JP2007223701A - Sheet processing device, and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent sheets from being damaged by setting contact pressure of an upper carrying roller to the sheet constant even when loaded height of sheets loaded on a processing tray is varied. <P>SOLUTION: In a finisher, the uppermost sheet is moved to a stapler by the upper carrying roller 127a which gets in contact with an upper surface of the uppermost sheet loaded on the processing tray 129 where a bundle of sheets to be processed by the stapler is loaded. A flag 301 and a sensor 302 are provided to detect the height position of the uppermost sheet. In addition, a slide arm 160 and a bracket 152 are provided to adjust the height position of the upper carrying roller in accordance with the height position of the uppermost sheet detected by the flag and the sensor so as to set the contact pressure of the upper carrying roller to the uppermost sheet constant. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sheet processing apparatus that processes a sheet, and an image forming apparatus including the sheet processing apparatus.

  In recent years, an image forming apparatus such as an electrophotographic copying machine, a laser beam printer, a facsimile machine, and a multifunction machine of these may have a sheet processing apparatus as an option on the side of the apparatus body. The sheet processing apparatus is configured to perform at least one process such as a sorter process for sorting sheets with images formed thereon, a binding process for binding a sheet bundle with a stapler, and an alignment process for aligning sheet bundles.

  For example, a sheet processing apparatus that performs a binding process stacks sheets conveyed into the apparatus main body of the sheet processing apparatus on a processing tray as a sheet bundle stacking unit, and uses a stapler for one or a plurality of positions (usually 2 ). As such a sheet processing apparatus, there is one described in Patent Document 1.

  This sheet processing apparatus has a function of discharging a sheet formed with an image from the apparatus main body of the image forming apparatus as it is by an upper conveying roller and a lower conveying roller, and reverses the upper conveying roller to a processing tray. It is equipped with a function to load the paper in the reverse direction, bind it with a stapler, and discharge it.

JP-A-2005-75481

  However, in the conventional sheet processing apparatus, as the stacking height of the sheets stacked on the processing tray increases, the contact pressure that comes into contact with the transport upper roller increases.

  For this reason, when the conventional sheet processing apparatus reversely feeds the succeeding sheet on the preceding sheet stacked on the processing tray, the sheets are rubbed with each other as the sheet stacking height increases, There was a risk of scratching. In addition, there is a possibility that an image formed on the sheet may be scratched or may be reflected on a sheet of a partner with which the image is in contact.

  In addition, an image forming apparatus provided with a conventional sheet processing apparatus cannot provide a sheet on which a high-quality image is formed.

  The present invention provides a sheet processing apparatus that keeps the contact pressure of a conveyance upper roller with respect to a sheet constant and avoids scratching the sheet even if the stack height of the sheet stacked on the processing tray changes. It is in.

  An object of the present invention is to provide an image forming apparatus that includes a sheet processing apparatus that avoids scratching a sheet and can provide a sheet on which a high-quality image is formed.

  The sheet processing apparatus of the present invention includes the uppermost rotating body that rotates in contact with the upper surface of the uppermost sheet stacked on the sheet bundle stacking unit on which the sheet bundle processed by the sheet processing unit is stacked. A sheet is moved to a sheet processing means, and a detection means for detecting a height position of the uppermost sheet and a height of the uppermost sheet detected by the detection means according to the position And adjusting means for adjusting the height position of the upper rotating body to make the contact pressure of the upper rotating body constant with respect to the uppermost sheet.

  The sheet processing apparatus of the present invention includes an upper rotating body and a lower rotating body that sandwich the conveyed sheet and rotate in the first direction and convey the sheet as it is to a sheet stacking unit, and the conveyed sheet A sheet bundle stacking means that is sandwiched between the upper rotating body and the lower rotating body and is fed back and stacked in a bundle by rotating the upper rotating body in the second direction, and the sheet bundle stacking means Sheet processing means for processing the sheet bundle, and the upper rotating body and the lower rotating body sandwich the sheet bundle processed by the sheet processing means with a predetermined discharge clamping pressure. The sheet bundle stacking means discharges the sheet stacking means to the sheet stacking means, and the height position of the uppermost sheet stacked on the sheet bundle stacking means is detected. And when the upper rotating body rotates in the second direction and reversely feeds the sheet, the height of the uppermost sheet detected by the detecting means depends on the position according to the position. And adjusting means for adjusting the height position of the upper rotating body to make the contact pressure of the upper rotating body with respect to the uppermost sheet constant.

  An image forming apparatus of the present invention includes: an image forming unit that forms an image on a sheet; and a sheet processing device that processes a sheet on which an image has been formed by the image forming unit. One of the features is that it is one of the sheet processing apparatuses.

  Since the sheet processing apparatus of the present invention adjusts the height position of the upper rotating body according to the height of the uppermost sheet, the contact pressure of the upper rotating body with respect to the sheet bundle is made constant. It is possible to avoid scratching the sheet. In addition, when an image is formed on a sheet, it is possible to avoid scratching the image or appearing on a counterpart sheet in contact with the image.

  The image forming apparatus of the present invention includes a sheet processing apparatus that avoids scratching the sheet, and can provide a sheet on which a high-quality image is formed.

  A sheet discharge apparatus and an image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings.

  It should be noted that the dimensions, numerical values, materials, shapes, relative arrangements, and the like of the components described in the present embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. .

(Image forming device)
The image forming apparatus of the present embodiment is, for example, a copying machine that employs an electrophotographic method as a recording method. In the image forming apparatus, there are an electrophotographic method, an inkjet method, and the like as a recording method. Specifically, there are a copying machine, a facsimile, a printer, and a complex machine of these. Therefore, the image forming apparatus of the present invention is not limited to a copying machine.

  FIG. 1 is a cross-sectional view of, for example, a copying machine which is an image forming apparatus of the present invention along the sheet conveying direction.

  The copying machine 100 includes an apparatus main body 101 and a finisher 119. On the upper part of the apparatus main body 101, a document conveying apparatus 102 is provided. The document feeder 102 is not always necessary.

