JP4858413B2 - Recording material stacking apparatus, image forming system, and program - Google Patents

Description

  The present invention relates to a recording material stacking apparatus, an image forming system, and a program.

For example, an image forming apparatus such as a printer or a copier, which is connected to a network such as a LAN and prints a large amount of image data sent from a terminal device or the like, is widely used. Such an image forming apparatus is provided with a post-processing device that performs processing (post-processing) of the recording material after printing, and a large amount of printed recording materials is accumulated. However, if curling occurs in the recording material accumulated in the post-processing apparatus, it becomes difficult to orderly stack the recording materials in the post-processing apparatus.
Therefore, as a technique for dealing with curling that occurs in a recording material, for example, in Patent Document 1, two or more sheet stacking heights of sheets (recording material) stacked on a sheet stacking unit are detected, and the detected stacking height is detected. A technique for detecting at least the curling direction of the sheet among the curling direction and the curling amount of the sheet based on the height and controlling the raising / lowering position of the sheet stacking means according to the detected curling direction of the sheet is described. .

JP 2002-68553 A

Here, in general, the curl generated in the recording material has various forms. For this reason, depending on the form of the curl, there is a problem that a stacking abnormality in which the recording material is unstabilized in a member on which the recording material is stacked occurs, the recording material collapses, or the recording material is damaged.
SUMMARY OF THE INVENTION An object of the present invention is to improve the detection accuracy for a recording material stacking abnormality in a member on which a recording material is stacked.

The invention described in claim 1 includes a recording material stacking unit for stacking a recording material carried in from the outside, a light emitting unit, and a light receiving sensor, and light emitted from the light emitting unit is received by the light receiving sensor. depending on whether the, and the reference position in the stacking direction of the recording media stacked on the recording medium stacking unit, and the upper position is the stacking direction above the said reference position, the stacking direction below the reference position A plurality of detection units for detecting whether or not the recording material exists at each of the lower positions, and the recording material stacking unit loaded on the recording material stacking unit based on the detection results of the plurality of detection units. A determination unit configured to determine a size of a curl generated on the recording material; and a moving unit configured to move the recording material stacking unit in the stacking direction , wherein the determination unit is configured such that the detection unit is the reference position or the upper position. To detect the presence of the recording material. In this case, after the recording material stacking unit is moved downward in the stacking direction by the moving means, and the recording material stacking unit starts moving downward in the stacking direction, the reference position or the upper position by the detection unit Either a detection result regarding the presence of the recording material at a position or a detection result regarding the presence of the recording material at a plurality of different positions among the reference position, the upper position, and the lower position by the detection unit is used. Thus, the recording material stacking apparatus is characterized by determining whether or not the curl generated in the recording material is larger than a predetermined amount .

According to a second aspect of the present invention, in the determination unit, the one detection unit detects the presence of the recording material, and the other detection unit is positioned below the stacking direction with respect to the one detection unit. 2. The recording material stacking apparatus according to claim 1, wherein when the presence of the recording material is not detected, the curl generated in the recording material is determined to be larger than a predetermined amount .
Invention of claim 3, the front SL determination section, when said moving means is moved toward the recording medium stacking portion to the stacking direction downward, the presence of the detector one said recording medium When the other detection unit positioned below the one detection unit does not detect the presence of the recording material when the detection is stopped, the curl generated on the recording material is more than a predetermined amount. 2. The recording material stacking apparatus according to claim 1, wherein the recording material stacking apparatus is determined to be large .
According to a fourth aspect of the invention, the pre-Symbol determination unit, when said moving means is a predetermined time has elapsed since to start moving toward the recording medium stacking portion to the stacking direction downward, the reference position or wherein the detection unit for detecting the presence of the recording material in said upper position when it detects the presence of the recording material, the curl generated in the recording material is characterized in that it is determined that greater than a predetermined amount The recording material stacking apparatus according to Item 1.

The invention according to claim 5 is characterized in that one or more of the plurality of detection units determines whether or not the recording material is present at the position in the stacking direction and the stacking direction passing through the position in the stacking direction. 2. The recording material stacking apparatus according to claim 1, wherein detection is performed at a plurality of positions in a plane orthogonal to each other.
According to a sixth aspect of the present invention, the determination unit determines whether or not a curl generated in the recording material using the detection result regarding the presence of the recording material by one or a plurality of the detection units is larger than a predetermined amount. Is determined every predetermined time, and it is determined that the curl generated on the recording material is larger than the predetermined amount when it is continuously determined that the curl of the recording material is larger than the predetermined amount a plurality of times. The recording material stacking apparatus according to claim 1, wherein:

The invention according to claim 7 is an image forming apparatus that forms an image on a recording material, and a recording material stacking apparatus that carries in the recording material on which an image is formed by the image forming apparatus and loads the loaded recording material The recording material stacking apparatus includes a recording material stacking section on which the recording material carried in from the image forming apparatus is stacked, a light emitting section, and a light receiving sensor, and light emitted from the light emitting section is received. A reference position in the stacking direction of the recording material stacked on the recording material stacking unit , an upper position that is higher in the stacking direction than the reference position, and the reference position depending on whether or not the light is received by the light receiving sensor A plurality of detection units for detecting whether or not the recording material is present at each of the lower positions below the stacking direction, and the recording material stacking based on the detection results of the plurality of detection units. Ca generated in the recording media stacked on section A determination unit that determines the size of the Le, the recording material mounting portion and a moving means for moving the stacking direction, wherein the determination unit, the recording material wherein the detecting unit is at the reference position or the upper position When the recording material stacking unit is moved downward in the stacking direction by the moving means and the recording material stacking unit starts moving downward in the stacking direction, A detection result regarding the presence of the recording material at the reference position or the upper position, and a detection result regarding the presence of the recording material at a plurality of different positions among the reference position, the upper position, and the lower position by the detection unit; The image forming system is characterized by determining whether or not the curl generated on the recording material is larger than a predetermined amount .

According to an eighth aspect of the present invention, the determination unit of the recording material stacking apparatus is configured such that one detection unit detects the presence of the recording material and is positioned below the stacking direction than the one detection unit. The image forming system according to claim 7, wherein when the other detection unit does not detect the presence of the recording material, the curl generated in the recording material is determined to be larger than a predetermined amount .
The invention according to claim 9, the front SL determination section, when said moving means is moved toward the recording medium stacking portion to the stacking direction downward, the presence of the detector one said recording medium When the other detection unit positioned below the one detection unit does not detect the presence of the recording material when the detection is stopped, the curl generated on the recording material is more than a predetermined amount. 8. The image forming system according to claim 7, wherein the image forming system is determined to be large .
The invention according to claim 10, the pre-Symbol determination unit, when said moving means is a predetermined time has elapsed since to start moving toward the recording medium stacking portion to the stacking direction downward, the reference position or The curl generated on the recording material is determined to be larger than a predetermined amount when the detection unit that detects the presence of the recording material at the upper position detects the presence of the recording material. Item 8. The image forming system according to Item 7.

According to an eleventh aspect of the present invention, when the determination unit determines that the curl generated in the recording material is larger than a predetermined amount , the recording material stacking apparatus notifies the image forming apparatus to that effect, and When the image forming apparatus receives a notification from the recording material stacking device that the curl generated on the recording material is larger than a predetermined amount , the image forming apparatus stops forming the image on the recording material , or the recording material The image forming system according to claim 7, wherein a display is made to indicate that the curl generated in the image is larger than a predetermined amount .
According to a twelfth aspect of the present invention, the image forming apparatus distributes the recording material on which an image is formed to the recording material stacking device at different positions in the width direction of the recording material every predetermined number of sheets. The setting to be performed and the setting to be performed at the same position in the width direction are selectable, and the recording material stacking apparatus is configured such that the recording material is unloaded in the width direction by the image forming apparatus. The image forming system according to claim 7, wherein the determination unit does not determine that the curl generated on the recording material is greater than a predetermined amount when the position is set to be performed at the position.

According to a thirteenth aspect of the present invention, the image forming apparatus distributes the recording material on which the image is formed to the recording material stacking device at different positions in the width direction of the recording material for every predetermined number of sheets. The setting to be performed and the setting to be performed at the same position in the width direction can be selected, and the determination unit of the recording material stacking apparatus is configured so as to be distributed to the left and right different positions in the width direction. 8. The image forming system according to claim 7, wherein when the curling of the recording material is determined to be larger than a predetermined amount, the setting is changed to a setting to carry out to the same position in the width direction. .
The recording material stacking apparatus may be configured such that when the determination unit determines that the curl generated in the recording material is greater than a predetermined amount , the recording material stacking unit moves the recording material stacking unit to the recording material stacking unit. 8. The image forming system according to claim 7, wherein the recording material loaded on the recording medium is moved to a position where it can be taken out from the outside.

According to the fifteenth aspect of the present invention, the computer detects the recording material loaded on the recording material stacking unit on which the recording material is loaded, based on whether or not the light emitted from the light emitting unit is received by the light receiving sensor. Based on signals from a plurality of detection units, a reference position in the stacking direction of the recording material loaded on the recording material stacking unit, an upper position that is higher in the stacking direction than the reference position, and the reference position A function of acquiring information on whether or not the recording material exists at each of the lower positions that are lower in the stacking direction, and the detection unit detects the presence of the recording material at the reference position or the upper position. A function of moving the recording material stacking unit downward in the stacking direction when detected, and the acquired reference position or the upper direction after the recording material stacking unit starts moving downward in the stacking direction. The detection result regarding the presence of the recording material in the recording medium and the detection result regarding the presence of the recording material at a plurality of different positions among the acquired reference position, the upper position, and the lower position, And a function of determining whether or not the curl generated in the recording material is larger than a predetermined amount .

According to a sixteenth aspect of the present invention, the function of determining whether or not the curl generated in the recording material is larger than a predetermined amount is that the recording material exists at one position in the stacking direction, and The curl is determined to be larger than a predetermined amount when the information indicating that the recording material does not exist at another position positioned below the one position is acquired. The program according to claim 15.
According to a seventeenth aspect of the present invention, the function for determining whether or not the curl generated in the recording material is larger than a predetermined amount is obtained when the recording material stacking portion is started to move downward in the stacking direction. In addition, when the recording material no longer exists at one position in the stacking direction, the information indicating that the recording material does not exist at another position below the one position. 16. The program according to claim 15, wherein the curl is determined to be larger than a predetermined amount when the value is acquired.
In the invention described in claim 18, the function of determining whether or not the curl generated in the recording material is larger than a predetermined amount is obtained by starting the movement of the recording material stacking portion downward in the stacking direction. The curl is determined to be larger than a predetermined amount when the information indicating that the recording material is present at the reference position or the upper position is acquired when a predetermined time has elapsed. The program according to claim 15.

  Note that this program may be executed by loading a program stored in a reserved area such as a hard disk or a DVD-ROM into the ROM, for example. In addition, there is a form that is executed by the CPU in a state stored in the ROM in advance. Further, when a rewritable ROM such as an EEPROM is provided, only a program may be provided and installed in the ROM after the device is assembled. In providing this program, it is also conceivable that the program is transmitted to a computer having a data recording device via a network such as the Internet and installed in a ROM of the data recording device.

According to the first aspect of the present invention, it is possible to improve the detection accuracy for the recording material stacking abnormality in the member on which the recording material is stacked, compared to the case where the present invention is not adopted.
According to the second aspect of the present invention, compared to the case where the present invention is not adopted, the recording material in which the curl is larger than the distance between a plurality of different positions set in the stacking direction of the recording material stacking section is generated. Can be accurately detected.
According to the third aspect of the present invention, as compared with the case where the present invention is not adopted, the recording material in which the curl is larger than the distance between the plurality of different positions set in the stacking direction of the recording material stacking section is generated. Can be accurately detected.
According to the fourth aspect of the present invention, compared to a case where the present invention is not adopted, a state in which the recording material on which the curl larger than the moving amount in which the recording material stacking unit moves in a predetermined time is generated is loaded. It can be detected with high accuracy.
According to the fifth aspect of the present invention, compared to the case where the present invention is not adopted, the curl larger than expected in the recording material having a different size or the curl larger than expected generated in the different region of the recording material is more accurate. It can be detected well.
According to the sixth aspect of the present invention, when a curl larger than expected is suddenly generated compared with the case where the present invention is not adopted, and then the curl is changed to a small curl within the assumption, the load abnormality is detected. It is possible to reduce erroneous detection.

