JP4606332B2 - Sheet stacking apparatus and sheet post-processing apparatus - Google Patents

Description

  The present invention can be applied to a sheet material such as an image-recorded paper or an OHP film which is attached to an image forming apparatus such as a copying machine, a printer, a facsimile, or a complex machine thereof, and discharged from such an image forming apparatus. The present invention relates to a sheet post-processing apparatus that performs post-processing such as punching and stapling. The present invention also relates to a sheet stacking apparatus that discharges and stacks sheet materials on a stacking tray in such a sheet post-processing apparatus.

  Conventionally, in image forming apparatuses such as copying machines, a sheet post-processing device is externally attached to a discharge port, and sheet materials such as paper and OHP film that have already been recorded with the image forming device are discharged from the discharge port. Some sheets are put into a sheet post-processing apparatus, post-processed, and then discharged and stacked on a stacking tray of a sheet stacking apparatus provided in the sheet post-processing apparatus.

  In this type of sheet stacking device, the sheet material is made constant by dropping the height from the discharge position of the sheet material toward the stacking tray to the upper surface of the uppermost stacking sheet material stacked on the stacking tray. In order to eliminate stacking disturbances and improve stackability, the stacking height of the sheet material on the stacking tray gradually increases and the stacking tray is gradually lowered so that the discharged sheet material is constantly and uniformly stabilized on the discharge tray. And was able to be loaded.

JP 2002-12362 A

  However, when the stacking height of the sheet material on the stacking tray becomes high, the stacking state of the sheet material becomes unstable and collapses, and in the worst case, the sheet material may fall from the stacking tray. In particular, when the size of the sheet material is small, it is more likely to collapse than when it is large, and the sheet stacking apparatus that shifts in the width direction perpendicular to the sheet discharge direction and sorts and discharges has a problem that it is more likely to collapse. It was.

  For example, as shown in FIG. 9, when the sheet material s of A5 (148 × 210) is shifted by 15 mm to the left and right in the width direction and discharged, the width of the overlapping portion becomes narrower from 148 mm to 133 mm of the full width. When the number of sheets increases, there is a possibility that the loading state becomes unstable at a lower loading height h than in the case where sorting is not performed.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a sheet stacking apparatus that discharges and stacks sheet materials on a stacking tray and moves the stacking tray up and down according to the stacking status of the stacking sheet material. Only when there is a possibility that the sheet will collapse, the collapse preventing member in the retracted state appears and disappears to prevent the sheet material from collapsing.

  The second object of the present invention is to eliminate the possibility that the sheet material will collapse more reliably as the height of the sheet material stacked on the stacking tray becomes higher and the risk of collapse increases.

  A third object of the present invention is to eliminate the possibility that the sheet material will collapse more reliably without increasing the number of parts and increasing the cost.

  A fourth object of the present invention is to eliminate the possibility that the sheet material loaded on the stacking tray will collapse only when a small-sized sheet material is stacked and the possibility of collapse is high.

  A fifth object of the present invention is to prevent collapse of sheet materials stacked on a stacking tray by limiting the stacking height when stacking small size sheet materials.

  According to a sixth object of the present invention, in the sheet post-processing apparatus, only when there is a risk that the sheet material stacked on the stacking tray of the sheet stacking apparatus may collapse, This is to prevent the sheet material from collapsing.

Therefore, according to the first aspect of the present invention, the sheet material such as paper / OHP film is discharged, the discharged sheet material is stacked on the stacking tray, and the stacking is increased as the number of sheet materials stacked on the stacking tray increases. In the sheet stacking apparatus for lowering the tray, a guide member for regulating a width direction orthogonal to the discharge direction of the sheet material stacked on the stacking tray is put in and out between the storage position and the use position. As the sheet material is discharged and stacked on the stacking tray, the stacking tray is lowered, and the guide member is moved based on the gravity to move up and down on the stacking tray .

  For example, when a small-sized sheet material is shifted in the width direction and sorted on the stacking tray and discharged, the guide member is moved from the storage position to the use position on the stacking tray, and the guide member The width direction of the sheet material stacked on the stacking tray is regulated.

Guide member, collapse easily, the sheet member stacked on the stacking tray only when more than a predetermined size, may be so infested onto the stacking tray.

