JP2009035371A - Sheet storage apparatus, post-processing apparatus using the same, and image forming apparatus - Google Patents

Abstract

Provided is a sheet storage device capable of simplifying a sensor mechanism for detecting a paper surface level when stacking and storing sheets, reducing the power consumption without causing the sheet to be bent. .
SOLUTION: A tray unit for stacking and storing sheets from a sheet discharge port, a sheet discharge unit disposed at the sheet discharge port for carrying out a sheet to the tray unit, and a paper surface level of an uppermost sheet on the tray unit are detected. Paper surface detecting means. The paper surface detection means includes a sensor lever, a detection sensor for detecting the position of the sensor lever, a paper surface detection position for engaging the sensor lever with the uppermost sheet on the tray means, and a retracted position retracted from the uppermost sheet. A paddle member having an elastic piece for pressing the uppermost sheet on the tray means, and a paddle drive means for rotating the paddle member. Place.
[Selection] Figure 2

Description

  The present invention relates to a post-processing apparatus such as a sheet storage apparatus and an image forming apparatus for stacking and storing sequentially conveyed sheets, and relates to an improvement of a stack mechanism for orderly storing sheets to be stacked and stored.

  In general, this type of sheet storage apparatus is widely known as an apparatus for stacking and storing sheets on which an image is formed by an image forming apparatus or the like on a tray from a sheet discharge port. Such a sheet storage device is attached to, for example, a sheet discharge port of the image forming apparatus, and stacks and stores sheets carried out from the image forming apparatus, or stores sheets from the image forming apparatus in a processing tray. After the post-processing, the sheet is widely used as a post-processing apparatus for storing the sheet.

  Conventionally, for example, Patent Document 1 includes a storage tray that stacks sheets from an image forming apparatus on a processing tray, performs post-processing such as punching and stapling, and stacks sheet bundles from the processing tray. After-treatment devices have been proposed. This document discloses a device in which a storage tray is provided on the downstream side of the processing tray, the storage tray is configured to be movable up and down in the stacking direction, and the tray is lowered according to the stacking amount of sheets. Japanese Patent Laid-Open No. 2004-228688 also widely discloses an apparatus for providing a storage tray fixed on the downstream side of the processing tray and stacking and storing sheets on the tray.

As described above, in the apparatus configuration of Patent Document 1 that raises and lowers the storage tray according to the sheet stacking amount, a paper surface level detection mechanism that detects the uppermost sheet on the tray is required. Although this paper level detection sensor is not disclosed in the publication, a structure in which a sensor lever that engages with the uppermost sheet on the tray is provided and the height position of the lever is detected by the sensor is generally employed. . Patent Document 2 discloses a sensor structure that engages with the uppermost sheet on the tray. Such a sensor for detecting the paper level on the storage tray waits at a position retracted from the sheet storage path (trajectory) when the sheet is carried in from the paper discharge outlet for tray use, and after the sheet is stored. The level detection is performed by engaging with the uppermost sheet.
Japanese Patent Laying-Open No. 2003-267622 (FIG. 2) JP 2006-248684 A (FIG. 2)

  As described above, the sheet level needs to be detected when sheets are stacked one by one or in a bundle on the storage tray. For example, in the apparatus configuration of Patent Document 1, the timing of lowering and retracting the storage tray is detected by this paper surface level sensor. In the apparatus structure of Patent Document 2, the sheet stored on the storage tray is detected. Fullness is detected by this paper level sensor.

  Conventionally, a sensor lever that engages (contacts) the paper level sensor with the uppermost sheet, and a position between the detection position where the sensor lever is engaged with the uppermost sheet on the tray and the retracted position retracted from the upper side of the tray. The structure that moves the position is adopted. In this case, when the sheet is unloaded, the sensor lever stands by at a position retracted from the unloading path, and is moved to a detection position where it comes into contact with the uppermost sheet after the sheet is stored.

  Therefore, the following problems occur in the conventional apparatus configuration. First, when the sensor lever moves from the standby position to the detection position, if the uppermost sheet on the tray curls and warps upward, the sensor lever frequently presses the curled edge of the sheet and causes a problem of bending the ears. To do. In other words, whenever the sheet is loaded, if the sensor lever is moved up and down, the curled sheet at the leading edge will be bent.

