JP3663995B2 - Sheet stacking device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a paper stacking technique used in a paper feeding mechanism such as a copying machine or a printer.
[0002]
[Prior art]
A copying machine, a printer, and the like are provided with a paper feed mechanism that feeds paper one by one from a paper feed tray on which paper for forming an image is placed. Thus, it can be fed to a photosensitive drum inside the apparatus.
[0003]
By the way, in copiers and printers that can stock a relatively large amount of paper, a lifting device is provided that can move a paper feed tray suspended by a plurality of wires up and down by winding or unwinding the wires. There is something that is. For example, when the sensor detects that the paper feed door has been opened, such a lifting device lowers the paper feed tray and moves it to a replenishment position where paper is easily replenished. When the sensor detects that the paper door is closed, the paper feed tray is raised to the paper feed position so that paper can be fed.
[0004]
[Problems to be solved by the invention]
However, in the conventional paper feeding mechanism, when the paper feeding tray is moved from the replenishing position to the paper feeding position, the number of rotations (or time) of the drive motor that winds the wire is detected, thereby An apparatus for determining the remaining amount of loaded paper has been developed. More specifically, when the paper feed tray is lowered from the paper feed position to the replenishment position, the amount of movement (lowering) of the paper feed tray is detected based on the reverse rotation speed of the drive motor at that time, and Remember. Further, since the amount of movement (rise) of the paper feed tray that rises after paper replenishment is detected, and the number of replenished papers can be determined based on a value obtained by subtracting the rise amount from the stored descent amount, the paper before refilling If the replenished number is added to the number of sheets, the number of sheets currently loaded in the sheet feeding tray can be obtained.
[0007]
However, for example, a wire-hanging type paper feed tray can be moved to the replenishment position by its own weight without being driven by the power of the drive motor. For example, when the paper is replenished with the power off, the drive motor It is also possible that the paper feed tray moves to the replenishment position without being able to detect the reverse rotation number. In such a case, an error may occur and the remaining amount of paper may become unclear if a difference from the rising amount of the paper feed tray after paper replenishment is taken while the paper feed tray lowering amount is zero.
[0010]
The present invention, the conventional view of the problems of the technology, and an object thereof is to provide a sheet stacking apparatus capable of accurately detected remaining amount of sheets Ri good.
[0011]
[Means for Solving the Problems]
In order to achieve the above-described object, the sheet stacking apparatus of the present invention includes:
A tray for loading sheets;
Drive means for moving the tray from the refill position to the paper feed position;
Detecting means for detecting the operation of the driving means;
A remaining amount detecting means for detecting and storing the remaining amount of the sheet based on the driving amount of the driving means;
A paper replenishing door that can be freely opened and closed;
A detection switch for detecting opening and closing of the door;
And a canceling means for canceling the remaining amount stored in the remaining amount detecting means,
When it is detected by the detection switch that the door is closed, the driving means is operated,
The canceling means detects that the door is closed by the detection switch, and when the driving means operates for a predetermined time or more , after canceling the remaining amount stored in the remaining amount detecting means, the remaining amount The sheet remaining amount calculated based on the movement amount of the tray detected by the detection unit is stored .
[0015]
[Action]
According to the sheet stacking apparatus of the present invention, a tray for stacking sheets, a driving unit for moving the tray from the replenishing position to the paper feeding position, a detecting unit for detecting the operation of the driving unit, Based on the driving amount, the remaining amount detecting means for detecting and storing the remaining amount of the sheet , the openable paper replenishing door, the detection switch for detecting the opening and closing of the door, and the remaining amount detecting means are stored. Cancellation means for canceling the remaining amount, and when the detection switch detects that the door is closed, the driving means is operated,
The canceling means detects that the door is closed by the detection switch, and when the driving means operates for a predetermined time or more , after canceling the remaining amount stored in the remaining amount detecting means, the remaining amount The remaining amount of the sheet calculated based on the movement amount of the tray detected by the detecting unit is stored . For example, when a tray of a type that can move from the paper feed position to the replenishment position due to its own weight or the like moves to the replenishment position with the power to the drive unit cut off, the remaining amount detection means detects the drive amount of the drive unit This is not possible, and the remaining amount of sheets different from the actual state is stored. Therefore, when the detection switch detects that the door is closed, the drive means is operated, and the cancellation means detects that the door is closed by the detection switch, and When the driving unit operates for a predetermined time or more , after the remaining amount stored in the remaining amount detecting unit is canceled, the remaining amount of the sheet calculated based on the movement amount of the tray detected by the remaining amount detecting unit. Since the amount is stored, the remaining amount can be detected with high accuracy.
