JP2000219397A - Paper discharger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper discharger favourable in workability when discharging and fetching a paper sheet while precisely detecting a filled-up state on a sheet stacking base regardless of a condition of the sheet. SOLUTION: Driving motion of a pressurizing means 7 to selectively move an arm member 2 provided free to make contact with and separate from an upper surface 1a of a paper sheet 1A stacked on a sheet stacking base to a pressurizing position to pressurize the stacked sheet 1A and a separating position to be separated from the stacked sheet 1A is controlled by a control means 18 in accordance with a paper discharging state of the sheet on a paper discharger furnished with the sheet stacking base 5 to stack the sheet 1 discharged from a discharge port 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper discharge device used for an image forming apparatus such as a printer, a facsimile, a copying machine, and the like.

[0002]

2. Description of the Related Art Japanese Patent Laying-Open No. 5-58545 discloses that a sheet discharged from a sheet discharge port is stacked on a sheet stacking table, and the position of an arm member is changed according to the amount of sheets stacked on the sheet stacking table. There has been proposed a paper discharging device which is provided so as to be displaceable and detects the full state of the paper stacking table by detecting the position of the arm member by full detection means. However, if the state of the discharged paper is, for example, curled, the arm member is displaced by the curled portion of the paper more than a position corresponding to the actual number of loaded paper, and the paper is discharged to the paper loading table. There is a problem that the state is full even though there is room to do so. As such an improvement, Japanese Patent Application Laid-Open No. Hei 6-212408 discloses a paper ejection device that presses an arm member from a direction perpendicular to a sheet mounting surface toward a sheet in order to suppress curling of the sheet on the sheet stacking table. It is proposed in the gazette.

[0003]

Problems to be Solved by the Invention
In the paper discharging device described in Japanese Patent Application Laid-Open No. 8 (1996) -1990, since the arm member is pressed toward the paper by the spring, it is possible to suppress the curl of the paper. However, since the arm member is urged by a spring in the direction of pressing the sheet, the arm member is always placed in a pressed state against the sheet, and is used when discharging the sheet to the sheet loading table or removing the sheet from the sheet loading table. It was in the way and there was a problem with workability. SUMMARY OF THE INVENTION It is an object of the present invention to provide a paper discharge device which has good workability at the time of discharging and taking out paper while accurately detecting a full state on a paper loading table regardless of the state of paper.

[0004]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a sheet discharging apparatus having a sheet stacking table for stacking sheets discharged from a discharge port. An arm member provided so as to be able to contact and separate from the upper surface of the stacked sheets, a pressing position for pressing the arm member against the stacked sheets, and a separating position for separating from the stacked sheets. And a control means for controlling the driving operation of the pressing means in accordance with the paper discharge state of the sheet. Therefore, the arm member is selectively positioned at a pressing position for pressing the discharged sheet and a separating position for separating from the sheet according to the sheet discharging state.

According to a second aspect of the present invention, there is provided the sheet discharging apparatus according to the first aspect, further comprising a sheet discharge detecting means for detecting a sheet discharged to the sheet stacking table, and the control means controlling the sheet by the sheet discharge detecting means. After a lapse of a predetermined time after the detection, the driving operation of the pressing means is controlled so that the arm member occupies the pressing position with respect to the discharged sheet. For this reason,
When a predetermined time has elapsed after the detection of the sheet, the arm member moves to the pressing position, and the stacked sheets are pressed.

[0006] The invention described in claim 3 is claim 1 or 2.
The sheet discharging device according to claim 1, further comprising sheet fullness detecting means for detecting a sheet stacking state of the sheet stacking table based on the position of the arm member, wherein the control means controls the arm member to be separated when the sheet full state detecting means detects the full state. It is characterized in that the driving operation of the pressing means is controlled so as to occupy the position. For this reason, when the sheet stacking table becomes full, the arm member moves to the separated position, and the pressing force on the stacked sheets is released.

