JP3608759B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a complex machine thereof. The present invention relates to an image forming apparatus that sends out and forms an image on the back surface.
[0002]
[Prior art]
A conventional image forming apparatus having a double-sided copying function temporarily stores an image formed on one side in an image forming unit on an intermediate tray, without discharging the sheet, and sends the image to the image forming unit again to transfer an image on the back side. It has a configuration and function for automatically forming images on both sides by forming.
7 and 8 are an overall schematic diagram of an image forming apparatus having a conventional double-sided copying function and a perspective view of a main part of an intermediate tray. The conventional double-sided image forming apparatus will be described in more detail.
In this image forming apparatus, the P paper is conveyed from the paper bank 109 through the conveyance path 110 to the electrophotographic image forming unit 101, and a toner image on the photosensitive member is formed by the photosensitive member 111 and the transfer separation device 112. After being transferred onto the paper, it is fixed by the fixing unit 113. In the case of single-sided copying, the paper is discharged from the paper discharge unit 114.
On the other hand, in the case of double-sided copying, after the paper is fixed by the fixing device 113, the paper is guided by the branching claw 115 and is discharged to the intermediate tray 102 and temporarily stored. The aligning plate 103a and the aligning plate 103b move outward in the direction of the arrow A shown in the figure, open, and retract so as not to obstruct paper discharge.
[0003]
Further, when the paper P guided and conveyed to the intermediate tray side by the branching claw 115 is discharged onto the intermediate tray 102, the rear end pushing member 105 moves in the arrow B direction so that the paper does not jump out of the intermediate tray 102. Since it is arranged so as to be supported and projecting vertically, it is fixed at a predetermined position according to the size of the paper to prevent the paper from popping out. When the discharge of the paper P onto the intermediate tray 102 is completed, the pair of alignment plates 103a and 103b move inward in the direction opposite to the arrow A direction and are in contact with both edges of the paper on the intermediate tray. At the same time as the closing, the approach roller 116 is lowered onto the paper and the operation of bringing the paper to the paper feeding position is repeated every time the paper is discharged.
When the stock of all the sheets on the intermediate tray is thus completed, refeeding (discharging from the lowermost sheet from the intermediate tray) for image formation on the back surface is performed. When the pressure member 106 is lowered onto the sheet and the sheet is pressed against the sheet feeding roller 117 to feed the sheet, a plurality of sheets are set one by one by the separation unit 118 including a combination of a belt and a roller. The sheet is separated and fed, passes through the sheet conveyance path 107 and the conveyance path 110, is copied on the back surface by the photosensitive member 111 and the transfer separation device 112 of the image forming unit 101, is fixed by the fixing device 113, and is copied on both sides. The paper is discharged from the paper discharge unit 114.
So both such Face The demand for an increase in the number of double-sided sheets is increasing with the increase in the number of P-pieces. However, 50 sheets is the limit in the case of the lower feed that separates and feeds a plurality of set sheets one by one from the bottom by the FRR separation system or belt separation system mainly used in the image forming apparatus. there were.
[0004]
Accordingly, various image forming apparatuses that increase the number of double-sided copies by providing an intermediate tray capable of stacking 50 sheets or more while being a lower sheet feeding type have been proposed and known.
For example, there is a known image processing apparatus that can increase the number of double-sided copies by providing a plurality of intermediate trays so that each destination can be designated as a destination and a paper feed stage (Japanese Patent Laid-Open No. Sho-05-230). 62-293258).
In addition, in order to shorten the copying time in the double-sided copying mode, a detection signal for detecting the sheet fed to the intermediate tray and stopping the drive while the sheet feeding roller and the separation roller pinch the trailing end of the sheet is provided. A technique in which a sensor that generates the light is provided is also known (see Japanese Patent Laid-Open No. 3-227886).
In addition, by restricting the upper layer portion of the sheet bundle re-feeded from the intermediate tray with the elastic feed amount regulating member, only the lower layer portion is allowed to pass so that the leading end of the sheet bundle becomes a wedge shape. A technique for improving the reliability of the lower feed is also known (see Japanese Patent Laid-Open No. 5-124774).