  Second, when a detection method is adopted in which the sensor lever is held at the detection position on the tray and the sheet detection on the tray is detected at the same time as full detection, the sensor lever is, for example, an electromagnetic solenoid. For example, it must be held at a detection position that engages with a sheet on the tray for a long time. For this reason, the energization time of an electromagnetic solenoid or the like becomes long, and power consumption becomes a problem.

  Therefore, the present inventor can solve the first and second problems by employing a mechanism that presses and holds the top sheet separately from the sensor lever that detects the paper level of the top sheet on the storage tray. I came up with the idea that I could do it.

In the present invention, when a sheet is stacked and stored on a storage tray, the sensor mechanism for detecting the paper surface level has a simple structure, and there is no risk of bending the sheet, and at the same time, the power consumption can be reduced. The main problem is to provide a sheet storage device.
Another object of the present invention is to provide a sheet storage device capable of detecting whether or not a stacked sheet is removed at the same time as the sheets stored on the storage tray are full.

  To achieve the above object, the present invention employs the following configuration. A sheet discharge port for carrying out a single sheet or a bundle of sheets; a tray unit for stacking and storing sheets from the sheet discharge port; a sheet discharge unit disposed at the sheet discharge port for carrying out a sheet to the tray unit; and the tray And a paper surface detecting means for detecting the paper surface level of the uppermost sheet on the means. The paper surface detection means includes a sensor lever, a detection sensor for detecting the position of the sensor lever, a paper surface detection position for engaging the sensor lever with the uppermost sheet on the tray means, and a retracted position retracted from the uppermost sheet. A paddle member having an elastic piece for pressing the uppermost sheet on the tray means, and a paddle drive means for rotating the paddle member. Place. The paddle driving means is configured to press the uppermost sheet on the tray means when the sensor lever is in the retracted position.

  The lever driving means includes an urging spring that urges the sensor lever toward the retracted position, and an electromagnetic solenoid that moves the sensor lever to a paper surface detection position against the urging spring, and drives the paddle The means controls rotation of the paddle member so as to press the uppermost sheet on the tray means in a state where the sensor lever is moved from the paper surface detection position to the retracted position.

  The paper surface detection means includes a determination means for determining whether a sheet stacked on the tray means is full based on a signal from the detection sensor that detects a sensor lever at a paper surface detection position, and the sensor driving means includes the determination means. The sensor lever is shifted to a standby position in response to a full detection signal from the paddle, and the paddle driving means rotationally drives the paddle member so as to press and support the uppermost sheet on the tray means in response to a full detection signal from the discrimination means. To do.

  A processing tray for aligning sheets conveyed from the image forming apparatus in a bundle, a post-processing unit for performing post-processing on the sheet bundle aligned on the processing tray, and an image disposed on the downstream side of the processing tray Tray means for stacking and storing sheets from the forming apparatus or sheet bundles post-processed by the post-processing means, paper discharge means for carrying out sheets on the processing tray to the tray means, and uppermost sheet on the tray means Paper surface detecting means for detecting the paper surface level of the paper, and the paper surface detecting means includes a sensor lever, a detection sensor for detecting the position of the sensor lever, and a paper surface for engaging the sensor lever with the uppermost sheet on the tray means. The lever driving means shifts between the detection position and the retracted position retracted from the uppermost sheet. A paddle member having an elastic piece for pressing the uppermost sheet on the tray means and a paddle driving means for rotating the paddle member are disposed at the paper discharge port. The paddle driving means is configured such that the sensor lever is retracted. When in position, the uppermost sheet on the tray means is configured to be pressed.

  The paddle member is composed of a rotating shaft and an elastic piece-capable paper touch piece supported by the rotating shaft, and the paddle driving means controls the rotation of the motor and a motor that rotates the rotating shaft. It consists of paddle control means. The paddle control means stops the rotation shaft at a position where the paper touch piece presses the uppermost sheet on the tray means when the sensor lever is shifted from the detection position to the retracted position.

