JPH0761697A - Paper sheet storing device - Google Patents

Abstract

PURPOSE:To improve the stacking performance of paper sheets discharged from a printer or the like. CONSTITUTION:A discharged paper sheet 100 is loaded on a loading table 2 which is provided in an elevatable manner. This paper sheet 100 is fed by a feeding roller 7 until the tip of the paper sheet pushes up an actuator 83. When a sensor detects the tip of the paper sheet, the feeding roller 7 is stopped and the loading table 2 is lowered by the distance equal to one paper sheet. The positional relationship between the loading table 2 and the feeding roller 7 and the tip of the paper sheet can be detected by one angle sensor to be turned by the actuator 83, and the detecting means can be simplified thereby.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet accommodating apparatus, and more particularly to a sheet accommodating apparatus for stacking a large amount of sheets discharged from an image forming apparatus such as a printer, a facsimile machine, and a copying machine.

[0002]

2. Description of the Related Art When a large amount of sheets discharged from an image forming apparatus such as a printer, a facsimile machine, and a copying machine are stacked on a sheet stacking apparatus, the sheets are stacked so that their leading ends are aligned in consideration of post-processing. Is desirable.

In order to align the leading edges of the sheets in this way, there is a device that equips the sheet stacking table with a restraining means having a surface orthogonal to the sheet conveying direction and brings the sheets into contact with the restraining means to align the leading edges ( See JP-A-3-61264 and JP-A-4-94369). In addition, the above-mentioned JP-A-
In the apparatus disclosed in Japanese Patent Publication No.-94369, a roll-in roller for the sheet is provided, and the sheet is fed to a predetermined position with a roll-in amount selected according to the size of the sheet to align the leading ends of the sheet.

On the other hand, when a large number of sheets are stacked, it is difficult to align the sheets and stack them unless the upper surface of the stacked sheets and the height of the sheet discharge port are adjusted to be substantially constant. For this reason, there is a device that lowers the paper stacking base in accordance with the stacking height of the paper (Japanese Patent Laid-Open No. 64-64-
13361, JP-A-59-203054,
JP-A-3-216455). It is also conceivable to raise the height of the paper discharge port according to the paper load.

[0005]

The above-mentioned conventional device has the following problems. In an apparatus in which the leading edges of the sheets are aligned only by the restraining means, the leading edges of the sheets may not necessarily reach the restraining means and may be uneven due to the frictional force between the sheets, the type of the sheet, and the like.

Further, in an apparatus having a forced retraction roller, the retraction amount is set in advance according to the size of the paper selected in advance, so that the leading edge of the paper may be bent due to excessive rerolling. , The carry-in amount sometimes became insufficient.

Further, in the conventional apparatus having means for adjusting the height by raising and lowering the stacking table and the discharge port, when the sheets are stacked and the height reaches the upper limit value, the stacking table is lowered by a certain amount. Alternatively, the relative positional relationship between the discharge port and the upper surface of the paper is reset to the initial state by raising the discharge port by a certain amount. Therefore, when the upper surface of the sheet is in the initial state and when it reaches the upper limit, the contact state when the ejected sheet is fed onto the already stacked sheets is different, There is a problem that it is difficult to align the leading ends of the paper when there is little difference between the height of the top surface of the paper and the discharge port.

Further, there is a problem in that a height detection sensor is required for both the upper limit and the lower limit of the loading table, which complicates the structure.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a sheet accommodating device in which so-called stacking performance is improved by aligning the leading ends of sheets discharged one by one in order to solve the above problems.

[0010]

SUMMARY OF THE INVENTION To solve the above problems and to achieve the object, the present invention is directed to a sheet discharged from the image forming apparatus, which is arranged above a stacking table on which discharged sheets are stacked. A feed roller for feeding the sheet in the sheet discharge direction, a sheet discharge sensor for detecting the sheet discharged from the image forming apparatus and outputting an ON signal, and a sheet front end disposed above an end of the stacking table in the sheet discharge direction. A detection sensor and a feed roller control unit that detects the discharge of the sheet and rotates the feed roller, and then stops the rotation of the feed roller when the leading edge of the sheet is detected by the sheet leading edge detection sensor. The first feature is that this is done.