In addition, a press plate that rotates in conjunction with the jogger fence that moves forward and backward in the width direction each time the paper enters the refeed tray can hold the paper from the top when the jogger fence moves away from or approaches the paper. Thus, there is also known a technique for improving the consistency of the transport direction of the paper on the refeed tray even when the next paper enters the refeed tray (Japanese Patent Laid-Open No. 5-193810). See the publication).
Furthermore, by dividing one intermediate tray into a plurality of sheets, it is possible to increase the number of frequently used paper sheets without increasing the size of the device, and to improve the storage capacity for high-speed copying. There is also known a technique that makes it possible to hold sheets in a state where sheets of various sizes are positioned on an intermediate tray (see Japanese Patent Laid-Open Nos. 6-43710, 6-289671, etc.) .
However, in such a conventional image forming apparatus, if the number of double-sided copies using an intermediate tray increases, a new apparatus, new members, new space, etc. are required, resulting in an increase in size and cost. In addition, the operation time is long, the productivity of image formation is poor, and the driving load increases.
[0005]
[Problems to be solved by the invention]
In the conventional image forming apparatus described above, when the number of double-sided copies using the intermediate tray increases, a new apparatus, new member, new space, etc. are required, which increases the size and cost. In addition, there is a problem that the operation time becomes long, the productivity of image formation is poor, and the driving load increases.
Therefore, an object of the present invention is to solve such problems. In other words, even if the number of double-sided copies using an intermediate tray increases, a new device or the like is not required, the size and cost are not increased, image formation productivity is high, and the driving load is not increased. The object is to provide a forming device.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, the image forming unit for forming an image on the paper temporarily stores the paper on which the image is formed on one side, and then sends it back to the image forming unit to send the image on the back side. Intermediate tray for forming When, The single-sided imaged paper that is discharged to the intermediate tray To the width direction A pair of aligning means for aligning the sheet bundle by moving forward and backward respectively; ,Up A moving means for moving the sheet bundle aligned by the aligning means in the paper feeding direction, and a pressure means for pressing the upper surface of the paper bundle moved to the paper feeding position by the moving means; The pair of aligning means each include a storage stage for storing a plurality of bundles of paper divided into a plurality of upper and lower stages, and all the sheets stored in the lower storage stage are sent out. After that, the aligning means moves in the opening direction so that the sheet bundle stored in the upper storage stage is dropped and stored in the lower storage stage. .
According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, each of the alignment means has a storage stage, and each storage stage has a two-stage configuration on the storage stage and on the storage stage. The bottom width of the counter gap below the step is narrower than the bottom width of the counter gap on the storage stage.
According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, the final sheet fed from the storage stage is detected by a detecting unit provided in a sheet conveyance path positioned on the downstream side. And
According to a fourth aspect of the present invention, in the image forming apparatus according to the first, second, or third aspect, the storage step provided in one of the pair of alignment means is such that the outer fence surface on the storage step is the storage step. It protrudes outward in the width direction from the lower fence surface.
According to a fifth aspect of the present invention, in the image forming apparatus according to the first, second, third, or fourth aspect, the pressing unit rotates to change the vertical position so that the image forming unit is directed toward the intermediate tray. The paper discharge direction of the conveyed paper is switched, and the paper storage position on the intermediate tray is switched to either the lower storage stage or the upper storage stage.
According to a sixth aspect of the present invention, in the image forming apparatus according to the first, second, third, fourth, or fifth aspect, the pressurizing unit pressurizes an upper surface of a sheet bundle stored under the storage stage. To do.
According to a seventh aspect of the present invention, in the image forming apparatus according to the first, second, third, fourth, fifth or sixth aspect, the moving means moves the leading edge of the sheet bundle stored on the storage stage in the paper feeding direction. It is characterized by having an inclined surface that causes the lower sheet to precede.
[0007]
[Action]
According to a first aspect of the present invention, there is provided an image forming apparatus including an intermediate tray that temporarily stores a sheet having an image formed on one side by the image forming unit and then sends the sheet to the image forming unit again. In this case, a plurality of bundles of sheets that are aligned by the aligning means provided in the intermediate tray are stored in the upper and lower storage stages and fed, so the number of double-sided copies using the intermediate tray Even if the image quality increases significantly, there is no need for a new device such as an alignment means, so there is no increase in size or cost, image formation productivity is good, and an image forming apparatus that does not increase the driving load is provided. I can do it.
