JP3721571B2 - Paper discharge device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a paper discharge device that stacks and stores sheets one by one on a stacker table provided so as to be movable up and down.
[0002]
[Prior art]
A stacker table that is supported so as to be movable up and down, and is configured to stack and store sheets on the stacker table while lowering the stacker table as the stacking amount of sheets discharged onto the stacker table increases. Devices are conventionally known. This type of paper discharge device may be used by being connected to an electrophotographic device such as a laser printer. In recent electrophotographic apparatuses, a double-sided printing mode that records and forms toner images on both front and back sides of the paper, a paper discharge with the toner image side facing up (face-up paper discharge mode), and vice versa. The operator can freely select a paper discharge mode or the like for discharging paper with the image side facing down (face-down paper discharge mode). In addition, consideration has been given to the paper that can be used in the electrophotographic apparatus so as to be compatible with various paper sizes, paper thicknesses (paper continuous amount), and paper quality.
[0003]
[Problems to be solved by the invention]
As a system for fixing a toner image formed on a sheet using a known electrophotographic process to the sheet, an electrophotographic apparatus generally employs a heat fixing roller system. The paper discharged through this type of heat fixing roller system is subject to thermal contraction due to the heating action, and the leading edge and the trailing edge of the sheet tend to warp toward the surface having the toner image and are likely to be bent. Thus, for example, when a toner image is thermally fixed on one side of a sheet, and then the sheet is discharged in the face-up discharge mode, it curves upward (in a U shape when the sheet is viewed from the side). When the paper is discharged in the face-down paper discharge mode, it tends to bend downward.
[0004]
In the conventional paper discharge device, the bending direction of the paper due to the paper discharge mode of the electrophotographic apparatus is taken into account, the curve direction of the discharged paper is determined based on the paper discharge mode from the host device, and the bending direction Although the paper path interval (height) was controlled by the paper stack and the paper was loaded, when loading paper with different curving directions on the same stacker table, the curving direction of the loaded paper is not considered and the paper is ejected. Since the paper path interval (height) was controlled taking into account only the direction of the incoming paper, the uppermost surface of the stacked paper stacked on the stacker table and the guide member were controlled. When stacking paper that is curved downward on the same stacker table after the paper is stacked at a wide interval, the interval is controlled to be narrow before the paper that is curved downward is discharged. The leading edge of the downwardly curved sheet discharged to the rear end of the stacked sheet that is curved in the direction interferes, causing a sheet stacking failure.
[0005]
The object of the present invention is to optimize the trigger for controlling the paper path interval (height) by judging the curving direction of the stacked paper and the curving direction of the ejected paper based on the paper ejection mode from the host device. Another object of the present invention is to provide a paper discharge device capable of stacking sheets satisfactorily.
[0006]
[Means for Solving the Problems]
A paper discharge device having a stacker table supported so as to be movable up and down, and stacking and storing sheets on the stacker table while lowering the stacker table with an increase in the stacking amount of sheets discharged onto the stacker table A conveying means provided above the stacker table for conveying the paper ejected on the stacker table to a predetermined position; and a leading end of the paper ejected on the stacker table provided in the vicinity of the conveying means. The table position of the stacker table is controlled so as to restrict the gap between the guide means guided to the conveying means, the upper surface of the stacker table or the uppermost surface of the stacked paper stacked on the stacker table, and the guide means to a narrow interval. 1st space | interval control means, the said stacker table upper surface, or the said stacker table On the stacker table top surface or on the stacker table, second interval regulating means for controlling the table position of the stacker table so as to regulate the gap between the uppermost surface of the stacked sheets stacked on the guide means and the guide means to a wide distance. Control means for controlling an opportunity to switch the interval between the uppermost surface of the stacked stacked sheets and the guide means to a narrow interval or a wide interval, and the control means discharges the interval to be regulated to a wide interval. In the case of the mode, and when the sheet is discharged from the stacker table to the discharge mode in which the interval should be restricted to a narrow interval, a predetermined number of sheets are loaded on the stacker table. After loading, the paper discharge mode should be restricted to a narrow interval and the paper discharge should be restricted to a narrow interval. If the paper is discharged on the stacker table and the paper discharge mode is set to restrict the interval to a wide interval, the corresponding paper arrives on the stacker table. Before the operation is performed, the interval is switched to a sheet discharge mode in which the interval should be restricted to a wide interval.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic front view showing the overall configuration of the paper discharge device of the present invention, FIG. 2 is a schematic side view for explaining a stacker table lifting mechanism in the paper discharge device of the present invention, and FIG. FIG. 4 is an operation timing chart, and FIG. 4 is a timing chart in the paper discharge device of the present invention.
