JP4811146B2 - Paper discharge device and image forming apparatus - Google Patents

Description

  The present invention relates to a paper discharge device and an image forming apparatus.

  As one of the prior arts, a technique is known in which air is blown onto a running sheet from a fixing device toward a sheet discharge stack to cool the sheet (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 11-30891

  An object of the present invention is to provide a paper discharge device and an image forming apparatus capable of preventing a paper sticking phenomenon due to adhesiveness (softening) of a developer when a paper on which an image is fixed is discharged. To do.

The paper discharge device according to claim 1 has a paper discharge device main body having a storage space for storing paper discharged from an image fixing device that fixes an image on the paper, and stacks the paper in the paper discharge device main body. A sheet that is discharged into the storage space and a sheet that is discharged into the accommodation space is supported with a space between the sheet stacking table and the sheet stacking base in the discharge apparatus body, and a first sheet that supports the discharged sheet. And a support member that operates between the second position for guiding the paper supported at the first position to the paper stacking base, and the number of papers supported by the support member at the first position. Control means for controlling the support member to move from the first position to the second position when the predetermined number of sheets exceeds a predetermined number, wherein the support member is moved from the first position to the second position . this having an elastic member to play the edge of the sheet of paper when operating the second position Is characterized in that said.

The image forming apparatus according to claim 2, the image forming apparatus main body to have a image fixing apparatus for fixing the image to the paper, an accommodation space for accommodating a sheet ejected from the image fixing apparatus of the image forming apparatus main body A paper discharge device main body, a paper stacking table on which paper is stacked in the paper discharge device main body, and a paper discharged into the accommodation space between the paper stacking base in the paper discharge device main body. And a support member that operates between a first position for supporting the paper to be discharged and a second position for guiding the paper supported at the first position to the paper stacking base. And a control for controlling the support member to move from the first position to the second position when the number of sheets supported by the support member at the first position exceeds a predetermined number. and means, said support member, said first position It is characterized in that an elastic member to play the edge of the sheet of paper when operating in al the second position.

According to the paper discharge device of the first aspect, for example, even when the paper to be discharged has heat after image fixing, it is possible to prevent the paper sticking phenomenon due to the adhesiveness (softening) of the developer. it can. Further, when the support member is moved from the first position to the second position, the edge of the sheet is flipped by the elastic member, so that the sheet can be curled and sticking between the sheets can be prevented.

According to the image forming apparatus of claim 2 , even when the paper ejected from the image forming apparatus main body has heat after image fixing, the paper sticking phenomenon due to the adhesiveness (softening) of the developer is prevented. can do. Further, when the support member is moved from the first position to the second position, the edge of the sheet is flipped by the elastic member, so that the sheet can be curled and sticking between the sheets can be prevented.

  Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic diagram showing a configuration example of an image forming apparatus to which the present invention is applied. The illustrated image forming apparatus 1 includes an image forming apparatus main body 2 and a paper discharge device 3. In the image forming apparatus main body 2, two sheet feeding apparatuses 4 and 5 are incorporated in two upper and lower stages. Each of the paper feeding devices 4 and 5 is configured using, for example, a paper storage unit having a tray shape, a cassette shape, a box shape, and the like, and a paper supply roll for feeding paper from the paper storage unit. It is.

  Further, the image forming apparatus main body 2 is formed with a sheet conveyance path for conveying sheets fed from the respective sheet feeding apparatuses 4 and 5. The paper transport path is formed by a transport path forming member (not shown). On the paper conveyance path, a plurality of conveyance rolls (roll pairs) 6 to 21 are provided at predetermined intervals.

  An image transfer device 22 and an image fixing device 23 are provided between the transport roll 10 and the transport roll 11 on the paper transport path. The image transfer device 22 transfers an image (toner image) onto a sheet conveyed along a sheet conveyance path. The image transfer device 22 includes a photosensitive drum 22A and a transfer roll 22B that are opposed to each other via a paper conveyance path. Although not shown, the image transfer device 22 exposes and scans the surface of the charger 22A charged to the photosensitive drum 22A and the photosensitive drum 22A charged to a predetermined potential by the charger with laser light. An image writing device for writing an electrostatic latent image and a developing device for developing the electrostatic latent image written by the image writing device using, for example, a two-component developer composed of toner and a carrier.