According to a second aspect of the present invention, there is provided an intermediate tray that receives and temporarily stores a sheet that has been recorded on one side by the image forming unit, and then sends it again to the image forming unit. Since the paper is stored and fed on a storage stage having an opposing gap wider than the bottom width of the opposing gap below the storage stage, even if the number of double-sided copies using the intermediate tray is greatly increased, An image that does not require a new device such as an aligning unit, does not increase in size and cost, improves image formation productivity, reduces the paper movement distance and the time required for driving, and does not increase the driving load. A forming apparatus can be provided.
[0008]
According to a third aspect of the present invention, when aligning the sheets discharged to the intermediate tray by the aligning means, a plurality of bundles of sheets are stored and fed into the upper and lower storage stages and fed from the storage stage. Since the final sheet to be detected is detected by the detection means provided in the paper conveyance path, a new device such as an alignment means is not required even if the number of double-sided copies using the intermediate tray is greatly increased. It is possible to provide an image forming apparatus in which the paper feeding operation is shortened, the image forming productivity is good, and the driving load is not increased without increasing the size and cost.
According to a fourth aspect of the present invention, when aligning the sheets discharged to the intermediate tray by the aligning means, a plurality of bundles of sheets are stored and fed in storage stages divided into upper and lower stages, and one aligning means is Since the upper part of the storage stage is wider than the lower part of the storage stage in the width direction, even if the number of double-sided copies using the intermediate tray is greatly increased, a new device such as an alignment unit is required. In addition, the image forming apparatus can be provided with no increase in size and cost, high productivity in image formation, no need for opening / closing driving of the alignment means, and no increase in driving load.
[0009]
According to a fifth aspect of the present invention, when aligning the sheets discharged to the intermediate tray by the aligning means, a plurality of bundles of sheets are stored and fed in the upper and lower storage stages and the pressurizing means is rotated. Since the paper transport direction is switched by movement to select the lower storage stage or upper storage stage, even if the number of double-sided copies using the intermediate tray increases significantly, a new device such as an alignment unit No need to increase the size and size, and the pressurizing means can be used to switch the paper to each aligning means, saving space and cost, and improving image formation productivity and driving load. A forming apparatus can be provided.
According to a sixth aspect of the present invention, when aligning the sheets discharged to the intermediate tray by the aligning means, a plurality of bundles of sheets are stored and fed in a storage stage divided into a plurality of upper and lower stages, and the pressurizing means is stored. Since the paper stored in the lower stage is pressurized, even if the number of double-sided copies using the intermediate tray is greatly increased, a new device such as an alignment unit is not required, resulting in an increase in size and cost. Accordingly, it is possible to provide an image forming apparatus in which paper misalignment is prevented, image forming productivity is good, and driving load is not increased.
In claim 7, when aligning the sheets discharged to the intermediate tray by the aligning means, a plurality of bundles of sheets are stored in a storing stage divided into a plurality of upper and lower stages, and an inclined surface positioned in front of the moving means Thus, even if the number of double-sided copies using the intermediate tray is significantly increased, a new device such as an alignment unit is required. Accordingly, an image forming apparatus can be provided in which separation of sheets is reliably performed, image forming productivity is good, and driving load is not increased without increasing the size and cost.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram of the overall configuration of an image forming apparatus according to an embodiment of the present invention, and FIG. 2 is a perspective view of an essential part of an intermediate tray portion. In the image forming apparatus of the present invention shown in FIG. 1, the sheet (P) is conveyed from the paper bank 9 through the conveyance path 10 to the electrophotographic image forming unit 1, and the photosensitive member 11 and the transfer separation device 12 are conveyed. At the intermediate position, the toner image on the photosensitive member is copied on one side and fixed by the fixing unit 13. In the case of single-sided copying, the toner image is discharged from the paper discharge unit 14 and stored on the paper discharge tray.
On the other hand, when performing double-sided copying, the paper (P) is guided by a branch claw 15 that rotates to the dotted line position after being fixed by the fixing device 13 and is discharged onto the intermediate tray 2. However, immediately before the storage, the pair of alignment plates 3a and alignment plates 3b as the alignment means 3 move outward in the direction of the arrow C and open, thereby obstructing the discharge of the sheet (P). It is supposed not to be.