[0018]
Further, if the driving means includes a motor and the driving amount of the driving means is obtained based on the rotation amount or the rotation time of the motor, the remaining amount of the sheet can be detected more easily.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments according to the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a sheet stacking apparatus according to an embodiment of the present invention . Such a sheet stacking apparatus is provided inside a copying machine or a printer and constitutes a part of a sheet feeding mechanism. In FIG. 1, a rectangular shallow dish-shaped tray 1 is loaded with sheets P that are stacked sheets. The tray 1 is suspended on both sides by a first wire 2 and a second wire 3 which are first string-like bodies, and a third wire 4 and a fourth wire 5 which are second string-like bodies. .
[0024]
Four pulleys 6 to 9 are rotatably disposed above the tray 1, and the first wire 2 is wound around the pulleys 6 and 7 among the wires 2 to 5 each having one end attached to the tray 1. The second wire 3 is wound around the pulley 7, the third wire 4 is wound around the pulleys 8 and 9, and the fourth wire 5 is wound around the pulley 9.
[0025]
The ends of the first wire 2 and the second wire 3 that are integrated when wound around the pulley 7 are attached to the outer periphery of the first hoisting pulley 10. The 1 wire 2 and the 2nd wire 3 are wound up integrally. Also, the ends of the third wire 4 and the fourth wire 5 that are integrated when wound around the pulley 9 are attached to the outer periphery of the second winding pulley 11, and the second winding pulley 11 rotates. The third wire 4 and the fourth wire 5 are wound up integrally.
[0026]
The first hoisting pulley 10 and the second hoisting pulley 11 having the same diameter are fixed to the drive shaft 12 and rotate integrally with the drive shaft 12. The drive shaft 12 is rotatably supported by bearing portions 13 and 14 mounted on a support base 16. The drive shaft 12 is attached to one end on the near side so that power can be transmitted to the motor M via the gear train 17. The number of rotations or operation time of the motor M is input to the CPU 30, and the CPU 30 determines the remaining amount of sheets stacked on the tray 1 in the manner described later based on those values and the paper quality coefficient c input from the input means 32. Can be sought. The remaining amount is stored in the memory 31.
[0027]
The support 16 is configured to be pivotable along a horizontal plane around a pivot 18 provided below the first winding pulley 10. A screw hole 16a is formed at an end portion of the support base 16 far from the pivot shaft 18 so as to extend in a direction orthogonal to the drive shaft 12, and a bolt 19 is screwed into the screw hole 16a. doing. The bolt 19 is rotatable with respect to a holder 20 attached to a fixed portion (not shown).
[0028]
Adjacent to the tray 1, a paper replenishing door D in a copying machine or a printer (not shown) is disposed so as to be freely opened and closed. When the door D is closed, the detection switch 21 disposed adjacent to the door D is turned on, and a locking mechanism (not shown) that locks the tray 1 is connected. Further, an upper position sensor 22 for detecting that the tray 1 has reached the upper paper feed position and a lower position sensor 23 for detecting that the tray 1 has reached the lower replenishment position are provided adjacent to the door D. It has been. In addition, the tray 1 to the support base 16 may be integrally pulled out as a paper feed cassette.
[0029]
The operation of the sheet stacking apparatus according to this embodiment will be described. First, when the user replenishes the paper P, by opening the door D, the detection switch 21 is turned off and the locking mechanism (not shown) is released, so that the tray 1 is lowered by its own weight. As a result, the tray 1 reaches the replenishment position shown in FIG. Such a state is detected by the lower position sensor 23.
[0030]
On the other hand, when the user closes the door D after the paper P is replenished, the detection switch 21 is turned on and power is supplied to the motor M. When the motor M rotates the drive shaft 12, the first hoisting pulley 10 and the second hoisting pulley 11 rotate integrally, thereby simultaneously winding the wires 2-5. When the tray 1 is raised by winding the wires 2 to 5 and the uppermost paper P reaches a paper feed mechanism (not shown) (paper feed position), the upper position sensor 22 is turned on, and the motor M Is stopped, whereby the winding of the first winding pulley 10 and the second winding pulley 11 is stopped.