According to the seventh aspect of the present invention, it is possible to improve the detection accuracy for the recording material stacking abnormality in the member on which the recording material is stacked, compared to the case where the present invention is not adopted.
According to the eighth aspect of the present invention, as compared with the case where the present invention is not adopted, the recording material in which the curl larger than the distance between the plurality of different positions set in the stacking direction of the recording material stacking section is generated. Can be accurately detected.
According to the ninth aspect of the present invention, compared to a case where the present invention is not adopted, the recording material in which the curl is larger than the distance between a plurality of different positions set in the stacking direction of the recording material stacking section. Can be accurately detected.
According to the tenth aspect of the present invention, compared to a case where the present invention is not adopted, a state in which the recording material on which the curl larger than the moving amount in which the recording material stacking unit moves in a predetermined time is generated is loaded. It can be detected with high accuracy.
According to the eleventh aspect of the present invention, it is possible to suppress the occurrence of the collapse of the recording material, the damage to the recording material, and the like as compared with the case where the present invention is not adopted.
According to the twelfth aspect of the present invention, compared to the case where the present invention is not adopted, the recording material is less likely to collapse from the recording material stacking portion, and the recording material stacking portion is less likely to be damaged. Are stacked in the same direction of the width direction, it is not necessary to stop the operation of the image forming apparatus, and the productivity of image formation can be increased.
According to the thirteenth aspect of the present invention, as compared with the case where the present invention is not adopted, the recording material is less likely to collapse from the recording material stacking portion, and the recording material stacking portion is less likely to be damaged. Therefore, it is not necessary to stop the operation of the image forming apparatus, and the productivity of image formation can be improved.
According to the fourteenth aspect of the present invention, it is possible to easily remove the recording material loaded on the recording material stacking portion from the recording material stacking portion in a state in which it is easily collapsed and easily damaged as compared with the case where the present invention is not adopted. it can.

According to the fifteenth aspect of the present invention, it is possible to improve the detection accuracy with respect to the recording material stacking abnormality in the member on which the recording material is stacked, as compared with the case where the present invention is not adopted.
According to the sixteenth aspect of the present invention, as compared with the case where the present invention is not adopted, the recording material in which the curl is larger than the distance between a plurality of different positions set in the stacking direction of the recording material stacking section is generated. Can be accurately detected.
According to the seventeenth aspect of the present invention, as compared with the case where the present invention is not adopted, the recording material in which the curl is larger than the distance between a plurality of different positions set in the stacking direction of the recording material stacking section is generated. Can be accurately detected.
According to the eighteenth aspect of the present invention, as compared with the case where the present invention is not adopted, a state in which the recording material on which the curl larger than the moving amount by which the recording material stacking unit moves in a predetermined time is generated is loaded. It can be detected with high accuracy.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a diagram illustrating a configuration of an image forming system to which the exemplary embodiment is applied. The image forming system shown in FIG. 1 includes, for example, an image forming apparatus 1 such as a printer or a copying machine that performs image formation (printing processing) by an electrophotographic method, and a recording material (paper) after image formation by the image forming apparatus 1 The sheet stacking apparatus 2 is an example of a recording material stacking apparatus that stacks sheets P.

The image forming apparatus 1 according to the present embodiment includes a photosensitive drum 11 that holds an electrostatic latent image and a toner image, a charger 12 that uniformly charges the photosensitive drum 11 at a predetermined potential, and a photosensitive drum based on image data. A laser exposure unit 13 that scans and exposes the laser beam 11 with a laser beam, a developing unit 14 that develops the electrostatic latent image formed on the photosensitive drum 11 with, for example, black toner, and a cleaner 15 that cleans the surface of the photosensitive drum 11 are provided. ing.
Further, the image forming apparatus 1 includes a transfer roll 16 that transfers the toner image formed on the photosensitive drum 11 onto the paper P, a fixing device 40 that fixes the transferred toner image onto the paper P, and an image forming apparatus. 1 is provided.
In the image forming apparatus 1, the charging process to the photosensitive drum 11 by the charger 12, the electrostatic latent image forming process to the photosensitive drum 11 by the laser exposure unit 13, and the static image formed on the photosensitive drum 11 by the developing unit 14. A toner image is formed on the photosensitive drum 11 through a developing process for the electrostatic latent image. The toner image formed on the photosensitive drum 11 is transferred onto the paper P by the transfer roll 16.

Further, in the image forming apparatus 1, as a paper transport system, for example, two paper storage trays 20A and 20B that store paper P of different sizes and different paper types are stored in either one of the paper storage trays 20A and 20B. Pick-up roll 21 that feeds the paper P that has been fed out at a predetermined timing, a transport roll 22 that transports the paper P that has been fed out by the pick-up roll 21, and a region where the transfer roll 16 is disposed at a predetermined timing ( A transfer belt 24, which is stretched between a registration roll 23, a transfer roll 16, and a stretch roll 25 that is fed to a transfer portion) T and conveys the paper P after the toner image is transferred, is provided.
Further, an offset roll 26 between the conveyance belt 24 and the fixing device 40 is configured to offset (position displacement) the conveyance direction of the paper P conveyed by the conveyance belt 24 in either the left or right direction toward the conveyance direction. It has.

  Further, as a double-sided conveyance system, the intermediate tray 30 that temporarily holds the paper P on which the toner image is fixed on the first surface by the fixing device 40 is disposed on the downstream side of the fixing device 40 in the paper P conveyance direction. A flapper 41 that selectively distributes the transport path K transported to the stacking device 2 and the transport path L transported to the intermediate tray 30, a transport roll 27 that transports the paper P guided from the flapper 41 to the intermediate tray 30, and the intermediate tray 30 Is provided with a pickup roll 28 that feeds the paper P held at a predetermined timing and sends it to a transfer portion T in which the transfer roll 16 is disposed.

At the time of image formation, in the paper transport system, when the main body control unit 35 designates the paper storage tray 20A, for example, the paper P is taken out from the paper storage tray 20A by the pick-up roll 21, and is registered one by one by the transport roll 22. It is conveyed to the position of the roll 23. The same applies to the case where the sheet storage tray 20B is designated by the main body control unit 35. In the double-sided conveyance system, the paper P on which one side (first side) has been printed is taken out from the intermediate tray 30 by the pickup roll 28 during double-sided printing.
Then, the paper P is fed out from the registration roll 23 in accordance with the timing at which the toner image formed on the photosensitive drum 11 is conveyed to the transfer portion T. Thus, the toner image is transferred onto the paper P by the action of the transfer electric field formed by the transfer roll 16 at the transfer portion T.

Thereafter, the sheet P on which the toner image is transferred is conveyed by the conveyance belt 24. After the conveyance by the conveyance belt 24, the paper P for which the printing process has been completed is offset to either the left or right side in the conveyance direction of the paper P by the offset roll 26. That is, the offset roll 26 controls the paper P to be in units of units or in units of documents under the control of the main body control unit 35, for example, when the same document is subjected to a plurality of print processing or a plurality of different documents. Then, the sheet is conveyed while being offset alternately in the left and right directions toward the conveying direction.
In this case, in the case of single-sided printing (only the first side), the offset roll 26 is offset in the transport direction of the paper P immediately after the toner image is transferred by the transfer roll 16. In the case of double-sided printing, during the printing process on the first side, the conveyance direction is not offset, and the toner image is transferred to the second side of the single-side printed paper P held on the intermediate tray 30. The transport direction is offset.
When it is not necessary to divide the printed paper P by, for example, each copy unit or document unit, as in the case of printing only one copy of a document, the offset roll 26 does not offset the paper P and does not offset it. Let it pass.

  The paper P that has passed through the offset roll 26 is conveyed to the fixing device 40. In the fixing device 40, the toner image is fixed on the paper P by a fixing process using heat and pressure, and an image is formed. The sheet P on which an image is formed (printed) is unloaded from the sheet unloading section E of the image forming apparatus 1 by the conveying roll 43 and is conveyed to the sheet stacking apparatus 2 connected to the image forming apparatus 1.

Next, the sheet stacking apparatus 2 according to the present embodiment will be described.
FIG. 2 is a diagram illustrating a configuration of the sheet stacking apparatus 2. As shown in FIG. 2, the sheet stacking apparatus 2 has a carry-in roll 71 that carries the paper P carried out from the paper carry-out section E of the image forming apparatus 1, for example, when only one copy of a document is printed. In addition, a first sheet stacking unit 70 is provided for stacking sheets P when a relatively small amount (for example, about 500 sheets at maximum) of printing processing is performed.
Further, the sheet stacking apparatus 2 stacks sheets P when a large amount of printing processing is performed, for example, when the same document is printed in a plurality of copies or different documents are printed. The second paper stacking unit 50, the width direction aligning mechanism 60 for aligning the width of the paper P stacked on the second paper stacking unit 50, and the transport direction of the paper P stacked on the second paper stacking unit 50 Is provided with a transport direction aligning mechanism 90 that performs the position alignment. Furthermore, a flapper 72 that distributes the paper P carried from the carry-in roll 71 to different paper conveyance paths M1, M2, and M3 is provided.
Here, the sheet conveyance path M1 to which the flapper 72 distributes is a path for conveying the sheet P from the carry-in roll 71 to the second sheet stacking unit 50, and the sheet conveyance path M2 is the second sheet stacking apparatus outside the sheet stacking apparatus 2. (Not shown) or the like is connected, a path for transporting the paper P from the carry-in roll 71 to the second sheet stacking apparatus or the like, the paper transport path M3, the paper P from the carry-in roll 71 to the first paper stacking unit 70. Is a route for transporting. A transport roll 73 is disposed in each of the paper transport paths M2 and M3. In addition, a carry-in roll 74 for carrying the paper P into the first paper stacking unit 70 is disposed at the entrance of the first paper stacking unit 70.
In addition, the sheet stacking apparatus 2 includes a sheet stacking control unit 80 that controls the operation of each unit of the sheet stacking apparatus 2.

The second paper stacking unit 50 of the present embodiment includes a paper storage container unit 53 as an example of a recording material stacking unit that stores and stacks the paper P on which image formation (printing processing) has been performed by the image forming apparatus 1, and paper A reference wall 88 that sets a reference position in the conveyance direction when aligning the paper P stored in the storage container portion 53, and a transport that transports the paper P carried from the image forming apparatus 1 to the paper storage container portion 53. A roll 56 and a paddle 57 for feeding the paper P stored in the paper storage container portion 53 to the reference wall 88 side and suppressing floating of the paper P in the stacking direction are provided.
Further, the second paper stacking unit 50 includes a container stage 51 that supports the paper container portion 53, an elevating mechanism unit 54 that supports the container stage 51 so as to be movable up and down, and ascends and descends the container stage 51 (moves vertically in the stacking direction of the paper P). ), And a pedestal portion 52 that supports the elevating mechanism portion 54 and the elevating drive portion 55. With such an elevating mechanism, the paper container portion 53 moves up and down in the stacking direction as the container stage 51 moves up and down, but the reference wall 88 is fixed. Therefore, the paper container 53 is configured to slide with respect to the reference wall 88. The elevating mechanism unit 54, the elevating drive unit 55, the sheet stacking control unit 80, and other components as necessary constitute moving means for moving the sheet storage container unit 53 in the stacking direction.
Further, the caster 52 a is disposed on the pedestal portion 52 of the second paper stacking unit 50, and the entire second paper stacking unit 50 is integrally attached to and detached from the sheet stacking device 2.

  Note that the “transport direction” of the paper P in this specification is the direction in which the paper P is transported, and is the x direction in FIG. Further, the “width direction” of the paper P is a direction orthogonal to the transport direction of the paper P within the plane (paper surface) of the paper P, and is the y direction in FIG. Further, the “stacking direction” of the sheets P is a direction in which the sheets P are stacked in the sheet container portion 53, and is a z direction orthogonal to both the x direction and the y direction in FIG. The same applies to the drawings used below.

Next, the width direction aligning mechanism unit 60 according to the present embodiment is stacked on the second sheet stacking unit 50 when, for example, the same document is subjected to a plurality of print processes or a plurality of different documents are subjected to a print process. Further, the paper P is aligned in the width direction while offsetting (position shifting) each of a plurality of documents or a plurality of different documents alternately in different directions in the width direction for each copy unit or each document unit.
FIG. 3 is a diagram illustrating the configuration of the width direction aligning mechanism unit 60. 3A is a diagram viewed from the width direction (y direction) of the paper P, and FIG. 3B is a diagram viewed from the reference wall 88 side in the transport direction (x direction) of the paper P. As shown in FIG. 3, the width direction aligning mechanism 60 has three sets of tampers 62A and 62B, tampers 63A and 63B, and tampers 64A and 64B, tampers 62A and 62B, and tampers 63A, which align the paper P in the width direction. 63B and support holders 61A and 61B that support the tampers 64A and 64B in a swingable manner (for the tamper 63B and the tamper 64B, refer to FIG. 8 below).