Each of the alignment plates 3a and 3b has a staircase shape having a storage step 4 (lower storage step 4a and upper storage step 4b), and a plurality of bundles of sheets (P) that are discharged to the intermediate tray 2 and aligned are arranged. The lower storage step 4a and the upper storage step 4b respectively provided on the alignment plates 3a and 3b are stored separately in the vertical direction.
[0011]
Further, when the paper (P) is guided by the branching claw 15 and discharged onto the intermediate tray, the rear end of the paper (P) of the moving means 5 is prevented so that the paper (P) does not jump out of the intermediate tray 2. The push member is arranged in a vertical posture so as to be movable in the direction of arrow D, and is fixed at a predetermined position in accordance with the size of the paper (P).
Since the front surface of the moving means 5 is an inclined surface 5a, the stacked state of the sheet bundle on the intermediate tray 2 is also matched with the shape of the inclined surface, and the set lower sheet (P) Becomes a wedge shape preceding the paper feeding direction.
When the discharge of the sheet (P) to the intermediate tray 2 is completed, the pair of aligning plates 3a and 3b as the aligning means 3 are moved and closed in the direction opposite to the direction of the arrow C, and at the same time, the roller 16 is pivoted. The operation of rotating about 16a and lowering on the paper and bringing the paper (P) to the paper feeding position is repeated every time the paper (P) is discharged.
When the stock on the intermediate tray is completed, refeeding for image formation on the back surface is performed from the bottom sheet. When the pressure member 6 that moves up and down about the rotation shaft 6a lowers and pressurizes the sheet (P), the sheet is pressed against the sheet feeding roller 17 and the sheet feeding roller 17 rotates to feed the sheet. The separating unit 18 (consisting of the belt 18a and the roller 18b) separates the set plurality of sheets (P) one by one, passes through the sheet conveying path 7 and the conveying path 10 and passes through the image forming unit 1 The sheet (P) that has been copied to the other side by the photoconductor 11 and the transfer separation device 12, fixed by the fixing unit 13, and copied on both sides is discharged from the paper discharge unit 14.
[0012]
FIG. 3 is a front view showing the entire details of the intermediate tray. The rear end pushing member (moving means) 5 of the paper (P) is fixed at a predetermined position according to the size of the paper (P) to be used. Waiting fixed by means.
Initially, since the pressurizing means 6 discharges and stores the paper (P) on the lower storage stage 4 a below the storage stage 4, the pressurizing means 6 rotates about the rotation shaft 6 a as a fulcrum and shows the broken line shown in the figure. Stopped at the pivot position.
For example, assuming that 50 sheets of paper (P) can be stored on each storage stage 4a, 4b of the storage stage 4, up to 50 sheets (P) are stored in the storage stage 4a. Immediately before being stored, the pair of alignment plates 3a and 3b move outward in the illustrated front-rear direction and open so as not to obstruct the discharge of the paper (P), thereby discharging the paper (P). Is completed, the closing roller 16 rotates in the direction of the arrow E with the rotation shaft 16a as a fulcrum, and moves down to the direction of the arrow F to move the sheet (P) to the sheet feeding position. Repeat for each discharge of P).
When up to 50 sheets (P) are stored in the lower storage stage 4a, the pressurizing means 6 rotates in the arrow G direction (downward direction) with the rotation shaft 6a as a fulcrum, and the solid line shown in the figure. In the rotation position, the sheet (P) stored in the storage stage lower 4a is pressurized, and the upper surface of the sheet (P) is pressed, so that the sheet to the second storage stage upper 4b is subsequently performed. When storing (P), the alignment plates 3a and 3b are opened and closed in the front-rear direction to prevent the sheet (P) stored in the storage step 4a from being displaced.