According to a fourth aspect of the present invention, in the paper discharge device according to the first, second or third aspect, the control means moves the arm member to the separated position after a lapse of a predetermined time after the arm member occupies the pressing position. The driving operation of the pressing means is controlled so as to occupy the pressure. Therefore, the arm member is returned from the pressed position to the separated position after a predetermined time has elapsed.

According to a fifth aspect of the present invention, in the paper discharge device according to any one of the first to fourth aspects, the separated position of the arm member is a position that does not interfere with the paper discharged from the paper discharge port. It is characterized by: Therefore, when the paper is discharged from the paper discharge port, the arm member does not hinder the discharge.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. The paper discharging device shown in FIG. 1 includes a paper loading table 5 on which the paper 1 discharged from the discharge port 17 in which the paper discharging rollers 4a and 4b are arranged, and an upper surface 1a of the paper 1A loaded on the paper loading table 5. As shown in FIG. 2, a filler 2 as an arm member, which is freely movable toward and away from, and whose position is displaceable in accordance with the amount of stacked sheets, and a tip 2a of the filler 2, A pressing unit 7 that selectively moves between a pressing position for pressing the stacked sheets 1A and a separation position that separates from the stacked sheets 1A as shown in FIG. Control means 18 for controlling the driving operation of the means 7.

As shown in FIG. 1, the separated position of the filler 2 is a position that does not interfere with the sheet 1 discharged from the paper discharge port 17, for example, above the paper discharge port 17. The paper discharge port 17 is provided in the paper discharge path 6 formed by the guide plates 6a and 6b.
At the end. The sheet discharge path 6 is connected to an image forming apparatus (not shown) so that the sheet 1 is conveyed from the image forming apparatus. Discharge rollers 4a,
On the upstream side in the sheet transport direction from 4b, a sheet discharge detecting means 8 for detecting the sheet 1 discharged to the sheet stacking table 5 is disposed facing the sheet discharge path 6. Here, an optical reflection type sensor is used for the sheet discharge detection means 8. The paper discharge detection means 8 is turned on when the paper 1 is detected.

The filler 2 has a base end 2b connected to the discharge port 17
It is fixed above a shaft 11 rotatably supported by a device main body (not shown), and is swingable about the shaft 11. The filler 2 has a length such that its leading end 2a can contact the upper surface 1a of the discharged paper 1A.

The shaft 11 has a shielding plate 12 and a spring hook 1
3 are provided. Shielding plate 12 and spring hanging member 1
3 indicates that when the filler 2 swings,
And move with it. The position of the filler 2 is detected within the swing range of the shielding plate 12 and the sheet loading table 5 is detected.
Paper full detecting means 3 for detecting the loaded state of the paper 1A, that is, the full state. Here, a photo inter lamp is used as the paper full detecting means 3. When the sheet full detecting means 3 detects the shielding plate 12, it outputs a full signal and turns on. A mechanical switch, for example, a limit switch may be used as the paper full detecting means 3.

The pressing means 7 is turned on when a driving signal is inputted.
Then, a pull-type electromagnetic solenoid for pulling the movable piece 7a into the main body is used here. The movable piece 7a is connected to one end of a spring hook 13 via a spring 10. The spring 10 absorbs a displacement of the positional relationship between the movable piece 7a and the filler 2 due to the swing of the filler 2. The other end of the spring hook 13 is engaged with the other end of the tension spring 9 having one end fixed to the fixed portion. The extension spring 9 constitutes an urging unit that gives the filler 2 a movement behavior toward the separated position, that is, a return unit. A stopper may be provided above the filler 2 to restrict the movement of the filler 2 in the separating direction and hold the filler 2 at the separated position.