  The photosensitive drum 22A and the transfer roll 22B are arranged in contact with each other with a predetermined pressure. The photosensitive drum 22A is rotationally driven in the counterclockwise direction in the figure when an image is formed on a sheet. The transfer roll 22B rotates following the photosensitive drum 22A, sandwiches a sheet with the photosensitive drum 22A, and applies a charge having a polarity opposite to that of the toner to the sheet. The toner image is transferred onto a sheet.

  The image fixing device 23 fixes an image (toner image) on a sheet conveyed along a sheet conveyance path. The image fixing device 23 includes a heating roll 23A that is heated to a predetermined temperature (fixing temperature) by a heater or the like, and a pressure roll 23B that contacts the heating roll 23A with a predetermined pressure.

  A main body (hereinafter, referred to as a “discharge device main body”) 24 of the paper discharge device 3 has a storage space 25 for storing the image-formed paper discharged from the image forming device main body 2. The paper discharge device 3 is provided with a discharge roll 26, a discharge sensor 27, and a paper stacking base 28. The discharge roll 26 takes in the paper transported (discharged) by the transport roll 13 in the image forming apparatus main body 2 into the paper discharge apparatus main body 24 and discharges the captured paper into the storage space 25.

  The discharge sensor 27 detects the passage of paper discharged by the discharge roll 26. The discharge sensor 27 is configured using, for example, a photosensor having a light emitting element and a light receiving element. When the leading edge of the paper discharged by the discharge roll 26 passes the sensor detection position (sensor optical axis). The sensor output signal is switched from the on state to the off state, and the sensor output signal is switched from the off state to the on state when the trailing edge of the sheet passes the sensor detection position.

  The paper stacking table 28 is for stacking paper 29 in the storage space 25 in the paper discharge device main body 24. The paper stacking table 28 is provided in the accommodation space 25 so as to be able to be raised and lowered. The discharge roll 26 and the discharge sensor 27 can be provided on the image forming apparatus main body 2 side. Further, the image forming apparatus main body 2 and the paper discharge apparatus main body 24 can be integrally formed.

  In the image forming apparatus 1 configured as described above, a sheet fed from one of the sheet feeding devices 4 and 5 is sent to the transport roll 10 according to the rotation of the transport rolls 6, 7, 8, and 9. Next, the sheet is fed into the image transfer device 22 according to the rotation of the transport roll 10. In the image transfer device 22, the toner image is transferred to the first surface of the paper when passing between the photosensitive drum 22 </ b> A and the transfer roll 22 </ b> B.

  Next, the sheet is sent to the image fixing device 23. In the image fixing device 23, the toner image is fixed on the first surface of the paper when passing between the heating roll 23A and the pressure roll 23B. Next, the paper is sent to the transport roll 13 according to the rotation of the transport rolls 11, 12, and further sent to the discharge roll 26 according to the rotation of the transport roll 13. Then, the paper is discharged into the storage space 25 in the paper discharge device 3 as the discharge roll 26 rotates. The above operation is the case of single-sided image forming processing for forming an image on one side of a sheet.

  In the case of double-sided image forming processing in which images are formed on both sides of the paper, the paper that has passed through the image fixing device 13 is sent to the transport rolls 14, 15, 16 according to the rotation of the discharge rolls 11, 12. Then, when the trailing edge of the sheet passes between the conveyance roll 14 and the conveyance roll 15 through the branch position of the sheet conveyance path toward the conveyance roll 17 side, after the rotation of the conveyance rolls 15 and 16 is temporarily stopped, until then The transport rolls 15 and 16 rotate in the opposite direction. As a result, the sheet is fed into the transport roll 17.

  Thereafter, the sheet is fed again to the transport roll 8 according to the rotation of the transport rolls 17 to 21. Thereafter, an image is formed (transferred and fixed) on the second surface of the sheet in the same procedure as that for forming an image on the first surface.