  As shown in FIG. 3B, the support holders 61A and 61B are fixed to a main body frame (not shown) of the sheet stacking apparatus 2 on both sides in the width direction of the paper P stored in the paper storage container portion 53. The support rod 58 is slidably supported. The sheet is moved along the width direction (y direction) of the paper P according to the size of the paper P and the offset direction by the offset roll 26 by a drive mechanism (not shown). Then, when the paper P is stored in the paper storage container portion 53, the paper P moves to the vicinity of the outside of the width direction end portion position of the stored paper P. Further, after moving to the width direction end portion of the paper P, the paper P is intermittently brought into contact with the width direction end portion of the paper P while reciprocating with a predetermined strake (for example, 10 mm). Functions to align.

The three sets of tampers 62A and 62B, tampers 63A and 63B, and tampers 64A and 64B are arranged in the conveyance direction (x direction) of the paper P by the support holders 61A and 61B, respectively, as shown in FIG. It is arranged at different positions along. The tampers 62A and 62B closest to the reference wall 88 are disposed at positions that also contact the width direction (y direction) end of the minimum size (for example, B6 size) paper P handled by the image forming apparatus 1, for example. . Further, the tampers 63A and 63B in the central portion contact the end in the width direction (y direction) on the leading end side of the A4 size paper P, for example, with the rear end of the A4 size paper P aligned with the reference wall 88. It is arranged at the position to do. Further, the tampers 64A and 64B farthest from the reference wall 88 are, for example, A3 in a state where the rear end of the maximum size (for example, A3 size) paper P handled by the image forming apparatus 1 is aligned with the reference wall 88. It is arranged at a position in contact with the end in the width direction (y direction) on the leading end side of the size paper P.
Further, each of the three sets of tampers 62A and 62B, tampers 63A and 63B, and tampers 64A and 64B is supported at a position p substantially orthogonal to the support holders 61A and 61B, as shown in FIG. It is configured to be able to move (swing) along the transport direction (x direction) of the paper P between the positions q stored inside the holders 61A and 61B. The position p is set when aligning the width direction of the paper P. The position q is set when the support holders 61A and 61B move.

Next, the alignment in the width direction of the paper P performed by the width direction alignment mechanism 60 will be described. FIG. 4 and FIG. 5 are diagrams for explaining the operation of the width direction aligning mechanism unit 60 when aligning a plurality of copies of documents in units of units, as an example. 4 and 5, the state in which the width direction of the second sheet P of the document is aligned from FIG. 4A showing the state in which the width direction of the first sheet P of the document is aligned. FIG. 5 (e) showing the above is shown.
First, in the case where a plurality of documents are printed by the image forming apparatus 1, for example, the offset roll 26 of the image forming apparatus 1 prints a plurality of documents under the control of the main body control unit 35. The sheet P is offset in units different from each other in the left and right directions alternately in the transport direction. Accordingly, when the paper P is stored in the paper storage container portion 53 of the second paper stacking portion 50, the first copy is stacked at a position offset, for example, to the right side from the center position in the width direction of the paper storage container portion 53. The second copy is stacked at a position offset, for example, to the left side from the center position in the width direction of the paper container portion 53. For example, when three or more documents are printed, similarly, odd-numbered documents are stacked at positions offset to the right, and even-numbered documents are alternately stacked at positions offset to the left.

Therefore, as shown in FIG. 4A, when the first sheet P is first aligned in the width direction, the support holders 61A and 61B are respectively positioned from the center position in the width direction of the sheet container portion 53. In addition, the sheet moves to the vicinity of both outer sides of the position in the width direction of the A4 size paper P stacked at the position offset to the right side. That is, the sheet stacking control unit 80 calculates the set positions of the support holders 61A and 61B based on the offset amount to the right by the offset roll 26 of the image forming apparatus 1 and the dimension in the width direction of the A4 size paper P. To do. Then, the support holders 61A and 61B are moved to the calculated set positions by a drive mechanism (not shown).
When the support holders 61A and 61B are moved to the set positions, the tampers 62A and 62B, the tampers 63A and 63B, and the tampers 64A and 64B are set at positions p substantially orthogonal to the support holders 61A and 61B. Then, as the paper P is loaded on the paper container 53, the support holders 61A and 61B reciprocate with a predetermined strake (for example, 10 mm) to change the width direction of the first paper P. Align.
The reciprocating motion of each of the support holders 61A and 61B is performed so as to alternately repeat the operation in which the support holders 61A and 61B are close to each other and the operation in which they are separated from each other. Further, when aligning the width direction of the A4 size paper P, the tampers 64A and 64B arranged at the positions contacting the width direction (y direction) end of the A3 size paper P are supported by the support holder 61A. , 61B may be set in the state of the position q housed inside.

  When the first paper P is stacked on the paper storage container 53, the width direction aligning mechanism 60 has a top position stacked on the paper storage container 53 by a paper position detection mechanism described later. The position of the paper P is detected. Then, the paper P can be carried into the paper storage container portion 53 from the transport roll 56, and the lowermost position of, for example, the support holders 61 </ b> A and 61 </ b> B of the width direction alignment mechanism portion 60 and the uppermost portion stacked on the paper storage container portion 53. The container stage 51 that supports the paper container portion 53 is moved up and down so as to maintain the state where the position of the paper P is separated. That is, the sheet stacking control unit 80 is driven up and down based on the detection result of the sheet position detection mechanism unit regarding the position of the sheet P stacked on the uppermost part of the sheet storage container unit 53 (also referred to as “the uppermost surface position of the sheet P”). By controlling the section 55, the sheet P can be carried into the sheet storage container section 53 from the transport roll 56, and loaded on the lowermost position of, for example, the support holders 61 </ b> A and 61 </ b> B of the width direction alignment mechanism section 60 and the sheet storage container section 53. The elevating mechanism 54 that supports the container stage 51 is moved downward to a position where the position of the uppermost sheet P is maintained at a distance.

Next, when the carry-in of the first paper P to the paper container 53 is completed, the second paper P stacked at a position offset to the left side is carried in. At that time, as shown in FIG. 4B, the right tamper 62A, tamper 63A, and tamper 64A are first moved to the position q housed inside the support holder 61A. As a result, in the middle of moving the support holders 61A and 61B to the left side, the first sheet P, which has already been aligned in the width direction, interferes with the tamper 62A, the tamper 63A, etc. It suppresses the occurrence of turbulence.
Next, as shown in FIG. 4C, before the second copy of the paper P is carried in, each of the support holders 61 </ b> A and 61 </ b> B is offset to the left side from the central position in the width direction of the paper storage container portion 53. For example, A4 size paper P stacked at the position moves to the vicinity of both outer sides of the width direction end position. That is, the sheet stacking control unit 80 calculates the set positions of the support holders 61A and 61B based on the offset amount to the left by the offset roll 26 of the image forming apparatus 1 and the width direction dimension of the A4 size paper P. To do. Then, the support holders 61A and 61B are moved to the calculated set positions by a drive mechanism (not shown).

  When the support holders 61A and 61B are set to a position where the second sheet P is stacked (see FIG. 4C), as shown in FIG. 5D, the right side in FIG. The tamper 62A, the tamper 63A, and the tamper 64A provided in the support holder 61A arranged in the above are set at a position p substantially orthogonal to the support holder 61A. However, the tampers 62A, 63A, and 64A are on the first copy of the paper P stacked at the position offset to the right, and are therefore set at a position p ′ that is in contact with the first copy of the paper P. The As a result, the tampers 62A, 63A, and 64A align the sheets while pressing the first sheet of paper P. On the other hand, the tampers 62B, 63B, 64B provided on the support holder 61B arranged on the left side in FIG. 5D do not come into contact with the first sheet P during the movement to the left side. , The position p is moved as it is set.

Then, as shown in FIG. 5 (e), as the paper P is stacked on the paper storage container 53, the support holders 61A and 61B are reciprocated by a predetermined strake (for example, 10 mm). The second sheet of paper P is aligned in the width direction.
In this case, even when the second sheet P is stacked on the sheet container 53, the width direction aligning mechanism 60 stacks the sheet P on the sheet container 53 by a sheet position detecting mechanism described later. The position of the uppermost sheet P thus detected is detected. Then, the paper P can be carried into the paper storage container portion 53 from the transport roll 56, and the lowermost position of, for example, the support holders 61 </ b> A and 61 </ b> B of the width direction alignment mechanism portion 60 and the uppermost portion stacked on the paper storage container portion 53. The container stage 51 that supports the paper container portion 53 is moved up and down so as to maintain the state where the position of the paper P is separated.
In this way, the width direction aligning mechanism unit 60 performs position alignment in the width direction of the paper P that is sent by being offset alternately to the left and right sides by the offset roll 26 of the image forming apparatus 1.

  On the other hand, the transport direction aligning mechanism 90 aligns the position of the paper P in the transport direction according to the size of the paper P. FIG. 6 is a diagram illustrating the configuration of the transport direction aligning mechanism 90. 6A is a diagram viewed from the width direction (y direction) of the paper P, and FIG. 6B is a diagram viewed from the reference wall 88 side in the transport direction (x direction) of the paper P. As shown in FIG. 6, the transport direction aligning mechanism 90 includes two sets of tampers 92A and 92B that align the paper P in the transport direction, and a support holder 91 that supports the tampers 92A and 92B in a swingable manner.

As shown in FIG. 6A, the support holder 91 is a support bar fixed to the main body frame (not shown) of the sheet stacking device 2 at the upper part of the paper P stored in the paper storage container portion 53. 59 slidably supported in the transport direction (x direction). And it moves along the conveyance direction (x direction) of the paper P by a drive mechanism (not shown). Then, when the paper P is stored in the paper storage container portion 53, the stored paper P is moved so as to be pressed against the reference wall 88 side along the transport direction.
The tampers 92A and 92B are arranged at different positions in the width direction (y direction) of the paper P by the support holder 91 as shown in FIG. Then, as shown in FIG. 6B, the width direction (y direction) of the paper P is between the position u substantially orthogonal to the support holder 91 and the position v inclined toward the support holder 91. It is configured to be movable along. The position u is set when the transport direction of the paper P is aligned. The position v is set when the support holder 91 moves.

FIG. 7 is a diagram for explaining the operation of the transport direction aligning mechanism 90 when sheets P of different sizes are stored in the sheet storage container 53 as an example. FIG. 7 shows a case where the A4 size paper P is loaded as the second copy, for example, when the A4 size paper P is loaded as the second copy after the A3 size paper P is loaded on the paper container 53. The case where the conveyance direction is aligned is shown. As indicated by broken lines in FIG. 7, before the second set of A4 size paper P is stacked, the tampers 92A and 92B are first moved to the position v inclined toward the support holder 91 side. As a result, in the middle of moving the support holder 91 to the A4 size paper P side, the first A3 size paper P that has been aligned in the transport direction interferes with the tampers 92A and 92B, and the paper P Suppress the occurrence of disorder in alignment.
Next, the support holder 91 is moved to the vicinity of the outside end position in the transport direction of the second A4 size paper P stacked on the paper storage container portion 53. When the support holder 91 is set to the position where the second sheet of paper P is stacked, the tampers 92A and 92B are moved to a position u substantially orthogonal to the support holder 91. As a result, the tampers 92A and 92B are placed on the first sheet of paper P, and the position u ′ in contact with the first sheet of paper P is set. In this state, the second paper P is aligned in the transport direction by pressing the stored paper P toward the reference wall 88 along the transport direction.

Next, a paper position detection mechanism unit that is provided in the second paper stacking unit 50 of the present embodiment and detects the position of the paper P stacked in the paper storage container unit 53 in the stacking direction (z direction) will be described.
FIG. 8 is a view of the paper position detection mechanism portion as viewed from above the stacking direction (z direction) of the paper P stored in the paper storage container portion 53. FIG. 9 shows the paper position detection mechanism portion of the paper storage container portion. FIG. 5 is a diagram viewed from the width direction (y direction) of the paper P stored in 53. FIG. As shown in FIGS. 8 and 9, the second paper stacking unit 50 of the present embodiment has a paper position for detecting the position in the stacking direction (z direction) of the paper P stacked on the paper storage container unit 53. The detection mechanism unit includes a plurality of detection units that detect whether or not the sheet P exists at each of a plurality of different positions set in the stacking direction (z direction) of the sheets P.