  The lever driving means includes an urging spring that urges the sensor lever toward the retracted position, and an electromagnetic solenoid that moves the sensor lever to a paper surface detection position against the urging spring, and detects the paper surface. And means for determining whether a sheet stacked on the tray means is full based on a signal from the detection sensor for detecting the sensor lever; and a control means for controlling the electromagnetic solenoid according to a determination result of the determination means. Is provided. When the determining means detects that the sheet is full, the control means shifts the sensor lever from the detection position to the retracted position, and at the same time, the paddle control means is a position where the paper touch piece presses the uppermost sheet on the tray means. To stop the rotating shaft.

  The image forming apparatus includes an image forming apparatus that sequentially forms an image on a sheet, and a post-processing apparatus that performs post-processing on the sheet from the image forming apparatus. The post-processing apparatus has the above-described configuration.

The present invention provides a sensor lever that moves between a detection position on the tray means and a retracted position, and a paddle member that presses the uppermost sheet disposed at the paper discharge port, and the paddle member is at the uppermost position when the sensor lever is at the retracted position. Since it is configured to press the sheet, the following effects can be obtained.
After the sensor lever detects the paper level of the uppermost sheet at the paper surface detection position, it can quickly move and stand by to the retracted position. At this time, since the uppermost sheet is pressed and held by the paddle member, the uppermost sheet curls. Does not warp upward. Thus, when the sensor lever is moved from the retracted position to the paper surface detection position, the curled sheet is not folded in a folded shape.

  Therefore, the sensor lever can be moved up and down between the standby position and the paper surface detection position according to the timing of detecting the paper surface, and when the sheet is full on the tray as in the past, this removal of the sheet is detected. It is not necessary to hold the sensor lever at the paper surface detection position for a long time in order to (residual detection). Thereby, for example, even with a mechanism that detects the paper surface by sucking the sensor lever with an electromagnetic solenoid or the like, the power consumption of the electromagnetic solenoid can be significantly reduced.

  As described above, according to the present invention, when the paper surface level of the uppermost sheet on the tray is detected by the sensor lever, the sensor lever is held at the standby position by an urging means such as a spring, and when detecting the paper surface, an electromagnetic solenoid or the like is used. It is possible to adopt a relatively simple detection structure that moves to the paper surface detection position. Even with such a simple detection structure, after the sensor lever is retracted from the paper surface, the paddle member presses the uppermost sheet, so that the sheets on the tray are held orderly without scattering. At the same time, when the sensor lever is moved from the retracted position to the paper surface detection position, the uppermost sheet is pressed and held by the paddle member, so that the sheet is not folded in a folded shape.

  Hereinafter, the present invention will be described in detail based on illustrated embodiments. FIG. 1 is an entire explanatory view of a post-processing apparatus having a sheet storage apparatus according to the present invention and an image forming apparatus for carrying out sheets to the post-processing apparatus, and FIG. 2 is a main part of the post-processing apparatus. FIG. Hereinafter, “image forming system” and “post-processing apparatus” will be described in this order.

[Image forming system]
The image forming system shown in FIG. 1 includes an image forming apparatus A and a post-processing apparatus B, and a sheet storage apparatus C is incorporated in the post-processing apparatus B. The image forming apparatus A includes a paper feed stacker 1, an image forming unit 2 that forms an image on a sheet from the paper feed stacker 1, a scanner unit 3, and a document feeding unit 4. The image forming unit 2 includes an electrostatic printing mechanism, an ink jet printing mechanism, an offset printing mechanism, and the like, and is configured to copy and print image data optically read by the scanner unit 3 on a sheet from the paper feed stacker 1. . The illustrated one shows an electrostatic printing mechanism, and a developing device 5 a, a charger 5 b, and a print head 6 are arranged around the photosensitive drum 5. Then, an electrostatic latent image is formed on the photosensitive drum 5 by the print head 6, toner ink is attached by the developing unit 5 a, and transfer printing is performed on the sheet by the charger 5 b. The sheet onto which the toner ink has been transferred is fixed by the fixing device 7 and is sequentially carried out from the paper discharge port 8. In FIG. 9, a circulation path is a circulation path for duplex printing in which a sheet printed on the front surface is fed again to the photosensitive drum 5 and an image is formed on the back surface of the sheet.

