JP2007137608A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device achieving excellent paper alignment performance on a paper stacking table by preventing paper irregularity on the paper stacking table caused by bending of paper delivered from the image forming device to a paper delivery device, and preventing paper jam. <P>SOLUTION: The paper delivery device is provided with the paper stacking table for staking and storing paper sent from the image forming device; a first paper aligning member arranged on the downstream side in the paper advancing direction, reciprocated and slid from a specified position to the paper advancing direction every time the paper is delivered to the paper stacking table, and regulating the position of the paper in the paper advancing direction; and a second paper aligning member arranged on the upstream side in the paper advancing direction and regulating the position of the paper in the paper advancing direction. The paper delivery device is further provided with a control means for varying a distance between the paper delivered to the paper stacking table and the first paper aligning member, based on paper delivery mode information on the paper sent from the image forming device and paper length information on the paper delivered from the image forming device. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine or a laser beam printer.

  FIG. 1 shows an image forming apparatus 3 and a paper discharge device 2 disposed adjacent to the image forming apparatus 3. In the following description, the front side in FIG. 1 is referred to as an operator side, the depth side is referred to as an anti-operator side, the right side is referred to as a paper traveling direction side, and the left side is referred to as an anti-paper traveling direction side.

  FIG. 2 is a schematic sectional view taken along line A-A ′ of FIG. 1. The paper discharge device 2 is provided at a subsequent stage of the image forming device 3 and is configured to stack printed sheets output from the image forming device 3 in a uniform manner. In consideration of post-processing such as bookbinding, the paper discharge device 2 needs to align the papers in a non-uniform manner in the paper advance direction and the direction perpendicular to the paper advance direction (paper width direction).

  The image forming apparatus 3 is an apparatus for fixing a toner image on the paper 1 using toner or the like and forming a predetermined image. The image forming apparatus 3 sends the paper 1 to the paper discharge device 2 through the discharge port by the transport roller 6. A path sensor 12 is attached in the vicinity of the discharge port of the image forming apparatus 3. The control unit 13 detects the paper 1 discharged to the paper discharge device 2 by the path sensor 12 and notifies the control unit 14 that the paper 1 is discharged. The control unit 13 notifies the control unit 14 of sheet information such as the sheet length, the sheet continuous amount, and the sheet discharge mode in advance before the sheet 1 is sent to the sheet discharge device 2. As for the paper discharge mode, a mode in which the toner image fixed on the paper 1 in single-sided printing is discharged downward is referred to as a face-down paper discharge mode, and a mode in which the toner image is discharged upward is referred to as a face-up paper discharge mode. And The control unit 14 is equipped with a memory 19, and the paper information sent from the control unit 13 is stored in the memory 19. The control unit 14 controls the paper discharge device 2 based on the paper information stored in the memory 19.

  The paper discharge device 2 includes a paper stacking table 4 on which the paper 1 is stacked, a transport roller 7 that transports the paper 1 received from the image forming device 3 onto the paper stacking table 4, a transport roller 8, a transport roller 9, and a reverse of the paper 1. A second sheet alignment member 5 for fixing the position of the sheet traveling direction side end, a first sheet alignment member 10 for aligning the sheet traveling direction side (hereinafter referred to as a sheet leading end stopper), a sheet on the operator side and the counter operator side For aligning the sheets 1 on the sheet stacking table 4 in the sheet aligning unit 18. The sheet aligning unit 18 has an operator-side sheet aligning member 15 and an anti-operator-side sheet aligning member (not shown). The sheet alignment member driving unit 16 and the first sheet alignment member driving unit 11 are arranged. The path sensor 17 is disposed on the paper transport path of the paper discharge device 2 to detect the paper position.

  Next, the operation of the paper leading edge stopper 10 will be described with reference to FIGS. FIG. 3 is a diagram showing the positions of the paper 1 and the paper leading edge stopper 10 on the paper stacking table 4, and FIG. 4 is a time chart showing the paper leading edge stopper operation.

  A Path Sensor-N signal in FIG. 4 is a signal input from the path sensor 17 to the control unit 14. The signal 1 is “L” when the sheet 1 is passing over the path sensor 17 and is “H” when the sheet 1 is not passing.

  The Stopper CCW-P signal is a signal indicating the operation direction of the paper front end stopper 14, and is output from the control unit 14 to the paper front end stopper driving unit 11, and when the paper front end stopper 14 operates in the counter paper advance direction, “ “H”, “L” when operating in the paper advance direction.

  The Stopper DRV-P signal is a signal indicating the operation of the paper leading end stopper 10 and is output from the control unit 14 to the paper leading end stopper driving unit 11 and becomes “H” during operation and “L” during non-operation.

  The paper front end stopper position represents the position of the paper front end stopper 10, and is A when the position A is shown in FIG. 3, B when the position B is shown, and undefined when the paper front end stopper 10 is in operation.