That is, as the paper position detection mechanism, first, a first detection unit is provided as an example of a detection unit that detects whether or not the paper P exists at a first position in the stacking direction (z direction) of the paper P. ing. For example, in the vicinity of the reference wall 88 in the central portion in the width direction (y direction) of the paper P, the first detection unit “the first plane orthogonal to the stacking direction (z direction) of the paper P at the first position” The first light emitting unit 101A and the first light receiving sensor 101B are configured to detect whether or not there is a sheet P that crosses the line.
Further, the detection unit detects whether or not the sheet P exists at the same position as the first position in the stacking direction (z direction) of the sheets P or a second position positioned above the first position. A second detection unit is provided as an example. The second detection unit detects whether or not there is a sheet P crossing a “second plane” orthogonal to the stacking direction (z direction) of the sheets P at the second position. 102A and the second light receiving sensor 102B, the third light emitting unit 103A and the third light receiving sensor 103B, the fourth light emitting unit 104A and the fourth light receiving sensor 104B, the fifth light emitting unit 105A and the fifth light receiving sensor 105B. Consists of.

In addition, a third detection unit as an example of a detection unit that detects whether or not the sheet P exists at a third position located below the first position in the stacking direction (z direction) of the sheets P. It has. For example, in the vicinity of the reference wall 88 in the central portion in the width direction (y direction) of the paper P, the third detection unit “third plane orthogonal to the stacking direction (z direction) of the paper P at the third position. ”Is configured by a sixth light emitting unit 201A and a sixth light receiving sensor 201B that detect whether or not there is a sheet P that crosses the line. In FIG. 8, the sixth light emitting unit 201A and the sixth light receiving sensor 201B are not shown because they are arranged at positions overlapping the first light emitting unit 101A and the first light receiving sensor 101B, respectively.
In addition, a fourth detection unit as an example of a detection unit that detects whether or not the sheet P exists at a fourth position located below the third position in the stacking direction (z direction) of the sheets P is provided. I have. For example, in the vicinity of the reference wall 88 in both end regions of the width direction (y direction) of the paper P, the fourth detection unit is orthogonal to the stacking direction (z direction) of the paper P at the fourth position. The seventh light emitting unit 202A and the seventh light receiving sensor 202B, the eighth light emitting unit 203A, and the eighth light receiving sensor 203B are configured to detect whether or not the sheet P crossing the “plane” exists.

FIG. 10 is a perspective view for explaining the “first plane”, “second plane”, “third plane”, and “fourth plane”. As shown in FIGS. 9 and 10, in the paper position detection mechanism of the present embodiment, the second plane orthogonal to the stacking direction (z direction) at the second position is at the first position. It is set at the same position as the orthogonal first plane or above the stacking direction (z direction) from the first plane. That is, as shown in FIG. 9, the first plane is set below the paddle 57 in the stacking direction (z direction), for example, in the upper region of the reference wall 88. The second plane is the same position as the first plane in the stacking direction (z direction), or the bottom surfaces 61t of the support holders 61A and 61B of the width direction alignment mechanism unit 60 in the stacking direction (z direction) and the first plane. 1 plane is set. In the present embodiment, the second plane is set as a plane passing through the bottom surfaces 61t of the support holders 61A and 61B.
The third plane orthogonal to the stacking direction (z direction) at the third position is set below the stacking direction (z direction) than the first plane orthogonal to the first position. The fourth plane orthogonal to the stacking direction (z direction) at the fourth position is set below the stacking direction (z direction) below the third plane orthogonal to the third position.

Further, the sheet position detecting mechanism section is located, for example, at the center of the sheet P in the width direction (y direction) of the sheet P and closer to the leading end in the transport direction (x direction) than the reference wall 88. A fifth detection unit is provided as an example of a detection unit that detects the position in the stacking direction (z direction) of the paper P stacked on the top. The fifth detection unit is in contact with the uppermost surface of the paper P stored in the paper storage container unit 53 and swings in accordance with the uppermost surface position of the paper P, and whether the actuator 210 is positioned at a predetermined position. The ninth light emitting unit 204A and the ninth light receiving sensor 204B are configured to detect the above.
FIG. 11 is a diagram illustrating the operation of the fifth detection unit. As shown in FIG. 11, the fifth detection unit is configured such that the actuator 210 rotates (swings) about the rotation shaft 211 as a rotation center. The actuator 210 includes a first arm 210a provided on the paper P side with respect to the rotation shaft 211, and a second arm provided on the ninth light emitting unit 204A and the ninth light receiving sensor 204B side with respect to the rotation shaft 211. The first arm 210a is urged by a spring member (not shown) so that the first arm 210a is always in contact with the uppermost surface of the paper P. Accordingly, as shown in FIG. 11A, when the uppermost surface of the paper P stored in the paper storage container portion 53 is positioned near the first position, for example, the first arm 210a is moved to the paper P. The second arm 210b is set at a position crossing a straight line connecting the ninth light emitting unit 204A and the ninth light receiving sensor 204B. As shown in FIG. 11B, when the uppermost surface of the paper P stored in the paper storage container portion 53 is positioned near the fifth position, for example, below the first position, When the first arm 210a comes into contact with the uppermost surface of the paper P, the second arm 210b is set at a position deviating downward from a straight line connecting the ninth light emitting unit 204A and the ninth light receiving sensor 204B. As described above, the fifth detection unit has, for example, the uppermost surface of the paper P stored in the paper storage container 53 based on the position of the second arm 210b that swings integrally with the first arm 210a. The state located below the fifth position below the position 1 is detected.

  Here, the first light emitting unit 101A to the ninth light emitting unit 204A are composed of light sources such as LEDs, for example. In addition, the first light receiving sensor 101B to the ninth light receiving sensor 204B are configured by a light detection sensor such as a photodiode (PD), for example. In addition, the first light emitting unit 101A to the ninth light emitting unit 204A and the first light receiving sensor 101B to the ninth light receiving sensor 204B are arranged on a main body frame (not shown) of the sheet stacking apparatus 2 and are a sheet storage container unit. The second sheet stacking unit 50 such as 53 is configured separately from the component that moves up and down (moves up and down in the stacking direction of the sheets P). Therefore, even if the paper container 53, the container stage 51, and the like are moved up and down, the positions of the first light emitting unit 101A to the ninth light emitting unit 204A and the first light receiving sensor 101B to the ninth light receiving sensor 204B do not change. .

  In addition, the first light emitting unit 101A and the first light receiving sensor 101B constituting the first detecting unit are configured so that the light emitted from the first light emitting unit 101A is in the first plane in the vicinity of the reference wall 88. It is arranged so that it is reflected by the existing paper P and received by the first light receiving sensor 101B. Accordingly, the sheet is placed at the first position in the stacking direction (z direction) near the reference wall 88 depending on whether or not the light emitted from the first light emitting unit 101A is received by the first light receiving sensor 101B. Detect whether P is present.

Similarly, the sixth light emitting unit 201A and the sixth light receiving sensor 201B constituting the third detecting unit are configured so that the light emitted from the sixth light emitting unit 201A is in the third plane near the reference wall 88. Is reflected by the sheet P present in the image and is received by the sixth light receiving sensor 201B. Accordingly, the sheet is placed at the third position in the stacking direction (z direction) near the reference wall 88 depending on whether or not the light emitted from the sixth light emitting unit 201A is received by the sixth light receiving sensor 201B. Detect whether P is present.
Further, the seventh light emitting unit 202A and the seventh light receiving sensor 202B, and the eighth light emitting unit 203A and the eighth light receiving sensor 203B constituting the fourth detecting unit are the seventh light emitting unit 202A and the eighth light receiving sensor 203B, respectively. Each of the light emitted from the eight light emitting sections 203A is reflected by the sheet P existing in the fourth plane in the vicinity of the reference wall 88 at two places in the width direction (y direction) end region of the sheet P. The seventh light receiving sensor 202B and the eighth light receiving sensor 203B are arranged to receive light respectively. Accordingly, depending on whether or not the light emitted from the seventh light emitting unit 202A is received by the seventh light receiving sensor 202B, one of the width direction (y direction) of the paper P near the reference wall 88 (reference wall) It is detected whether or not the sheet P is present at the fourth position in the stacking direction (z direction) in the end region on the right side as viewed from the 88 side. Further, depending on whether or not the light emitted from the eighth light emitting unit 203A is received by the eighth light receiving sensor 203B, the other in the width direction (y direction) of the paper P in the vicinity of the reference wall 88 (reference wall 88). It is detected whether or not the sheet P exists at the fourth position in the stacking direction (z direction) in the end region on the left side when viewed from the side.

Further, in the ninth light emitting unit 204A and the ninth light receiving sensor 204B provided in the fifth detection unit, the light emitted from the ninth light emitting unit 204A is shielded by the second arm 210b of the actuator 210. Whether or not the uppermost surface of the sheet P is positioned below the fifth position in the stacking direction (z direction) at a position closer to the leading end in the transport direction (x direction) than the reference wall 88. To detect.
That is, as shown in FIG. 11A, when the uppermost surface of the paper P stored in the paper storage container portion 53 is positioned at, for example, the first position, the second arm 210b performs the ninth light emission. The position is set to cross a straight line connecting the portion 204A and the ninth light receiving sensor 204B. Therefore, the light from the ninth light emitting unit 204A is blocked by the second arm 210b and is not received by the ninth light receiving sensor 204B. In that case, it is detected that the uppermost surface of the paper P is positioned above the fifth position. On the other hand, as shown in FIG. 11B, when the uppermost surface of the paper P stored in the paper storage container portion 53 is located at, for example, a fifth position below the first position, the second The arm 210b is set at a position deviating downward from a straight line connecting the ninth light emitting portion 204A and the ninth light receiving sensor 204B. Therefore, the light from the ninth light emitting unit 204A is not shielded by the second arm 210b but is received by the ninth light receiving sensor 204B. In that case, it is detected that the uppermost surface of the paper P is located at the fifth position or below the fifth position.

  On the other hand, the second light emitting unit 102A to the fifth light emitting unit 105A and the second light receiving sensor 102B to the fifth light receiving sensor 105B constituting the second detection unit are the second light emitting unit 102A to the fifth light emitting unit. Each of the light emitted from the portion 105A passes through the second plane and is arranged to be received by the second light receiving sensor 102B to the fifth light receiving sensor 105B. That is, the optical axes of the light emitted from the second light emitting unit 102A to the fifth light emitting unit 105A are set so as to pass through the second plane. Accordingly, at least the sheet P is determined depending on whether or not the light emitted from the first light emitting unit 101A to the fifth light emitting unit 105A is received by the first light receiving sensor 101B to the fifth light receiving sensor 105B. It is detected on the optical axis (line) whether or not the uppermost surface exists at the second position in the stacking direction (z direction).

Here, as shown in FIG. 8 and FIG. 10, in the paper position detection mechanism unit of the present embodiment, the first light emitting unit 101A and the first light receiving sensor 101B constituting the first detecting unit are In one plane, it is arranged at the center in the width direction (y direction) of the paper P on the reference wall 88 side where the reference position for alignment in the transport direction of the paper P is set.
On the other hand, the fifth light emitting unit 105A arranged at one (rear end side) end position in the transport direction (x direction) constituting the second detection unit and the other (front end side) end position are arranged. The fifth light receiving sensors 105B are arranged in the second plane so as to face each other in the transport direction (x direction) of the paper P at the center in the width direction (y direction) of the paper P. .

Further, the second light emitting unit 102A to the fourth light emitting unit 104A arranged at one end position in the width direction (y direction) constituting the second detection unit, and the other end position. The second light receiving sensor 102B to the fourth light receiving sensor 104B are disposed so as to face each other in the width direction (y direction) of the paper P in the second plane. Further, the second light emitting unit 102A to the fourth light emitting unit 104A and the second light receiving sensor 102B to the fourth light receiving sensor 104B are respectively transported in the conveyance direction (x direction) of the paper P at both side portions (y direction) of the paper P. ) Along different positions.
That is, the second light emitting unit 102A and the second light receiving sensor 102B closest to the reference wall 88 are handled by, for example, the image forming apparatus 1 with the rear end position of the paper P aligned with the reference wall 88. Position where the front end in the transport direction on the side surface (y direction) of the minimum size (for example, B6 size) paper can be irradiated with light (for example, near (182-10) mm from the reference wall 88: reference 10 mm from the front end in the transport direction) On the wall 88 side). In addition, the third light emitting unit 103A and the third light receiving sensor 103B at the center are arranged on the A4 size paper P with the rear end position of the A4 size paper P aligned with the reference wall 88, for example. It is arranged at a position (for example, in the vicinity of (297-10) mm from the reference wall 88: the reference wall 88 side by 10 mm from the front end in the transport direction) where the front end in the transport direction on the side surface side (y direction) can be irradiated. The fourth light emitting unit 104A and the fourth light receiving sensor 104B, which are the farthest from the reference wall 88, are based on the rear end position of the maximum size (for example, A3 size) paper P handled by the image forming apparatus 1, for example. A position where the front end in the transport direction on the side surface side (y direction) can be irradiated with light on the A3 size paper P with the wall 88 aligned (eg, near (420-10) mm from the reference wall 88: transport It is arranged on the side of the reference wall 88 by 10 mm from the direction tip.