  The scanner unit 3 includes a platen 3a for placing a document, a reading carriage 3b for scanning a document image in line order along the platen 3a, and a photoelectric conversion element 3c. The document feeding unit 4 is mounted above the scanner unit 3 and separates the documents placed and set on the document tray 4a one by one, feeds them to the platen 3a, and stores them on the paper discharge tray 4b. In addition, the print head 6 is provided with a network printer function for transferring image data from an external image forming apparatus such as a computer and forming an image on a sheet based on the data.

[Post-processing equipment]
The post-processing apparatus B according to the present invention is connected to the paper discharge port 8 of the image forming apparatus A described above, and sequentially receives the sheets on which the images have been formed, and performs “bookbinding binding processing”, “jogging processing”, and “sheet carrying out (storage) processing”. I do. Accordingly, the image forming system includes an image forming apparatus main body having a copying machine, a printing function, a facsimile function, and the like, and a post-processing apparatus connected thereto. Then, the post-processing apparatus B processes a series of post-processing operations such as a paper binding process for aligning and binding sheets after image formation in the page order, or a jog process for sorting and storing the sheets after they are aligned when the sheets are discharged and stored. It is provided as an operation mode. In the control of each operation mode, the operator sets the post-processing mode such as “paper binding processing”, “jog processing”, “sheet carry-out (storage) processing” at the same time as the printing mode such as the number of copies and the printing function in the image forming apparatus A. In accordance with the command signal from the image forming apparatus A, the post-processing apparatus B executes processing corresponding to each operation mode.

  Therefore, the post-processing apparatus B receives the sheets sequentially discharged from the image forming apparatus A and discharges them to the downstream side, and a discharge port of the discharge path 11 (discharge of the post-processing apparatus B). The processing tray 20 disposed below the mouth 13 and a storage tray (sheet storage device; hereinafter the same) 30 disposed on the downstream side of the processing tray 20 are configured. The processing tray 20 incorporates the following sheet alignment mechanism. The paper discharge path 11 is provided with a transport roller 14 for transporting the sheet sent toward the carry-in entrance 12, and the transport roller 14 is composed of a pair of rollers in pressure contact with each other. The paper discharge path 11 is provided with an inlet sensor S1 for detecting the leading edge and the trailing edge of the conveyed sheet.

  The paper discharge path 11 is branched into a first paper discharge path 11a and a second paper discharge path 11b, and a processing tray 20, which will be described later, is disposed on the downstream side in the first paper discharge path 11a. A first storage tray 30a is disposed downstream of the processing tray 20, and a second storage tray 30b is disposed in the second paper discharge path 11b.

  That is, the sheet from the image forming apparatus A is guided to the carry-in path 11 by the transport roller 14 and is selectively sent to the first paper discharge path 11a and the second paper discharge path 11b via the path switching piece 15. A processing tray 20 is disposed downstream of a discharge outlet (hereinafter referred to as “first discharge outlet”) 13a of the first discharge path 11a, and a discharge outlet (hereinafter referred to as “second discharge outlet”) of the second discharge path 11b. A second storage tray 30b is disposed at 13b). Accordingly, it is selected whether the sheet from the image forming apparatus A is guided to the processing tray 20 side via the path switching piece 15 of the paper discharge path 11 or to the second storage tray 30b. The sheets guided to the processing tray 20 are, for example, arranged in a bundle and subjected to post-processing such as stapling and stored in a first storage tray 30a prepared on the downstream side thereof. On the other hand, the sheets guided toward the second storage tray 30b are accumulated on the second storage tray 30b.

[Processing tray configuration]
A processing tray 20 is disposed with a step formed below the first paper discharge outlet 13a, and the sheet is temporarily placed and supported. In this state, the sheet is post-processed. The processing tray 20 incorporates a mechanism corresponding to a post-processing function to be applied to the sheet. In the illustrated one, the “bookbinding binding function” and the “jog function” and the sheet from the first paper discharge outlet 13a are arranged on the downstream side. A “sheet carry-out function” for carrying out to one storage tray 30a is provided.

  The “binding binding function” stacks a series of sheets carried out from the image forming apparatus A on the processing tray 20 in the order of pages and staples them, and carries out the processed sheet bundle to the first storage tray 30a for storage. The “jog function” sorts and stores a series of sheets carried out from the image forming apparatus A in the first storage tray 30a. Therefore, the processing tray 20 is provided with a jog shift mechanism that shifts the sheet by a predetermined amount in a direction orthogonal to the conveyance direction. In the illustrated jog shift mechanism, the width adjusting and matching means (not shown) has the function. Further, forward / reverse roller means 26 is disposed on the processing tray 20.