  The paper on which images are formed on both sides in this way is sent to the discharge roll 26 via the transport rolls 11, 12 and 13 in order. When the paper is turned upside down and discharged, the paper is sent to the transport roll 14 according to the rotation of the transport rolls 11 and 12, and then the paper is sent to the transport roll 13 by the reverse rotation of the transport roll 14.

  FIG. 2 is a schematic diagram illustrating an example of the internal configuration of the paper discharge device 3. In FIG. 2, the main body frame 30 is arranged vertically at the four corners of the paper discharge device main body 24 so as to surround the accommodation space 25, for example. The main body frame 30 is arranged at a slightly larger interval than the width of the paper 29 discharged by the discharge roll 26 in the horizontal direction (left-right direction in the figure) orthogonal to the paper discharge direction by the discharge roll 26. In this specification, the direction perpendicular to the vertical direction (the direction of gravity) is described as the horizontal direction.

  In addition, a pair of paper support guides 31 and 32 and a pair of paper support guides 33 and 34 are supported on the main body frame 30 above the paper stacking base 28. The pair of paper support guides 31 and 32 and the pair of paper support guides 33 and 34 are arranged in a vertical (upper and lower) positional relationship. That is, the pair of paper support guides 31 and 32 are arranged in the upper stage, and the pair of paper support guides 33 and 34 are arranged in the lower stage. The pair of paper support guides 31 and 32 are arranged at the same height in the vertical direction, and the pair of paper support guides 33 and 34 are also arranged at the same height in the vertical direction.

  The pair of sheet support guides 31 and 32 support the sheet 29 at a position higher than the pair of sheet support guides 33 and 34, and the pair of sheet support guides 33 and 34 are positioned higher than the sheet stacking base 28. The paper 29 is supported. The paper stacking base 28 is a plate-like member that finally stacks and stores the paper discharged from the image forming apparatus main body 2 in the storage space 25 in the paper discharge apparatus main body 24. The paper 29 supported by the pair of paper support guides 31 and 32 and the paper 29 supported by the pair of paper support guides 33 and 34 are arranged with a space in the vertical direction. In addition, the paper 29 supported by the pair of paper support guides 33 and 34 and the paper 29 stacked on the paper stacking base 28 are also arranged with a space in the vertical direction.

  Each of the paper support guides 31 to 34 is a long member along a paper discharge direction (depth direction in the drawing) by the discharge roll 26. The paper support guide 31 is provided with a paper receiving portion 31A. A rotation shaft 35 is fixed to the paper support guide 31 by bonding, screwing, press fitting, or the like, and the paper support guide 31 is supported by the main body frame 30 via the rotation shaft 35. Further, the paper support guide 31 is formed in a triangle (right triangle) when viewed from the axial direction of the rotation shaft 35.

  Similarly, the paper support guide 32 is provided with a paper receiver 32A, the paper support guide 33 is provided with a paper receiver 33A, and the paper support guide 34 is provided with a paper receiver 34A. The paper support guide 32 is provided with a rotation shaft 36 in a fixed state, the paper support guide 33 is provided with a rotation shaft 37 in a fixed state, and the paper support guide 34 is provided with a rotation shaft 38 in a fixed state. Yes. The paper support guide 32 is supported on the main body frame 30 via a rotation shaft 36, the paper support guide 33 is supported on the main body frame 30 via a rotation shaft 37, and the paper support guide 34 is supported on the main body via a rotation shaft 38. It is supported by the frame 30.

  Each of the rotating shafts 35 to 38 is provided so as to be rotatable in both directions (clockwise direction and counterclockwise direction in the figure) using an actuator such as a motor or an electromagnetic plunger as a drive source. When the rotary shaft 35 is rotated, the paper support guide 31 rotates integrally with the rotary shaft 35, and when the rotary shaft 36 rotates, the paper support guide 32B rotates integrally with the rotary shaft 35. When the rotation shaft 37 is rotated about the rotation shaft 37 and the rotation shaft 37 is rotated, the sheet support guide 33 is rotated about the rotation shaft 37 and when the rotation shaft 38 is rotated, the rotation is performed. Thus, the sheet support guide 34 is configured to rotate about a rotation shaft 38.