Further, according to the present invention, when the discharge of the sheet is detected and the leading edge of the sheet is not detected after a predetermined time, the feeding roller and the upper surface of the sheet discharged onto the stacking table are brought into contact with each other. A second feature is that a means for changing the height relationship with the loading table is provided and the feeding roller is rotated after the height relationship is changed.

The detection of the leading edge of the sheet and the detection of the height relationship are performed by comparing the output signal of the sheet leading edge detection sensor with the predetermined height data.

[0013]

The height relationship between the loading table and the feed roller is detected by comparing the output signal of the paper edge detection sensor with the predetermined height data. Further, when the sheets are stacked on the stacking table, the height of the upper surface of the sheets can be detected. That is, if the output signal of the paper leading edge detection sensor reaches the predetermined value, it can be determined that the leading edge of the paper has been fed to the planned position.

According to the second feature, the feed roller can be rotated only when the paper is not fed to the predetermined position.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings. FIG. 1 is a sectional view showing a sheet storage device according to an embodiment of the present invention, and FIG. 2 is a plan view of the sheet storage device. In this embodiment, the paper storage device is attached to a laser printer as an image forming device.

In FIGS. 1 and 2, a stacking base 2 is provided in the paper storage tray 1. The loading platform 2 is suspended by a wire 4 whose one end is connected to a lifting motor 3. Therefore, when the wire 4 is wound up by the rotation of the motor 3, it goes up, and conversely, when it is unwound, it goes down. The connection position between the wire 4 and the loading platform 2 is provided at the end of the loading platform 2 so that the sheets loaded on the loading platform 2 do not interfere with each other.

A discharge roller 5 is provided near the upper edge of the sheet storage tray 1, and a discharge sensor 6 (hereinafter referred to as an s0 sensor) for detecting the sheet 100 is provided downstream of the discharge roller 5 in the discharge direction. The s0 sensor 6 is, for example, a reflective sensor, and detects the presence / absence of the sheet 100 based on the presence / absence of reflected light. Further, a feeding roller 7 is provided on the downstream side of the s0 sensor 6, that is, in the right direction in the drawing, and is a position where the leading end of the sheet 100 fed by the feeding roller 7 of the sheet accommodating tray 1 comes into contact with the stacking table 2. Sensor near the upper reference position HU (below,
8) is provided.

An actuator 83 is fixed to the shaft 82 of the s1 sensor 8 so that the tip of the actuator 83 comes into contact with the vicinity of the leading edge of the sheet 100 by its own weight when the upper surface of the sheet 100 is at the upper reference position HU. Positioned. The positioning is performed by fixing the flange 81 of the sensor to the main body of the sheet accommodating device or the laser printer with an appropriate fastening part.

In the arrangement example shown in FIG. 2, the s0 sensor 8 is arranged so that the shaft 82 is parallel to the sheet conveying direction (arrow X).
However, the axis 82 may be orthogonal to the paper transport direction X as shown by the dotted line. Which of the arrangements is selected depends on the lifting motor 3 and the feed roller 7.
The better one is selected depending on the positional relationship with other components. The detailed configuration of the s1 sensor 8 will be described later.

The mounting position of the feeding roller 7 in the height direction is as follows.
When the stacking table 2 is at the upper reference position HU with no sheets stacked, the stacking table 2 and the feeding roller 7 are
Adjust so that the height is the same as the bottom surface of. The feeding roller 7 is preferably made of an elastic material such as rubber. Code 2
Reference numeral a denotes the loading platform 2 at the upper reference position HU.

The feed roller 7 may be movably fixed in the vertical direction, for example, so that its lowermost position is below the upper reference position HU. Then, the discharged paper can be pressed by the weight of the roller 7 against the previously stacked paper or the upper surface of the stacking base 2 to give a feeding force, so that the delicate gap adjustment is not necessary. is there.