[0013]
When the pressurizing means 6 is in the lowered state shown by the solid line, the sheet (P) transport path toward the intermediate tray is switched in the direction of the second storage stage 4b, and from the 51st sheet, the second stage is changed to the second stage. It is stored in the storage stage 4b above the eyes. That is, the front end 6A of the pressurizing unit 6 of the pressurizing means 6 has a triangular shape, and prevents the paper discharged from the discharge roller 20 from being discharged onto the storage step 4a when it is at the raised position indicated by the broken line. However, when it is lowered as indicated by the solid line, the sheet that has come out of the nip portion of the discharge roller 20 is discharged along the upper surface of the tip end 6A of the pressurizing unit, and therefore is not discharged onto the storage step 4a. Instead, the shape is designed so that the upper surface of the pressure member tip 6A guides the sheet onto the storage stage 4b.
Further, as apparent from FIG. 3, the sheet feeding direction positions of the sheet bundle stacked on the storage stage 4a and the sheet bundle stacked on the storage stage 4b are shifted, and the former is on the front side. It protrudes.
When the paper (P) is stored in the second storage stage 4b, the distance (l) between the pressurizing means 6 (the rear end portion of the pressurizing portion tip 6A) and the moving means 5 is the paper size. (P) Since the moving means 5 moves and stands by so as to be a position that is about 3 mm longer than the size, the roller 16 does not operate.
[0014]
The standby position of the moving means 5 at the time of discharging the first lower storage stage 4a is the position behind the tip (H) of the pressurizing means 6 by (1).
The alignment plates 3a and 3b align the sheets by opening and closing in the front-rear direction shown in the drawing, like the first storage lower 4a.
When the last sheet (P) is stored, both sides of the sheet are fed, and the sheet is fed from the lowest sheet (P) in the first storage stage 4a.
Since the sheet (P) bundle stored in the second storage stage 4b is partitioned by the storage stage 4b, the influence of the weight of the paper (P) is stored in the first storage stage 4a. Is not given to the bundle of sheets (P) to be printed.
The sheet (P) bundle stored in the first storage lower stage 4a is already waiting at the sheet feeding position by the shift operation of the shift roller 16, and the pressurizing means 6 is also in the pressurized state indicated by the solid line in the figure. .
[0015]
Completion of feeding of a bundle of sheets (P) stored in the first storage stage 4a is stored as the number of sheets (P) stored in the storage stage 4a and compared with the number of sheets fed on both sides. As a result, when the last sheet (P) to be fed is detected and the leading end of the last sheet (P) is detected by the sensor of the detection means 8 provided in the sheet conveyance path 7, the above addition is performed. The pressure means 6 is rotated in the reverse direction of the arrow G shown in the figure with the rotary shaft 6a as a fulcrum, and is moved into a broken line state, and the alignment plates 3a and 3b are opened in the front-rear direction shown in the figure to form two steps. The sheet (P) bundle stored in the upper storage stage 4b is dropped to the lower storage stage 4a. Immediately thereafter, the alignment plates 3a and 3b are closed again in the front-rear direction shown in the figure, and the moving means 5 is moved in the direction indicated by the arrow (I) by the driving means (not shown) so that the sheet (P) bundle is fed into the paper feed position. To move to.
[0016]
Since the moving means 5 has the inclined surface 5a in the moving direction of the arrow I, the sheet (P) is stored in the lower storage stage 4a of the storage stage 4 and the second upper storage stage 4b. In the lower sheet (P), the leading edge is stored in advance in the sheet feeding direction.
Even when the moving means 5 moves in the moving direction indicated by the arrow I, the paper (P) stored in the second storage stage 4b is separated at the paper feeding position along the inclined surface 5a. Move while creating an advantageous state.
Therefore, if the moving distance of the paper (P) is about 30 mm, it is possible to realize the above behavior. In the prior art, the paper (P) needs to be larger than the size of the paper (P), for example, 210 mm or more in the A4 lateral feed. ) Travel distance and driving time are small, and even if the number of double-sided copy paper (P) using the intermediate tray 2 is increased, a new apparatus or the like is not required, resulting in an increase in size and cost. Accordingly, it is possible to provide an image forming apparatus in which the paper feeding operation is shortened, the image forming productivity is good, and the driving load is not increased.
Incidentally, it is possible to provide an image forming apparatus that is not restricted by the size of the paper (P) by extending the length of the alignment plates 3a and 3b in the paper feeding direction.