The main part of the control means 18 comprises a well-known microcomputer. The control unit 18 displays the full state of the sheet loading detection unit 3, the pressing unit 7, the discharge detection unit 8, the discharge driving unit 14 that drives one of the discharge rollers 4 a and 4 b, and the sheet stacking table 5. Display means 15 and a timer 16 for measuring time are electrically connected to each other. The storage unit (not shown) of the control unit 18 stores a predetermined time T1 after the sheet is detected by the sheet discharge detection unit 8.
A control program shown in FIG. 5 is stored together with seconds and a predetermined time T2 seconds after the driving operation of the pressing means 7.

The predetermined time T1 second is the time required from when the paper discharge detecting means 8 stops detecting the paper 1 to when the paper 1 is completely discharged onto the paper loading table 5. The predetermined time T2 seconds is a time from the time when the filler 2 presses the paper 1 to the time when the filler 1 completely stops.

The operation of the paper discharging device thus configured will be described with reference to the flowchart shown in FIG. In steps A1 and A2 in FIG. 5, the pressing means 7 is initialized and turned on.
If it is in the state, it is turned off and the process proceeds to step A3. In step A3, the image forming apparatus (not shown) is operated to form an image on the sheet 1, and in step A4, the sheet discharge drive unit 14 is driven to rotate the sheet discharge rollers 4a and 4b. When the sheet 1 is conveyed to the sheet discharge rollers 4 a and 4 b via the sheet discharge conveyance path 6, the sheet 1 starts to be discharged toward the sheet stacking table 5. In steps A5 and A6, the sheet 1 is detected and turned ON by the sheet ejection detecting means 8 just before reaching the sheet ejection rollers 4a and 4b. This detection is performed until the sheet 1 passes through the sheet discharge detection means 8.

When the paper discharge detection means 8 is turned off after the paper 1 has passed the paper discharge detection means 8, in step A7,
The measurement of the predetermined time T1 second is performed by the timer 16, and when the predetermined time T1 second has elapsed, the pressing means 7 is turned on and driven in step A8. As a result, the filler 2 occupying the separated position shown in FIG. 1 rotates counterclockwise in FIG. 1 around the shaft 11, and as shown in FIG. Occupies a pressing position where the upper surface 1a of the first member is pressed by the tip 2a. For this reason, as shown by the broken line in FIG. 2, even if the stacked paper 1A is in a curled state, the loaded paper 1A is pressed down by the filler 2, so that the position of the filler 2 becomes inaccurate due to the curl. However, it is possible to detect an accurate loading state (paper height).

When the pressing means 7 is turned on in step A8, the operation proceeds to step A9, in which
N is determined, and if not ON, the process proceeds to step A10, where the timer 16 measures a predetermined time T2 seconds. When the predetermined time T2 seconds has elapsed, the pressing means 7 is turned off in step A11, and the process returns to step A5. For this reason, the pressing force from the pressing means 7 against the filler 2 is released, and the filler 2 rotates clockwise around the shaft 11 in FIG.
1 is returned to the separated position shown in FIG.

That is, if the sheet full detecting means 3 is not turned on, the sheet 1 can still be discharged onto the sheet loading table 5, so that the loaded sheet 1A is firmly stopped by receiving the pressing force of the filler 2. When the curl has occurred, the filler 2 is moved to a separation position where it does not interfere with the next sheet 1 even after the next sheet 1 is ejected after the curl is removed. Does not interfere with discharge. The operation of contacting / separating the filler 2 with respect to the stacked sheets 1A is continued until the sheet full detecting unit 3 is turned on.

As shown in FIG. 3, when the stacking of the sheets 1 increases and the shielding plate 12 blocks the space between the sheet full detecting means 3, the sheet full detecting means 3 is turned on in step A9, and step A
The program proceeds to step 12, where the pressing means 7 is turned off, and the procedure proceeds to step A13. In this case, the sheet 1 on which the filler 2 occupying the pressing position shown in FIG.
A moves from above A to the separated position shown in FIG.