  The document D is placed on the document placing unit 103 by the user, sequentially separated one by one by the feeding unit 104, and supplied to the registration roller pair 105. Subsequently, the document D is temporarily stopped by the registration roller pair 105, a loop is formed, and skew is corrected. Thereafter, the document D passes through the introduction path 106 and passes through the reading position 107, whereby the image formed on the surface of the document is read. The document D that has passed the reading position 107 passes through the discharge path 108 and is discharged onto the discharge tray 109.

  When reading both the front and back sides of a document, first, the document D passes through the reading position 107 as described above, whereby one image surface of the document is read. Thereafter, the document D passes through the discharge path 108, is switched back by the reverse roller pair 110, and is sent again to the registration roller pair 105 in a state where the front and back are reversed. Then, in the same manner as when the image of one side is read, the skew of the original D is corrected by the registration roller pair 105, passes through the introduction path 106, and the other image side is read at the reading position 107. Thereafter, the document D passes through the discharge path 108 and is discharged to the discharge tray 109.

  The document passing through the reading position 108 is irradiated with light from the illumination system 111. The reflected light reflected from the original is guided to the optical element 113 (CCD or other element) by the mirror 112 and converted into image data. Then, by irradiating the photosensitive drum 114 with laser light based on the image data, a latent image is formed on, for example, the photosensitive drum 114 as image forming means. The latent image formed on the photosensitive drum 114 is developed with toner supplied from a toner supply device (not shown) to become a toner image.

  In addition, a sheet P such as paper or plastic film stacked on the cassette 115 in accordance with the toner image forming operation is sent out from the cassette 115 according to a recording signal, and between the photosensitive drum 114 and the transfer device 116. enter in. If the sheet is skewed before entering between the photosensitive drum 114 and the transfer device 116, the sheet is straightened by the registration roller pair 150.

  Then, the toner image on the photosensitive drum 114 is transferred to the sheet by the transfer device 116. The sheet on which the toner image has been transferred is heated and pressed while passing through the fixing device 117, and the toner image is fixed.

  When images are formed on both sides of the sheet, the sheet on which the toner image is fixed on one side by the fixing unit 117 is switched back and conveyed on the way through the double-sided path 118 provided on the downstream side of the fixing unit 117. Are reversed. The sheet is fed between the photosensitive drum 114 and the transfer device 116, and the toner image is also transferred to the back surface. Thereafter, the toner image on the back surface of the sheet is fixed by the fixing device 117, and the sheet is sent to the finisher 119.

  FIG. 2 is a control block diagram of the entire copying machine. The entire copying machine 100 is controlled by a CPU circuit 201. In the CPU circuit 201, there are provided a ROM 202 that stores a sequence of each unit, that is, a control procedure, and a RAM 203 that temporarily stores various information as necessary.

  The document conveying device control unit 204 controls the document feeding operation of the document conveying device 102. The image reader control unit 205 controls the illumination system 111 and the like to control reading of a document. The image signal control unit 206 receives the reading information of the image reader control unit 205 or the image information sent from the external computer 207 via the external I / F 208, processes the information, and processes the printer unit control unit. A processing signal is sent to 209. The printer control unit 209 controls the apparatus main body 101 having the photosensitive drum 114 and the like based on an image processing signal from the image signal control unit 206 to form an image on a sheet. The operation unit 210 includes an operation panel (not shown) that operates the copying machine 100 and a display panel (not shown) that displays an operation state of the copying machine 100.

  The finisher control unit 211 controls the finisher 119. The fax control unit 212 sends and receives an external fuck and a fax signal to cause the copying machine 100 to perform a fuck operation.

  Note that the CPU circuit 201 and the finisher control unit 211 may be integrated by incorporating one of them into the other.

(Sheet processing equipment)
For example, a finisher that is a sheet processing apparatus according to this embodiment will be described. FIG. 3 is a cross-sectional view of the finisher in the embodiment of the present invention along the sheet conveying direction.

  The case where the finisher 119 is an optional device configured to be detachable from the apparatus main body 101 of the copying machine 100 as an independent apparatus will be described as an example. However, it is needless to say that the finisher 119 is applied to a case where the finisher 119 is provided integrally with the apparatus main body 101 of the copying machine 100, and the description thereof is omitted.

  The finisher 119 has a function of binding a sheet bundle. The finisher 119 includes, for example, a stapler 132 that is a sheet processing unit that binds near the edge of the sheet bundle, a stapler 138 that binds the center of the sheet bundle, a folding unit 139, and the like. The folding unit 139 is configured to bend the sheet bundle at the binding position of the sheet bundle bound by the stapler 138 to form a sheet bundle.

  The finisher 119 uses the stapler 132 to create the sheet bundle, but the finisher 119 is not limited to this. For example, a glue binding mechanism may be used. Moreover, you may provide a punching device instead of a stapler. Accordingly, the sheet processing means is not limited to the stapler.

  The finisher 119 receives a sheet on which an image is formed by the apparatus main body 101 of the copying machine 100 and is discharged from a discharge guide (not shown) by a pair of reception rollers 137, and conveys the sheet to the buffer unit 140 through the flapper 122.

  The buffer unit 140 accumulates (buffers) a plurality of sheets in a straight state when the stapler 132 is operated. Since the buffer unit 140 is configured to store a plurality of sheets in a straight state, the buffer unit 140 is flattened unlike a conventional mechanism including a buffer roller that stores sheets by winding the sheets. Is formed. For this reason, the finisher 119 can be reduced in size and weight. Further, since the buffer unit 140 can store the sheets in a straight state, unlike the buffer roller, the sheets are not rounded and the sheets can be handled easily. Accordingly, the processing time of the sheet as the finisher can be shortened.

(Explanation for binding and discharging sheet bundles)
When the user selects the sheet binding process display of the operation unit 210 (see FIG. 2) of the copying machine 100, the CPU circuit 201 controls each unit of the apparatus body 101 of the copying machine 100 to control the apparatus body of the copying machine 100. 101 is moved to a copying operation, and a sheet binding processing signal is sent to the finisher control unit 211.