  Each of the paper support guides 31 to 34 is supported at a first position for supporting the paper 29 discharged from the discharge roll 26 by the rotation of the corresponding rotation shafts 35 to 38, and at this first position. The sheet 29 is provided so as to operate between the second position for guiding the sheet 29 to the sheet stacking base 28. FIG. 2 shows a state in which the respective sheet support guides 31 to 34 are arranged at the first position. The pair of paper support guides 31 and 32 are arranged in a state of facing each other with the minimum acute angle portion facing each other in the horizontal direction orthogonal to the paper discharge direction by the discharge roll 26. Similarly, the pair of paper support guides 33 and 34 are disposed in a state where the minimum acute angle portions face each other in the horizontal direction perpendicular to the paper discharge direction by the discharge roll 26. Further, the sheet receiving portions 31A to 34A of the respective sheet support guides 31 to 34 are arranged in a state parallel to a horizontal plane (a plane perpendicular to the vertical direction).

  On the other hand, in a state where the respective paper support guides 31 to 34 are arranged at the second position, the minimum acute angle portions of the respective paper support guides 31 to 34 are arranged obliquely downward. That is, the paper support guide 31 is disposed at a position obtained by rotating the rotation shaft 35 by a predetermined angle in the clockwise direction in the drawing from the first position shown in FIG. 2, and the paper support guide 32 is shown in FIG. From the first position, the rotary shaft 36 is disposed at a position rotated by the predetermined angle in the counterclockwise direction in the figure. Further, the paper support guide 33 is arranged at a position where the rotation shaft 37 is rotated by the predetermined angle in the clockwise direction in the drawing from the first position shown in FIG. 2, and the paper support guide 34 is shown in FIG. From the first position shown, the rotary shaft 38 is disposed at a position rotated by the predetermined angle in the counterclockwise direction in the figure.

  When the pair of paper support guides 31 and 32 are moved from the first position to the second position according to the rotation of the rotation shafts 35 and 36, the positions of the rotation shafts 35 and 36 are separated from each other during the operation. When moving the pair of paper support guides 31 and 32 from the second position to the first position in accordance with the rotation of the rotation shafts 35 and 36, the rotation shaft is moved during the operation. The positions 35 and 36 move in a direction approaching each other (inward in the horizontal direction). Similarly, when the pair of paper support guides 33 and 34 are moved from the first position to the second position according to the rotation of the rotation shafts 37 and 38, the positions of the rotation shafts 37 and 38 are separated from each other during the operation. When the pair of paper support guides 33 and 34 are moved from the second position to the first position in accordance with the rotation of the rotation shafts 37 and 38, they are rotated during the operation. The positions of the shafts 37 and 38 move in a direction in which they approach each other (inward in the horizontal direction).

  Accordingly, when each of the paper support guides 31 to 34 is moved from the first position to the second position, each of the paper support guides 31 to 34 is retracted from the space where the paper is discharged by the discharge roll 26. . Conversely, when each of the paper support guides 31 to 34 is moved from the second position to the 21st position, each of the paper support guides 31 to 34 protrudes into a space where the paper is discharged by the discharge roll 26. It will be in the state.

  Further, blower fans 39, 40, 41, 42 are attached to the main body frame 30. Among them, the blower fans 39 and 40 blow cooling air from the horizontal direction onto the paper 29 supported by the pair of paper support guides 31 and 32. The blower fans 41 and 42 blow cooling air from the horizontal direction onto the paper 29 supported by the pair of paper support guides 33 and 34.