  In addition, detection means such as an optical sensor and a micro switch are provided to detect the lowering lower limit position of the stacking tray when the sheet material stacked on the stacking tray is smaller than a predetermined size, and stop discharging the sheet material exceeding a certain stacking amount. Good.

  According to a second aspect of the present invention, in a sheet post-processing apparatus that performs post-processing such as punching holes and stapling on a sheet, the sheet stacking apparatus according to the first aspect described above is provided.

  Therefore, according to the first aspect of the present invention, in the sheet stacking apparatus that discharges and stacks the sheet material on the stacking tray and moves the stacking tray up and down according to the stacking condition of the stacked sheet material, If the sheet material loaded on the stacking tray is likely to collapse, such as when shifting small sheets in the width direction and sorting and discharging them on the stacking tray, place the guide member in the retracted state on the stacking tray. It is possible to prevent the sheet material loaded on the stacking tray from collapsing by restricting the width direction of the sheet material.

  Here, if the guide member appears and disappears on the stacking tray as the stacking tray descends, the height of the sheet material loaded on the stacking tray increases, and the guide member appears and disappears as the possibility that the sheet material collapses increases. In addition, it is possible to eliminate the possibility that the sheet material on the stacking tray will collapse more reliably.

  When the guide member is moved based on the gravity so as to appear on the stacking tray, it is not necessary to provide a means for driving the guide member, and the stacking tray is lowered without increasing the number of parts without increasing the cost. As a result, it is possible to eliminate the possibility that the guide member will appear on the stacking tray and the sheet material may collapse more reliably.

  When the sheet material loaded on the stacking tray is smaller than the specified size, guides on the stacking tray only when stacking a small-sized sheet material that tends to collapse if the guide member is projected and retracted on the stacking tray. With the guide member, the sheet material stacked on the stacking tray can be prevented from collapsing.

  When the sheet material loaded on the stacking tray is smaller than the specified size, the lower limit position of the stacking tray is detected and the discharge of the sheet material exceeding a certain load capacity is stopped. When stacking materials, it is possible to prevent collapse of sheet materials stacked on the stacking tray by limiting the stacking height to a low level.

  According to the second aspect of the present invention, since the sheet post-processing apparatus includes the sheet stacking apparatus as in the first aspect, the sheet material stacked on the stacking tray of the sheet stacking apparatus of the first aspect collapses. Only when there is a fear, the guide member in the retracted state can be moved in and out to prevent the sheet material on the stacking tray from collapsing.

The best mode for carrying out the present invention will be described below in detail with reference to the drawings.
FIG. 1 shows an appearance of an image forming apparatus in which a sheet stacking device is externally attached to a paper discharge port.

  The image forming apparatus A is configured by placing the image forming apparatus main body 10 on a paper feed table 11, and includes a paper feed cassette 12 provided in a lower portion of the image forming apparatus main body 10 and a paper feed cassette 13 provided in the paper feed table 11. Then, after the sheet as the sheet material is fed out and an image is recorded on the fed-out sheet in the image forming apparatus main body 10, the sheet is discharged from a sheet discharge port (not shown) to the sheet stacking apparatus B.

FIG. 2 shows the configuration of the sheet stacking apparatus B as viewed from the front, and FIG.
The sheet stacking apparatus B includes a sheet transport unit 15 that transports the sheet discharged from the image forming apparatus A into the apparatus casing 100 and discharges the sheet onto the stacking tray 14. The paper sorting means 16 that shifts in the paper width direction orthogonal to the discharge direction, the paper alignment means 17 that aligns the discharged paper on the stacking tray 14, and the stacking tray 14 according to the stacking status of the discharged paper on the stacking tray 14 A tray vertical movement means 18 that moves up and down is provided.

  The paper transport unit 15 includes a transport motor 20, a transport driving roller 22 that transmits the rotation of the transport motor 20 via a timing belt 21, a transport driven roller 23 that is driven to rotate by the transport drive roller 22, and a transport drive. A paper discharge driving roller 25 that transmits the rotation of the roller 22 via the second timing belt 24 and a paper discharge driven roller 26 that rotates following the paper discharge driving roller 25 are provided. Then, the conveyance motor 20 rotates the conveyance driving roller 22 and the paper discharge driving roller 25 and the conveyance driven roller 23 and the paper discharge driven roller 26 are driven to rotate, and the paper discharged from the image forming apparatus A is indicated by the direction of arrow a in FIG. Are discharged from the apparatus housing 100 onto the stacking tray 14.