  The processing tray 20 is provided with a stapling means (post-processing means; shown in FIG. 2) 24, a sheet end regulating member 20a and a side regulating member 21 for positioning and aligning the sheet at the post-processing position. The sheet end regulating member 20a is formed to protrude upward from the processing tray 20 so as to abut and regulate the front end or the rear end of the sheet conveying direction, and similarly, the side regulating member 21 has a sheet side edge orthogonal to the sheet conveying direction. It protrudes upward from the processing tray 20 so as to restrict the butting.

  The processing tray 20 includes a belt transfer unit 17 that guides a sheet from the first discharge port 13a onto the tray, and a sheet that has been loaded onto the processing tray 20 is loaded downstream, and is then switched back to the upstream side. Reversing roller means 26, sheet feeding and conveying means for transferring the sheet on the processing tray 20 toward the sheet end regulating member 20a (the one shown in the figure is also used as the belt transferring means 17), and the processing tray 20 A width alignment means (not shown) for transferring the sheet toward the side regulating member 21 is disposed.

  First, as shown in FIG. 2, the belt transfer means (paper feeding / conveying means; the same applies below) 17 is constructed by bridging a caterpillar belt 18 between a pair of pulleys 16 a and 16 b. Are arranged along the sheet conveying direction.

  A pinch roller 29 is disposed at the paper discharge port of the processing tray 20. 31 shown in the figure is a paddle for scraping the sheet, and is composed of a flexible blade member. Further, forward / reverse roller means 26 is disposed on the processing tray 20, and a sheet conveyed onto the processing tray 20 is fed downstream to a space between a first storage tray 30 a and the processing tray 20 described later. Support the bridge with. That is, the sheet from the sheet discharge outlet 13 a is supported at the leading end side by the first storage tray 30 a and at the trailing end side by the processing tray 20. Therefore, the forward / reverse roller means 26 is supported so as to be swingable up and down with respect to the processing tray 20, and is connected to a drive motor so as to rotate in both forward and reverse directions.

  The processing tray 20 thus configured is provided with post-processing means, and the illustrated one shows a stapling device 24. Then, the sheet from the paper discharge port 13a is carried onto the processing tray 20 by the belt transfer means 17 and the forward / reverse roller means 26 described above, and after the trailing edge of the sheet enters the processing tray 20, the forward / reverse roller means 26 reverses. When the sheet is switched back, the sheet enters the lower belt half of the belt transfer means 17. After that, the sheet is controlled by the belt transfer means 17 with the rear end being abutted against the sheet end regulating member 20a.

  Further, in order to transfer the post-processed sheet to the first storage tray 30a on the downstream side, a sheet pushing means 25 (paper discharge means; the same applies hereinafter) is arranged on the processing tray 20 as follows. A guide groove (not shown) through which the pushing claw 25a moves is provided at the center of the processing tray 20 in the sheet width direction, and the pushing claw 25a moves the sheet positioned on the downstream sheet end regulating member 20a along the guide groove. It is transferred to a paper discharge port 13c (hereinafter referred to as “third paper discharge port”). For this reason, a belt member 48 is bridged between a pair of pulleys 46, 47 provided on the back side of the processing tray 20, and an extrusion claw 25 a is integrally fixed to the belt member 48. The pulley 46 is connected to a sheet pushing claw drive motor M5. Accordingly, the pushing claw 25a is wound around the processing tray 20 by the sheet pushing claw drive motor M5. Similar to the push-out pawl 25a, the third paper discharge port 13c is provided with the forward / reverse roller means 26 having the above-described structure.

[Sheet storage device]
The following sheet storage device D is disposed on the downstream side of the processing tray 20 described above. As shown in FIG. 2, the first storage tray 30a is disposed with a step formed at the third paper discharge outlet 13c. As shown in FIG. 2, the first storage tray 30a is composed of a tray member attached to the apparatus frame, and stacks and stores sheets from the third paper discharge port 13c. A sensor lever 19 is disposed above the first storage tray 30a. The sensor lever 19 determines whether or not the number of sheets stacked on the first storage tray 30a has reached an allowable maximum amount, and whether or not sheets are stacked on the tray. Is configured to detect.