  FIG. 3 is a block diagram illustrating a configuration example of a control system that controls the operation of the paper discharge device 3. The paper discharge control unit 43 controls the rotation operation of the discharge roll 26, the lifting operation of the paper stacking table 28, the operation of the paper support guides 31 to 34, and the operation of the blower fans 39 to 42, respectively. The rotation operation of the discharge roll 26 is controlled to synchronize with the rotation operation of the discharge roll 13 provided on the image forming apparatus main body 2 side, for example. Further, the raising / lowering operation of the paper stacking table 28 is controlled so that the position of the paper stacking table 28 gradually decreases (in steps) as the height of the paper 28 stacked on the paper stacking table 28 increases. . How the operations of the paper support guides 31 to 34 and the operations of the blower fans 39 to 42 are controlled will be described later.

  A sheet number counter 44, a guide driving unit 45, and a fan driving unit 46 are connected to the paper discharge control unit 43 along with the discharge sensor 27 described above. The sheet number counter 44 counts the number of sheets discharged by the discharge roll 26 into the storage space 25 in the sheet discharge apparatus main body 24. The guide driving unit 45 operates each of the paper support guides 31 to 34 from the first position to the second position or from the second position to the first position based on an instruction from the paper discharge control unit 43. It drives to make it. The fan drive unit 46 drives each of the blower fans 39 to 42 based on an instruction from the paper discharge control unit 43.

  FIG. 4 is a flowchart illustrating a processing procedure executed by the paper discharge control unit 43 of the paper discharge device 3 when the paper on which the image is formed in the image forming apparatus main body 2 of the image forming apparatus 1 is discharged to the paper discharge device 3. It is.

  First, the paper discharge control unit 43 determines whether or not the conditions for image formation executed on the image forming apparatus main body 2 side satisfy a predetermined condition set in advance (step S1). In step S1, for example, it is determined whether the number of sheets on which images are formed is greater than a preset threshold number. In addition, it is determined whether or not the type of paper to be subjected to image formation (paper feeding) matches a preset paper type (thick paper, OHP sheet). Also, it is determined whether the density of the image formed on the paper is higher than a preset threshold density. The threshold density may be set at a different density for each paper type.

  If the image forming conditions do not satisfy the predetermined conditions in step S1, the paper discharge control unit 32 performs normal paper discharge processing (step S2). In a normal paper discharge process, the paper support guides 31 to 34 are arranged at the second position, and the blower fans 39 to 42 are stopped, and the rotation operation of the discharge roll 26 and the paper stacking table 28 are stopped. The paper is discharged by the lifting operation. In this case, the paper 29 discharged by the discharge roll 26 is discharged (stacked) directly onto the paper stacking table 28 without being supported by the paper support guides 31 to 34.

  In step S1, when the image forming condition satisfies a predetermined condition, the paper discharge control unit 43 gives driving instructions to the guide driving unit 45 and the fan driving unit 46, respectively, thereby each paper support guide 31. -34 are moved from the second position to the first position, and the blower fans 39-42 are rotated (step S3).

  Next, the paper discharge control unit 43 resets the value of the number counter 44 to zero (step S4). Next, the paper discharge control unit 43 determines whether the paper has passed the detection position of the discharge sensor 27 while monitoring the output signal of the discharge sensor 27 (step S5). When the paper passes the detection position of the discharge sensor 27, the output signal of the discharge sensor 27 is switched from the on state to the off state by passing the leading edge of the paper, and then from the off state to the on state by passing the rear end of the paper. Switch. For this reason, the conveyance control unit 43 determines that the sheet has passed the detection position of the discharge sensor 27 when the output signal of the discharge sensor 27 is switched in the order of on state → off state → on state.

  Here, a pair of sheets 29 discharged by the discharge roll 26 are sequentially placed on the sheet receiving portions 31A and 32A of the pair of sheet support guides 31 and 32 in the storage space 24 in the sheet discharge apparatus main body 25. Are supported in a horizontal state by the paper support guides 31, 31.