Next, the operating principle of the angle sensor suitable as the s1 sensor 8 will be described with reference to FIG. Figure 3
FIG. 3A is a connection diagram for explaining the principle of the angle sensor, FIG. 3B is an equivalent circuit diagram thereof, and FIG. 3C shows an output signal of the angle sensor and a rotation angle of the shaft of the sensor. It is a figure which shows a relationship.

3 (a) and 3 (b), a magnet M is fixed to the end surface of the shaft 82 of the s1 sensor 8 in the positional relationship shown in the drawing, and further, concentrically with the shaft 82, the magnet M is attached. A magnetoresistive element R is provided so as to be opposed to M with a constant air gap in the extending direction of the shaft 82.
The magnetoresistive element R is a magnetoelectric conversion element made of a semiconductor material whose resistance value increases in proportion to the strength of the magnetic field acting on it. With the terminal portion t at the center of the magnetoresistive element R as a boundary, one side forms a resistance section R1 and the other side forms a resistance section R2. A power source 9 is connected to both ends of the magnetoresistive element R, and the voltage between the ground (GND) and the central terminal portion t becomes the sensor output Vout.

When the shaft 82 rotates in the direction of arrow 10, the magnet M also rotates together with it, and the relative positions of the magnet M and the resistance portions R1 and R2 change. As a result, the resistance portion R1 and the resistance portion R2 are moved along with the displacement of the shaft 82, that is, the magnet M.
Changes its resistance value, and a sensor output Vout corresponding to the relative positions of the magnet M and the resistance portions R1 and R2 is obtained.

The sensor output Vout changes as shown in FIG. 3C according to the rotation angle of the shaft 82. For example, in the positional relationship between the magnet M and the magnetoresistive element R shown in FIG. Since the resistance value of the resistance part R1 is low and the resistance value of the resistance part R2 is high, the sensor output Vout becomes the maximum value.
Since the sensor output Vout has a linear range A as shown in FIG. 3C, when the angle sensor is used, the positional relationship between the respective constituent parts is set so that the linear range A is used. It is better to adjust.

FIG. 4 shows a hardware configuration of a control device for processing the output signals of the s0 sensor 6 and the s1 sensor 8 to align the leading ends of the sheets. In the figure, s
The output signal of the 1 sensor 8 is converted into a digital signal by the A / D converter 11 so as to be convenient for computer processing, and then input to the CPU 12. A conveyance sensor (hereinafter referred to as an s3 sensor) 18, which is provided on the laser printer side, for detecting that a sheet has passed a predetermined position, and s
0 The output signal of the sensor 6 is ON / OFF of whether the paper is detected or not.
It is an off signal, and this signal is also input to the CPU 12.
The ROM 13 stores system data, programs of the microcomputer, and the like, and the RAM 14 stores data obtained by the processing, reference values, and the like.

The output signal of the CPU 12 is a drive circuit 15 for driving the motor 3 for raising and lowering the loading platform 2, the motor 16 for feeding, and the motor 17 for discharging rollers.
The drive circuit 15 outputs a drive signal to each of the motors 3, 16 and 17 in accordance with a command from the CPU 12. The distance between the s3 sensor 18 and the s0 sensor 6 is equal to or less than the length of one sheet.

Next, the operation of the control device in the sheet accommodating device having the above-mentioned hardware structure will be described. First, as a first embodiment, the control "when the discharge of the paper is detected, the feed roller 7 is always rotated to align the leading ends of the paper" will be described.

In the flowchart of FIG. 5, in step S1, first, a forward rotation command is output to the lifting motor 3 to raise the loading platform 2 to the initial state. In step S2, it is determined whether or not the output signal of the s1 sensor 8 has reached a value lower than the upper reference position HU by a predetermined amount, that is, a position of (HU-Δt). Here, it is preferable that the value Δt is set to the thickness of the thinnest paper that is considered to be used in general.