  The finisher control unit 211 starts the entrance conveyance motor M2 (see FIG. 4) and the bundling motor M3 based on the sheet binding processing signal. Further, the finisher controller 211 operates the buffer roller separation plunger SL1 (see FIG. 4) to separate the buffer roller 124 from the lower conveyance guide plate 123b. Further, the buffer roller separation plunger SL1 operates a swing roller mechanism described later to separate the transport upper roller 127a of the swing roller pair 127 from the transport lower roller 127b. Note that the start and stop of the inlet conveyance motor M2 and the bundling motor M3 may be controlled one by one in accordance with the movement of the sheet.

  The first sheet sent from the discharge roller pair 120 of the apparatus main body 101 of the copying machine 100 (see FIG. 1) is conveyed by the receiving roller pair 137 and guided by the flapper 122 shown in FIGS. It is conveyed to the inlet roller pair 121. The receiving roller pair 137 is rotated by a common transport motor M1 that rotates the discharge roller pair 120.

  As shown in FIG. 5A, the inlet roller pair 121 is rotated by an inlet conveyance motor M2 (see FIG. 4) to convey the first sheet P1. The sheet P1 is conveyed to the discharge roller pair 126 by the guide 123 formed by the upper conveyance guide plate 123a and the lower conveyance guide plate 123b.

  As shown in FIG. 5B, the sheet P1 is further conveyed by the rotation of the discharge roller pair 126 (rotation in the first direction, normal rotation), and as shown in FIG. It is conveyed to. Then, as shown in FIG. 6B, the sheet P1 falls across, for example, a stack tray 128 that is a sheet stacking unit and a processing tray 129 that is a sheet bundle stacking unit. Thereafter, as shown in FIGS. 7A and 7B, the transport upper roller 127a is lowered by a swing roller mechanism described later, and the sheet is sandwiched between the transport lower roller 127b. At this time, the swing roller pair 127 serves not as a sheet bundle conveying unit but as a sheet conveying unit.

  Thereafter, the transport upper roller 127a and the transport lower roller 127b are rotated in the arrow direction shown in FIG. 7B (rotated in the second direction and reversely rotated) by the bundling motor M3 (see FIG. 4). Further, the return roller 130 that can contact and separate from the processing tray 129 is also rotated (reversely rotated) in the direction of the arrow shown in FIG. 7B by the bundling motor M3 (see FIG. 4). By the way, when the first sheet is conveyed, the lower conveyance roller 127b is connected to the drive by the operation of the lower bundle clutch CL (see FIG. 4), but is turned off when the second and subsequent sheets are conveyed. It has come to idle. This is because, when the second and subsequent sheets are stacked, if the lower conveyance roller 127b is rotating, the lower conveyance roller 127b also pushes the first sheet into the stopper 131 side, so that the first sheet becomes the first sheet. This is because there is a risk of causing wrinkles.

  As shown in FIG. 8A, the sheet slides in the direction of the arrow on the processing tray 129 that is lowered to the right by the rotation of the swing roller pair 127 and the return roller 130. At that time, the rear end assist 134 is in a standby position. As shown in FIG. 8B, when the sheet P1 comes into contact with the stopper 131, the transport upper roller 127a is separated from the sheet P1. The sheet P1 is brought into contact with the stopper 131, so that the alignment in the sheet conveyance direction is performed. Thereafter, the sheet P1 is subjected to sheet width alignment by a known pair of alignment plates 144 (see FIG. 4).

  Thereafter, the subsequent sheets are stacked on the preceding sheet stacked on the processing tray 129. As shown in FIG. 9, when a predetermined number of sheets are stacked on the processing tray 129 as a sheet bundle, the sheet bundle is bound by the stapler 132 shown in FIGS. The sheet bundle may be punched by a punch unit (not shown) instead of being bound by the stapler 132.

  As shown in FIG. 10A, the transport upper roller 127a is lowered by a swing roller mechanism described later, and the sheet is sandwiched between the transport lower roller 127b (S101 in FIG. 11). Then, the lower bundle clutch CL is operated (S102 in FIG. 11). After about 150 mmsec (S103 in FIG. 11), the alignment plate 144 is retracted from the sheet bundle (S104 in FIG. 11). Then, the stack tray 128 moves to a position detected by the paper surface detection lever 133 and waits at a position where it can easily receive the discharged sheet bundle (S105 in FIG. 11).

  As shown in FIG. 10B, the transport upper roller 127a rotates in the second direction (arrow direction) across the sheet bundle P with the transport lower roller 127b (S106 in FIG. 11). At this time, the trailing edge assist 134 pushes the trailing edge of the sheet bundle P (S107 to S109 in FIG. 11). As a result, the sheet bundle is discharged to the stack tray 128 (S110 to S112 in FIG. 11). As shown in FIG. 12, the rear end assist 134 is provided on a belt 142 that rotates forward and backward by a rear end assist motor M4.

  In FIG. 10B, when the sheet bundle starts to be discharged, the first sheet in the next sheet bundle is fed into the inlet roller pair 121.

(Oscillating roller mechanism)
Next, the swing roller mechanism 400 for conveying the finisher sheet and the sheet bundle of the present invention to the processing tray 129 or the stack tray 128 shown in FIG. 5 will be described with reference to FIGS.

  For example, a bracket 152, which is a support member provided with, for example, a transport upper roller 127a that is an upper rotating body of the swing roller pair 127, is configured to rotate in the vertical direction about a shaft 153. A hook arm 152 a is provided on the upper surface of the bracket 152. In the vicinity of the hook arm 152a, a slide arm 160 that slides up and down is provided so as to hook the hook arm 152a and rotate the bracket 152 up and down.

  As shown in FIG. 14, the transport upper roller 127 a is held in the elongated round hole 152 d of the bracket 152. The elongated round hole 152d is formed in the bracket 152 so as to be long in the vertical direction. For this reason, the conveyance upper roller 127a can move in the vertical direction within the elongated round hole 152d. The transport upper roller 127a is received by the transport lower roller 127b, and when the shaft 178 of the transport upper roller 127a is not in contact with the upper and lower ends of the elongated round hole 152d of the bracket 152, it does not receive the weight of the bracket 152. become.