  Therefore, as shown in FIG. 3, the sensor lever 19 is rotatably supported on the apparatus frame by a support shaft 19a, and a paper touch piece 19b is provided at the distal end portion and a flag 19c is provided at the proximal end portion. The paper touch piece 19b swings around the support shaft 19a so as to be in contact with the uppermost sheet on the first storage tray 30a, and the flag 19c is configured to detect its position with a photosensor. The sensor lever 19 is urged by the urging spring 19S so as to be always in the retracted position, and is connected to the electromagnetic solenoid 19M so as to move to the detection position against the spring.

  The flag 19c of the sensor lever 19 performs "sheet full detection", "sheet empty detection", and "lever standby position detection" at the position when the paper touch piece 19b moves to follow the sheet on the tray. A first flag fr1 and a second flag fr2 are provided. As for the “sensors” for detecting both the flags fr1 and fr2, the first sensor Sa and the second sensor Sb are respectively arranged at the positions shown in FIG.

  Therefore, the positional relationship between the first and second flags fr1 and fr2 and the first and second sensors Sa and Sb is (Sa = ON) when the paper touch piece 19b is at the full detection position (state shown in FIG. 6F). & (Sb = ON), and when the paper touch piece 19b is at the sheet empty detection position on the first storage tray 30a (the state shown in FIG. 4A), (Sa = OFF) & (Sb = OFF) When the touch piece 19b detects a paper surface other than these (state of FIG. 5C), (Sa = ON) & (Sb = OFF), and the paper touch piece 19b is in the retracted position (state of FIG. 5D). Is set so that (Sa = OFF) & (Sb = ON).

  On the other hand, a paddle member 31 is disposed at the third paper discharge port 13c for carrying out the sheet to the first storage tray 30a. The paddle member 31 is composed of an elastic piece 31a that presses the uppermost sheet on the first storage tray means 30a, and is rotatably attached to the rotating shaft 31b. The rotating shaft 31b is connected to paddle driving means 31M (not shown) such as a motor, and is rotated counterclockwise in FIG. A home position sensor (not shown) is disposed on the rotating shaft 31b, and the paddle driving means 31M (not shown) is controlled to rotate in accordance with a detection signal of this sensor.

[Paper detection control]
Therefore, the present invention is characterized in that the electromagnetic solenoid 19M and the paddle driving means 31M of the sensor lever 19 are controlled as follows. First, these control means are constituted by a control CPU (not shown) of the post-processing apparatus B. The control will be described with reference to the operation state diagrams shown in FIGS.

  First, the control CPU (not shown) of the above-described post-processing device energizes the electromagnetic solenoid 19M “when the device is turned on” or “when the device is restarted after being stopped”. That is, the control CPU performs an initial operation when the apparatus is started and when the apparatus is restarted after an abnormality such as a jam occurs. In this initial operation, it is determined by a signal from each sheet sensor whether a sheet is accumulated in the apparatus, and the apparatus is reset to an initial state. At this time, the control CPU energizes the electromagnetic solenoid M19 to shift the sensor lever 19 to the position in contact with the sheet on the first storage tray 30a in the state of FIG.

  When both the first and second sensors Sa and Sb are “OFF” in this initial operation, it is determined that there is no sheet on the tray (empty). Accordingly, when the first and second sensors Sa and Sb are not “OFF” at the time of starting the apparatus, a warning is issued to remove the sheet on the tray. When the apparatus is restarted, the post-processing operation is resumed even if a sheet exists on the tray.

  Energization of the electromagnetic solenoid 19M during the initial operation is performed for a preset detection time (for example, 5 mmS). Therefore, when the control CPU cuts off the power to the electromagnetic solenoid 19M, the sensor lever 19 returns to the retracted position retracted from the sheet on the tray in the state of FIG. Therefore, the control CPU permits the sheet to be unloaded from the processing tray. In addition, although carrying out of this sheet | seat shows the case where one single sheet is carried out, it is the same also when carrying out a bundle-like sheet | seat. Therefore, the control CPU accumulates sheets from the image forming apparatus A on the processing tray 20 and performs post-processing. The post-processed sheet (bundle) is carried out to the third paper discharge port 13c by the pushing claw 25a. At this time, the forward / reverse roller 26 is retracted above the tray.