The output signal of the s1 sensor 8 indicates that the position "H"
If it becomes a value indicating “U−Δt”, it is determined that the loading platform 2 is in the initial state, the process proceeds to step S3, and a stop command is output to the lifting motor 3.

In step S4, it is determined whether the s0 sensor 6 is on. If the sheet is discharged, the s0 sensor 6 outputs an ON signal, the determination in step S4 becomes affirmative, and the process proceeds to step S5. In step S5, it is determined whether the scheduled time Ts seconds have elapsed. This time Ts seconds is almost the time from when the sheet is detected by the s0 sensor 6 to when it reaches the feed roller 7. When the time Ts seconds have elapsed, the process proceeds to step S6, and a rotation command is output to the motor 16 for the feeding roller to feed the sheet.

In step S7, it is determined whether or not the output signal of the s1 sensor 8 has reached a value indicating the upper reference position HU. Based on this determination, it is determined whether the actuator 83 of the s1 sensor 8 has been pushed up by the ejected paper, that is, whether the leading edge of the paper has been fed to a predetermined position.

In step S8, a stop command is output to the feed roller motor 16. In step S9, a reverse rotation command is output to the motor 3 in order to lower the loading platform 2. In step S10, it is determined whether or not the output signal of the s1 sensor 8 has become "HU-Δt" or less. If the determination in step S10 is affirmative, the process proceeds to step S11,
A stop command is output to the lifting motor 3 to stop the lifting of the loading platform 2.

As described above, in the first embodiment, when the discharge of the sheet is detected, the feeding roller 7 is rotated, and when the actuator 83 of the s1 sensor is pushed up by the tip of the sheet by the predetermined amount Δt or more. , The rotation of the feeding roller 7 is stopped when it is determined that the leading ends are aligned. Then, in order to accommodate the next sheet, the stacking table 2 is lowered by the predetermined amount Δt.

Next, the main function of the control device for executing the procedure of the first embodiment will be described. In the functional block diagram of FIG. 6, the same symbols as in FIG. 1 indicate the same or equivalent parts. When the power is turned on, the lifting control unit 19 outputs a forward rotation command to the lifting motor 3 of the mounting table 2. Lifting control unit 19
Compares the output signal of the s0 sensor 8 with the ROM value “HU-Δt”, and when the output signal of the s1 sensor 8 reaches the value “HU-Δt”, outputs a stop command to the lifting motor 3.

The feed roller driving unit 20 is the s0 sensor 6
In response to the ON signal of, the time measurement is started, and after the time Ts seconds have elapsed, a drive signal is output to the feed motor 16.
After the driving signal is output, the feed roller driving unit 20
Starts comparing the ROM value "HU" with the output signal of the s1 sensor 8, and the output signal of the s1 sensor 8 is changed to the ROM value "HU".
If it is determined that the value exceeds the limit, a stop command is output to the feed motor 16.

This stop command is also supplied to the lifting control unit 19, which outputs a reverse rotation command to the lifting motor 3 and outputs the output signal of the s1 sensor 8 to the ROM value "H".
U-Δt ”, the output signal of the s1 sensor 8 has a value“ HU-
When Δt ”is reached, a stop command is output to the lifting motor 3.

The feed roller driving unit 20 immediately responds to the ON signal of the discharge sensor 6 and immediately sends the feed motor 16
It may be modified so as to output a drive signal.

Next, as a second embodiment, the control "to rotate the feeding roller 7 to align the leading ends of the sheets only when the sheet irregularities are detected" will be described with reference to FIGS. In the flowchart of FIG. 7, step S
At 21, the normal rotation command is output to the motor 3 to raise the loading platform 2 to the initial state. In step S22, it is determined whether or not the output signal of the s1 sensor 8 has reached a value indicating the lower reference position HL. Here, the lower reference position HL is set to a position lower than the upper reference position HU.

