JPH09202472A - Paper feeder of image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To share a paper feeding means corresponding to a manual feeding function and a paper feeding function having a specified capacity so as to reduce the cost by controlling the vertical movement of a paper sheet placing base based on the detection result of a height detecting means when paper sheets are fed from a manual paper feeding base and a paper feeding unit. SOLUTION: A manual paper feeding base 3 is provided in the upper part of the paper feeding unit 2 of a copying machine or the like and a paper feeding mechanism 4 is assembled in a connection part between a device main body 1 and the paper feeding unit 2. In this paper feeding mechanism 4, a nudger roller 5 is contacted by pressure with the uppermost surface of paper sheets and by its rotary-driving, the paper sheets are sent out to a feed roller 6 from the sheet in the uppermost position in sequence. In the main body of the paper feeding unit 2, a paper sheet placing base 10 for placing a large number of paper sheets P is assembled and supported on a vertical moving mechanism, and this vertical moving mechanism is moved associatively with the movement of the nudger roller 5 so as to maintain the uppermost position of the paper sheets fed to a paper sheet calling position F based on the output of a height detecting sensor 11 for detecting the uppermost position height of the paper sheets in the paper sheet calling position F.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device of an image forming apparatus having a manual sheet feeding function and a sheet feeding unit having a vertically movable sheet stacking table.

[0002]

2. Description of the Related Art Generally, in an image forming apparatus such as a large-sized copying machine, a multi-stage type paper feed tray is incorporated in a cabinet portion of a main body of the apparatus. Papers of different sizes are stored in these paper feed trays, and the paper of the size selected by the operator side or the apparatus side is automatically called from the paper feed trays. In addition to the automatic paper feeding function by the paper feeding tray, a manual feeding tray is provided as a manual paper feeding function on the side of the apparatus main body, and the paper can be manually fed from this manual feeding tray. .

By the way, generally, the number of sheets that can be stored in a multi-stage type sheet feeding tray is limited to several hundred sheets to at most about 1,000 sheets. However, on the user side, paper of a specific size is often used intensively, and in some cases, the capacity of the paper feed tray becomes insufficient, and the paper has to be replenished many times a day. Therefore, recently, as the frequency of use of copiers, printers, printing machines and the like and the processing speed are improved, it is attempted to cope with the increase in capacity of the paper feeding unit. For example, a large copying machine can be equipped with an external type paper feeding unit as an option.

[0004]

However, in the sheet feeding device of the image forming apparatus of this type, a sheet feeding mechanism for feeding the sheet fed from the manual feed tray toward the image forming section,
Since the paper feed mechanism that feeds the paper supplied from the large-capacity paper feed unit to the image forming unit is configured separately, the mechanical mechanism and control form are complicated and the cost is high. It was.

Therefore, in the present invention, as described above, the paper feeding device of the image forming apparatus equipped with the manual paper feeding function and the paper feeding function of a predetermined capacity has a common paper feeding means corresponding to each function. It is an object of the present invention to achieve simplification of the configuration and cost reduction by achieving the above.

[0006]

In a sheet feeding device of an image forming apparatus according to the present invention, a sheet feeding device that feeds sheets fed to a predetermined sheet calling position toward the image forming section in order from the top. Means, a manual paper feed table for supplying paper to the paper call position, and a paper stacking table that can be moved up and down below the manual paper feed table. A paper feed unit that supplies paper to the paper call position, a height detection unit that detects the highest height of the paper at the paper call position, and a height detection unit that feeds paper from the manual paper feed tray and paper feed unit. And a control means for controlling the raising / lowering operation of the sheet stacking table based on the detection result.

In the sheet feeding device of the image forming apparatus having the above-described structure, when the sheet is fed from the manual sheet feeding table, the control means lowers the sheet stacking table of the sheet feeding unit to bring the sheet feeding position from the manual sheet feeding table. Paper can be fed to the paper feeding position, and the control means raises the paper stacking base based on the detection result of the height detection means at the paper calling position to determine the highest height of the paper fed from the manual paper feed base. Set. In contrast,
When feeding paper from the paper feed unit, the control means raises the paper stacking base based on the detection result of the height detection means at the paper call position to set the highest height of the paper fed from the paper feed unit. To do. As a result, the sheets fed from the manual sheet feed tray and the sheet feeding unit to the sheet calling position are positioned at the same height detected by the height detecting means, so that the common sheet feeding means is used. It is possible to feed the image from the highest order toward the image forming unit.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic side sectional view showing an embodiment of a sheet feeding device of an image forming apparatus according to the present invention. In the paper feeding device shown in FIG. 1, a paper feeding unit 2 having a predetermined capacity is connected to a device body 1 such as a copying machine. The capacity of the paper feeding unit 2 is appropriately set according to its use. A manual paper feed tray 3 is provided above the paper feed unit 2.
Is provided, and the manual paper feed tray 3 constitutes an upper cover of the paper feed unit 2. Further, a paper feed mechanism (paper feed means) 4 having a plurality of rolls is incorporated in a connecting portion between the apparatus main body 1 and the paper feed unit 2. Here, in the present embodiment, the upper cover of the sheet feeding unit 2 is configured as the manual sheet feeding tray 3, so that the unit housing is simplified.