  As shown in FIGS. 15 and 16, the swing arm 250 is supported by the bracket 152. The swing arm 250 is disposed at both ends of the shaft 178 of the transport upper roller 127a. The swing arm 250 has a fulcrum portion 250c attached to a protrusion 152e of the bracket 152, and swings in the left-right direction in the figure around the fulcrum portion 250c. The rear end 250a of the swing arm 250 is received by an arm stopper 251 fixed to the fixed member when the swing arm 250 swings.

  As shown in FIG. 15, when the bracket 152 is rotated upward, the rear end 250a of the swing arm 250 hits the arm stopper 251 and the tip 250b of the swing arm 250 is lifted as the bracket 152 is rotated upward. The tip 250b of the swing arm 250 hits the shaft 178 of the transport upper roller 127a, lifts and supports the transport upper roller 127a within the range of the oblong hole 152d of the bracket 152, and retracts upward from the bottom 152f of the bracket 152. .

  Accordingly, the swing arm 250 shown in FIG. 15 is regulated by the rear end 250a being received by the arm stopper 251 to swing leftward by the weight of the transport upper roller 127a supported by the front end 250b. This means that the support state of the upper roller 127a is maintained.

  Further, when the bracket 152 rotates downward from the state of FIG. 15 to the state of FIG. 16, the swing arm 250 also rotates downward together, and the rear end 250 a of the swing arm 250 moves away from the arm stopper 251. Then, the swing arm 250 tilts to the left in FIG. 16 due to the weight of the transport upper roller 127a, the tip portion 250b is lowered, and the transport upper roller 127a is also lowered. As a result, the transport upper roller 127a protrudes downward from the bottom 152f of the bracket 152 and is received by the transport lower roller 127b. At this time, the tip 250b of the swing arm 250 is separated downward from the shaft 178 of the transport upper roller 127a. Further, the shaft 178 of the transport upper roller 127a is movable up and down in an elongated round hole 152d shown in FIG. In the swing arm 250 shown in FIG. 16, the protrusion stopper 250d is received by the bracket 152 and the inclination is restricted, so that the leading end 250b does not interfere with the conveyed sheet.

  In the above configuration, the swing arm 250 and the arm stopper 251 are examples of standby means. 15 and 16, a member denoted by reference numeral 291 is a static elimination needle that contacts the sheet and grounds the static electricity of the sheet.

  Therefore, when the sheet conveyed as shown in FIG. 5 is received, the bracket 152 is raised and rotated as shown in FIG. 15, and the conveying upper roller 127a is retracted above the bottom 152f of the bracket 152. become. For this reason, even if the sheet curled upward is conveyed, the sheet processing apparatus 119 can smoothly convey the sheet without the curled sheet being caught by the conveyance upper roller 127a. In addition, the occurrence of jam can be prevented.

  As shown in FIG. 22, for example, a guide guide 290 that is a sheet guide member projecting in a reverse trapezoidal shape downwardly on the bottom 152 f of the bracket 152 guides the curled sheet upward, so that the curled sheet is conveyed upward. You may make it not catch on 127a. The swing arm 250 in FIG. 22 is not necessarily required. It may be omitted.

  The guide guide 290 is formed so as to protrude downward from the transport upper roller 127a when the bracket 152 is rotated upward and to be retracted upward from the transport upper roller 127a when the bracket 152 is rotated downward.

  Therefore, the guide guide 290 can guide the curl sheet so that it does not get caught by the transport upper roller 127a by protruding downward from the transport upper roller 127a when the bracket 152 is rotated upward. Further, since the guide guide 290 is retracted above the transport upper roller 127a when the bracket 152 is rotated downward, the guide guide 290 does not disturb the sheet transport.

  As shown in FIG. 17, the height detection flag 301 detects the height of a sheet bundle stacked on the processing tray 129. When the stacking height of the sheet bundle becomes high, the height detection flag 301 is pushed on the upper surface of the sheet bundle and rotates about the shaft 301 a protruding from the bracket 152 to turn on the height detection sensor 302. It has become. The height detection sensor 302 is provided on the bracket 152. The height detection flag 301 and the height detection sensor 302 are examples of detection means.

  As shown in FIG. 13, the slide arm 160 is guided by slide shafts 161 disposed at both ends of the slide arm 160, and is moved up and down in the arrow X direction or the arrow Y direction in the figure. The slide arm 160 is formed with a rack 160b with which the swing gear 162 is engaged. As the swing gear 162 rotates, the slide arm 160 moves up and down in the directions of arrows X and Y. Further, the oscillating gear 162 receives a rotational force from the oscillating motor M5 via the oscillating shaft 163 that is the rotating axis of the oscillating gear 162, via the torque limiter 164, the intermediate gears 165 and 166, and the oscillating motor gear 167. To receive.

  Here, the torque limiter 164 and the swing motor M5 constitute a sandwiching force load portion that changes the sheet sandwiching force of the swing roller pair 127. Since the torque limiter 164 is provided between the intermediate gear 165 and the swing shaft 163, when the driving force of the swing motor M5 exceeds a certain level, a limit is applied and the wheel rotates idly. As a result, the force by which the upper conveying roller 127a of the swing roller pair 127 presses, for example, the lower conveying roller 127b as the lower rotating body does not exceed a predetermined force. As a result, even if the thickness of the sheet bundle conveyed by the swing roller pair 127 changes depending on the number of sheets, the sheet conveying force can be made substantially constant to ensure stable conveyance.

  FIG. 18 (a diagram viewed from the direction of arrow Z in FIG. 13) is a diagram showing a configuration for transmitting the driving of the bundling motor M3 for rotating the transport upper roller 127a and the transport lower roller 127b shown in FIG. First, the bundling motor gear 168 attached to the bundling motor M3 is interlocked with the lower conveying roller 127b via the intermediate gear 169 and the lower bundling clutch CL.