If the output signal of the s1 sensor 8 has a value indicating the lower reference position HL, it is determined that the loading platform 2 is in the initial state, and the process proceeds to step S23, where the lifting motor 3
The stop command is output to. In step S24, it is determined whether the s0 sensor 6 is on. If the paper is discharged, the s0 sensor 6 outputs an ON signal, and step S24
Is affirmative, the process proceeds to step S25. In step S25, it is determined whether the scheduled time Ty seconds has elapsed. This time Ty seconds is almost the time from when the sheet is detected by the s0 sensor 6 to when it reaches the position of the actuator 83.

If Ty seconds have elapsed, step S26
Then, it is determined whether or not the output signal of the s1 sensor has become a value indicating a position higher than the lower reference position HL by the predetermined value Δt, that is, whether the leading edge of the paper has reached the position of the actuator 83. If the determination in step S26 is affirmative, it is determined that the sheets are normally accommodated, and the process proceeds to step S27 to output a reverse rotation command to the lifting motor 3 to lower the stacking table 2. In step S28, it is determined whether or not the output signal of the s1 sensor 8 is a value that is equal to or lower than the lower reference position HL. If the determination in step S28 is affirmative, the process proceeds to step S29, in which a stop command is output to the lifting motor 3 to stop the lifting of the loading platform 2.

On the other hand, if the determination in step S26 is negative, the leading edge of the sheet has not reached the expected position, and therefore the feeding motor 16 performs a process for feeding the sheet. First, in step S30, a forward rotation command is output to the lifting motor 3 to raise the loading platform 2. Step S31
Then, whether or not the output signal of the s1 sensor 8 becomes a value indicating a position lower than the upper reference position HU by the predetermined value Δt, that is, up to the position where the feeding roller 7 comes into contact with the upper surface of the sheet which is being conveyed midway It is determined whether or not the loading platform 2 has risen.

In step S32, a stop command is output to the lifting motor 3. In step S33, a rotation command is output to the feed roller motor 16. Step S3
In step 4, it is determined whether the output signal of the s1 sensor 8 is equal to or higher than the value indicating the upper reference position HU, that is, whether the leading edge of the sheet has reached the position of the actuator 83. If the determination in step S34 is affirmative, the process proceeds to step S35,
A stop command is output to the feed roller motor 16.

In the second embodiment, as described below, when there is a margin of time until the next sheet is discharged after the sheet is fed, the upper surface of the accommodated sheet is If the next sheet is to be immediately discharged, the sheet is fed to the predetermined position by rotating the feed roller 7 at the position where the sheet is immediately discharged.

In step S36 of FIG. 8, the s0 sensor 6
It is determined whether or not the output of is on. If this determination is affirmative, the sheet is being discharged, and the process proceeds to step S37 to output the reverse rotation command to the lifting motor 3 in order to lower the stacking table 2. In step S38, the s1 sensor 8
It is determined whether or not the output signal of is below a value indicating a position lower than the upper reference position HU by a predetermined value Δt. Step S
If the determination at 38 is affirmative, the process proceeds to step S39 to output a stop command to the lifting motor 3 to stop the lifting of the loading platform 2.

In step S40, it is determined whether or not Ts seconds have elapsed since the s0 sensor 6 was turned on. If Ts seconds have elapsed, the process proceeds to step S41, in which the motor for the feed roller is used to feed the paper. The rotation command is output to 16. In step S42, it is determined whether or not the output signal of the s1 sensor 8 is greater than or equal to the value indicating the upper reference position HU. If this determination is fixed, it is determined that the leading edge of the paper has been fed to the predetermined position, and the process proceeds to step S43 to output a stop command to the motor 16 for the feed roller.

If the determination in step S36 is negative, it is determined that the paper is not being ejected, and the process proceeds to step S44 to determine whether the paper will be ejected soon. This decision is
It is determined whether or not the s3 sensor 18 is in the on state or within the scheduled time Tz seconds after the on state. Time Tz
Is within the time obtained by subtracting the time required for lowering the stacking table 2 to a predetermined position from the time required for the sheet to be ejected after passing the s3 sensor 18.

