) attached to the support shaft 50. Therefore, the reaction force of the spring increases as the angle at which the pressing plate 51 is rotated clockwise increases, and the pressing force against the paper S in the paper discharge tray 7 increases. Furthermore, a detection piece 53 is integrally formed on the pressing plate 51, and by detecting the detection piece 53, the first rotation angle of the pressing plate 51 is detected in a plurality of steps (two steps in the embodiment). The second pressure sensors 54 and 55 are provided at the tip of the pickup 49.
[0052]
A feed screw 56 parallel to the guide rod 47 is screwed to the lift 48 and the lift 48 is raised or lowered by rotating the feed screw 56 with a lift motor 57 that can rotate forward and backward. Further, an advancing / retreating motor (pickup driving unit) 58 that can rotate forward and backward is supported on the lift 48, and a pinion 59 driven by the advancing / retreating motor 58 is engaged with a rack 60 formed on the pickup 49. In FIG. 9, an opening (not shown) for allowing the pickup 49 to move forward and backward is formed in the partition plate 7 b of the paper discharge tray 7.
[0053]
The sorting process in the paper discharge sorting apparatus B will be described with reference to the flowchart shown in FIG. Normally, the lifting platform 48 is located at the initial position (upward position), and the pickup 49 is located at the initial position where the pressing plate 51 stands by outside the paper delivery platform 7. As in the case of the previous embodiment, the state in which the sorting printing mode is set is recognized (Y in S10-1), the waiting time is recognized (Y in S10-2), and the paper Sa to be sorted is determined. When it is recognized that the sheet has been discharged onto the discharge table 7 (Y in S10-3), the advance / retreat motor 58 is rotated forward to advance the pickup 49 toward the inside of the discharge table 7 (S10-4). This forward position is a position indicated by a solid line in FIG. When the pickup 49 recognizes the state where the pickup 49 has reached the foremost position (position where the pressing plate 51 advances into the paper discharge tray 7) as shown in FIG. 9 based on a detection signal of a stroke sensor (not shown) (S10-5). Y), the advance / retreat motor 58 is stopped, and the pickup 49 is stopped (S10-6).
[0054]
Subsequently, the elevator motor 57 is rotated forward to lower the elevator 48 (S10-7), and when the first pressure sensor 53 or the second pressure sensor 54 is recognized as being turned on (S10-). 8), the elevating motor 57 is stopped, and the elevating table 48 is stopped (S10-9). In this case, comparing the case where the elevator 48 is lowered until the first pressure sensor 53 is turned on with the case where the elevator 48 is lowered until the second pressure sensor 54 is turned on, the latter is more The pressing force (paper holding force) for pressing the paper Sa with the pressing plate 51 is large. The latter corresponds to the paper Sa having a large size and a large thickness and a heavy weight. It may be set in advance which of the pressure sensors 53 and 54 is used to stop the lifting platform 48 based on the detection signal.
[0055]
Subsequently, when it is recognized that the waiting time has elapsed (Y in S10-10), the advance / retreat motor 58 is reversed, the pickup 49 is moved backward (S10-11), and a detection signal of a stroke sensor (not shown) is detected. Thus, when it is recognized that the pickup 49 has moved back to the paper shifting position (Y in S10-12), the advance / retreat motor 58 is stopped and the pickup 49 is stopped (S10-13). The length at which the pickup 49 is retracted at this time is a length for shifting the paper Sa to be sorted to the vicinity of the partition plate 7b.
[0056]
Subsequently, when the elevator motor 57 is reversed, the elevator 48 is raised (S10-14), and it is recognized by the detection signal of the upper limit sensor (not shown) that the elevator 48 has reached the initial position ( (S10-15 Y), the lift motor 57 is stopped, the lift base 48 is stopped (S10-16), the advance / retreat motor 58 is reversed, and the pickup 49 is moved backward to the outside of the paper discharge base 7 (S10-17). When it is recognized by the detection signal of the HP sensor that the pickup 49 has reached the initial position (Y of S10-18), the advance / retreat motor 58 is stopped and the pickup 49 is stopped at the initial position (S10-19). .
[0057]
Here, S10-2 to S10-11 correspond to time changing means for changing the waiting time from when the paper Sa to be sorted is discharged to when the pickup driving unit (advance / retreat motor 58) is driven.