  The intermediate gear 169 is also coupled to the transport upper roller 127 a via an intermediate belt 171, an intermediate belt 172, and an upper roller gear 173 that slide and rotate using the intermediate belt 170 and the shaft 153. Thereby, the conveyance upper roller 127a and the conveyance lower roller 127b can be rotated forward and backward by rotating the bundling motor M3 forward and backward.

  Further, by rotating or stopping the conveying lower roller 127b, the rotational force of the bundling motor M3 is transmitted to or disconnected from the conveying lower roller 127b by connecting or releasing the lower clutch CL. Can do.

  In the above configuration, the slide arm 160 and the swing motor M5 are examples of driving means. The bracket 152 is an example of a support member. The slide arm 160, the swing motor M5, and the bracket 152 are an example constituting an adjusting means.

  Based on FIGS. 17 to 21, the operation of the upper conveying roller 127a and the lower conveying roller 127b of the swing roller pair 127 sandwiching and separating the sheet will be described.

  17 and 19 to 21 are sectional views of the vicinity of the central portion of a mechanism for rotating the bracket 152 having the transport upper roller 127a in the vertical direction.

  The operation of the swing roller mechanism 400 when a sheet is carried in from the discharge roller pair 126 will be described with reference to FIGS.

  FIG. 17 is a view showing a state in which the transport upper roller 127a of the swing roller pair 127 is separated from the transport lower roller 127b, and the operation when the sheet is carried in from the discharge roller pair 126 in FIG. It is a figure for doing.

  17 and 18, the swing motor M5 is held in a state in which the bracket 152 is rotated upward while the swing home sensor S2 detects a detection unit (not shown) attached to a part of the slide arm 160. It is held by torque. Accordingly, the transport upper roller 127a is separated from the transport lower roller 127b and does not transport the transported sheet. Further, even if there is a sheet that is already stacked on the processing tray 129 and is awaiting post-processing, the conveying upper roller 127a does not apply a sheet conveying force to the sheet and erroneously conveys the sheet to the stack tray 128. There is no.

  Based on FIG. 19, the operation of the swing roller mechanism 400 when a sheet conveyed to the discharge roller pair 126 and dropped onto the processing tray 129 is conveyed to the stack tray 128 as it is will be described.

  FIG. 19 is a view showing a state in which the bracket 152 is rotated downward by its own weight, the transport upper roller 127a is received by the transport lower roller 127b, and the weights of the bracket 152 and the transport upper roller 127a are added to the transport lower roller 127b. is there.

  As shown in FIG. 7, when the trailing edge of the sheet is discharged from the discharge roller pair 126 and the sheet falls onto the processing tray 129, the swing motor M5 (see FIG. 13) rotates. The rocking gear 162 is rotated by the rotation of the rocking motor M5, and the slide arm 160 is lowered in the direction of the arrow Y, and is separated from the rocking home sensor S2.

  As the slide arm 160 is lowered, the bracket 152 rotates downward about the shaft 153 while the hook arm 152a of the bracket 152 is supported by the support portion 160a of the slide arm 160. The bracket 152 has an upper conveying roller 127a, and the upper conveying roller 127a is received by the lower conveying roller 127b with the sheet therebetween.

  When the transport upper roller 127a is received by the transport lower roller 127b, it does not descend thereafter. However, since the transport upper roller 127a is supported by the elongated round hole 152d of the bracket 152 shown in FIG. 14, the bracket 152 descends together with the slide arm 160 by the length of the elongated round hole 152d in the vertical direction. When the upper edge of the elongated round hole 152d comes into contact with the shaft 178 of the transport upper roller 127a, the bracket 152 stops descending. However, the slide arm 160 continues to descend, and stops descending after the support portion 160a of the slide arm 160 is separated from the hook arm 152a of the bracket 152. The lowering of the slide arm 160 is stopped by stopping the rotation of the swing motor M5.

  As a result, the bracket 152 supported by the support portion 160a and the transport upper roller 127a are supported by the transport lower roller 127b with the sheet therebetween.

  For this reason, the transport upper roller 127a and the transport lower roller 127b discharge the sheet to the stack tray 128 by the transport clamping pressure (F1) due to the weight of the bracket 152 and the transport upper roller 127a.

  Based on FIG. 20, the operation of the swing roller mechanism 400 when the sheet conveyed to the discharge roller pair 126 (see FIG. 4) and dropped onto the processing tray 129 is sent back to the stopper 131 will be described.

  FIG. 20 is a diagram illustrating a state in which the bracket 152 is rotated downward, the transport upper roller 127a is in contact with the transport lower roller 127b, and the weight of the transport upper roller 127a is applied to the transport lower roller 127b. In FIG. 19, the weights of the bracket 152 and the transport upper roller 127a are added to the transport lower roller 127b, but the weight of the bracket 152 is not applied in FIG. In the state shown in FIGS. 19 and 20, as shown in FIG. 16, the swing arm 250 has a rear end 250a away from the arm stopper 251 and a front end 250b away from the shaft 178 of the conveying upper roller 127a. Of course, the protrusion stopper 250d is received by the bracket 152.

  As shown in FIG. 7, when the trailing edge of the sheet is discharged from the discharge roller pair 126 and the sheet falls onto the processing tray 129, the swing motor M5 (see FIG. 13) rotates and the swing gear 162 rotates. To do. Then, the slide arm 160 descends in the arrow Y direction and moves away from the swing home sensor S2.

  As the slide arm 160 is lowered, the bracket 152 rotates downward about the shaft 153 while the hook arm 152a of the bracket 152 is supported by the support portion 160a of the slide arm 160.

  While the bracket 152 is rotating downward about the shaft 153, the tip of the height detection flag 301 comes into contact with the upper surface of the sheet or sheet bundle. The height detection flag 301 rotates in the direction of the arrow Z around the shaft 301a to operate the height detection sensor 302. As a result, the height detection flag 301 detects the height of the sheet or sheet bundle stacked on the processing tray 129.