If the judgment in step S44 is affirmative, it is judged that the paper is not discharged yet, and the upper surface of the paper is lowered to the lower reference position HL for the processing of step S27.
Proceed to (Fig. 7). If the determination in step S44 is negative,
Since it is likely that the paper will be ejected immediately, step S
Proceed to 37.

The procedure shown in the second embodiment can be modified as follows. That is, instead of lowering the stacking table every time one sheet of paper is accommodated, the stacking table 2 may be lowered each time a certain amount of paper is accommodated.

FIG. 9 is a flow chart showing a procedure for lowering the stacking table 2 every time a fixed amount of paper is stored. The procedure shown in the figure is replaced with the steps S24 to S29 (FIG. 7), and only the main parts are shown. In step S100, it is determined whether the s0 sensor 18 is on. When the s0 sensor 18 is on, the process proceeds to step S101, and the counter value n is incremented (+1). In step S102, a timer for the scheduled time Ty seconds is started and it is determined whether or not the time has elapsed. When the time has elapsed, the process proceeds to step S103, and it is determined whether or not the output signal of the s1 sensor 8 has a value higher than the position obtained by adding nΔt to the lower reference position HU. If the determination is affirmative, the process proceeds to step S104, and if the determination is negative, the process proceeds to step S30 (FIG. 7).

In step S104, the height position "H"
It is determined whether or not “U + n · Δt” exceeds the planned height position “HU + α”. If the determination in step S104 is affirmative, the process proceeds to step S105 to clear the counter value n.
If the determination in step S104 is negative, step S10
Go to 0. Since steps S106 to S108 are the same as steps S27 to 29 (FIG. 7), description thereof will be omitted.

As described above, in this modification, if the leading edge of the sheet does not become irregular even without using the feeding motor 16, the stacking table is lowered until the sheet stacking height n · Δt reaches the predetermined value α. Do not let And the feed motor 1
In the case where the sheets become uneven when 6 is not used, the stacking table 2 is lowered even before the sheet stacking height n · Δt reaches the predetermined value α.

Next, the main function of the control device for executing the procedure of the second embodiment will be described. In the functional block diagram of FIG. 10, the same symbols as in FIG. 1 indicate the same or equivalent parts. When the power is turned on, the first lifting control unit 21 outputs a forward rotation command to the lifting motor 3 of the mounting table 2. The first elevating control unit 21 outputs the output signal of the s1 sensor 8 and the ROM value "HL".
When the output signal of the s1 sensor 8 reaches the value "HL", a stop command is output to the lifting motor 3.

The judging section 22 detects the ON signal of the s0 sensor 6 and judges whether the output signal of the s1 sensor 8 has reached the ROM value "HL + Δt" after the elapse of the time Ty seconds. If the value is reached, the normal signal R is output, and if not, the abnormal signal E is output to the first lift control unit 21.

In response to the normal signal R, the first elevating / lowering control section 21 outputs a reverse rotation command to the elevating / lowering motor 3, whereby the loading platform 2 is lowered, and the output signal of the s1 sensor 8 is stored in the ROM.
When the value falls below "HL", a stop command is output. On the other hand, the first elevating / lowering control unit 21 outputs a normal rotation command to the elevating / lowering motor 3 in response to the abnormal signal E, whereby the loading platform 2 is raised, and the output signal of the s1 sensor 8 is the ROM value "HU-.
When Δt ”is reached, a stop command is output.

When the output signal of the s1 sensor 8 reaches the ROM value "HU-Δt", the feed roller driving unit 23 determines that
The rotation command is output to the feed motor 16 and the s1 sensor 8
When the output signal of 1 reaches the ROM value "HU", a stop command is output to the feed motor 16. Feeding roller 7
After the stop, the second lifting control unit 24 controls the lifting motor 3
Output a reverse rotation command to the output signal of the s1 sensor 8
When the value "HL" is reached, a stop command is output to the lifting motor 3.