  When it is determined in step S5 that the sheet has passed the detection position of the discharge sensor 27, the sheet discharge control unit 43 determines whether or not the passed sheet is the final sheet (step S6). If it is determined that the sheet is the final sheet, the process proceeds from step S6 to step S10. If it is determined that the sheet is not the final sheet, the process proceeds from step S6 to step S7. The last sheet is the last sheet discharged from the image forming apparatus main body 2 to the sheet discharge apparatus 3 in one image forming process (image forming job). For example, when the image forming apparatus body 2 forms an image on 100 sheets, the 100th sheet discharged from the image forming apparatus body 2 is determined as the final sheet.

  In step S7, the paper discharge control unit 43 increments the value of the number counter 44 by one. As a result, the value of the sheet counter 44 indicates the number of sheets supported by the pair of sheet support guides 31 and 32. Next, the paper discharge control unit 43 determines whether or not the value of the number counter 44 has exceeded a predetermined number set in advance (step S8). The predetermined number of sheets is supported by the pair of sheet support guides 31 and 32 when the pair of sheet support guides 31 and 32 are disposed at the first position and a plurality of sheets are continuously discharged from the sheet discharge roll 26. The sheet is set in advance based on experimental data or the like so that the sticking phenomenon does not occur between the sheets due to the adhesiveness (softening) of the toner as the developer. As the value of the predetermined number of sheets, a different value may be applied depending on the type of paper that is an object of image formation.

  If the value of the number counter 44 is equal to or smaller than the predetermined number in step S8, the process returns to step S5. When the value of the sheet counter 44 exceeds the predetermined number, the paper discharge control unit 43 gives a drive instruction to the guide driving unit 45, thereby moving the pair of paper support guides 33 and 34 from the first position to the second position. Then, the pair of sheet support guides 33 and 34 are moved again from the second position to the first position, and subsequently, the pair of sheet support guides 31 and 32 are moved from the first position. After being moved to the second position, the pair of paper support guides 31 and 32 are moved again from the second position to the first position (step S9). After operating the respective paper support guides 31 to 34 as described above, the process returns to step S4.

  At this time, when the pair of paper support guides 33 and 34 are moved from the first position to the second position, the paper 29 supported by the pair of paper support guides 33 and 34 is converted into the pair of paper support guides 33 and 34. It falls with its own weight while being guided by. Similarly, when the pair of paper support guides 31 and 32 are moved from the first position to the second position, the paper 29 supported by the pair of paper support guides 31 and 32 is converted into the pair of paper support guides 31 and 32. It falls with its own weight while being guided by. Therefore, as shown in FIG. 2, when a plurality of sheets 29 are supported by the pair of sheet support guides 33 and 34, these sheets 29 are transferred from the pair of sheet support guides 33 and 34 to the sheet stacking base. Passed to 28. When a plurality of sheets 29 are supported on the pair of sheet support guides 31 and 32, these sheets 29 are transferred from the pair of sheet support guides 31 and 32 to the pair of sheet support guides 33 and 34. Delivered.

  On the other hand, in step S10, the paper discharge control unit 43 gives a drive instruction to the guide drive unit 45 to move the pair of paper support guides 33 and 34 from the first position to the second position. Then, the pair of paper support guides 33 and 34 are moved again from the second position to the first position, and then the pair of paper support guides 31 and 32 are moved from the first position to the second position. After that, the pair of paper support guides 33 and 34 are moved from the first position to the second position.

  Thus, the paper supported by the pair of paper support guides 33 and 34 is transferred from the pair of paper support guides 3 and 34 to the paper stacking base 28. The paper supported by the pair of paper support guides 31 and 34 is transferred from the pair of paper support guides 31 and 32 to the pair of paper support guides 33 and 34, and then the pair of paper support guides 33 and 34. To the paper stacking base 28.

  Thereafter, the paper discharge control unit 43 stops the rotation of each of the blower fans 39 to 42 by giving an instruction to stop driving to the fan drive unit 46 (step S11).