  The bracket 152 has a conveyance upper roller 127a. As the bracket 152 moves downward, the conveyance upper roller 127a conveys the sheet or sheet bundle between the sheets or the sheet bundle at substantially the same time as the leading edge of the height detection flag 301 contacts the upper surface of the uppermost sheet of the sheet or sheet bundle. It is received by the lower roller 127b.

  The transport upper roller 127a is supported by an elongated round hole 152d of the bracket 152 shown in FIG. For this reason, when the transport upper roller 127a is received by the transport lower roller 127b, the bracket 152 moves down together with the slide arm 160. When the middle part of the elongated round hole 152d is lowered to the shaft 178 of the transport upper roller 127a, the lowering of the slide arm 160 is stopped. The timing of the slide arm 160 to be lowered is set after a predetermined time (T1) after the height detection sensor 302 detects the stacking height of the sheets or sheet bundles. This time T1 is input in advance in the ROM 202 of FIG.

  When the lowering of the slide arm 160 is stopped, the lowering rotation of the bracket 152 is also stopped while the hook arm 152a of the bracket 152 is supported by the support portion 160a of the slide arm 160.

  At this time, since the middle portion of the oblong hole 152d of the bracket 152 faces the shaft 178 of the transport upper roller 127a, the weight of the bracket 152 is not applied to the transport upper roller 127a.

  Accordingly, the transport upper roller 127a is not supported by the elongated round hole 152d of the bracket 152, and is received by the transport lower roller 127b with the sheet or the sheet bundle interposed therebetween.

  Therefore, the transport upper roller 127a sandwiches the sheet with the transport lower roller 127b by its own weight and transports the sheet toward the stopper 131 as shown in FIG. 7B. . At this time, the transport upper roller 127a rotates in the reverse direction by the bundling motor M3 shown in FIG. However, since the lower bundle clutch CL is operated, the lower conveyance roller 127b does not receive the rotational force of the bundle extraction motor M3 and rotates in the reverse direction following the upper conveyance roller 127a.

  The contact pressure (F2) at which the conveyance upper roller 127a contacts the sheet is smaller than the conveyance clamping pressure (F1) in FIG. 19 by the weight of the bracket 152. That is, there is a relationship of F1> F2.

  In addition, the lowered position of the bracket 152 and the slide arm 160 can be adjusted according to the stack height of the sheet bundle detected by the height detection flag 301 and the height detection sensor 302. For this reason, the contact pressure (F2) can be made substantially constant regardless of the sheet stacking height.

  Accordingly, when the finisher 119 reversely feeds the succeeding sheet on the preceding sheet, the finisher 119 is less rubbed between the sheets, and scratches the image of the sheet or reduces show-through to the already stacked sheets. be able to.

  The contact pressure (F2) is preferably set to a minimum value necessary for the transport upper roller 127a to reversely feed the sheet. For this reason, it is preferable that the shaft 178 of the transport upper roller 127a is made hollow so that the entire transport upper roller 127a is light and the optimum contact pressure (F2) is obtained.

  Based on FIG. 21, the operation of the swing roller mechanism 400 when the sheet bundle bound by the stapler 132 is discharged from the processing tray 129 to the stack tray 128 will be described.

  FIG. 21 is a diagram illustrating a state where the slide arm 160 is further lowered from the operation described with reference to FIG. 19 and the conveying upper roller 127a is pressed against the sheet bundle by the rotational force of the swing motor M5.

  When the sheet bundle is bound by the stapler 132, the swing motor M5 rotates. The rocking gear 162 is rotated by the rotation of the rocking motor M5, and the slide arm 160 is lowered in the direction of the arrow Y, and is separated from the rocking home sensor S2.

  As the slide arm 160 is lowered, the bracket 152 rotates downward about the shaft 153 while the hook arm 152a of the bracket 152 is supported by the support portion 160a of the slide arm 160. The bracket 152 has an upper conveying roller 127a, and the upper conveying roller 127a is received by the lower conveying roller 127b with a sheet bundle interposed therebetween.

  When the transport upper roller 127a is received by the transport lower roller 127b, it does not descend thereafter. However, since the transport upper roller 127a is supported by the elongated round hole 152d of the bracket 152 shown in FIG. 14, the bracket 152 descends together with the slide arm 160 by the length of the elongated round hole 152d in the vertical direction. The upper edge of the elongated round hole 152d comes into contact with the shaft 178 of the transport upper roller 127a. For this reason, the bracket 152 is stopped from rotating downward.

  However, the slide arm 160 continues to descend. For this reason, the support portion 160 a of the slide arm 160 moves away from the hook arm 152 a of the bracket 152 and presses the upper surface of the bracket 152. The lowering of the slide arm 160 is stopped by stopping the rotation of the swing motor M5.

  For this reason, the discharge clamping pressure (F3) by the transport upper roller 127a and the transport lower roller 127b is a value obtained by adding the pressing force of the slide arm 160 to the weight of the transport upper roller 127a and the bracket 152. The discharge clamping pressure (F3) is larger than the conveyance clamping pressure (F1) and the contact pressure (F2). That is, the relationship is F3> F1> F2.

  When the bundling motor M3 shown in FIG. 4 is started and the lower bundle clutch CL is operated, the upper conveying roller 127a and the lower conveying roller 127b rotate to convey the sheet bundle in the upper left direction in the drawing, The sheet is discharged from the processing tray 129 to the stack tray 128.

  As shown in FIG. 13, a torque limiter 164 is provided between the intermediate gear 165 and the swing shaft 163. For this reason, when the support portion 160a of the slide arm 160 presses the upper surface of the bracket 152, a limit is applied when the driving force of the swing motor M5 exceeds a predetermined force, and the swing motor M5 rotates idly. It will be. As a result, the discharge clamping pressure (F3) by the transport upper roller 127a and the transport lower roller 127b can be made substantially constant regardless of the thickness of the sheet bundle, and the swing roller pair 127 ensures the sheet bundle. Can be discharged.