The paper front end stopper 10 moves to the position A shown in FIG. 3 in accordance with the paper length sent from the control unit 13 to the control unit 14 before the paper 1 is discharged to the paper discharge device 2. Distance of the sheet 1 and the sheet leading edge stopper 10 on the paper loading table 4 is L _1. When the image forming apparatus 3 sheet 1 is fed to the sheet discharge unit 2, as shown in (X1) in FIG. 4, the control unit 14, after passing through the rear end of the sheet 1 is a path sensor 17, after specified time T ₁ The Stopper CCW-P signal is set to “H”, and the Stopper DRV-P signal is output to the paper leading edge stopper driving unit 11 so as to operate for L ₁ minutes. As a result, the paper leading edge stopper 10 moves to the position B shown in FIG. 3, and the paper 1 on the paper stacking table 4 is pushed by the paper leading edge stopper 10. After aligning the paper 1 for a specified time T2 and waiting for the paper leading edge stopper 10 at the position B, as shown in (X2) of FIG. 4, the control unit 14 sets the Stopper CCW-P signal to “L”. ”And the Stopper DRV-P signal is output to the paper leading end stopper driving unit 11 so as to operate for L ₁ minutes. As a result, the paper leading end stopper 10 returns to the position A shown in FIG. When the sheets 1 are continuously discharged, this operation is repeated for each discharged sheet.

  In the image forming apparatus 3, as a method for fixing a toner image transferred onto the paper 1, a heat fixing roller method in which heating and pressurization are performed by a heat fixing roller is generally employed. The paper 1 discharged through this heat fixing roller system tends to warp and bend easily due to the thermal contraction of the paper due to the heating action. As a result, in the face-down paper discharge mode in which the toner image is thermally fixed and then discharged with the toner image down, the paper 1 is curved downward and discharged with the toner image face up. In this case, the sheet 1 is sent from the image forming apparatus 3 to the sheet discharge apparatus 2 in a state of being curved upward. Further, the amount of curvature of the heat-fixed paper 1 tends to be large when the paper length is short.

  On the other hand, in Patent Document 1, the curving direction of the ejected paper 1 is determined based on the paper ejection mode of the paper 1 sent from the image forming apparatus 3 to the paper ejection apparatus 2, and the paper stacking table is determined based on the curving direction. 4 discloses a paper discharge device 2 that can change the vertical position of 4 and control the distance of the paper conveyance path so that the paper 1 can be stacked satisfactorily.

Japanese Patent Laid-Open No. 11-130317

  However, in the paper discharge device 2 of Patent Document 1, when the paper 1 having a short paper length and curved downward in the face-down paper discharge mode is sent from the image forming device 3, it is placed on the paper stacking table 4. The paper 1 enters between the stacked paper 1 and the paper leading edge stopper 10, and the paper 1 cannot be aligned by the paper leading edge stopper 10, resulting in paper stacking failure or paper jam.

  A paper stacking table for stacking and storing sheets sent from the image forming apparatus, and a reciprocating slide from the specified position to the sheet traveling direction each time the sheet is discharged to the sheet stacking table. A paper discharge device having a first paper alignment member that moves and restricts a paper advance direction position of the paper, and a second paper alignment member that is disposed upstream of the paper advance direction and restricts the paper advance direction position of the paper. The paper discharged to the paper stacking table and the first paper based on the paper discharge mode information of the paper sent from the image forming apparatus and the paper length information of the paper discharged from the image forming apparatus Control means for varying the distance from the alignment member is provided.

  According to the present invention, by changing the operation of the paper leading end stopper of the paper discharge device, it is possible to prevent paper stacking failure and paper jam due to paper curvature.

  An object of the present invention is to prevent a paper stacking failure caused by the paper 1 entering between the paper 1 discharged onto the paper stacking table 4 and the paper front end stopper 10 due to the curvature of the paper 1 discharged from the image forming apparatus 3. By changing the distance between the paper 1 stacked on the paper stacking table 4 and the paper front end stopper 10 according to the paper discharge mode of the fixed paper 1 sent from the forming apparatus 3 and the paper length, the same configuration as in the prior art is achieved. It was realized.

  An embodiment of the present invention will be described with reference to FIGS.

  FIG. 5 is a diagram showing the positions of the sheet 1 and the sheet leading end stopper 10 on the sheet stacking table 4 in the present invention. FIG. 6 is a flowchart showing the paper leading edge stopper control in the present invention. FIG. 7 is a time chart showing the paper leading edge stopper operation in the present invention.