  FIG. 5 is a schematic diagram illustrating another configuration example of the inside of the paper discharge device 3. In the configuration of the paper discharge device 3 shown in the figure, the arrangement of the pair of paper support guides 31 and 32 and the arrangement of the pair of paper support guides 33 and 34 are particularly different from the configuration of the apparatus shown in FIG. That is, the pair of paper support guides 31 and 32 are arranged at different height positions in the vertical direction, and the pair of paper support guides 33 and 34 are also arranged at different height positions in the vertical direction. More specifically, among the pair of paper support guides 31 and 32, the paper support guide 31 on the left side in the figure is arranged at a position higher than the paper support guide 32 on the right side in the figure. Of the pair of paper support guides 33, 34, the paper support guide 33 on the left side in the drawing is disposed at a position lower than the paper support guide 34 on the right side in the drawing.

  FIG. 5 shows a state in which the respective sheet support guides 31 to 34 are arranged at the first position. In this state, the pair of paper support guides 31 and 32 are arranged in a state of facing each other with the minimum acute angle portion facing each other on an imaginary line that is not shown, and the pair of paper support guides 33 and 34 is not shown. On the imaginary line rising to the right, they are arranged in a state of facing each other with the minimum acute angle portions facing each other.

  On the other hand, in a state where the respective paper support guides 31 to 34 are arranged at the second position, the minimum acute angle portions of the respective paper support guides 31 to 34 are arranged obliquely downward. That is, the paper support guide 31 is disposed at a position obtained by rotating the rotation shaft 35 by a predetermined angle in the clockwise direction in the drawing from the first position shown in FIG. 5, and the paper support guide 32 is shown in FIG. From the first position, the rotary shaft 36 is disposed at a position rotated counterclockwise in the figure by an angle larger than the predetermined angle. Further, the paper support guide 33 is disposed at a position where the rotation shaft 37 is rotated by the predetermined angle in the clockwise direction in the drawing from the first position shown in FIG. 5, and the paper support guide 34 is shown in FIG. From the first position shown, the rotary shaft 38 is arranged at a position rotated counterclockwise in the figure by an angle larger than the predetermined angle.

  When the pair of paper support guides 31 and 32 are moved from the first position to the second position according to the rotation of the rotation shafts 35 and 36, the positions of the rotation shafts 35 and 36 are separated from each other during the operation. When moving the pair of paper support guides 31 and 32 from the second position to the first position in accordance with the rotation of the rotation shafts 35 and 36, the rotation shaft is moved during the operation. The positions 35 and 36 move in a direction approaching each other (inward in the horizontal direction). Similarly, when the pair of paper support guides 33 and 34 are moved from the first position to the second position according to the rotation of the rotation shafts 37 and 38, the positions of the rotation shafts 37 and 38 are separated from each other during the operation. When the pair of paper support guides 33 and 34 are moved from the second position to the first position in accordance with the rotation of the rotation shafts 37 and 38, they are rotated during the operation. The positions of the shafts 37 and 38 move in a direction in which they approach each other (inward in the horizontal direction).

  When the paper discharge device 3 having the above configuration is operated according to the flowchart shown in FIG. 4, the paper 29 discharged by the discharge roll 26 is a pair of paper support guides 31, 32 and a pair of paper support guides 33, Then, the paper is delivered (stacked) onto the paper stacking table 28. At this time, the pair of paper support guides 31 and 32 support the paper 29 in a state of being inclined obliquely with respect to the horizontal plane, and the pair of paper support guides 33 and 34 are also provided in a state of being inclined obliquely with respect to the horizontal plane. 29 is supported. More specifically, the posture of the paper 29 supported by the pair of paper support guides 31 and 32 is a posture in which the paper 29 is inclined upward to the left as shown in FIG. The posture of the paper 29 supported by the guides 33 and 34 is a posture inclined to the right as shown in FIG.

  FIG. 6 is an enlarged view showing another configuration example of the paper support guide. Although only the paper support guide 31 is shown in FIG. 6, the other paper support guides 32 to 34 have the same configuration. An elastic member 47 made of, for example, a resin film (for example, mylar film) is provided on the front end side (minimum acute angle side) of the paper support guide 31. The elastic member 47 is attached to the paper receiving portion 31 </ b> A of the paper support guide 31 by adhesion or the like while protruding from the minimum acute angle portion of the paper support guide 31.