[0008]
The configuration of the paper discharge device according to the present invention will be described with reference to FIGS.
[0009]
In the figure, reference numeral 2 is a table support member. As shown in FIG. 2, one end of the belt member 3 is fixed to one end of the table support member 2. The belt member 3 is folded back by a bar member 4a fixed at a predetermined position, and the other end of the belt member 3 is fixed to the shaft 4b. Here, the shaft 4 b is provided so as to be rotationally driven by the motor 5. Further, a stacker table 1 is provided on the table support member 2 so as to be detachable from the table support member 2. When a predetermined amount of paper is loaded on the stacker table 1, the stacker table 1 is moved from the table support member 2 to the stacker table 1. The entire table 1 can be taken out and transported.
[0010]
With the above configuration, the table support member 2 rises when the shaft 4b is rotated in the direction of winding the belt member 3, and descends when the shaft 4b is rotated in the direction of rewinding the belt member 3.
[0011]
Reference numeral 11 is a stopper. The stopper 11 is fixed to a frame (not shown) or the like so as to be positioned near the side edge of the stacker table 1. Above the stacker table 1, a paper transport paddle 9 that transports the paper 12 discharged to the stacker table 1 toward the stopper 11 is provided. Further, a guide member 10 that guides the leading end of the paper 12 discharged to the stacker table 1 to the paper transport paddle 9 is provided in the vicinity of the paper transport paddle 9. Here, the paper transport paddle 9 is provided so as to be rotationally driven by a motor 13.
[0012]
Further, above the stacker table 1, a first detector 7 constituted by, for example, an actuator type photo interrupter, and a second detector provided at a position lower than the first detector 7 by an interval L. 8 are provided.
[0013]
In FIG. 1, reference numeral 15 is a paper conveyance roller, and the paper conveyance roller 15 is provided so as to be rotationally driven by a motor 14.
[0014]
Further, the table support member raising / lowering motor 5, the paper conveyance paddle motor 13, the paper conveyance roller motor 14, the first detector 7 and the second detector 8 are connected to the control device 6.
[0015]
Next, the table operation of the paper discharge device will be described with reference to FIG. In the following description, in the paper discharge mode in which the distance between the upper surface of the stacker table 1 or the uppermost surface of the stacked sheets 12 stacked on the stacker table 1 and the guide member 10 should be restricted to a narrow interval (hereinafter, referred to as “the discharge mode”) The description will be divided into “first paper discharge mode” and a case of paper discharge mode in which the interval should be restricted to a wide interval (hereinafter referred to as “second paper discharge mode”).
[0016]
(First discharge mode)
When the host device is an electrophotographic device such as a laser printer, the paper discharge mode that should be restricted to a narrow interval is, for example, the mode in which the paper is printed face-down so that the printing surface of the single-sided printed paper faces down In addition, this is applicable to a mode in which the paper after double-sided printing is discharged as it is without being turned upside down. That is, in these modes, the sheet tends to be discharged in a downward curved state, so that the landing on the upper surface of the stacker table 1 which is the sheet stacking surface or the uppermost surface of the stacked sheets 12 stacked on the stacker table 1 is performed. When the angle is large, the leading edge of the discharged paper interferes with the top surface of the stacked paper 12 when landing, and stacking defects are likely to occur. Further, since the leading end of the sheet is lower than the detection position on the uppermost surface of the stacked sheet 12, the alignment of the stacked sheet 12 is deteriorated by passing through the stopper 11. In order to prevent these problems, the uppermost surface of the stacked paper 12 is made as high as possible to stabilize the paper discharge operation.