  In the state where the light emitted from the first light emitting unit 101A to the fifth light emitting unit 105A is received by the first light receiving sensor 101B to the fifth light receiving sensor 105B, respectively, the first light receiving sensor 101B. For example, a signal “1” is output from the fifth light receiving sensor 105B. On the other hand, in a state where light is not received by the first light receiving sensor 101B to the fifth light receiving sensor 105B, for example, a signal “0” is output from the first light receiving sensor 101B to the fifth light receiving sensor 105B. The signals “1” or “0” output from the first light receiving sensor 101B to the fifth light receiving sensor 105B are printed in the first position to the fifth position in the stacking direction (z direction), respectively. Information regarding whether or not P exists is transmitted to the sheet stacking control unit 80.

When the signal “0” is output from the first light receiving sensor 101B, the sheet P does not cross the light from the first light emitting unit 101A. The uppermost surface position means that the uppermost surface position is located below the first plane (first position). In that case, since there is room for stacking the sheets P in the sheet storage container section 53, the sheet stacking control section 80 does not raise or lower (move downward) the container stage 51.
On the other hand, when the signal “1” is output from the first light receiving sensor 101B, the sheet P crosses the light from the first light emitting unit 101A, and therefore the sheets stacked in the sheet container portion 53 are stacked. The position of the uppermost surface of P means that the position is located above the first plane (first position). In that case, the paper storage container portion 53 is in a state where there is no room for loading the paper P or a state where there is no room. Therefore, the sheet stacking control unit 80 drives and controls the elevation drive unit 55 that raises and lowers the container stage 51 to move the container stage 51 downward. Then, when the sheet stacking control unit 80 transmits a signal “0” from the first light receiving sensor 101 </ b> B, the driving of the elevation driving unit 55 is stopped. Thereby, when the paper P is not curled in the image forming apparatus 1 or when the curl is slight, the uppermost surface position of the paper P loaded in the paper container portion 53 is the first position. It is set below the first plane (first position). Thereby, when the paper P is carried from the carry-in roll 71 into the paper container portion 53, occurrence of a situation in which the paper P is not normally carried into the paper container portion 53 is reduced.

  In this case, since the first light emitting unit 101A and the first light receiving sensor 101B are arranged in the central portion in the width direction (y direction) of the paper P on the reference wall 88 side, the image P in the image forming apparatus 1 is used. If the curl is not generated or if the curl is slight, the uppermost surface position of the paper P of various sizes loaded in the paper container portion 53 is detected with high accuracy.

On the other hand, when the curl generated on the paper P in the image forming apparatus 1 is larger than a predetermined amount, even if a signal of “0” is output from the first light receiving sensor 101B, There is a case where a part of the upper sheet P is located above the first plane (first position). That is, the curl is generated at, for example, the end portion in the width direction (y direction) and the end portion in the transport direction (x direction) of the paper P stacked on the paper container portion 53. A state occurs in which the region of the portion is positioned above the first plane (first position). When it is positioned above the second plane (second position), when the width direction aligning mechanism 60 aligns the paper P in the width direction, the support holders 61A and 61B are At the time of movement, one of the support holders 61A and 61B interferes with the paper P that has already been aligned and disturbs the stacking.
Therefore, in the sheet stacking apparatus 2 according to the present embodiment, the second detection unit is used to detect whether or not there is a sheet P that crosses the second plane. Even when the signal “0” is output from the first light receiving sensor 101B, when the second detection unit detects that there is a sheet P crossing the second plane, The sheet stacking control unit 80 controls the container stage 51 to move downward.

That is, when a signal “0” is output from any one or more of the second light receiving sensor 102B to the fifth light receiving sensor 105B, any of the second light emitting unit 102A to the fifth light emitting unit 105A is output. It means that the light emitted from one or a plurality of light is in a state of being blocked by the paper P in the second plane. At that time, the position of at least a part of the uppermost sheet P stacked on the sheet container 53 is positioned above the second plane (second position). Therefore, if the width direction aligning mechanism 60 tries to align the width direction of the paper P in that state, one of the support holders 61A and 61B is already aligned when the support holders 61A and 61B are moved. It interferes with the completed paper P and disturbs the orderly aligned stacking.
Therefore, the sheet stacking control unit 80 moves up and down the container stage 51 when a signal “0” is transmitted from any one or more of the second light receiving sensor 102B to the fifth light receiving sensor 105B. The unit 55 is driven and controlled to move the container stage 51 downward. Then, when the sheet stacking control unit 80 transmits a signal “1” from all of the second light receiving sensor 102 </ b> B to the fifth light receiving sensor 105 </ b> B, the driving of the elevating drive unit 55 is stopped. As a result, even when curl of a predetermined amount or more is generated on the paper P in the image forming apparatus 1, the position of the uppermost paper P stacked on the paper container portion 53 (the uppermost surface position of the paper P). ) Is set below the second plane (second position). Accordingly, the support holders 61A and 61B are moved while suppressing the disturbance of the stacking of the sheets P that have already been aligned and are neatly stacked in the sheet container portion 53, and the sheets P that are further stacked on the upper part thereof. Paper alignment is performed.

Here, FIG. 12 is a view showing a state in which a curl having a size equal to or larger than a predetermined amount is generated at an end portion in the width direction (y direction) of the paper P loaded on the paper container portion 53. As shown in FIG. 12, the central portion of the uppermost surface of the paper P stacked in the paper storage container portion 53 is positioned below the first plane (first position), but the paper P In some cases, a curl having a size greater than or equal to a predetermined amount occurs at the end in the width direction (y direction).
In this case, a signal of “0” is output from the first light receiving sensor 101B, but the end portion (region C) where the curl of the uppermost paper P stacked on the paper storage container portion 53 is generated. Is located above the second plane (second position). Therefore, in the second detection unit that detects whether or not there is a sheet P that crosses the second plane, for example, the light emitted from the second light emitting unit 102A is an area of the sheet P that crosses the second plane. Blocked by C. Accordingly, a signal “0” is output from the second light receiving sensor 102B. Similarly, a signal of “0” is also output from the third light receiving sensor 103B and the fourth light receiving sensor 104B depending on the size of the paper P stacked in the paper container portion 53, the form of the curl generated, and the like. .

  In that case, as shown in FIG. 13 (a diagram showing a state in which the paper container 53 is moved downward), the sheet stacking control that receives the signal “0” from the second light receiving sensor 102B or the like. The unit 80 drives and controls the elevating drive unit 55 that moves the container stage 51 up and down to move the container stage 51 downward. Then, when the sheet stacking control unit 80 transmits a signal “1” from all of the second light receiving sensors 102 </ b> B, the driving of the elevating drive unit 55 is stopped. As a result, even when a curl of a predetermined amount or more is generated at the end in the width direction of the paper P in the image forming apparatus 1, the position of the uppermost paper P loaded on the paper storage container 53 (paper) The uppermost surface position of P is set below the second plane (second position). Therefore, the support holders 61A and 61B are moved while suppressing the disturbance of the stacking of the sheets P that have already been aligned and are neatly stacked in the sheet container portion 53, and the sheets P to be further stacked on the upper part thereof are suppressed. Paper alignment is performed.

By the way, as described above, the second light emitting unit 102A and the second light receiving sensor 102B convey the side surface (y direction) of the paper P of the minimum size (for example, B6 size) handled by the image forming apparatus 1, for example. It arrange | positions in the position which can light-irradiate a direction front-end | tip part. In addition, the third light emitting unit 103A and the third light receiving sensor 103B are arranged at a position where, for example, the front end in the transport direction on the side surface side (y direction) can be irradiated with light on the A4 size paper P. In addition, the fourth light emitting unit 104A and the fourth light receiving sensor 104B are arranged at a position where, for example, the front end in the conveyance direction on the side surface (y direction) can be irradiated with light on the A3 size paper P.
Here, FIG. 14 shows the second light emitting unit 102A and the second light receiving sensor 102B, the third light emitting unit 103A and the third light receiving sensor 103B, and the fourth light emitting unit 104A and the fourth light receiving sensor 104B, respectively. It is the figure which showed a mode that detected curl. As shown in FIG. 14, each is disposed at a different position in the transport direction (x direction) of the paper P, so that only the front side in the transport direction of the paper P of the different size (the side opposite to the reference wall 88). The resulting curl is also detected.

In the paper position detection mechanism unit of the present embodiment, the second light emitting unit 102A, the second light receiving sensor 102B, and the third light emitting unit 103A are provided at different positions in the transport direction (x direction) of the paper P, respectively. The third light receiving sensor 103B, the fourth light emitting unit 104A, and the fourth light receiving sensor 104B are arranged. However, in addition to such a configuration, the arrangement position is moved according to the size of the paper P conveyed to the paper container portion 53 using, for example, a pair of light emitting units and light receiving sensors. May be.
In the paper position detection mechanism of the present embodiment, the second light emitting unit 102A and the second light receiving sensor 102B, the third light emitting unit 103A and the third light receiving sensor 103B, and the fourth light emitting unit 104A and The fourth light receiving sensor 104B constituted a second plane which is one plane. However, in addition to such a configuration, the second light emitting unit 102A and the second light receiving unit are set so that the arrangement positions in the stacking direction (z direction) differ depending on the curl shape generated on the paper P. The surface formed by the sensor 102B, the third light emitting unit 103A and the third light receiving sensor 103B, and the fourth light emitting unit 104A and the fourth light receiving sensor 104B may be set so as not to form a plane.

Next, FIG. 15 is a diagram illustrating a state in which curl is generated at one end portion (front end side) in the conveyance direction (x direction) of the paper P loaded on the paper storage container portion 53. As shown in FIG. 15, when a curl larger than a predetermined amount is generated only at the leading end side in the conveyance direction (x direction) of the paper P, the paper P loaded in the paper container portion 53 The top surface position is located below the first plane (first position) on the leading end side in the transport direction. For this reason, a signal “0” is output from the first light receiving sensor 101B that detects whether or not the sheet P exists in the first plane on the reference wall 88 side.
On the other hand, curl having a predetermined amount or more is generated only at the leading end side in the conveyance direction (x direction) of the paper P, and therefore, for example, two sheets P stacked on the top of the paper container portion 53. The position of the end portion (region C1 and region C2) where the curl is generated is located above the second plane (second position). Therefore, in the second detection unit that detects whether or not there is a sheet P that crosses the second plane, the conveyance direction of the sheet P in the center of the width direction (y direction) of the sheet P in the second plane. In the fifth light emitting unit 105A and the fifth light receiving sensor 105B arranged along the (x direction), the light emitted from the fifth light emitting unit 105A is a region C1 of the paper P crossing the second plane and Blocked by region C2. Accordingly, a signal “0” is output from the fifth light receiving sensor 105B.

In that case, as shown in FIG. 16 (a diagram showing a state in which the paper container 53 is moved downward), the sheet stacking control unit that has received the signal “0” from the fifth light receiving sensor 105B. 80 drives and controls the raising / lowering drive part 55 which raises / lowers the container stage 51, and moves the container stage 51 below. Then, when the sheet stacking control unit 80 transmits a signal “1” from the fifth light receiving sensor 105 </ b> B, the driving of the elevation driving unit 55 is stopped. As a result, even when a curl of a predetermined amount or more is generated at the front end portion in the transport direction of the paper P in the image forming apparatus 1, the position of the uppermost paper P loaded on the paper storage container portion 53 (paper The uppermost surface position of P is set below the second plane (second position). Therefore, the support holders 61A and 61B are moved while suppressing the disturbance of the stacking of the sheets P that have already been aligned and are neatly stacked in the sheet container portion 53, and the sheets P that are further stacked on the upper portion thereof are moved. Paper alignment is performed.
In addition, when a curl of a predetermined amount or more occurs at the rear end portion in the conveyance direction of the paper P, the curl is detected by the first light emitting unit 101A and the first light receiving sensor 101B.