  Therefore, the control CPU drives the paddle driving means 31M in the state of FIG. 5C and pushes the rear end of the sheet toward the first storage tray 30a side by the elastic piece 31a of the paddle member 31. At this time, the sensor lever 19 stands by at the retracted position. Next, the control CPU energizes the electromagnetic solenoid 19M after the expected time that the sheet is carried out onto the first storage tray 30a. Then, the sensor lever 19 moves to a detection position where the paper touch piece 19b comes into contact with the uppermost sheet on the tray as shown in FIG. Then, the control CPU energizes the electromagnetic solenoid 19M for a predetermined time set in advance. During or immediately after this energization time, the control CPU rotates the paddle driving means 31M and stops the paddle driving means in the state shown in FIG. 6E in which the elastic piece 31a presses the uppermost sheet on the tray. Then, the elastic piece 31a presses and holds the uppermost sheet on the tray as shown in FIG.

  Thus, the present invention controls the sensor lever 19 and the paddle member 31. This control will be described with reference to the timing chart shown in FIG. 6. The control CPU energizes the electromagnetic solenoid 19M at “when the apparatus power is turned on”, “when the apparatus is restarted after stopping the apparatus”, and “when the sheet is loaded onto the tray”. Energization is cut off after a predetermined time. Then, the sensor lever 19 moves from the retracted position to the detection position. The control CPU determines “sheet full” or “sheet removal (empty)” based on the state signals of the sensors Sa and Sb at this time. At the same time, the control CPU drives the paddle driving means 31M to control the uppermost sheet on the tray with the elastic piece 31a of the paddle member 31 when the sensor lever 19 is in the retracted position.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall explanatory diagram of an image forming system including a post-processing apparatus having a sheet storage device according to the present invention and an image forming apparatus for carrying out a sheet to the post-processing apparatus. The principal part expansion explanatory drawing of the post-processing apparatus in the apparatus of FIG. FIG. 3 is an explanatory diagram of a sheet detection mechanism on a storage tray in the apparatus of FIG. 2. FIGS. 4A and 4B are operation state explanatory diagrams of the sheet detection mechanism of FIG. 3, in which FIG. 3A illustrates an operation state when the apparatus is activated, and FIG. FIGS. 4A and 4B are operation state explanatory diagrams of the sheet detection mechanism of FIG. 3, in which FIG. 3C shows a state where a sheet is carried out on the tray, and FIG. 3D shows a state where a paper surface level of the sheet carried out on the tray is detected. . FIGS. 4A and 4B are operation state explanatory diagrams of the sheet detection mechanism of FIG. 3, in which FIG. 3E shows a state after detecting the paper surface level of the sheet on the tray, and FIG. FIG. 4 is a timing chart showing control of a sensor lever and a paddle member in the sheet detection mechanism of FIG. 3.

Explanation of symbols

A Image forming apparatus B Post-processing apparatus C Sheet alignment mechanism D Sheet storage apparatus 8 Paper discharge port (image forming apparatus)
11 Paper discharge path 11a First paper discharge path 11b Second paper discharge path 13 Paper discharge port (post-processing device)
13a First paper discharge port 13b Second paper discharge port 13c Third paper discharge port 14 Conveying rollers 16a, 16b Pulley 17 Belt transfer means (paper feed conveying means)
18 Caterpillar belt 19 Sensor lever 19a Support shaft 19b Paper contact piece 19c Flag 19M Electromagnetic solenoid 19S Energizing solenoid 20 Processing tray 20a Sheet end regulating member 21 Side regulating member 24 Staple means (post-processing means)
25 Sheet extrusion means (paper discharge means)
25a Extrusion claw 26 Forward / reverse roller means 29 Pinch roller 30 Storage tray (sheet storage device)
30a First storage tray 30b Second storage tray 31 Paddle member 31a Elastic piece 31b Rotating shaft 31M Paddle drive means 46, 47 Pulley M5 Sheet pushing claw drive motor fr1 First flag fr2 Second flag Sa First sensor Sb Second sensor