  The paper sorting means 16 is fed with a sorting motor 28, a worm 30 that transmits the rotation of the sorting motor 28 via a timing belt 29, a worm wheel 31 that meshes with the worm 30, and the rotation of the worm wheel 31. A rack (not shown). The rack is provided integrally with the stacking tray 14. When the sheets are discharged onto the stacking tray 14, the sorting motor 28 is driven to shift the stacking tray 14 in the direction orthogonal to the sheet transport direction a, and the sheets are moved in the width direction for each copy as shown in FIG. Shift and sort and load.

  The sheet aligning unit 17 includes two drive gears 34 provided on the roller shaft 33 of the paper discharge drive roller 25, two transmission gears 35 that mesh with the two drive gears 34, and the two transmission gears 35, respectively. Two driven gears 36 that mesh with each other and two reverse rollers 37 that are coaxial with the two driven gears 36 are provided. Then, the reverse roller 37 is rotated based on the rotation of the roller shaft 33, the paper discharged onto the stacking tray 14 is returned and abutted against the outer surface of the apparatus housing 100, and aligned and stacked on the stacking tray 14.

  The tray vertical movement means 18 is provided with a vertical movement motor 40 and a drive shaft 43 provided along the bottom in the apparatus housing 100 to transmit the rotation of the vertical movement motor 40 through the engagement of the two gears 41 and 42. The lower pulley 44 provided at both ends of the drive shaft 43, the upper pulley 45 provided above the lower pulley 44 in the upper part in the apparatus housing 100, and the corresponding lower pulley 44 and upper pulley 45 A timing belt 46 that is wound around and stretched up and down is provided. Both sides of the base of the stacking tray 14 are attached to the timing belt 46.

  Each time a sheet is stacked on the stacking tray 14, the vertical movement motor 40 is driven to lower the stacking tray 14, and from the sheet discharge position of the apparatus housing 100 toward the stacking tray 14, The height of the uppermost sheet stacked on the top of the sheet is made constant so that the sheet s falls without being disturbed, thereby improving the stackability of sheets on the stacking tray 14. Conversely, when the sheet s is removed from the stacking tray 14, the stacking tray 14 is raised to the home position, and the stacking tray 14 is moved up and down according to the stacking condition of the sheets s.

  By the way, in the present invention, as shown in FIG. 4, two fan-shaped plate-like guide members 50 are placed in parallel in the apparatus casing 100 as a sheet collapse prevention member, and are orthogonal to the sheet conveyance direction a. Prepare with spacing in the direction. The guide members 50 are provided so as to be rotatable in the paper transport direction a around a fixed shaft 51 provided at the position where the main fan is located downward. And, normally, it is provided with a counterclockwise turning behavior in FIG. 4 by gravity, and can be freely put in and out of the stacking tray 14 through a slit (not shown) provided in the apparatus housing 100. In the standby state, the base of the stacking tray 14 is provided. This is a storage position for holding the rotation position and storing it in the apparatus housing 100.

  When the sheet is discharged from the image forming apparatus A to the sheet stacking apparatus B having the above-described configuration, the sheet is conveyed by the sheet conveying unit 15 and sorted by the sheet sorting unit 16 on the stacking tray 14. The stacking tray 14 is gradually lowered by the tray up-and-down moving means 18 while being aligned by the sheet aligning means 17.

  Then, as shown in FIG. 5, the stacking tray 14 that has held the rotation position of the guide member 50 is lowered, and as the stacking tray 14 is lowered, the guide member 50 is moved based on gravity and gradually moved. The width direction of the sheet s loaded on the stacking tray 14 is regulated as a use position that appears on the stacking tray 14 and protrudes from the inside of the apparatus housing 100.

  When the stacking tray 14 is lowered to the lowering lower limit position, as shown in FIG. 6, the detection unit 53 detects fullness, restricts further lowering of the stacking tray 14, and outputs a signal to the image forming apparatus A. Then, image formation in the image forming apparatus A is also stopped. At this time, the guide member 50 protrudes to the maximum on the stacking tray 14 to a complete use position, thereby regulating the width direction of the sheets s stacked on the stacking tray 14 as shown in FIG. The sheet s to be broken is prevented from collapsing and falling from the stacking tray 14, for example. The gap c between the sheet s and the guide member 50 is set to 10 mm or less, with a gap c that can recognize the portion of the sheet s.