The sheet leading edge stopper control based on the sheet information discharged to the sheet discharge device 2 will be described with reference to FIG. When the sheet 1 is conveyed from the image forming apparatus 3 to the sheet discharge apparatus 2, the control unit 14 recognizes the sheet length and the sheet discharge mode based on the sheet information sent from the control unit 13 (Step 1). Here, it is determined whether or not the length of the paper 1 sent to the paper discharge device 2 is 8.5 inches or more (Step 2). When the paper length of the paper 1 is 8.5 inches or more, the paper front end stopper position is set to A, and the paper front end stopper operation amount is set to L ₁ in the memory 19 (Step 3). When the paper length of the paper 1 is 8.5 inches or less, it is determined whether or not the paper discharge mode is the face-up paper discharge mode (Step 4). Discharge mode is the case of face-up sheet ejection mode, set the paper leading edge stopper position A, in the memory 19 of the sheet leading edge stopper operation amount as L ₁ (Step3). On the other hand, when the paper discharge mode is the face-down paper discharge mode, the paper front end stopper position is set to C and the paper front end stopper operation amount is set to L ₂ (L ₂ <L ₁ ) in the memory 19 (Step 5). Then, before being sent from the image forming apparatus 3 to the paper discharge apparatus 2, the control unit 14 operates the paper front end stopper 10 to the set position by the paper front end stopper position set in the memory 19 (Step 6). Here, when the sheet leading edge stopper position of the paper leading edge stopper information A, the sheet leading edge stopper operation amount is set to L _1, in order to perform the same operation as the prior art, a description thereof will be omitted in this embodiment.

Next, if the sheet leading edge stopper position of the paper leading edge stopper information C, the sheet leading edge stopper operation amount is set to L _2, will be described with reference to FIGS. 5 and 7. Note that the signal names and signal polarities shown in FIG.

As shown in FIG. 5, the paper leading end stopper 10 moves to the position C before the paper 1 is discharged to the paper discharge device 2. Distance of the sheet 1 and the sheet leading edge stopper 10 on the paper loading table 4 is L _2. Here, L ₂ is a distance at which the sheet 1 that is curved downward and discharged from the image forming apparatus 3 does not enter the gap between the sheet 1 on the sheet stacking table 4 and the sheet front end stopper 10. When the image forming apparatus 3 sheet 1 is fed to the sheet discharge unit 2, as shown in (X3) in FIG. 7, the control unit 14, the rear end of the sheet 1 is passed through the path sensor 17, the specified time T ₁ The Stopper CCW-P signal is set to “H”, and the Stopper DRV-P signal is output to the sheet leading end stopper driving unit 11 so as to operate for L ₂ , and the sheet leading end stopper 10 is moved to the B position. After aligning the paper 1 for a specified time T ₂ and waiting for the paper leading edge stopper 10 at the position B, the control unit 14 sends a Stopper CCW-P signal as “X4” in FIG. and L ", and outputs the stopper DRV-P signal to the paper leading edge stopper driving unit 11 to operate _{L 2} minutes. As a result, the paper leading end stopper 10 returns to the position C. When the sheets 1 are continuously discharged, this operation is repeated for each discharged sheet.

  As described above, when the sheet information of the sheet 1 discharged to the sheet discharge device 2 is 8.5 inches or less and the face-down sheet discharge mode is selected, it is determined that the sheet 1 is greatly curved downward. By setting the distance between the paper 1 on the paper stacking table 4 and the paper leading edge stopper 10 to be small, the discharged paper 1 enters the gap between the paper 1 and the paper leading edge stopper 10 to prevent a paper stacking failure. be able to.

The figure which showed the printing system in this invention. FIG. 2 is a schematic cross-sectional view of the paper discharge device taken along line A-A ′ of FIG. 1. The figure which shows the conventional paper stacking table and a paper front-end | tip stopper position. The time chart which shows the conventional tip stopper operation | movement. FIG. 5 is a diagram illustrating a paper stacking table and a paper leading end stopper position according to the present invention. The flowchart which shows the front-end | tip stopper control of this invention. The time chart which shows the front-end | tip stopper operation | movement of this invention.

Explanation of symbols

1 is a paper, 2 is a paper discharge device, 3 is an image forming device, 4 is a paper stacking table, 5 is a second paper alignment member, 6, 7, 8, and 9 are transport rollers, and 10 is a first paper alignment member (paper) (Tip stopper), 11 is a first sheet alignment member drive unit, 12 and 17 are path sensors, 13 and 14 are control units, 15 is an operator side sheet alignment member, 16 is a sheet alignment member drive unit, 18 is a sheet alignment unit, 19 Is memory.

Claims (2)

A paper stacking table for stacking and storing sheets sent from the image forming apparatus;
A first paper alignment member that is disposed downstream of the paper traveling direction and reciprocally slides in a paper traveling direction from a specified position each time the paper is discharged to the paper stacking table, and regulates the paper traveling direction position of the paper; ,
A paper discharge device having a second paper alignment member disposed upstream of the paper travel direction and regulating a paper travel direction position of the paper;
The paper discharged to the paper stacking table and the first paper alignment member based on the paper discharge mode information of the paper sent from the image forming apparatus and the paper length information of the paper discharged from the image forming apparatus An image forming apparatus comprising control means for varying the distance to the image forming apparatus. When the paper discharge mode is a face-down paper discharge mode in which paper is discharged with the image side down, and the paper length is equal to or less than a specified length, the paper discharged to the paper stacking table and the first paper alignment The paper discharge device according to claim 1, wherein a distance from the member is narrowed.

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