[0058]
Next, the present invention The fruit A third embodiment will be described with reference to FIG. This embodiment In The paper discharge sorting apparatus C in this embodiment uses a pickup 61 in place of the pickup 49 shown in FIGS. The pickup 61 is driven by an elevating motor 57 and is held by an elevating table 48 that moves up and down. The pickup 61 is driven by an advancing / retracting motor 58 so as to reciprocate between the outside and the inside of the paper discharge table 7. The pickup 61 has a pressing portion 62 at the lower end of the tip, and an inclined surface 63 is formed on the upper portion of the pressing portion 62 for guiding the discharged paper S to the end plate 7a side. The pressing portion 62 is formed in a sharp shape in order to increase the friction coefficient with respect to the paper Sa to be sorted. Further, the pickup 61 is provided with a pressure reference sensor (not shown) that is turned on when the paper Sa in the paper discharge tray 7 is pressed with a certain pressing force. This pressure reference sensor detects the pressure on the paper Sa and outputs a detection signal.
[0059]
In such a paper sorting apparatus C, when the paper Sa to be sorted is ejected to the paper ejection tray 7, the pickup 61 is advanced to the inside of the paper ejection tray 7 to press the paper Sa to be sorted. The procedure for lowering the lift 48 and sorting by the backward movement of the pickup 61 is the same as in the previous embodiment. That is, as the lifting table 48 is lowered, the pressing unit 62 eventually presses the sheet Sa in the sheet discharge table 7 and the pressure reference sensor is turned on. When this state is recognized, the operation of the lifting motor 57 is controlled. The elevator 48 is stopped at a predetermined height. Thereby, as in the case of the previous embodiment, the pressing of the pickup 61 against the paper Sa is determined.
[0060]
Subsequently, when it is recognized that the waiting time from when the paper Sa to be sorted is discharged until the pickup driving unit (advance / retraction motor 58) is driven, the advancing / retreating motor 58 is reversed and the pickup 61 is moved. When the pickup 61 recognizes that the pickup 61 has moved back to the paper shifting position by the detection signal of the stroke sensor (not shown), the advance / retreat motor 58 is stopped and the pickup 61 is stopped. Accordingly, the paper Sa to be sorted is shifted to the partition plate 7b side by the sharp pressing portion 62 of the pickup 61. However, since the sorting is performed after the waiting time elapses, the next-layer paper is added to the sorted paper Sa. S ink does not adhere.
[0061]
As described above, in the present embodiment, the structure and sorting of the paper discharge sorting apparatus C are described. The Although the operation is different from the previous embodiment, Sorting Since the control operation for changing the waiting time from when the paper Sa to be discharged to when the sorting operation is performed is the same as in the first and second embodiments, the description thereof is omitted. The same applies to the following embodiments.
[0062]
Next, the present invention The fruit A fourth embodiment will be described with reference to FIG. This embodiment In The paper discharge sorting apparatus D in this embodiment uses a pickup 64 in place of the pickup 49 shown in FIGS. The pickup 64 is driven by a lift motor 57 and is held by a lift 48 that moves up and down. The pickup 64 is driven by an advancing / retracting motor 58 so as to reciprocate between the outer side and the inner side of the paper discharge table 7. The pickup 64 has a gripping portion 65 for gripping the paper Sa to be sorted at the front end in the vertical direction, and an opening / closing drive portion (not shown) for opening and closing the gripping portion 65.
[0063]
In such a paper discharge sorting apparatus D, when the number of prints in one sorting group is n, the pickup 64 is moved to the paper discharge tray 7 when the (n-1) th paper S is discharged to the paper discharge tray 7. , The elevator 48 is lowered to the (n-1) th sheet S, and when the nth sheet, that is, the sheet Sa to be sorted, is discharged to the sheet discharge table 7, the gripping is performed. The unit 65 is driven to grip the sheet Sa to be sorted by the gripping unit.
[0064]
Subsequently, when it is recognized that the waiting time from the time when the paper Sa to be sorted is discharged until the pickup drive unit (advance / retraction motor 58) is driven, the advancing / retreating motor 58 is reversed and the pickup 64 is moved. When the pickup 64 recognizes that the pickup 64 has moved back to the paper shifting position by a detection signal of a stroke sensor (not shown), the advance / retreat motor 58 is stopped and the pickup 64 is stopped. As a result, the paper Sa to be sorted is shifted to the partition plate 7b while being gripped by the gripping portion 65 of the pickup 64. However, since the sorting is performed after the waiting time elapses, the paper Sa is next to the sorted paper Sa. The ink of the layer paper S does not adhere.
[0065]
【The invention's effect】
According to the present invention, The sheets to be sorted can be shifted in the sorting direction at a time that matches the dry state of the printed images of the sheets that overlap on the lower side of the sheets to be sorted. Therefore, it is possible to avoid a state in which the ink of the paper discharged to the paper discharge tray before the paper to be sorted adheres to the back surface of the discharged paper. In the case of printing conditions that can accelerate the drying of ink, the time from when the paper to be sorted is discharged until the sorting operation is performed can be shortened, so that the printing cycle can be shortened.