  Incidentally, the sheets s loaded on the stacking tray 14 are more likely to collapse as the size decreases. Therefore, the interval D between the two guide members 50 is set to an interval corresponding to the small size paper s, and only when the paper s loaded on the stacking tray 14 is not larger than a predetermined size, it is placed on the stacking tray 14 as shown in FIG. The guide member 50 is caused to appear and disappear. When the paper s having a size larger than the interval D is discharged onto the stacking tray 14, the guide member 50 is prevented from appearing on the stacking tray 14 when hitting the paper s stacked on the stacking tray 14.

  Further, in the case of the paper s having a predetermined size or less, even if the width direction is regulated by the guide member 50, there is a limit to the stacking height that can prevent the collapse. In particular, considering the case where the sheets s are sorted and discharged for each set, it is necessary to reduce the stacking height. Therefore, in addition to the normal size detection means 53, a detection means 54 (see FIG. 6) for detecting the lowering lower limit position of the stacking tray 14 when the sheets s loaded on the stacking tray 14 are not larger than a predetermined size is provided. When the sheet s stacked on the tray 14 is not larger than a predetermined size, the lowering lower limit position of the stacking tray 14 is detected, and the discharge of the sheet s exceeding a certain load amount may be stopped. Thereby, when stacking small sized sheets s that are easily collapsed, it is possible to prevent collapse of the sheets s loaded on the stacking tray 14 by limiting the stacking height to a low level.

  The detection means 53 and 54 are configured by an optical sensor, a micro switch, or the like. When the lowering lower limit position is detected by the detection means 53 and 54 according to the paper size, it is determined that the stacking limit has been reached. When the sheets s loaded on the stacking tray 14 are removed, the stacking tray 14 is raised until the home position is detected by a home position detecting unit (not shown). This home position detecting means is also composed of an optical sensor, a micro switch, or the like. Then, as the stacking tray 14 is raised, the guide member 50 is pushed and stored in the apparatus housing 100.

  In the above-described example, the sheet stacking apparatus B that is externally attached to the sheet discharge position of the image forming apparatus A has been described. However, the present invention is not limited to such an independent sheet stacking apparatus, but includes the sheet stacking apparatus as described above, punching holes or stapling a sheet material such as paper, and stacking on a stacking tray. The present invention can also be applied to a sheet post-processing apparatus for discharging.

1 is an external perspective view of an image forming apparatus in which a sheet stacking device is externally attached to a paper discharge port. FIG. 3 is an internal configuration diagram illustrating the sheet stacking apparatus as viewed from the front. FIG. 3 is an internal configuration diagram illustrating the sheet stacking device as viewed obliquely from above. It is a guide member installation configuration diagram of the sheet stacking apparatus. FIG. 3 is a configuration diagram illustrating a state in which sheets are stacked on a stacking tray of the sheet stacking apparatus. It is a block diagram when the stacking tray becomes a lowering lower limit position. It is a sheet loading state diagram at that time. It is the paper loading state perspective view. FIG. 6 is a state diagram in which sheets are shifted and stacked.

Explanation of symbols

DESCRIPTION OF SYMBOLS 14 Loading tray 15 Paper conveyance means 16 Paper sorting means 17 Paper alignment means 18 Tray vertical movement means 50 Guide member 53 Detection means 54 Detection means A Image forming apparatus B Sheet stacking apparatus s Paper (sheet material)

Claims (4)

In the sheet stacking apparatus that discharges the sheet material, stacks the discharged sheet material on the stacking tray, and lowers the stacking tray as the number of sheet materials stacked on the stacking tray increases.
On the stacking tray, a guide member that regulates the width direction of the sheet material stacked on the stacking tray is detachably provided ,
The sheet stacking apparatus according to claim 1, wherein the guide member moves based on gravity as the stacking tray descends so as to appear and disappear on the stacking tray . 2. The sheet stacking apparatus according to claim 1, wherein the guide member protrudes and retracts on the stacking tray only when a sheet material stacked on the stacking tray has a predetermined size or less. 3. The sheet stacking apparatus according to claim 1, further comprising a detection unit configured to detect a lowering lower limit position of the stacking tray when a sheet material stacked on the stacking tray has a predetermined size or less. Characterized in that it comprises a sheet stacking apparatus according to any one of claims 1 to 3, the sheet post-processing apparatus.

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