[0031]
At such a paper feeding position, the lowering of the tray 1 is prevented by a locking mechanism (not shown), but the motor M is driven and the tray 1 is gradually raised according to the paper feeding.
[0032]
Here, a method for detecting the remaining amount of paper will be described. The remaining amount of paper can be calculated from the rise time (motor rotation time) of the tray 1 and the number n of paper fed from the tray 1 by the paper feed mechanism. This calculation formula will be described.
[0033]
When the remaining amount of paper in the tray 1 that can accept 1000 sheets is S1, the remaining amount S1 can be expressed by the following equation.
S1 = 1000− (t−a1) / b1− (n * c) (1)
here,
a1: Rise time to the paper feed point when the rated number of sheets is set on the tray (2.7 seconds for 1000 sheets)
b1: Motor drive time for one sheet of paper when the lift motor is continuously driven (500 ms or longer) (0.0064 seconds for 1000 sheets)
n: Number of sheets fed from tray 1 t: Ascent time of tray 1 (rotation time of motor M)
c: Paper quality factor. The number n of sheets fed can be determined in a known manner based on the number of operations of the sheet feeding mechanism.
[0034]
Further, the paper quality coefficient c will be described. The paper quality factor c is 1 for plain paper (normal thickness), but if this factor is applied to thin paper and thick paper, the calculated value of the number of sheets with respect to the rising time of the tray 1 and the actual Deviation occurs between the numbers. Therefore, in the case of thin paper and thick paper, the number of sheets corresponding to the rising time of the tray 1 is corrected as a value less than 1 or more than 1, thereby enabling more accurate detection. Specific coefficient values are as follows.
Plain paper (normal): c = 1
Cardboard 1 (˜160 g / m ² ): c = 1.5
Cardboard 2 (160 to 200 g / m ² ): c = 2
Thin paper (˜60 g / m ² ): = 0.85
In the present embodiment, the paper quality factor c is set by the user confirming the sheets stacked on the tray 1 and then pressing a selection button (not shown) provided on the input means 32. For example, the paper quality coefficient c may be automatically set using a known measuring device that can determine whether the paper is thick or thin using the stiffness of the paper.
[0035]
On the other hand, when the remaining amount of paper in the tray 1 capable of receiving 500 sheets is S2, the remaining amount S2 can be expressed by the following equation.
S2 = 500− (t−a2) / b2− (n * c) (2)
here,
a2: Rise time to the paper feed point when the rated number of sheets is set in the tray (1.9 seconds for 500 sheets)
b2: Motor driving time for one sheet of paper when the elevating motor is continuously driven (500 ms or longer) (0.0061 seconds for 500 sheets)
n: Number of sheets fed from tray 1 t: Ascent time of tray 1 (rotation time of motor M)
c: Paper quality factor.
[0036]
These values S1 and S2 are calculated as described above, assuming that the sheet M is newly replenished when the motor M is operated for 500 ms or more when the detection switch 21 determines that the door D is opened and closed. Remembered. The values S1 and S2 continue to be stored in the memory 31 even when the power is off, but the motor M when the power switch is turned on with the door D closed by the CPU 30 as the detecting means, canceling means, and calculating means. This value is canceled when a value of 500 ms is operated for 500 ms or more, and a new calculation is performed. As a result, the latest value can always be stored. For example, it is possible to prevent the occurrence of an error that occurs when the accumulated value is stored. The CPU 30 and the memory 31 constitute a remaining amount detection unit.
[0037]
By the way, if the tray 1 that has reached the paper feed position is not horizontal, the paper feed mechanism may not operate normally. Therefore, an aspect of adjusting the tray 1 horizontally will be described. Since the pivot 18 is arranged near the gear train 17 and the motor M as drive means, the support train 16 can be pivoted without greatly moving the relatively heavy gear train 17 and the motor M. Easy to do.