In step A13, the image forming apparatus is stopped, and in step A14,
When FF is performed, a predetermined time T1 second is measured in step A15, and after the predetermined time T1 second has elapsed, the process proceeds to step A16, in which the driving operation of the paper discharge driving unit 14 is stopped, and the paper discharge rollers 4a,
4b is stopped, and in step A17, the display unit 1 is stopped.
At 5, the full state is displayed and the control is terminated. That is, here, the image forming apparatus is stopped in order not to perform a new image forming operation after the full state is detected. The discharge rollers 4 until the paper is completely discharged to the section 5
When the sheet 1 is completely discharged by rotating the rollers a and 4b, the rotation of the discharge rollers 4a and 4b is stopped, and then the full state is displayed to notify the operator. Therefore, when the operator takes out the loaded paper 1A from the paper loading table 5, since the filler 2 has already occupied the separated position, the pressing force on the paper 1A has been released and the filler 2 has also been released. Since it is located at a position where it does not interfere with the removal of the first unit, the removal operation can be easily performed. Further, it is possible to prevent the paper jam in the paper discharge conveyance path 6 of the paper 1 and the paper discharge rollers 4a and 4b.

In the present embodiment, an electromagnetic solenoid is exemplified as the pressing means, but the pressing means is not limited to this. The pressing means only needs to selectively move the filler 2 between the pressed position and the separated position, and may be, for example, a motor. In this case, a one-way clutch for transmitting the driving force from the motor to the filler 2 only when the filler 2 is moved to the pressing position may be provided between the filler 2 and the output shaft of the motor.

[0023]

According to the present invention, it is possible to accurately detect a full state on a sheet loading table irrespective of the state of sheets, and to enhance workability in discharging and removing sheets. Can be.

[Brief description of the drawings]

FIG. 1 is an enlarged view illustrating a schematic configuration of a paper discharge device according to an embodiment of the present invention and a state when an arm member occupies a separated position.

FIG. 2 is an enlarged view showing a state when an arm member occupies a pressing position.

FIG. 3 is an enlarged view showing a state of an arm member when fullness is detected by paper fullness detection means.

FIG. 4 is a block diagram showing one embodiment of the control means of the present invention.

FIG. 5 is a flowchart showing one form of control by the control means of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 paper 1A loaded paper 1a upper surface 2 arm member 3 paper full detection means 5 paper loading table 7 pressing means 8 discharge detection means 17 discharge port 18 control means T1 predetermined time after paper detection T2 predetermined time after driving operation

Claims (5)

[Claims] A sheet stacker for stacking sheets ejected from an outlet, comprising: an arm member provided so as to be able to freely contact and separate from an upper surface of the sheets stacked on the sheet stacker; A pressing means for selectively moving the arm member to a loaded sheet; a pressing means for selectively moving the arm member to a separating position for separating from the loaded paper; and the pressing means in accordance with a paper discharge state of the paper. And a control means for controlling the driving operation of the sheet discharging device. 2. A sheet discharging device according to claim 1, further comprising a sheet discharging detecting means for detecting a sheet discharged to said sheet stacking table, wherein said control means detects a sheet discharged by said sheet discharging detecting means. A sheet discharge device for controlling a driving operation of the pressing means so that the arm member occupies a pressing position on the discharged sheet after a predetermined time has elapsed. 3. The paper discharging device according to claim 1, further comprising a paper full detecting means for detecting a paper loading state of said paper loading table based on a position of said arm member, wherein said control means is provided with said paper full. When the detecting means detects the full state, the driving operation of the pressing means is controlled so that the arm member occupies the separated position. 4. The sheet discharging apparatus according to claim 1, wherein said control means controls said arm member to occupy the separated position after a lapse of a predetermined time after said arm member occupies the pressing position. A sheet discharging device for controlling a driving operation of the pressing means. 5. The paper discharge device according to claim 1, wherein the separated position is a position that does not interfere with a sheet discharged from the discharge port. apparatus.