[0066]
Claim 1 The image forming apparatus described According to A waiting time from when the paper to be sorted is discharged to the paper discharge stand to when the pickup driving unit is driven is determined according to the image amount. As a result, it is possible to shift the paper to be sorted in the sorting direction at a time that matches the dry state of the printed images of the sheets that overlap below the paper to be sorted.
[0067]
Claim 2 The image forming apparatus described According to A waiting time from when the paper to be sorted is discharged to the paper discharge stand to when the pickup driving unit is driven is determined according to the type of the specified paper. As a result, it is possible to shift the paper to be sorted in the sorting direction at a time that matches the dry state of the printed images of the sheets that overlap below the paper to be sorted.
[0068]
Claim 3 description Image forming apparatus According to The waiting time from when the paper to be sorted is discharged to the paper discharge stand to when the pickup driving unit is driven is determined according to the detected temperature. As a result, it is possible to shift the paper to be sorted in the sorting direction at a time that matches the dry state of the printed images of the sheets that overlap below the paper to be sorted.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional front view showing a paper discharge sorting apparatus according to a first embodiment of the present invention together with a stencil printing apparatus.
FIG. 2 is a perspective view showing a swing arm.
FIG. 3 is a longitudinal sectional front view showing a paper discharge sorting apparatus.
FIG. 4 is an electrical block diagram.
FIG. 5 is a flowchart showing a printing process of the stencil printing apparatus.
FIG. 6 is a flowchart showing a sorting process.
FIG. 7 is a front view showing a modification of a pickup roller.
FIG. 8 is a perspective view showing a paper discharge sorting apparatus according to a second embodiment of the present invention.
FIG. 9 is a longitudinal front view of the paper discharge sorting apparatus.
FIG. 10 is a flowchart showing a sorting process.
FIG. 11 is a longitudinal front view showing a paper discharge sorting apparatus according to a third embodiment of the present invention.
FIG. 12 is a longitudinal front view showing a paper discharge sorting apparatus according to a fourth embodiment of the present invention.
[Explanation of symbols]
7 Output tray
25, 49, 61, 64 pickup
30, 58 Pickup drive
P Printing department
S paper
Sa Paper to be sorted
S6-2 to S6-8 Time changing means
S10-2 to S10-11 Time changing means

Claims (3)

A paper discharge stand for sequentially stacking printed sheets that are discharged from the image forming apparatus, and driven by a pickup driving unit when a sheet to be sorted is discharged from the image forming apparatus when the sorting print mode is set. A pickup for shifting the paper to be sorted in the sorting direction, and a time changing unit for changing a waiting time from when the paper to be sorted from the image forming apparatus is discharged to when the pickup driving unit is driven. Equipped with a paper output sorting device,
Driving a printing unit, an image detecting means for detecting the amount of image to be printed on paper, the pickup drive unit from time to paper to be sorted according to the image volume has detected is discharged to the discharge tray An image forming apparatus comprising: an output unit that outputs a command to change the waiting time until the time changing unit of the paper discharge sorting device. A paper discharge stand for sequentially stacking printed sheets that are discharged from the image forming apparatus, and driven by a pickup driving unit when a sheet to be sorted is discharged from the image forming apparatus when the sorting print mode is set. A pickup for shifting the paper to be sorted in the sorting direction, and a time changing unit for changing a waiting time from when the paper to be sorted from the image forming apparatus is discharged to when the pickup driving unit is driven. Equipped with a paper output sorting device,
A printing unit, of the paper setting means for specifying the type of paper, the timing of the paper to be sorted according to the type for the specified paper sheet is discharged to the discharge tray until driving the pickup drive unit An image forming apparatus comprising: an output unit that outputs a command to change the waiting time to the time changing unit of the paper discharge sorting device. A paper discharge stand for sequentially stacking printed sheets that are discharged from the image forming apparatus, and driven by a pickup driving unit when a sheet to be sorted is discharged from the image forming apparatus when the sorting print mode is set. A pickup for shifting the paper to be sorted in the sorting direction, and a time changing unit for changing a waiting time from when the paper to be sorted from the image forming apparatus is discharged to when the pickup driving unit is driven. Equipped with a paper output sorting device,
Changing a printing unit, a temperature detecting means for detecting the temperature, the waiting time from the time that the paper should be sorted according to test out temperature is discharged to the discharge tray until driving the pickup drive unit An image forming apparatus comprising: an output unit that outputs a command to the effect to a time changing unit of the paper discharge sorting device.

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