[0017]
In the first paper discharge mode, the motor 5 is driven by the instruction from the control device 6 to raise the table support member 2. Along with this ascending operation, the upper surface of the stacker table 1 or the uppermost surface of the sheet discharged onto the stacker table 1 first activates the second detector 8, and the output of the second detector 8 is logic “H ( high) ". Further, when the table support member 2 is raised, the upper surface of the stacker table 1 or the uppermost surface of the sheet discharged onto the stacker table 1 activates the first detector 7, and the output of the first detector 7 is also increased. Logic “H”.
[0018]
When the outputs of the first detector 7 and the second detector 8 become logic “H”, the ascending operation of the table support member 2 is stopped, and then the motor 5 is turned on for a time T1 according to an instruction from the controller 6. The table support member 2 is lowered and the table position is controlled.
[0019]
3A, when the first detector 7 detects the upper surface of the stacker table 1 or the uppermost surface of the paper discharged onto the stacker table 1 even after the time T1 has elapsed. In response to an instruction from the control device 6, the motor 5 is further driven for a time T2, and the first detector 7 is lowered to a position where it does not detect the upper surface of the stacker table 1 or the uppermost surface of the sheet discharged onto the stacker table 1. .
[0020]
Sheet loading starts from the position where the table position control is completed. In response to an instruction from the control device 6, the motor 14 is driven when the stacked paper 12 is transported, and the paper 12 is transported by the paper transport roller 15, so that the paper is between the upper surface of the stacker table 1 and the guide member 10, or The sheet is conveyed between the uppermost surface of the stacked sheets 12 stacked on the stacker table 1 and the guide member 10. Further, the conveyed paper 12 is conveyed until it abuts against the stopper 11 by the contact of the paper conveyance paddle 9.
[0021]
(Second delivery mode)
When the host device is an electrophotographic device such as a laser printer, the paper discharge mode that should be regulated over a wide interval is, for example, the mode in which the paper is printed face up so that the printing surface of the single-sided printed paper faces upward This also applies to a mode in which the paper after double-sided printing is reversed and ejected. That is, in these modes, since the sheet tends to be discharged in a curved state upward, the trailing edge of the sheet is at a higher position than the detection position of the uppermost surface of the stacked sheet 12, so the stacked sheet 12 The trailing edge of the sheet closes the entrance path of the discharged paper, and stacking defects are likely to occur. In order to prevent this, the top surface of the stacked paper 12 is made as low as possible to stabilize the paper discharge operation.
[0022]
In the second paper discharge mode, the motor 5 is driven by the instruction from the control device 6 to raise the table support member 2. Along with this ascending operation, the upper surface of the stacker table 1 or the uppermost surface of the paper discharged onto the stacker table 1 operates the second detector 8, and the output of the second detector 8 is logic “H (high)”. "
[0023]
In the first paper discharge mode, the table support member 2 is further raised to a position where the first detector 7 is operated. In the second paper discharge mode, the second detector 8 is operated. At that time, the ascending operation is stopped and the first detector 7 is not raised to the position where it is operated. That is, the raising operation of the table support member 2 is stopped while the output of the second detector 8 is logic “H” and the output of the first detector 7 is logic “L (low)”.
[0024]
Thereafter, the motor 5 is driven for a time T1 in accordance with an instruction from the control device 6, and the table support member 2 is lowered to perform table position control. 3B, when the second detector 8 detects the upper surface of the stacker table 1 or the uppermost sheet discharged onto the stacker table 1 even after the time T1 has elapsed. In response to an instruction from the control device 6, the motor 5 is further driven for a time T2, and the second detector 8 is lowered to a position where it does not detect the upper surface of the stacker table 1 or the uppermost surface of the paper discharged onto the stacker table 1. .
[0025]
Sheet loading starts from the position where the table position control is completed. In response to an instruction from the control device 6, the motor 14 is driven when the stacked paper 12 is transported, and the paper 12 is transported by the paper transport roller 15, so that the paper is between the upper surface of the stacker table 1 and the guide member 10, or The sheet is conveyed between the uppermost surface of the stacked sheets 12 stacked on the stacker table 1 and the guide member 10. Further, the conveyed paper 12 is conveyed until it abuts against the stopper 11 by the contact of the paper conveyance paddle 9.