  Accordingly, the finisher 119 has a relationship in which the discharge nipping pressure (F3) is F3> F1> F2, and therefore, when the sheet bundle such as a color sheet having a small coefficient of friction is discharged, the bundler 119 has a misalignment or discharge failure due to insufficient nipping force. Can be prevented. Further, by driving both the transport upper roller 127a and the transport lower roller 127b, it is possible to prevent bundle misalignment and discharge failure due to insufficient clamping force particularly when discharging a sheet bundle such as a color sheet.

  In addition, although the torque limiter 164 is provided between the intermediate gear 165 and the swing shaft 163, the torque limiter 164 is not necessarily required. The lowered position of the slide arm 160 may be controlled using the height detection sensor 302 shown in FIG.

  That is, the tip of the height detection flag 301 shown in FIG. 20 comes into contact with the upper surface of the sheet bundle while the slide arm 160 is lowered and the bracket 152 is rotating downward about the shaft 153. . For this reason, the height detection flag 301 rotates in the direction of the arrow Z about the shaft 301a, operates the height detection sensor 302, and detects the thickness (height) of the sheet bundle.

  Therefore, if the timing for stopping the lowering of the slide arm 160 is set after a predetermined time (T2) after the height detection sensor 302 detects the thickness of the sheet bundle, it is not necessary to use the torque limiter 164. In addition, since the height detection sensor 302 detects the thickness of the sheet bundle, the timing of the slide arm 160 to be lowered can be changed according to the thickness of the sheet bundle, and the discharge clamping pressure (F3) can be set to the sheet stacking height. It can be made substantially constant regardless of the size. The predetermined time (T2) is input in advance in the ROM 202 shown in FIG. 2, and is of course set longer (T2> T1) than the predetermined time (T1) in the operation description shown in FIG. .

  In the above description, the relationship of F3> F1> F2 is as follows. That is, when a sheet is stacked on the processing tray 129, the sheet slides down the processing tray 129 that is lowered to the right (about 30 degrees gradient) in each figure, so that the contact pressure (F2) is reduced. However, when the sheets are stacked on the stack tray 128, the sheets rise on the stack tray 128 that is lowered to the right (gradient of about 30 degrees) in each figure, so that the conveyance clamping pressure (F1) is made larger than the contact pressure (F2). There must be. Further, when the sheet bundle on the processing tray 129 is discharged, the discharge nipping pressure (F3) is set to be higher than the conveyance nipping pressure (F1) in order to raise the processing tray 129 for the sheet bundle in which a plurality of sheets overlap. Must also be large.

1 is a cross-sectional view of an image forming apparatus according to the present invention, for example, a copying machine along a sheet conveying direction. 2 is a control block diagram of the entire copying machine. FIG. It is sectional drawing of the finisher which is the sheet processing apparatus in embodiment of this invention along the sheet conveyance direction, for example. It is sectional drawing which showed each drive system of the sheet processing apparatus. FIG. 10 is a diagram for explaining the operation of the sheet processing apparatus when it is not necessary to store sheets during sheet processing. FIG. 6A is a diagram illustrating a state where a first sheet has been fed into the sheet processing apparatus. (B) It is the figure of the state which received the 1st sheet | seat. FIG. 6 is a diagram for explaining the operation of the sheet processing apparatus when it is not necessary to store sheets during the sheet processing, and is a diagram for explaining the operation following FIG. 5. FIG. 4A is a diagram illustrating a state where a first sheet has passed a pair of discharge rollers. (B) It is a figure of the state which the 1st sheet fell across the stack tray and the processing tray. FIG. 7 is a diagram for explaining the operation of the sheet processing apparatus when it is not necessary to accumulate sheets during sheet processing, and is a diagram for explaining the operation following FIG. 6. (A) It is a figure of the state which sends the 1st sheet | seat into a process tray. FIG. 6B is a diagram illustrating a state in which the first sheet is further fed into the processing tray. FIG. 8 is a diagram for explaining the operation of the sheet processing apparatus when it is not necessary to store sheets during sheet processing, and is a diagram for explaining the operation following FIG. 7. FIG. 5A is a diagram illustrating a state where a second sheet has been fed into the sheet processing apparatus. (B) It is a figure in the state where the 1st sheet contacted the stopper. FIG. 6 is a diagram for explaining the operation of the sheet processing apparatus when it is not necessary to store sheets during sheet processing, and is a diagram in a state where three sheets are stacked on a processing tray. FIG. 10 is a diagram for explaining the operation of the sheet processing apparatus when it is not necessary to accumulate sheets during sheet processing, and is a diagram for explaining the operation following FIG. 9. (A) It is a figure of the state which begins to discharge | emit a sheet bundle from a processing tray to a stack tray. FIG. 6B is a diagram illustrating a state where the sheet bundle is being discharged from the processing tray to the stack tray. FIG. 10 is a flowchart for explaining operations when discharging a sheet bundle. It is an enlarged view of the principal part of a sheet processing apparatus. It is a perspective view of a rocking roller mechanism. It is a perspective view of a rocking roller mechanism. FIG. 6 is a view in which a swing roller mechanism is provided with a mechanism for preventing a jam of a curled sheet, and an upper roller and a lower roller are in a separated state. It is the figure which the upper roller and the lower roller contacted from the state of FIG. It is a figure explaining the operation | movement from which an upper roller and a lower roller of a rocking | fluctuating roller mechanism are clamped and separated, and is a figure in which an upper roller and a lower roller are in a separated state. It is a figure explaining the drive system of a rocking roller mechanism. It is a figure explaining the operation | movement from which the upper roller of a rocking | fluctuation roller mechanism and a lower roller are pinched and spaced apart, and is a figure in which the upper roller and the lower roller are in contact. It is a figure explaining the operation | movement which the upper roller and the lower roller of a rocking | fluctuation roller mechanism pinch | interpose and isolate | separate, and is a figure in the state withdrawn to the processing tray. It is a figure explaining the operation | movement from which an upper roller and a lower roller clamp and separate | separate a rocking | fluctuating roller mechanism, the upper roller and a lower roller are in a contact state, and the state which the rocking | fluctuation moving mechanism pressurizes the upper roller more FIG. FIG. 16 is a view of a mechanism different from the mechanism shown in FIG. 15 that prevents the swing roller mechanism from jamming the curled sheet.