When the second raising / lowering control unit 24 determines that the sheet is about to be discharged by the output signal of the s3 sensor 18, the output signal of the s1 sensor 8 outputs the ROM value "HL".
The output signal of the s1 sensor 8 is ROM
When the value “HU-Δt” is reached, a stop command can be output to the lifting motor 3.

Further, the first elevating / lowering control section 21 is operated by the arithmetic section 26 based on the count value n of the counter 25 which counts the number of times the normal signal R is continuously output, that is, the number of normally stored sheets. “HU + n · Δt” is calculated, and until this value “n · Δt” exceeds the planned loading height “α”,
Even if the normal signal is detected, it is possible not to output the reverse rotation command to the loading platform 2.

As described above, in this embodiment, the stacking table 2 is moved up and down. However, depending on the layout of the image forming apparatus and the sheet accommodating apparatus, a portion corresponding to the discharge roller 5 on the image forming apparatus side and the feed roller may be provided. You may make it raise / lower integrally.

[0060]

As is clear from the above description, according to the present invention, the leading edge of the accommodated sheet can be aligned by feeding the sheet until the leading edge of the sheet is reliably detected by the sheet leading edge detection sensor. .

According to the third aspect of the present invention, the operating time of the motor is reduced by performing the paper feeding operation only when the leading edge of the paper is not detected within a predetermined time after the paper is ejected. You can

Further, the stacking performance can be improved by keeping the uppermost surface of the stacked sheets substantially constant, and both the leading edge of the sheet and the height of the uppermost sheet of the sheet can be detected by the sensor for detecting the leading edge of the sheet. The configuration can be simplified.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of essential parts of a sheet storage device showing an embodiment of the present invention.

FIG. 2 is a plan view of an essential part of a sheet storage device showing an embodiment of the present invention.

FIG. 3 is a principle diagram of an angle sensor and a relationship diagram of output and rotation angle.

FIG. 4 is a block diagram showing a hardware configuration of a control device of the sheet storage device.

FIG. 5 is a flowchart showing the operation of the first embodiment.

FIG. 6 is a block diagram showing the main functions of the control device of the first embodiment.

FIG. 7 is a flowchart showing an operation (No. 1) of the second embodiment.

FIG. 8 is a flowchart showing an operation (No. 2) of the second embodiment.

FIG. 9 is a flowchart showing a modified operation of the second embodiment.

FIG. 10 is a block diagram showing the main functions of the control device of the second embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Paper storage tray, 2 ... Stacking table, 3 ... Elevating motor, 6 ... Ejection sensor, 7 ... Feed roller, 8 ... Paper leading edge detection sensor, 83 ... Paper leading edge detection sensor actuator, 100 ... Paper

Claims (8)