[0026]
Next, the operation of the paper discharge device of the present invention will be described with reference to FIG. In the case of the second discharge mode described above, and when the sheets are stacked on the stacker table 1, it is necessary to discharge the sheets on the same stacker table 1 in the first discharge mode. In the case of switching to the mode, as shown in FIG. 4A, after a predetermined number of sheets corresponding to the first discharge mode are stacked on the stacker table 1 in the second discharge mode, the motor is instructed by the control device 6. 5 is driven to raise the table support member 2. With this rising operation, the uppermost surface of the sheet discharged onto the stacker table 1 first activates the second detector 8 and the output of the second detector 8 becomes logic “H (high)”. . Further, when the table support member 2 is raised, the uppermost surface of the sheet discharged onto the stacker table 1 operates the first detector 7, and the output of the first detector 7 is also logic “H”. Become.
[0027]
When the outputs of the first detector 7 and the second detector 8 become logic “H”, the ascending operation of the table support member 2 is stopped, and then the motor 5 is turned on for a time T1 according to an instruction from the controller 6. The table support member 2 is lowered and the table position is controlled.
[0028]
If the first detector 7 detects the uppermost surface of the sheet discharged onto the stacker table 1 even after the elapse of time T1, as indicated by a broken line in FIG. In response to this instruction, the motor 5 is further driven for a time T2, and the first detector 7 is lowered to a position where the uppermost surface of the sheet discharged onto the stacker table 1 is no longer detected. Paper stacking is started in the first stacking mode from the position where the table position control is completed.
[0029]
As described above, when there is a high tendency for the stacked paper 12 to be stacked in a curved state in the upward direction, if the next transport paper is highly likely to be discharged in a curved state in the downward direction, the top surface of the stacked paper 12 is Since the rear end of the stacked paper 12 is higher than the detection position, it interferes with the front edge of the next downwardly curved conveyance paper, so that it is stacked on the stacker table 1 in the second paper discharge mode. The distance between the uppermost surface of the loaded paper 12 and the guide member 10 is set wide, and the uppermost surface of the loaded paper 12 is made as low as possible so that the rear end of the loaded paper 12 interferes with the front end of the conveyed paper. In addition, by stacking a predetermined number of sheets conveyed on the stacker table 1 and then stacking them in the first discharge mode, the upward curved state of the loaded sheets 12 is alleviated, and the conveyed sheets are stopped by the stopper 1. It can be transported smoothly until. Further, by making it possible to adjust the number of sheets to be stacked, it is possible to adjust the relaxation of the upwardly curved state of the stacked sheets 12, and it is possible to satisfactorily stack the sheets.
[0030]
Further, in the case of the above-described first discharge mode and when the sheets are stacked on the stacker table 1, it is necessary to discharge the sheet onto the same stacker table 1 in the second discharge mode. When switching to the paper discharge mode, as shown in FIG. 4B, before the paper corresponding to the second paper discharge mode arrives at the stacker table 1, the motor 5 is driven by an instruction from the controller 6 to support the table. The member 2 is raised. With this ascending operation, the uppermost surface of the sheet discharged onto the stacker table 1 activates the second detector 8 and the output of the second detector 8 becomes logic “H (high)”.
[0031]
When the second detector 8 is activated, the ascending operation is stopped, and the first detector 7 is not raised to the position where it is activated. That is, the raising operation of the table support member 2 is stopped while the output of the second detector 8 is logic “H” and the output of the first detector 7 is logic “L (low)”.
[0032]
Thereafter, the motor 5 is driven for a time T1 in accordance with an instruction from the control device 6, and the table support member 2 is lowered to perform table position control. If the second detector 8 detects the uppermost surface of the sheet discharged onto the stacker table 1 even after the elapse of time T1, as indicated by a broken line in FIG. In response to this instruction, the motor 5 is further driven for a time T2, and the second detector 8 is lowered to a position where the uppermost surface of the sheet discharged onto the stacker table 1 is no longer detected. Paper stacking is started in the second stacking mode from the position where the table position control is completed.