As described above, when a curl of a predetermined amount or more is generated at one end (front end side) in the conveyance direction (x direction) of the paper P, the position where the curl of the paper P is generated is the first position. There may occur a case in which the second light emitting unit 102A to the fourth light emitting unit 104A and the second light receiving sensor 102B to the fourth light receiving sensor 104B deviate from the positions where they are arranged. In that case, curl cannot be detected from the second light emitting unit 102A to the fourth light emitting unit 104A and the second light receiving sensor 102B to the fourth light receiving sensor 104B.
Therefore, in the second plane, the fifth light emitting unit 105A and the fifth light receiving sensor 105B are arranged along the conveyance direction (x direction) of the paper P at the center in the width direction (y direction) of the paper P. is doing. The fifth light emitting unit 105A and the fifth light receiving sensor 105B detect curl generated in any region in the conveyance direction (x direction) of the paper P, and the second light emitting unit 102A to the fourth light emitting unit 104A. The curl that is not detected by the second light receiving sensor 102B to the fourth light receiving sensor 104B is detected. This reduces the occurrence of curl detection omission in the recording material.

Subsequently, the operation control performed by the sheet stacking control unit 80 for the elevation drive unit 55 that raises and lowers the sheet storage container unit 53 will be described. FIG. 17 is a flowchart illustrating an example of processing performed when the sheet stacking control unit 80 performs operation control of the lifting drive unit 55.
As shown in FIG. 17, the sheet stacking control unit 80 first detects whether or not there is a sheet P crossing the first plane (first position) by the first detection unit (S101). Specifically, light is emitted from the first light emitting unit 101A, and it is detected whether or not the emitted light is received by the first light receiving sensor 101B.
When the first detection unit detects the sheet P present at the first position (S102), the sheet stacking control unit 80 drives the lifting drive unit 55 that moves the container stage 51 up and down to drive the sheet. The container part 53 is moved downward (S103). The sheet stacking control unit 80 monitors the signal output from the first light receiving sensor 101B while moving the paper container 53 downward (S104), and the first detection unit no longer detects the paper P. When the state, that is, when the signal output from the first light receiving sensor 101B becomes “0” (S105), the driving of the elevating drive unit 55 is stopped (S106).

Next, when the sheet P is not detected by the first detection unit in step 102 or in the state where the driving of the lifting drive unit 55 is stopped in step 106, the second plane is detected by the second detection unit. It is detected whether or not there is a sheet P crossing (second position) (S107). Specifically, the light is emitted from all of the second light emitting unit 102A to the fifth light emitting unit 105A, and is the emitted light received by the second light receiving sensor 102B to the fifth light receiving sensor 105B? Detect whether or not.
When the second detection unit detects the sheet P existing at the second position (S108), specifically, from one or more of the second light receiving sensor 102B to the fifth light receiving sensor 105B. When the “0” signal is output, the sheet stacking control unit 80 drives the lifting drive unit 55 that lifts and lowers the container stage 51 to move the sheet storage container unit 53 downward (S109).
The sheet stacking control unit 80 monitors signals output from the second light receiving sensor 102B to the fifth light receiving sensor 105B while moving the paper container 53 downward (S110), and the second light receiving sensor 102B. To a state in which all of the fifth light receiving sensors 105B no longer detect the paper P, that is, when the signals output from all of the second light receiving sensors 102B to 105B become “0” ( (S111), the drive of the raising / lowering drive part 55 is stopped (S112).

  Thereafter, when the sheet P is not detected by the second detection unit at Step 108 or when the driving of the lifting / lowering drive unit 55 is stopped at Step 112, the sheet stacking control unit 80 performs the sheet storage container unit 53. The operation control of the elevating drive unit 55 that elevates and lowers is completed.

Next, a function (loading abnormality detecting function) for detecting a loading abnormality when the paper P is loaded on the paper container portion 53 of the present embodiment will be described.
As described above, in the sheet stacking apparatus 2 according to the present embodiment, the sheet stacking control unit 80 sets the elevation position of the sheet storage container unit 53 based on the detection result regarding the sheet P by the first detection unit and the second detection unit. By setting, the uppermost surface position of the sheets P stacked on the sheet container portion 53 is set below the first plane (first position). Thereby, when the paper P is carried from the carry-in roll 71 into the paper container portion 53, occurrence of a situation in which the paper P is not normally carried into the paper container portion 53 is reduced. Further, even when the paper P is curled by a predetermined amount or more in the image forming apparatus 1, the position of the uppermost sheet P stacked on the sheet storage container unit 53 (the uppermost position of the sheet P). Is set below the second plane (second position). Accordingly, the support holders 61A and 61B are moved while suppressing the disturbance of the stacking of the sheets P that have already been aligned and are neatly stacked in the sheet container portion 53, and the sheets P that are further stacked on the upper part thereof. The paper is arranged in an orderly manner.

By the way, in the sheet stacking apparatus 2 of the present embodiment, the detection results of the first detection unit and the second detection unit described above, regardless of the size of the curl generated on the paper P in the image forming apparatus 1. By controlling the raising / lowering position of the paper container portion 53 based on the above, the uppermost surface position of the paper P stacked on the paper container portion 53 is lower than the first plane (first position) and the second Is set below the plane (second position). However, when the curl larger than the predetermined amount assumed on the paper P occurs, the top surface position of the paper P is the first plane (first position) and the second plane (second position). In the state set below, the stacking state of the sheets P in the sheet container portion 53 may become unstable. In that case, the paper P collapses from the paper container 53, or the paper P is damaged.
Therefore, the sheet stacking apparatus 2 of the present embodiment has a stacking abnormality detection function. That is, in the sheet stacking device 2, when it is determined that a curl larger than a predetermined amount assumed on the paper P is generated when the raising / lowering position of the paper container portion 53 is controlled, The stacking control unit 80 assumes that a stacking abnormality has occurred in the paper container 53 and performs a predetermined operation for the stacking abnormality. At that time, a curl larger than a predetermined amount assumed for the paper P is generated, and it is determined that a stacking abnormality has occurred in the paper storage container portion 53. In accordance with the predetermined judgment criteria (judgment conditions) set according to the detection results of the first to fifth detection units that detect whether or not the sheet P exists at each different position. Depending on whether or not. Accordingly, the sheet stacking control unit 80 here functions as a determination unit that determines whether or not a stacking abnormality has occurred in the sheet storage container unit 53.

Here, a determination criterion when the sheet stacking control unit 80 determines that a stacking abnormality has occurred in the sheet storage container unit 53 will be described. The determination criterion here is set according to the detection results of any two detection units of the first detection unit to the fifth detection unit.
[First Judgment Criteria: Judgment Criteria Based on Movement Time of Paper Container 53]
First, as a first determination criterion set in the sheet stacking control unit 80, when the paper container portion 53 starts to move downward based on the detection result of the first detection unit (for example, step 103 in FIG. 17). ) When a predetermined time elapses, the first detection unit is still detecting the paper P, that is, the signal output from the first light receiving sensor 101B is not “0” (for example, FIG. 17). In step 105), it is determined that a stacking abnormality has occurred in the paper container 53.
Similarly, the second detection is performed when a predetermined time elapses from the time when the paper container 53 starts to move downward based on the detection result of the second detection unit (for example, step 109 in FIG. 17). In a state where the part is still detecting the paper P, that is, when the signals output from all of the second light receiving sensor 102B to the fifth light receiving sensor 105B are not “0” (for example, step 111 in FIG. 17), It is determined that a stacking abnormality has occurred in the paper container portion 53.

FIG. 18 is a diagram for explaining an example of a stacking abnormality that matches the first criterion, and shows a state after a predetermined time has elapsed since the paper container portion 53 started to move downward. . Here, for example, the detection result of the second detection unit is changed from the above-described state of FIG. 15 that shows the state in which the curl is generated at one end (front end side) in the conveyance direction (x direction) of the paper P. Based on this, it is assumed that the raising / lowering position of the paper container 53 is set. In this case, a signal “0” is output from, for example, the fifth light receiving sensor 105 </ b> B of the second detection unit. Therefore, the sheet stacking control unit 80 drives the elevation driving unit 55 to drive the sheet storage container unit 53. Is moved downward.
However, as shown in FIG. 18, even after a predetermined time has elapsed since the paper container portion 53 started to move downward and the paper container portion 53 has moved a predetermined distance, For example, when the positions of the end portions (region C1 and region C2) on the front end side of the two sheets P stacked on the uppermost position are located above the second plane (second position), the sheet P On the leading end side in the transport direction (x direction), a curl larger than the movement distance in the paper container portion 53 for a predetermined time occurs. Therefore, it can be determined that the paper P has a curl larger than a predetermined amount assumed. Similarly, when setting the raising / lowering position of the paper container portion 53 based on the detection result of the first detection unit, it can be determined that the paper P has a curl larger than a predetermined amount. .

Therefore, when the first detection unit or the second detection unit is still detecting the paper P when a predetermined time has elapsed since the paper container 53 started to move downward. The sheet stacking control unit 80 determines that a curl larger than a predetermined amount has occurred on the sheet P, and a stacking abnormality has occurred in the sheet storage container unit 53.
Here, when the second detection unit is detecting the paper P when a predetermined time has elapsed since the paper container 53 started to move downward, the first detection unit also The presence of the paper P is detected. However, in this case, it is determined that a stacking abnormality has occurred regardless of whether the first detection unit detects the paper P. On the other hand, whether or not the first detection unit detects the paper P may be referred to. That is, when the first detection unit does not detect the paper P, the accuracy of determination that a large curl is generated on the leading end side in the conveyance direction (x direction) of the paper P is increased.
Similarly, when the first detection unit is detecting the paper P when a predetermined time has elapsed since the paper container 53 started to move downward, the second detection unit Whether or not the paper P is detected is determined to be that a stacking abnormality has occurred. On the other hand, whether or not the second detection unit detects the paper P may be referred to.

[Second Judgment Criteria: Judgment Criteria for Curled Inclined in the Transport Direction]
Next, as a second determination criterion set in the sheet stacking control unit 80, after the sheet storage container unit 53 starts to move downward based on the detection result of the second detection unit (for example, step of FIG. 17). 109) before the second detection unit no longer detects the sheet P (for example, step 111 in FIG. 17), the sheet is in a third position positioned below the first position in the stacking direction (z direction). When the third detection unit that detects whether or not P is detected does not detect the sheet P, it is determined that a stacking abnormality has occurred in the sheet storage container unit 53.

FIG. 19 is a diagram illustrating an example of a stacking abnormality that matches the second determination criterion, and shows a state after a predetermined time has elapsed since the paper container portion 53 started to move downward. .
For example, when the fifth light receiving sensor 105B of the second detection unit detects the sheet P, for example, the end portion (for example, the front end side) of the plurality of sheets P stacked on the uppermost part of the sheet storage container unit 53 ( The position of the region CF) is located above the second plane (second position). On the other hand, the third detection unit uses the sixth light emitting unit 201A and the sixth light receiving sensor 201B, for example, in the width direction (y direction) of the paper P, in the vicinity of the reference wall 88 in the center of the paper P, It is detected whether there is a sheet P that crosses the “third plane” orthogonal to the z direction) at the third position. Therefore, when the third detection unit does not detect the paper P, the position of the end portion (region CR) on the reference wall 88 side (rear end side) of the paper P is the third plane (third position). It is located below.

Then, the sheet P stacked on at least the uppermost portion of the sheet container portion 53 has a leading end side above the second plane (second position) and a trailing end side of the third plane (third position). ). In other words, the paper P has a large curl extending between the second position and the third position located on both the upper and lower sides across the first position. Therefore, it can be determined that the paper P has a curl inclined in the transport direction (x direction) that is larger than the predetermined amount assumed.
Therefore, when the second detection unit (for example, the fifth light receiving sensor 105B) detects the sheet P and the third detection unit does not detect the sheet P, the sheet stacking control unit 80 It is determined that the paper P is curled larger than a predetermined amount. Such a determination may be made not only after a predetermined time has elapsed since the paper container portion 53 started moving downward, but also when the paper container portion 53 starts moving downward. .

[Third Judgment Criteria: Judgment Criteria for Curls Formed Concave in the Conveyance Direction]
Next, as a third determination criterion set in the sheet stacking control unit 80, after the paper container portion 53 starts to move downward based on the detection result of the first detection unit or the second detection unit. (For example, step 103 and step 109 in FIG. 17), the first detection unit detects the paper P, and the fifth detection unit has a fifth position in the stacking direction (z direction) where the top surface of the paper P is placed. If it is detected that the sheet storage container unit 53 is positioned below the sheet storage container unit 53, it is determined that a stacking abnormality has occurred in the sheet container portion 53.