[Claims] 1. A sheet accommodating device attached to an image forming apparatus for accommodating sheets ejected from the image forming apparatus, wherein a stacking platform for stacking the ejected sheets, and a stacking table disposed above the stacking platform, A feed roller for feeding the sheet discharged from the image forming apparatus in the discharge direction, a discharge sensor provided at a sheet discharging position of the image forming apparatus, for detecting the discharged sheet, and outputting an ON signal, A paper leading edge detection sensor that is disposed above the end of the stacking direction in the paper discharge direction and outputs a signal according to the amount of rotation of the actuator; and detects the ON signal of the discharge sensor to rotate the feed roller, and then Feeding roller control means for stopping the rotation of the feeding roller when the leading edge of the sheet is detected by the sheet leading edge detection sensor; When the roller is not rotating, an elevating control unit that outputs an elevating command so that the height relationship between the feeding roller and the loading platform is in a storage ready state, and the feeding roller and the loading platform based on the elevating command. And an ascending / descending driving means for relatively moving the sheet up and down, and the detection of the leading edge of the sheet and the detection of the height relationship are performed by comparing an output signal of the sheet leading edge detection sensor with predetermined height data. A sheet accommodating device characterized by being configured. 2. The feeding roller control means rotates the feeding roller after a predetermined delay time after detecting the ON signal of the discharge sensor, and then the leading edge of the sheet is detected by the sheet leading edge detection sensor. The sheet accommodating apparatus according to claim 1, wherein the feeding roller is configured to be stopped from rotating at times. 3. A sheet accommodating device attached to an image forming apparatus for accommodating and accommodating sheets ejected from the image forming apparatus, wherein a stacking platform for stacking the ejected sheets and an upper part of the stacking platform. A feed roller arranged to feed the sheet discharged from the image forming apparatus in the discharge direction, and a discharge provided at the sheet discharging position of the image forming apparatus, which detects the discharged sheet and outputs an ON signal A sensor, a paper leading edge detection sensor that is arranged above the end of the stacking table in the paper discharge direction, and outputs a signal according to the amount of rotation of the actuator, and detects the ON signal of the paper discharge sensor, and a scheduled delay time After that, a determination unit that outputs a normal signal or an abnormal signal depending on whether the leading edge of the sheet is detected by the sheet leading edge detection sensor; and, when the normal signal is detected, A second height relationship in which the feed roller and the loading table are brought into a first height relationship in a storage ready state, and when the abnormal signal is detected, the upper surface of the sheet on the loading table and the feeding roller are in contact with each other. A first elevating control means for outputting an elevating command for moving the feeding roller to the upper surface of the sheet on the stacking table and the feeding roller by the sheet leading edge detection sensor when the feeding roller is in the second height relationship. A feed roller control unit that rotates the feed roller and stops rotation of the feed roller when the leading edge of the sheet is detected by the sheet leading edge detection sensor; and, after the feed roller stops, the feeding roller and the loading table. The second elevation control means for outputting an elevation command for returning to the first height relationship, and the first and second elevation control means And an elevating and lowering drive means for moving the feed roller and the loading table relative to each other up and down according to an elevating and lowering command. For detection of the leading edge of the sheet and detection of the respective height relationships, an output signal of the sheet leading edge detection sensor is planned. The sheet storage device is configured to be performed by comparing with height data of the sheet. 4. A conveyance sensor for detecting a sheet immediately before being ejected in the image forming apparatus, and a first height from the second height relationship based on an output signal of the conveyance sensor until the sheet is ejected. And a means for determining whether or not there is a time to be able to return to the above relationship, and when the second elevating and lowering control means has time to discharge the sheet, the feeding roller and the loading table are An elevating command for returning to the height relationship of 1 is output, and when there is no margin, the loading platform is set to a third height relationship lower than the feeding roller by a predetermined value as compared with the second height relationship. 4. The sheet accommodating apparatus according to claim 3, wherein the sheet accommodating apparatus is configured to output an elevating and lowering command for outputting. 5. The first elevation control means has a fourth height relationship in which a loading platform is located higher than the first height relationship while the normal signal continues. At the same time, an elevation command for outputting the feed roller and the loading table to the first height relationship is output, and when the abnormal signal is detected, the upper surface of the sheet on the loading table and the feeding roller contact each other. 5. The sheet accommodating apparatus according to claim 3, wherein the sheet accommodating apparatus is configured to output an elevating / lowering command for achieving a height relationship of 2. 6. The sheet accommodating apparatus according to claim 1, wherein the elevating and lowering drive means is an elevating and lowering device for the stacking table. 7. The sheet accommodating apparatus according to claim 1, wherein the elevating / lowering drive unit is an elevating / lowering unit for a sheet discharging unit provided in the feed roller and the image forming apparatus. . 8. The paper leading edge detection sensor includes a shaft that rotatably supports the actuator, a magnet fixed to the shaft, and a magnetoresistive element that is arranged to face the magnet. The angle sensor configured to output, as a detection signal, a signal corresponding to the resistance value of the magnetoresistive element that changes depending on the relative positional relationship between the resistance element and the magnet. The sheet storage device according to any one of claims.