[0033]
As described above, when there is a high tendency that the stacked sheets 12 are stacked in a curved state in the downward direction, if there is a high tendency for the next transport sheet to be discharged in a curved state in the upward direction, the sheet corresponding to the second discharge mode The second paper discharge mode is switched to the second paper discharge mode before the paper corresponding to the second paper discharge mode arrives at the stacker table 1 so that the paper is accurately fed to the paper transport paddle 9 without getting over the guide member 10. In the mode, the gap between the uppermost surface of the stacked paper 12 stacked on the stacker table 1 and the guide member 10 is widely defined, so that the uppermost surface of the stacked paper 12 is made as low as possible so that the rear of the stacked paper 12 By preventing the end of the paper from entering the discharge path, the paper can be stacked well by stabilizing the paper discharge operation.
[0034]
In the present invention, the signal for switching between the first discharge mode / second discharge mode is a signal output depending on whether the operator has selected the single-sided printing mode or the double-sided printing mode, or , Based on a signal output depending on whether the operator has selected a mode for reversing and discharging the printed paper, or a mode for discharging without reversing, or a signal based on the paper size selected by the operator, etc. When these signals are input to the control device 6, the timing for switching between the first paper discharge mode and the second paper discharge mode is optimized.
[0035]
【The invention's effect】
As described above, according to the present invention, the curving direction of the stacked paper and the curving direction of the ejected paper are determined based on the paper ejection mode from the host device, and the paper path interval is controlled by the curving direction. It is possible to provide a paper discharge device that optimizes the opportunity and can stack the sheets satisfactorily.
[Brief description of the drawings]
FIG. 1 is a schematic front view showing an overall configuration of a paper discharge device according to the present invention.
FIG. 2 is a schematic side view for explaining a stacker table lifting mechanism in the paper discharge device of the present invention.
FIG. 3 is a table operation timing chart in the paper discharge device.
FIG. 4 is a timing chart in the paper discharge device of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Stacker table, 2 ... Table support member, 3 ... Belt member, 4b ... Shaft, 5, 13, 14 ... Motor, 6 ... Control apparatus, 7 ... 1st detector, 8 ... 2nd detector, 9 ... paper transport paddle, 10 ... guide member, 11 ... stopper, 12 ... paper, 15 ... paper transport roller.

Claims (2)

A paper discharge device having a stacker table supported so as to be movable up and down, and stacking and storing sheets on the stacker table while lowering the stacker table with an increase in the stacking amount of sheets discharged onto the stacker table In
A transport unit provided above the stacker table and configured to transport a sheet discharged onto the stacker table to a predetermined position;
A guide unit provided in the vicinity of the transport unit and guiding a leading end of the sheet discharged onto the stacker table to the transport unit;
First interval regulating means for controlling the table position of the stacker table so as to regulate the gap between the upper surface of the stacker table or the uppermost surface of the stacked sheets stacked on the stacker table and the guide means to a narrow interval;
Second interval regulating means for controlling the table position of the stacker table so as to regulate the gap between the upper surface of the stacker table or the uppermost surface of the stacked sheets stacked on the stacker table and the guide means at a wide interval;
Have a control means for controlling the trigger for switching the distance between said guide means and the top surface of the stacked paper sheets stacked on the stacker table top or the stacker table to a narrow interval or widely spaced,
The control means is a paper discharge mode in which the interval should be restricted to a wide interval, and the paper discharge mode in which the interval should be restricted to a narrow interval from a state where the paper is being discharged onto the stacker table. When a predetermined number of sheets are stacked on the stacker table, the sheet is switched to a paper discharge mode in which the interval should be restricted to a narrow interval.
In the case of the paper discharge mode in which the interval should be restricted to a narrow interval and when the paper is discharged on the stacker table to the paper discharge mode in which the interval should be restricted to a wide interval The paper discharge device is switched to a paper discharge mode in which the interval should be restricted to a wide interval before the paper arrives on the stacker table . An electrophotographic apparatus comprising the paper discharge device according to claim 1.

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