FIG. 20 is a diagram illustrating an example of a stacking abnormality that matches the third determination criterion, and shows a state after a predetermined time has elapsed since the paper container portion 53 started to move downward. .
The first detection unit determines whether or not the end portion (region CR) on the rear end side of the paper P stacked on the uppermost portion of the paper container portion 53 exists on the first plane (first position). To detect. On the other hand, the fifth detection unit has the uppermost surface of the paper P in the stacking direction (z direction) at a position closer to the leading end in the transport direction (x direction) than the reference wall 88 (central position in the transport direction: region CC). It is detected whether it is located below the fifth position. Therefore, when the first detection unit detects the paper P and the fifth detection unit detects that the central position (area CC) in the transport direction of the paper P is located below the fifth position. The paper P stacked on at least the uppermost part of the paper container portion 53 has a rear end side above the first plane (first position) and a central position in the transport direction at the fifth plane (first plane). (Position 5). That is, the paper P has a large curl extending from the first position to the fifth position. Therefore, it can be determined that the paper P has a curl formed in a concave shape in the transport direction (x direction), which is larger than an assumed predetermined amount.
Therefore, when the first detection unit detects the paper P and the fifth detection unit detects that the central position (region CC) in the transport direction of the paper P is located below the fifth position. In this case, the sheet stacking control unit 80 determines that the paper P has a curl larger than a predetermined amount assumed. Such a determination may be made not only after a predetermined time has elapsed since the paper container portion 53 started moving downward, but also when the paper container portion 53 starts moving downward. .

[Fourth Judgment Criteria: Judgment Criteria for Curls Formed Projectively in the Conveyance Direction]
Next, as a fourth determination criterion set in the sheet stacking control unit 80, after the paper container portion 53 starts to move downward based on the detection result of the first detection unit or the second detection unit. (For example, in step 103 and step 109 in FIG. 17), the third detection unit does not detect the paper P, and the fifth detection unit detects the fifth in the stacking direction (z direction). When it is detected that the position is higher than the position, it is determined that a stacking abnormality has occurred in the paper container portion 53.

FIG. 21 is a diagram illustrating an example of a stacking abnormality that matches the fourth determination criterion, and shows a state after a predetermined time has elapsed since the paper container portion 53 started to move downward. .
The third detection unit determines whether or not the end portion (region CR) on the rear end side of the paper P stacked on the uppermost portion of the paper container portion 53 exists on the third plane (third position). To detect. On the other hand, the fifth detection unit has the uppermost surface of the paper P in the stacking direction (z direction) at a position closer to the leading end in the transport direction (x direction) than the reference wall 88 (central position in the transport direction: region CC). It is detected whether it is located below the fifth position.
Therefore, when the third detection unit does not detect the paper P, and the fifth detection unit detects that the central position (area CC) in the transport direction of the paper P is located above the fifth position. That is, the sheet P stacked on at least the uppermost part of the sheet container portion 53 has a rear end side below the third plane (third position) and a central position in the transport direction at the fifth plane ( It will be located above the (fifth position). That is, the paper P has a large curl extending from the third position to the fifth position. Therefore, it can be determined that the paper P has a curl formed in a convex shape in the transport direction (x direction) that is larger than a predetermined amount assumed.
Therefore, the third detection unit does not detect the paper P, and the fifth detection unit detects that the central position (area CC) in the transport direction of the paper P is located above the fifth position. In this case, the sheet stacking control unit 80 determines that a curl larger than an assumed predetermined amount has occurred on the paper P. Such a determination may be made not only after a predetermined time has elapsed since the paper container portion 53 started moving downward, but also when the paper container portion 53 starts moving downward. .

[Fifth Judgment Criteria: Judgment Criteria for Curls Formed Concave in the Width Direction]
Next, as a fifth determination criterion set in the sheet stacking control unit 80, after the sheet storage container unit 53 starts to move downward based on the detection result of the second detection unit (for example, step of FIG. 17). 109), when the second detection unit no longer detects the paper P, the fifth detection unit has the uppermost surface of the paper P positioned below the fifth position in the stacking direction (z direction). Is detected, it is determined that a stacking abnormality has occurred in the paper container portion 53.

FIGS. 22 and 23 are diagrams for explaining an example of a stacking abnormality that matches the fifth determination criterion. FIG. 22 and FIG. 23 show a state after a predetermined time has elapsed since the paper container portion 53 started to move downward. Show. 22 is a diagram viewed from the reference wall 88 side in the conveyance direction (x direction) of the paper P, and FIG. 23 is a diagram viewed from the width direction (y direction) side of the paper P.
After the paper container portion 53 starts to move downward, when all of the second light receiving sensor 102B to the fifth light receiving sensor 105B of the second detection unit no longer detect the paper P, the paper container The unit 53 stops (for example, step 111 to step 112 in FIG. 17). At this time, when the fifth detection unit detects that the uppermost surface of the paper P is positioned below the fifth position in the stacking direction (z direction), as shown in FIGS. In addition, at least one end in the width direction of the paper P stacked on the uppermost portion of the paper storage container portion 53 is positioned below the second plane (second position). In addition, the central position (region CSC) in the width direction is located below the fifth plane (fifth position). In other words, the paper P has a large curl extending between the second position and the fifth position located on both the upper and lower sides across the first position. Therefore, it can be determined that the paper P has a curl formed in a concave shape in the width direction (x direction) that is larger than the predetermined amount assumed.
Therefore, when the second detection unit stops detecting the paper P, the fifth detection unit detects that the uppermost surface of the paper P is located below the fifth position in the stacking direction (z direction). In such a case, the sheet stacking control unit 80 determines that a curl larger than an assumed predetermined amount has occurred on the paper P.

[Sixth Judgment Criteria: Judgment Criteria for Curls Forming Projections in the Width Direction]
Next, as a sixth determination criterion set in the sheet stacking control unit 80, after the sheet storage container unit 53 starts moving downward based on the detection result of the second detection unit (for example, step of FIG. 17). 109), when the second detection unit does not detect the paper P and the fourth detection unit does not detect the paper P, it is determined that a stacking abnormality has occurred in the paper container portion 53.

FIG. 24 and FIG. 25 are diagrams for explaining an example of a stacking abnormality that matches the sixth determination criterion, and shows a state after a predetermined time has elapsed since the paper container portion 53 started to move downward. Show. 24 is a diagram viewed from the reference wall 88 side in the conveyance direction (x direction) of the paper P, and FIG. 25 is a diagram viewed from the width direction (y direction) side of the paper P.
After the paper container portion 53 starts to move downward, when all of the second light receiving sensor 102B to the fifth light receiving sensor 105B of the second detection unit no longer detect the paper P, the paper container The unit 53 stops (for example, step 111 to step 112 in FIG. 17). At that time, at least one of the seventh light emitting unit 202A and the seventh light receiving sensor 202B (region CSR) of the fourth detection unit, and the eighth light emitting unit 203A and the eighth light receiving sensor 203B (region CSL). If either of them does not detect the paper P, as shown in FIGS. 24 and 25, the paper P stacked on the uppermost portion of the paper container portion 53 has at least one end portion in the width direction. It is located below the fourth plane (fourth position). Further, the central position in the width direction is located near the second plane (second position) and below. That is, the paper P has a large curl extending between the second position and the fourth position that are located on both the upper and lower sides across the first position and the third position. Therefore, it can be determined that the paper P has a curl formed in a concave shape in the width direction (x direction) that is larger than the predetermined amount assumed.
Therefore, when the fourth detection unit does not detect the paper P when the second detection unit no longer detects the paper P, the sheet stacking control unit 80 causes the paper P to exceed the predetermined amount assumed. Judge that there is a big curl.

As described above, when the sheet stacking control unit 80 according to the present embodiment sets the elevation position of the paper container portion 53 based on the detection results of the first detection unit and the second detection unit, It is monitored whether a state that matches the first to sixth determination criteria described above has occurred. If a state that matches any of the first to sixth determination criteria has occurred, the sheet stacking control unit 80 determines that a stacking abnormality has occurred in the sheet storage container unit 53. To do.
The first to sixth determination criteria described above are set according to the detection results of any two detection units of the first detection unit to the fifth detection unit. You may set according to the detection result in any 3 or more detection parts of a part-a 5th detection part.
Further, in this case, when the sheet stacking control unit 80 determines that a stacking abnormality has occurred in the paper storage container unit 53, the stacking abnormality is monitored at a predetermined interval, and continuously (for example, twice). Thus, when a state that matches any of the first to sixth determination criteria occurs, it may be determined that a stacking abnormality has occurred in the paper storage container portion 53. Good. As a result, it is possible to reduce erroneous detection of a stacking abnormality when, for example, a curl more than expected occurs unexpectedly and then changes to a curl within the expected range.

When the sheet stacking control unit 80 determines that a stacking abnormality has occurred in the sheet storage container unit 53, the sheet stacking control unit 80 executes a predetermined measure for the stacking abnormality. For example, the sheet stacking control unit 80 transmits information indicating that a stacking abnormality has occurred in the sheet storage container unit 53 to the main body control unit 35 that controls the operation of the image forming apparatus 1. The main body control unit 35 that has acquired the information indicating that the stacking abnormality has occurred stops the operation of the image forming apparatus 1. Or it may be displayed on a display panel (not shown) to warn the user.
In addition, when the main body control unit 35 stops the operation of the image forming apparatus 1, the sheet stacking control unit 80 is configured to be detachable from the sheet stacking device 2 with the casters 52 a disposed on the pedestal unit 52. The second paper stacking unit 50 may be set so as to move to a position where the paper P stacked on the paper container 53 can be taken out from the outside.

On the other hand, when the width direction of the sheet P offset by the offset roll 26 of the image forming apparatus 1 is set to the same direction, the sheet stacking control unit 80 causes a stacking abnormality to occur in the sheet storage container unit 53. You may control so that it does not judge that it exists. This is because when the paper storage container portion 53 is stacked in the same width direction, the paper P is unlikely to collapse from the paper storage container portion 53 and the paper P is not easily damaged.
Further, when the offset roll 26 of the image forming apparatus 1 is set so as to be alternately offset to the left and right sides, the sheet to be offset when it is determined that a stacking abnormality has occurred. You may control to change so that the width direction of P may be set to the same direction.

  Here, FIG. 26 is a block diagram showing an internal configuration of the sheet stacking control unit 80 of the present embodiment. As shown in FIG. 26, the sheet stacking control unit 80 is set in advance when executing the operation control related to the above-described lifting drive unit 55 and the determination process of whether or not a stacking abnormality has occurred in the sheet storage container unit 53. A CPU 801 that executes digital arithmetic processing according to a processing program, a RAM 802 that is used as a working memory for the CPU 801, a ROM 803 that stores a processing program executed by the CPU 801, and is rewritable and retains data even when power supply is interrupted Signals to and from each unit such as an SRAM (Static Random Access Memory) backed up by a battery, a non-volatile memory 804 such as a flash memory, and a first detection unit and a second detection unit connected to the sheet stacking control unit 80 Interface as an example of information acquisition unit for controlling input / output of (information) It is equipped with a 805.

  Then, the sheet stacking control unit 80 has a program that realizes the operation control related to the above-described lifting drive unit 55 and the determination process of whether or not a stacking abnormality has occurred in the sheet storage container unit 53, for example, an external provided in the sheet stacking device 2 The data is read from the storage unit 81 into the ROM 803 in the sheet stacking control unit 80. Then, based on the program read into the ROM 803, the CPU 801 performs processing related to operation control. As this program, for example, a program stored in a reserved area such as a hard disk or a DVD-ROM as the external storage unit 81 is provided by being loaded into the ROM 803. As another provision form, there is a form provided in a state stored in the ROM 803 in advance. Further, when a rewritable ROM 803 such as an EEPROM is provided, after the sheet stacking control unit 80 is assembled, only a program is provided and installed in the ROM 803. Further, there is a form in which a program is transmitted to the sheet stacking control unit 80 via a network such as the Internet and installed in the ROM 803 of the sheet stacking control unit 80.

  As described above, in the sheet stacking apparatus 2 according to the present embodiment, the sheet stacking control unit 80 moves up and down the sheet storage container unit 53 based on the detection result regarding the sheet P by the first detection unit and the second detection unit. When controlling the above, it is monitored whether or not a state corresponding to the first to sixth determination criteria is generated. When a state that matches any of the first to sixth determination criteria occurs, the sheet stacking control unit 80 determines that a stacking abnormality has occurred in the sheet storage container unit 53. Furthermore, when it is determined that a stacking abnormality has occurred in the paper container portion 53, a predetermined measure for the stacking abnormality is executed.