[0017]
With reference to the schematic diagram of FIG. 4, the illustrated opening and closing operations of the alignment plates 3a and 3b will be described in more detail. When aligning the normal sheets (P) one by one, the width (l2) when the alignment plates 3a and 3b are opened in the front-rear direction is slightly wider than the width (l1) of the sheet (P). For example, (l2) = (l1) +10 (mm). The sheet (P) bundle stored in the second storage stage 4b is dropped to the storage stage 4a. (Drop and store) In some cases, the bottom width (L2) of the facing gap of the upper storage stage top 4b is slightly wider than the width (l1) of the sheet (P), for example, (L2) = (l1) +5 (mm) The alignment plates 3a and 3b are respectively in the arrow K direction and the M direction. (Opening direction) To open. The state shown in the figure shows an open state when the sheet (P) bundle stored in the second storage stage upper 4b is dropped to the storage stage lower 4a. At that time, the bottom width (L1) of the facing gap of the lower storage step 4a is narrower than the bottom width (L2) of the facing gap of the upper storage step 4b (L1 <L2), and the lower storage step 4a. Determines the bottom width (L1) of the facing gap of the lower storage step 4a so that it overlaps the paper (P) and aligns the plates 3a, 3b. But Reverse direction of arrow K direction and reverse direction of M direction respectively (Closing direction) It does not become an obstacle when closing.
[0018]
FIG. 5 is a diagram for explaining the specific operation of the storage stage according to another embodiment of the present invention. In this embodiment, the shapes of the alignment plates 3a and 3b are different, and the upper storage stage 4b of one alignment plate 3a is The lower alignment step 3a protrudes outward from the lower storage step 4a, and the other alignment plate 3b has a substantially U-shape in which the storage step lower 4a is longer inward.
In FIG. 5A, when the sheet (P) is stored in the storage stage 4a, the alignment by the alignment plates 3a and 3b and the movement by the inclined moving roller 16b are performed for each sheet (P). It is like that.
When the storage of the paper (P) is completed in the lower storage stage 4a, the paper (P) is stored in the upper storage stage 4b. At that time, the alignment plates 3a and 3b remain closed.
The fence surface (N) of the upper storage stage 4b on the near side of the sheet (P) of either the alignment plate 3a or the alignment board 3b is the fence surface (O ) Slightly outside (only for dimension l3), for example, 5 mm (l3 = 5 mm) wide, so that even if the alignment plates 3a and 3b remain closed, it does not hinder the discharge of the paper (P). .
Next, when the storage of the paper (P) in the second storage stage upper 4b is completed by bringing the inclined roller 16b close to the fence surface (N), the paper (P) stored in the storage lower 4a. The bundle is fed.
[0019]
In FIG. 5B, when the feeding of the bundle of sheets (P) stored in the lower storage stage 4a is finished, the alignment plates 3a and 3b are opened in the directions of arrows K and M, respectively, and the second storage stage. A bundle of sheets (P) stored in the upper 4b falls and is stored in the lower storage stage 4a in the arrow Q direction.
In FIG. 5C, the sheet (P) bundle that has been stored in the storage stage 4a is shifted in the width direction by (l3), but the alignment plates 3a and 3b are each in the direction of the arrow K. By being closed in the reverse direction and the reverse direction of the M direction, the sheet (P) bundle that has been stored in the storage stage lower 4a is moved to the correct position as shown in the figure immediately before paper supply. .
[0020]
FIG. 6 is a plan view of the intermediate tray, and the inclined approach rollers 16b are slightly inclined, for example, about 4 degrees with respect to the sheet feeding direction so that the sheet (P) can be brought closer to the fence surface (N). .
When the paper (P) is stored in the lower storage stage 4a, the moving means 5 is in the position of the arrow R, and the discharged paper (P) is closed to the paper feeding position by the inclined approaching rollers 16b. It is moved toward (along) the alignment plate 3a and the alignment plate 3b.
When the sheet (P) is stored in the second storage stage 4b, the moving means 5 moves to the position of the arrow S and brings the discharged sheet (P) toward the fence surface (N) of the alignment plate 3a. To a fully retracted position (distance (l4) retracted position).
Next, after the inclined roller 16b is lowered and the sheet (P) is brought into contact with the pressurizing means 6 while being brought close to the fence surface (N) of the aligning plate 3a of the aligning means 3 (state of FIG. 3), Rise.