  When the elastic member 47 is provided on the paper support guide 31 as described above, a predetermined number of sheets (a plurality of sheets) 29 are supported by the paper support guide 31 (the paper 29 is placed on the paper receiving portion 31A). When the paper support guide 31 is moved from the first position to the second position, the elastic member 47 flips the end of the paper 29. As a result, the paper 29 delivered from the paper support guide 31 to the paper support guide 33 is rolled by the elastic member 47. Such a sheet winding operation is similarly performed when the elastic members 47 are provided in the other sheet support guides 32 to 34.

  In the above-described embodiment, the pair of sheet support guides 31 and 32 and the pair of sheet support guides 33 and 34 are provided in two upper and lower stages above the sheet stacking table 28. However, the present invention is not limited to this. Instead of providing the pair of sheet support guides 33, 34, the sheet 29 may be directly transferred from the pair of sheet support guides 31, 32 to the sheet stacking base 28. Alternatively, the pair of paper support guides may be provided in three or more stages in the vertical direction.

  A paper discharge device according to the present invention includes a paper discharge device main body having a storage space for storing paper to be discharged, a paper stacking table on which paper is stacked in the paper discharge device main body, and paper discharged to the storage space. The sheet is supported in a state where a space is provided between the sheet stacker and the sheet stacking base in the sheet discharge apparatus main body, and at the first position for supporting the sheet to be discharged and the first position. A support member that operates between a second position that guides the supported paper to the paper stacking table, and the number of papers supported by the support member at the first position exceeds a predetermined number; Control means for controlling the support member to move from the first position to the second position, and the support member is provided in a plurality of stages in the vertical direction.

  According to this paper discharge device, the sticking phenomenon of the paper stacked on the paper stacking base can be more effectively prevented as compared with the case where only one stage of the support member is provided in the vertical direction.

1 is a schematic diagram illustrating a configuration example of an image forming apparatus to which the present invention is applied. 3 is a schematic diagram illustrating an example of an internal configuration of a paper discharge device. FIG. 3 is a block diagram illustrating a configuration example of a control system that controls the operation of the paper discharge device. FIG. 6 is a flowchart illustrating a processing procedure of the paper discharge device. FIG. 10 is a schematic diagram illustrating another configuration example inside the paper discharge device. FIG. 10 is an enlarged view showing another configuration example of the paper support guide.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 2 ... Image forming apparatus main body, 3 ... Paper discharge apparatus, 26 ... Discharge roll, 27 ... Discharge sensor, 28 ... Paper stacking base, 31-34 ... Paper support guide, 43 ... Paper discharge control part

Claims (2)

A paper discharge device main body having a storage space for storing paper discharged from an image fixing device that fixes the image on the paper ;
A paper stacking table for stacking paper in the paper discharge device body;
A sheet discharged into the storage space is supported in the sheet discharge apparatus body with a space between the sheet stacking table and a first position for supporting the discharged sheet, A support member that operates between a second position for guiding the paper supported at the first position to the paper stack;
Control means for controlling the support member to move from the first position to the second position when the number of sheets supported by the support member at the first position exceeds a predetermined number; equipped with a,
The discharge device according to claim 1, wherein the support member includes an elastic member that flips an end portion of the sheet when the support member moves from the first position to the second position . And an image forming apparatus main body to have a image fixing apparatus for fixing an image on a sheet,
A paper discharge apparatus main body having a storage space for storing paper discharged from the image fixing device of the image forming apparatus main body;
A paper stacking table for stacking paper in the paper discharge device body;
A sheet discharged into the storage space is supported in the sheet discharge apparatus body with a space between the sheet stacking table and a first position for supporting the discharged sheet, A support member that operates between a second position for guiding the paper supported at the first position to the paper stack;
Control means for controlling the support member to move from the first position to the second position when the number of sheets supported by the support member at the first position exceeds a predetermined number; equipped with a,
The image forming apparatus according to claim 1, wherein the support member includes an elastic member that flips an end portion of a sheet when the support member moves from the first position to the second position .

Images