Explanation of symbols

M1 common transport motor M5 swing motor (drive means, adjustment means)
P1 sheet 100 copier (image forming device)
101 Copier (image forming apparatus) main body 102 Document conveying apparatus 114 Photosensitive drum (image forming means)
119 Finisher (sheet processing device)
126 Discharge roller pair 127 Swing roller pair 127a Conveying upper roller (upper rotating body)
127b Conveying lower roller (lower rotating body)
128 Stack tray (sheet stacking means)
129 Processing tray (sheet bundle stacking means)
132 Stapler (sheet processing means)
140 Buffer unit 152 Bracket (support member, adjusting means)
152a hook arm 152c holding part 152d oblong hole 152e protrusion 152f bottom 153 bracket shaft 160 slide arm (driving means, adjusting means)
160a Supporting portion 160b Rack 162 Swing gear 178 Conveying upper roller shaft 201 CPU circuit 209 Printer unit control unit 211 Finisher control unit 250 Swing arm (standby means)
250a rear end 250b front end 250c fulcrum 250d protrusion stopper 251 arm stopper (standby means)
290 Guide Guide (Sheet Guide Member)
301 Height detection flag (detection means)
301a Shaft 302 of height detection flag Height detection sensor (detection means)
400 Swing roller mechanism

Claims (11)

The uppermost sheet is moved to the sheet processing unit by the upper rotating body that rotates in contact with the upper surface of the uppermost sheet stacked on the sheet bundle stacking unit on which the sheet bundle processed by the sheet processing unit is stacked. In the sheet processing apparatus,
Detecting means for detecting a height position of the uppermost sheet;
The height position of the upper rotating body is adjusted according to the height of the uppermost sheet detected by the detecting means to make the contact pressure of the upper rotating body with respect to the uppermost sheet constant. Adjusting means;
A sheet processing apparatus comprising: An upper rotating body and a lower rotating body that sandwich the conveyed sheet, rotate in the first direction, and convey the sheet as it is to the sheet stacking unit;
A sheet bundle stacking unit that holds the conveyed sheet between the upper rotating body and the lower rotating body and is fed back and stacked in a bundle by rotating the upper rotating body in a second direction;
Sheet processing means for processing the sheet bundle stacked on the sheet bundle stacking means,
The upper and lower rotating bodies sandwich the sheet bundle processed by the sheet processing means with a predetermined discharge clamping pressure and rotate in the first direction. From the sheet bundle stacking means to the sheet stacking means In the sheet processing apparatus for discharging
Detecting means for detecting the height position of the uppermost sheet stacked on the sheet bundle stacking means;
When the upper rotating body rotates in the second direction and reversely feeds the sheet, the height of the upper rotating body depends on the height of the uppermost sheet detected by the detecting means. Adjusting means for adjusting the position to make the contact pressure of the upper rotating body with respect to the uppermost sheet constant;
A sheet processing apparatus comprising: The adjusting means adjusts the height position of the upper rotating body according to the position of the uppermost sheet detected by the detecting means to make the discharge clamping pressure constant.
The sheet processing apparatus according to claim 2.   The sheet processing apparatus according to claim 2, wherein the contact pressure is set lower than the discharge clamping pressure.   The conveyance clamping pressures of the upper rotating body and the lower rotating body with respect to the sheet when the sheets conveyed by the upper rotating body and the lower rotating body are discharged to the sheet stacking unit as they are are the contact pressure and the discharge clamping pressure. The sheet processing apparatus according to claim 2, wherein the sheet processing apparatus is set between the two. The adjustment means includes a support member that supports the upper rotating body so as to be movable up and down, and a drive means that moves the support member in the vertical direction.
The drive means moves the support member in the vertical direction according to the height position of the upper surface of the sheet bundle detected by the detection means, and the uppermost rotating body is movable up and down by its own weight. Contacting the upper surface of the upper sheet with the contact pressure,
The sheet processing apparatus according to claim 1, wherein the sheet processing apparatus is a sheet processing apparatus. The adjustment means includes a support member that supports the upper rotating body so as to be movable up and down, and a drive means that moves the support member in the vertical direction.
When the driving unit discharges the processed sheet bundle from the sheet bundle stacking unit by the upper rotating body and the lower rotating body, the driving unit moves the support member in the vertical direction, and the upper member is moved by the support member. A rotating body is pressed against the upper surface of the uppermost sheet, and the clamping pressure between the upper rotating body and the lower rotating body with respect to the sheet bundle is set to the discharge clamping pressure.
The sheet processing apparatus according to claim 2, wherein the sheet processing apparatus is a sheet processing apparatus. The adjustment means includes a support member that supports the upper rotating body so as to be movable up and down, and a drive means that moves the support member in the vertical direction.
When the driving means discharges the sheet, on which the upper rotating body and the lower rotating body have been conveyed, to the sheet stacking means as it is, the supporting member is moved down, and the support member and the upper rotating body Applying its own weight to the upper surface of the uppermost sheet, the clamping pressure between the upper rotating body and the lower rotating body with respect to the sheet is set as the conveyance clamping pressure.
The sheet processing apparatus according to claim 5. A retracting means for retracting the upper rotating body upward when the supporting member moves upward, and releasing the retracting of the upper rotating body when the supporting member moves downward;
The sheet processing apparatus according to claim 6, wherein the sheet processing apparatus is provided. The support member includes a sheet guide member provided on the upstream side of the upper rotating body in the sheet conveyance direction,
The sheet guide member protrudes below the upper rotating body when the support member moves upward, and retracts above the upper rotating body when the support member moves downward;
The sheet processing apparatus according to claim 6, wherein the sheet processing apparatus is provided. Image forming means for forming an image on a sheet;
A sheet processing apparatus for processing a sheet on which an image is formed by the image forming unit,
The image forming apparatus according to claim 1, wherein the sheet processing apparatus is the sheet processing apparatus according to claim 1.

Images