Accordingly, it is not necessary to open and close the alignment plates 3a and 3b when aligning the sheet (P) stored in the second storage stage 4b, so that the double-sided copy sheet (P) using the intermediate tray 2 is not necessary. It is possible to provide an image forming apparatus that does not require a new apparatus or the like even if the number of sheets increases, does not increase in size or cost, has good image forming productivity, and does not increase the driving load. became.
[0021]
【The invention's effect】
As described above, according to the first aspect of the present invention, the image forming unit is provided with the intermediate tray that temporarily stores the paper on which the image is formed on one side and then sends the paper to the image forming unit again, and is discharged to the intermediate tray. When aligning paper with the aligning means, multiple bundles of paper are stored and fed in separate upper and lower storage stages, which greatly increases the number of double-sided copies using the intermediate tray. However, it is possible to provide an image forming apparatus that does not require a new device such as an aligning unit, does not increase in size and cost, has good image forming productivity, and does not increase the driving load. became.
According to the second aspect of the present invention, when aligning the sheets discharged to the intermediate tray by the aligning means, the bottom width of the opposing gap below the storage stage and the storage stage below the plurality of bundles of paper divided into a plurality of upper and lower stages. Since the paper is stored and fed on a storage stage having a wider facing gap, a new device such as an alignment unit is required even if the number of double-sided copies using an intermediate tray is greatly increased. Therefore, it is possible to provide an image forming apparatus that does not increase in size and cost, has good image forming productivity, has a reduced paper moving distance and driving time, and does not increase driving load. .
[0022]
According to the invention of claim 3, when aligning the sheets discharged to the intermediate tray by the aligning means, a plurality of bundles of sheets are stored and fed into the storage stages divided into a plurality of upper and lower stages, and from the storage stage. Since the last paper to be fed is detected by the detection means provided in the paper conveyance path, a new device such as an alignment means is required even if the number of double-sided copies using the intermediate tray is greatly increased. In addition, it is possible to provide an image forming apparatus in which the paper feeding operation is shortened, the image forming productivity is good, and the driving load is not increased without increasing the size and cost.
According to the fourth aspect of the present invention, when aligning the sheets discharged to the intermediate tray by the aligning means, a plurality of bundles of sheets are stored in the storage stages divided into a plurality of upper and lower stages and fed, and the sheets are shifted. The storage stage on the side is wider outward in the width direction than the storage stage (the fence on the storage stage protrudes outward in the width direction than the fence under the storage stage), so both sides using an intermediate tray Even if the number of copies is significantly increased, new devices such as alignment means are not required, so there is no increase in size and cost, image formation productivity is good, and alignment means need not be opened and closed. An image forming apparatus that does not increase the driving load can be provided.
[0023]
According to the invention of claim 5, when the sheets discharged to the intermediate tray are aligned by the aligning means, a plurality of bundles of sheets are stored in the storage stages divided into a plurality of upper and lower stages and fed, and the pressing means The lower or upper storage stage is selected by rotating the paper (the pressurizing means plays a role of sorting the storage direction of the paper discharged onto the intermediate tray up and down), so both sides using the intermediate tray Even if the number of copies is greatly increased, a new device such as an aligning unit is not required and the size is not increased, and the paper switching to each aligning unit is also used by the pressurizing unit, which saves space. It is possible to provide an image forming apparatus that is low in cost, has good image forming productivity, and does not increase the driving load.
According to the sixth aspect of the present invention, when aligning the sheets discharged to the intermediate tray by the aligning means, a plurality of bundles of sheets are stored in the storage stages divided into upper and lower stages and fed, and the pressurization is performed. Since the paper stored under the storage stage in which the paper selected by the means is stored is pressed, even if the number of double-sided copies using the intermediate tray is greatly increased, a new device such as an aligning means, etc. Therefore, it is possible to provide an image forming apparatus that does not require an increase in size and cost, prevents paper displacement, improves image forming productivity, and does not increase the driving load.