[0038]
Here, since the third wire 4 and the fourth wire 5 are slightly longer, the back side of the tray 1 is assumed to be lowered. In such a case, the bolt 19 is rotated clockwise. Thereby, the support base 16 pivots clockwise around the pivot 18 as viewed from above. By such pivoting, the first hoisting pulley 10 hardly moves, but the second hoisting pulley 11 moves in a direction away from the fourth pulley 9, so that only the third wire 4 and the fourth wire 5 are pulled. Thereby, the tray 1 is adjusted horizontally.
[0039]
On the other hand, since the third wire 4 and the fourth wire 5 are slightly short, when the back side of the tray 1 is raised, the adjustment opposite to that described above may be performed. That is, when the bolt 19 is rotated counterclockwise, the support base 16 pivots counterclockwise around the pivot 18 as viewed from above. By such pivoting, the first hoisting pulley 10 hardly moves, but the second hoisting pulley 11 moves in a direction closer to the fourth pulley 9, so that only the third wire 4 and the fourth wire 5 are returned. Thereby, the tray 1 is adjusted horizontally. In this embodiment, the support base 16 is rotated around the pivot 18, but a long hole is provided in the fixed support base 16 without providing the pivot 18, and a bolt is attached to the long hole. If the bearings 13 and 14 are attached, the drive shaft 12 pivots by moving the bolt in the range of the long hole, so that the same effect can be obtained.
[0045]
The present invention has been described above with reference to the embodiments. However, the present invention should not be construed as being limited to the above-described embodiments, and can be modified or improved as appropriate.
[0046]
【The invention's effect】
According to the sheet stacking apparatus of the present invention, a tray for stacking sheets, a driving unit for moving the tray from the replenishing position to the paper feeding position, a detecting unit for detecting the operation of the driving unit, Based on the driving amount, the remaining amount detecting means for detecting and storing the remaining amount of the sheet , the openable paper replenishing door, the detection switch for detecting the opening and closing of the door, and the remaining amount detecting means are stored. Cancellation means for canceling the remaining amount, and when the detection switch detects that the door is closed, the driving means is operated, and the cancellation means closes the door. detection of the said detected by the detection switch, when the drive means is operated a predetermined time or more, after canceling the remaining amount stored in the remaining amount detecting means, said remaining amount detecting means that Storing the remaining amount of sheets calculated based on the amount of movement of the trays. For example, when a tray of a type that can move from the paper feed position to the replenishment position due to its own weight or the like moves to the replenishment position with the power to the drive unit cut off, the remaining amount detection means detects the drive amount of the drive unit This is not possible, and the remaining amount of sheets different from the actual state is stored. Therefore, when the detection switch detects that the door is closed, the drive means is operated, and the cancellation means detects that the door is closed by the detection switch, and When the driving unit operates for a predetermined time or more , after the remaining amount stored in the remaining amount detecting unit is canceled, the remaining amount of the sheet calculated based on the movement amount of the tray detected by the remaining amount detecting unit. Since the amount is stored, the remaining amount can be detected with high accuracy.
[Brief description of the drawings]
1 is a perspective view of the engagement Ru sheet stacking apparatus to the embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Tray 10 1st winding pulley 11 2nd winding pulley 12 Drive shaft
30 CPU
31 memory
32 input means D door P paper

Claims (3)

A tray for loading sheets;
Drive means for moving the tray from the refill position to the paper feed position;
Detecting means for detecting the operation of the driving means;
A remaining amount detecting means for detecting and storing the remaining amount of the sheet based on the driving amount of the driving means;
A paper replenishing door that can be freely opened and closed;
A detection switch for detecting opening and closing of the door;
And a canceling means for canceling the remaining amount stored in the remaining amount detecting means,
When it is detected by the detection switch that the door is closed, the driving means is operated,
The canceling means detects that the door is closed by the detection switch, and when the driving means operates for a predetermined time or more , after canceling the remaining amount stored in the remaining amount detecting means, the remaining amount A sheet stacking apparatus that stores a remaining amount of sheets calculated based on a movement amount of the tray detected by a detecting unit. Further, the cancellation of the remaining amount stored in the remaining amount detecting means by the canceling means is when the driving means is operated for a predetermined time or more when the power switch is turned on with the door closed. The sheet stacking apparatus according to claim 1, wherein The sheet stacking apparatus according to claim 1, wherein the driving unit includes a motor, and the driving amount of the driving unit is obtained based on a rotation amount or a rotation time of the motor.

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