  As described above, in the sheet stacking apparatus 2 of the present embodiment, based on the detection result as to whether or not the sheet P exists at each of a plurality of different positions set in the stacking direction (z direction) of the sheet P. Therefore, it is possible to detect various types of curls that occur on the paper P, and the detection accuracy for the stacking abnormality in the paper container 53 is increased.

1 is a diagram illustrating a configuration of an image forming system to which the exemplary embodiment is applied. FIG. 3 is a diagram illustrating a configuration of a sheet stacking apparatus. It is a figure explaining the structure of the width direction alignment mechanism part. It is a figure explaining operation | movement of the width direction alignment mechanism part in the case of aligning the document of several copies by each unit. It is a figure explaining operation | movement of the width direction alignment mechanism part in the case of aligning the document of several copies by each unit. It is a figure explaining the structure of a conveyance direction alignment mechanism part. It is a figure explaining operation | movement of the conveyance direction alignment mechanism part when the paper of a different size is accommodated in the paper storage container part. FIG. 6 is a view of a paper position detection mechanism section as viewed from above in the stacking direction (z direction) of sheets stored in a sheet storage container section. FIG. 6 is a diagram of a paper position detection mechanism section viewed from the width direction (y direction) of a sheet stored in a sheet storage container section. It is a perspective view explaining "the 1st plane", "the 2nd plane", "the 3rd plane", and "the 4th plane". It is a figure explaining operation | movement of a 5th detection part. FIG. 6 is a diagram illustrating a state in which a curl having a size equal to or larger than a predetermined amount is generated at an end portion in a width direction (y direction) of sheets stacked on a sheet storage container. FIG. 6 is a diagram illustrating a state in which a paper container portion is moved downward. It is the figure which showed a mode that each of a 2nd light emission part and a 2nd light reception sensor, a 3rd light emission part and a 3rd light reception sensor, and a 4th light emission part and a 4th light reception sensor detected a curl. . FIG. 6 is a diagram illustrating a state in which a curl is generated at one end portion (front end side) in a conveyance direction (x direction) of a sheet loaded on a sheet storage container portion. FIG. 6 is a diagram illustrating a state in which a paper container portion is moved downward. 6 is a flowchart illustrating an example of processing performed when an operation of a lift driving unit performed by a sheet stacking control unit is controlled. It is a figure explaining an example of the stacking | fluctuation abnormality which corresponds to a 1st criterion. It is a figure explaining an example of the stacking abnormality which corresponds to the 2nd judgment standard. It is a figure explaining an example of the loading abnormality which agree | coincides with a 3rd criteria. It is a figure explaining an example of the stacking abnormality which corresponds to the 4th judgment standard. It is a figure explaining an example of the stacking | fluctuation abnormality which corresponds to the 5th criterion. It is a figure explaining an example of the stacking | fluctuation abnormality which corresponds to the 5th criterion. It is a figure explaining an example of the stacking abnormality which corresponds to the 6th judgment standard. It is a figure explaining an example of the stacking abnormality which corresponds to the 6th judgment standard. 4 is a block diagram illustrating an internal configuration of a sheet stacking control unit. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 2 ... Sheet stacking apparatus, 35 ... Main body control part, 50 ... 2nd paper stacking part, 60 ... Width direction alignment mechanism part, 61A, 61B ... Support holder, 62A, 62B, 63A, 63B, 64A , 64B ... Tamper, 80 ... Sheet stacking control unit, 90 ... Conveying direction alignment mechanism unit, 101A ... First light emitting unit, 101B ... First light receiving sensor, 102A ... Second light emitting unit, 102B ... Second light receiving Sensor, 103A ... third light emitting unit, 103B ... third light receiving sensor, 104A ... fourth light emitting unit, 104B ... fourth light receiving sensor, 105A ... fifth light emitting unit, 105B ... fifth light receiving sensor, 201A: Sixth light emitting unit, 201B: Sixth light receiving sensor, 202A ... Seventh light emitting unit, 202B ... Seventh light receiving sensor, 203A ... Eighth light emitting unit, 203B ... Eighth light receiving sensor, 204A ... 9th departure Parts, 204B ... ninth light receiving sensor, 210 ... actuator

Claims (18)

A recording material stacking unit for loading recording material carried from the outside;
A reference position in the stacking direction of the recording material stacked on the recording material stacking unit , depending on whether or not the light emitted from the light emitting unit is received by the light receiving sensor. , A plurality of detecting whether or not the recording material exists at each of an upper position that is above the stacking direction from the reference position and a lower position that is below the stacking direction from the reference position . A detection unit;
A determination unit that determines the size of curl generated in the recording material stacked on the recording material stacking unit based on the detection results of the plurality of detection units ;
Moving means for moving the recording material stacking section in the stacking direction ,
When the detection unit detects the presence of the recording material at the reference position or the upper position, the determination unit moves the recording material stacking unit downward in the stacking direction by the moving unit, and After the material stacking unit starts moving downward in the stacking direction, the detection result by the detection unit regarding the presence of the recording material at the reference position or the upper position, the reference position and the upper position by the detection unit, It is determined whether or not the curl generated on the recording material is larger than a predetermined amount using any of the detection results regarding the presence of the recording material at a plurality of different positions from the lower position. Recording material loading device. In the determination unit, one of the detection units detects the presence of the recording material, and the other detection unit positioned below the one detection unit in the stacking direction does not detect the presence of the recording material. 2. The recording material stacking apparatus according to claim 1, wherein the curl generated in the recording material is determined to be larger than a predetermined amount . When the moving unit moves the recording material stacking portion downward in the stacking direction, the determining unit detects the presence of the recording material when the one detecting unit stops detecting the presence of the recording material. The curl generated on the recording material is determined to be larger than a predetermined amount when the other detection unit positioned below the detection unit in the stacking direction does not detect the presence of the recording material. Item 1. A recording material loading device according to Item 1. The determination unit is configured to detect the presence of the recording material at the reference position or the upper position when a predetermined time has elapsed after the moving unit starts moving the recording material stacking unit downward in the stacking direction. the when the detecting unit for detecting detects the presence of the recording material, a recording material stacking apparatus of claim 1, wherein the curl generated in the recording material is characterized in that it is determined that greater than a predetermined amount.   One or more of the plurality of detection units determines whether or not the recording material is present at the position in the stacking direction at a plurality of positions in a plane orthogonal to the stacking direction passing through the position in the stacking direction. The recording material stacking apparatus according to claim 1, wherein the recording material stacking apparatus detects the recording material. The determination unit determines whether or not curl generated in the recording material using the detection result related to the presence of the recording material by one or a plurality of the detection units is larger than a predetermined amount, every predetermined time, 2. The curl generated in the recording material is determined to be larger than a predetermined amount when it is determined that the curl of the recording material is larger than a predetermined amount a plurality of times . Recording material loading device. An image forming apparatus for forming an image on a recording material;
A recording material stacking device that carries in the recording material on which an image has been formed by the image forming apparatus and loads the recording material that has been carried in;
The recording material loading device is:
A recording material stacking unit for stacking the recording material carried in from the image forming apparatus;
A reference position in the stacking direction of the recording material stacked on the recording material stacking unit , depending on whether or not the light emitted from the light emitting unit is received by the light receiving sensor. , A plurality of detecting whether or not the recording material exists at each of an upper position that is above the stacking direction from the reference position and a lower position that is below the stacking direction from the reference position . A detection unit;
A determination unit that determines the size of curl generated in the recording material stacked on the recording material stacking unit based on the detection results of the plurality of detection units ;
Moving means for moving the recording material stacking section in the stacking direction ,
When the detection unit detects the presence of the recording material at the reference position or the upper position, the determination unit moves the recording material stacking unit downward in the stacking direction by the moving unit, and After the material stacking unit starts moving downward in the stacking direction, the detection result by the detection unit regarding the presence of the recording material at the reference position or the upper position, the reference position and the upper position by the detection unit, It is determined whether or not the curl generated on the recording material is larger than a predetermined amount using any of the detection results regarding the presence of the recording material at a plurality of different positions from the lower position. An image forming system. The determination unit of the recording material stacking apparatus is configured such that one detection unit detects the presence of the recording material and the other detection unit positioned below the one detection unit in the stacking direction 8. The image forming system according to claim 7, wherein when the presence of the material is not detected, it is determined that the curl generated in the recording material is larger than a predetermined amount . When the moving unit moves the recording material stacking portion downward in the stacking direction, the determining unit detects the presence of the recording material when the one detecting unit stops detecting the presence of the recording material. The curl generated on the recording material is determined to be larger than a predetermined amount when the other detection unit positioned below the detection unit in the stacking direction does not detect the presence of the recording material. Item 8. The image forming system according to Item 7. The determination unit is configured to detect the presence of the recording material at the reference position or the upper position when a predetermined time has elapsed after the moving unit starts moving the recording material stacking unit downward in the stacking direction. wherein when the detection unit detects the presence of the recording material, the image forming system according to claim 7, wherein the curl generated in the recording material is determined to be greater than the predetermined amount detected. The recording material stacking apparatus notifies the image forming apparatus to that effect when the determination unit determines that the curl generated in the recording material is larger than a predetermined amount ,
When the image forming apparatus receives a notification from the recording material stacking apparatus that the curl generated on the recording material is larger than a predetermined amount , the image forming apparatus stops forming an image on the recording material, or the recording material 8. The image forming system according to claim 7, wherein a display indicating that the curl generated in the material is larger than a predetermined amount . The image forming apparatus has a setting in which the recording material on which an image is formed is delivered to the recording material stacking device in different positions on the left and right in the width direction of the recording material. It is configured to be selectable with settings made on the same side position,
In the recording material stacking apparatus, when the image forming apparatus is set so that the recording material is carried out at the same position in the width direction, the determination unit causes the curl generated in the recording material to be curled. The image forming system according to claim 7, wherein the image forming system is not determined to be larger than a predetermined amount . The image forming apparatus has a setting in which the recording material on which an image is formed is delivered to the recording material stacking device in different positions on the left and right in the width direction of the recording material. The setting performed at the same side position is selectable, and the determination unit of the recording material stacking device sets the curl of the recording material to a predetermined amount by setting to be distributed to the left and right different positions in the width direction. The image forming system according to claim 7, wherein the image forming system is changed to a setting to be carried out to a position on the same side in the width direction when it is determined that the value is larger . When the determination unit determines that the curl generated in the recording material is greater than a predetermined amount , the recording material stacking device causes the recording material loaded on the recording material stacking unit to be transferred from the outside. 8. The image forming system according to claim 7, wherein the image forming system is moved to a position where it can be taken out. On the computer,
The recording material is detected by signals from a plurality of detection units that detect whether or not the light emitted from the light emitting unit is received by the light receiving sensor. At each of a reference position in the stacking direction of the recording material stacked on the stacking unit, an upper position that is higher in the stacking direction than the reference position, and a lower position that is lower in the stacking direction than the reference position , A function for acquiring information on whether or not the recording material exists,
A function of moving the recording material stacking portion downward in the stacking direction when the detection unit detects the presence of the recording material at the reference position or the upper position;
After the recording material stacking unit starts moving downward in the stacking direction, the acquired detection result regarding the presence of the recording material at the reference position or the upper position, the acquired reference position, the upper position, and the lower position A function of determining whether or not the curl generated on the recording material is larger than a predetermined amount by using any of the detection results regarding the presence of the recording material at a plurality of positions different from the position is realized. A program characterized by that. The function of determining whether or not the curl generated in the recording material is larger than a predetermined amount is that the recording material exists at one position in the stacking direction and is lower than the one position. 16. The program according to claim 15, wherein the curl is determined to be larger than a predetermined amount when the information indicating that the recording material does not exist at another position is obtained. The function of determining whether or not the curl generated in the recording material is larger than a predetermined amount is that when the recording material stacking unit is started to move downward in the stacking direction, a position in the stacking direction is determined. when the the recording material is no longer present in the case where the recording material at the other position located below the position of the one has obtained the information indicating that it does not, the curl 16. The program according to claim 15, wherein the program is determined to be larger than a predetermined amount . The function of determining whether or not the curl generated in the recording material is larger than a predetermined amount is that when a predetermined time elapses after the recording material stacking unit starts moving downward in the stacking direction , 16. The program according to claim 15, wherein the curl is determined to be larger than a predetermined amount when the information indicating that the recording material is present at the reference position or the upper position is acquired.

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