Claims (7)

A paper discharge port for carrying out a single sheet or a bundle of sheets;
Tray means for stacking and storing sheets from the discharge port;
A paper discharge means disposed at the paper discharge port for carrying out the sheet to the tray means;
A paper surface detecting means for detecting a paper surface level of the uppermost sheet on the tray means;
With
The paper surface detecting means is
A sensor lever;
A detection sensor for detecting the position of the sensor lever;
Lever driving means for shifting between a paper surface detection position where the sensor lever engages with the uppermost sheet on the tray means and a retracted position retracted from the uppermost sheet;
Consists of
In the paper outlet,
A paddle member having an elastic piece for pressing the uppermost sheet on the tray means;
Paddle drive means for rotating the paddle member;
Is placed,
The sheet storage device, wherein the paddle driving means is configured to press the uppermost sheet on the tray means when the sensor lever is in the retracted position. The lever driving means is
A biasing spring that biases the sensor lever toward the retracted position;
An electromagnetic solenoid that moves the sensor lever to a paper surface detection position against the biasing spring;
Consists of
The paddle driving means controls the rotation of the paddle member so as to press the uppermost sheet on the tray means in a state where the sensor lever is moved from the paper surface detection position to the retracted position. Sheet storage device. The paper surface detection means includes
A discriminating means for discriminating whether the sheets stacked on the tray means are full based on a signal from the detection sensor for detecting a sensor lever at a paper surface detection position;
The sensor driving means shifts the sensor lever to a standby position by a full detection signal from the discrimination means,
3. The sheet storage according to claim 1, wherein the paddle driving unit rotationally drives the paddle member so as to press and support the uppermost sheet on the tray unit by a full detection signal from the determination unit. apparatus. A processing tray for aligning sheets conveyed from the image forming apparatus in a bundle;
Post-processing means for performing post-processing on the sheet bundle aligned on the processing tray;
Tray means for stacking and storing sheets from the image forming apparatus disposed on the downstream side of the processing tray or a sheet bundle post-processed by the post-processing means;
A paper discharge means for carrying out the sheet on the processing tray to the tray means;
A paper surface detecting means for detecting a paper surface level of the uppermost sheet on the tray means;
With
The paper surface detecting means is
A sensor lever;
A detection sensor for detecting the position of the sensor lever;
Lever driving means for shifting between a paper surface detection position where the sensor lever engages with the uppermost sheet on the tray means and a retracted position retracted from the uppermost sheet;
Consists of
A paddle member having an elastic piece for pressing the uppermost sheet on the tray means and a paddle driving means for rotating the paddle member are disposed at the discharge port,
The paddle driving means is configured to press the uppermost sheet on the tray means when the sensor lever is in the retracted position. The paddle member is
A rotation axis;
An elastic piece-capable paper touch piece supported by the rotating shaft;
Consists of
The paddle driving means includes
A motor that rotationally drives the rotating shaft;
Paddle control means for controlling rotation of the motor;
Consists of
When the sensor lever is shifted from the detection position to the retracted position,
The post-processing apparatus according to claim 4, wherein the rotation shaft is stopped at a position where the paper touch piece presses the uppermost sheet on the tray means. The lever driving means is
A biasing spring that biases the sensor lever toward the retracted position;
An electromagnetic solenoid that moves the sensor lever to a paper surface detection position against the biasing spring;
Consists of
The paper surface detection means includes
Discriminating means for discriminating whether the sheets stacked on the tray means are full by a signal from the detection sensor for detecting the sensor lever;
Control means for controlling the electromagnetic solenoid according to the discrimination result of the discrimination means;
With
When the discrimination means detects that the sheet is full,
The control means shifts the sensor lever from the detection position to the retracted position,
The paddle control means stops the rotating shaft at a position where the paper touch piece presses the uppermost sheet on the tray means,
The post-processing apparatus according to claim 5. An image forming apparatus having image forming means for sequentially forming images on sheets;
A post-processing apparatus that performs post-processing on the sheet from the image forming apparatus;
Consisting of
An image forming apparatus comprising the post-processing apparatus having the configuration according to claim 5 or 6.

Images