According to the seventh aspect of the present invention, when aligning the sheets discharged to the intermediate tray by the aligning means, a plurality of bundles of sheets are stored in the storing stages divided into a plurality of upper and lower stages and fed by the inclined surface of the moving means. Since the paper is fed so that the lower paper is leading in the paper direction, even if the number of double-sided copies using the intermediate tray is greatly increased, a new device such as an aligning unit is not required, and the large size is required. Thus, it is possible to provide an image forming apparatus in which separation of sheets is reliably performed, image forming productivity is high, and driving load is not increased without increasing the cost and cost.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram illustrating an outline of an image forming apparatus according to an embodiment of the present invention.
FIG. 2 is a perspective view illustrating a main part of the image forming apparatus in FIG.
3 is a front view illustrating another main part of the image forming apparatus in FIG. 1. FIG.
4 is a configuration and operation explanatory diagram of an alignment unit of the image forming apparatus in FIG. 1. FIG.
FIGS. 5A, 5B, and 5C are diagrams illustrating a main part of an image forming apparatus according to another embodiment of the present invention.
6 is a plan view of the embodiment shown in FIG.
FIG. 7 is an explanatory diagram illustrating an outline of a conventional image forming apparatus.
FIG. 8 is an explanatory diagram for explaining a main part of a conventional image forming apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Image forming part, 2 Intermediate tray, 3 Alignment means, 3a Alignment plate, 3b Alignment plate, 4 Storage stage, 4a Storage stage bottom, 4b Storage stage top, 5 Moving means, 5a Inclined surface, 6 Pressure means, 6a times Moving shaft, 7 paper transport path, 8 detection means, 9 paper bank, 10 transport path, 11 photoconductor, 12 transfer separation device, 13 fixing device, 14 paper discharge section, 15 branching claw, 16 trailing roller, 16a rotating shaft , 16b Inclining roller, 17 Feed roller, 18 Separating unit, 101 Image forming unit, 102 Intermediate tray, 103a Alignment plate, 103b Alignment plate, 105 Rear end pushing member, 106 Pressure member, 107 Paper transport path, 109 paper Bank, 110 Conveying path, 111 Photoconductor, 112 Transfer separation device, 113 Fixing device, 114 Paper discharge unit, 115
Branch claw, 116 roller, 117 paper feed roller, 118 separator

Claims (7)

An intermediate tray that temporarily stores a sheet that has undergone image formation on one side in an image forming unit that forms an image on a sheet and then sends the sheet again to the image forming unit to form an image on the back side, and is discharged to the intermediate tray moving means for moving a pair of alignment means for aligning the sheet bundle, the sheet bundle aligned on SL aligning means in the sheet feeding direction by each moved forward and backward in the width direction of the one-side image-formed paper, the movement An image forming apparatus comprising: a pressurizing unit that pressurizes an upper surface of a sheet bundle moved to a paper feeding position by the unit ;
Each of the pair of aligning means includes a storing stage for storing a plurality of bundles of paper in a plurality of upper and lower stages, and after all the sheets stored in the lower storing stage are sent out, the aligning means moves in the opening direction. An image forming apparatus configured to drop and store a sheet bundle stored in an upper storage stage into a lower storage stage by moving . 2. The image forming apparatus according to claim 1, wherein each of the aligning means has a storage stage, and each storage stage has a two-stage configuration on the storage stage and on the storage stage. An image forming apparatus, wherein a bottom width is narrower than a bottom width of an opposing gap on the storage stage. 3. The image forming apparatus according to claim 1, wherein the last sheet fed from the storage stage is detected by a detection unit provided in a sheet conveyance path located on the downstream side. 4. The image forming apparatus according to claim 1, wherein the storage step provided in one of the pair of aligning means is such that an outer fence surface on the storage step is wider than a fence surface below the storage step. An image forming apparatus that protrudes outward in the direction. 5. The image forming apparatus according to claim 1, wherein the pressurizing unit is rotated to change the vertical position of the sheet to be conveyed from the image forming unit toward the intermediate tray. An image forming apparatus characterized in that the paper discharge direction is switched, and the paper storage position on the intermediate tray is switched to either the lower storage stage or the upper storage stage. 6. The image forming apparatus according to claim 1, wherein the pressurizing unit pressurizes an upper surface of a sheet bundle stored under the storage stage. 7. The image forming apparatus according to claim 1, wherein the moving unit moves the leading edge of the bundle of sheets stored on the storage stage in advance toward the sheet feeding direction. An image forming apparatus having an inclined surface.

Images