The paper feed mechanism 4 has a roll group such as a nudger roll 5, a feed roll 5, a retard roll 6 and a pair of takeaway rolls 7. Of these, the nudger roll 5 is rotationally driven by a sheet feeding motor, which will be described later, and can be moved forward and backward (movable up and down) by a roll supporting member (not shown) with respect to a sheet calling position F set therebelow. It is supported. This najar roll 5
The uppermost surface of the sheet supplied to the sheet calling position F is pressed against the sheet, and the rotation of the sheet feeds the sheet sequentially from the uppermost side to the feed roll 6 side. The feed roll 6 is rotationally driven by a paper feed motor (described later) that is common with the nudger roll 5, and power transmission from the paper feed motor is interrupted by a paper feed clutch (not shown). The feed roll 6 sandwiches the paper called by the najar roll 5 with the retard roll 6, and separates the paper one by one by the frictional resistance of the retard roll 6,
Send it to the takeaway roll 7. The pair of takeaway rolls 7 are held in pressure contact with each other, one on the rotation drive side and the other on the driven side. The takeaway roll 7 sandwiches the paper fed by the feed roll 6 between the rolls and feeds the paper onto a paper transport path leading to an image forming unit (not shown).

The manual paper feed tray 3 mainly calls special papers different from the papers stored in the multi-stage paper feed tray, such as officially made postcards, tracing papers, non-standard size papers, etc. For supplying to position F,
Special paper (in some cases, plain paper) supplied by hand is set on the manual paper feed tray 3. Here, in the present embodiment, the so-called MSI (multi-sheet inserter) system, which allows a plurality of sheets to be collectively set, is adopted as the configuration of the manual paper feed tray 3. This MS
In the I method, the required number of sheets are fed from the plurality of sheets set on the manual feed tray 3 even if the operator does not replenish the sheets one by one at the feeding timing. It will be sent automatically according to.

Further, a paper detection sensor 9 as a paper detection means is attached to the manual paper feed tray 3 adopting the MSI system. The paper detection sensor 9 detects the presence or absence of paper on the manual paper feed tray 3, and is composed of, for example, a light work switch in which a movable detection piece 9 a is projected on the manual paper feed tray 3. In the case of the paper detection sensor 9, when the paper is set on the manual paper feed tray 3, the movable detection piece 9a is pushed by the paper and retracts, whereby the on / off state of the sensor output is switched. There is.
The paper detection sensor 9 is not limited to the mechanical switches (contact type sensors) as described above, but an optical sensor (non-contact type sensor) in which a light emitting element and a light receiving element are combined may be employed. By providing the paper detection sensor 9 for detecting the presence or absence of the paper on the manual paper feed tray 3 in this way, the paper supplied to the paper call position F is fed by the manual paper feed tray 3
It is possible to discriminate whether the paper is the paper set in or the paper stacked and stored in the paper feeding unit 2.

The paper feeding unit 2 has a large number of papers P (usually about 2000 to 3000 sheets) of frequently used sizes set therein in addition to the multi-stage paper feeding trays incorporated in the apparatus body 1. In this unit body, a paper stacking base 10 capable of stacking a large amount of paper P is incorporated. The sheet stacking table 10 is disposed below the manual sheet feeding table 3 and is supported so as to be able to move up and down by an elevating mechanism (not shown). In the paper feeding unit 2, the paper P stacked on the paper stacking base 10 is raised together with the paper stacking base 10 by the drive of the elevating mechanism and is supplied to the paper calling position F of the paper feeding mechanism 4.

By the way, in the present embodiment, as the elevating mechanism of the paper feeding unit, the paper loading table 10 is supported by the wire wound around the pulley, and the feeding length of the paper is changed by driving the elevating motor (described later). A so-called elevator system for raising and lowering the loading platform 10 is adopted. In addition,
In addition to the elevator system described above, various mechanisms may be used as the mechanism for raising and lowering the sheet stacking table 10, such as a system utilizing the engagement between a rack and a pinion, a system utilizing a ball screw mechanism, a link mechanism, or the like. be able to.

Further, in the present embodiment, as a main component of the sheet feeding device, a height detection sensor 11 (height detection) for detecting the highest height of the sheet at the sheet calling position F is provided in the vicinity of the retard roll 5. Means) is attached. The height detection sensor 11 is for maintaining the uppermost position of the sheet supplied to the sheet calling position F at the same height, and in the illustrated example, the movement of the najar roll 5 that contacts the uppermost sheet (up and down). It employs a sensor configuration that operates (on / off) in conjunction with motion.

Next, the configuration of the drive control system of the sheet feeding device in this embodiment will be described with reference to FIG. FIG.
The drive control system shown in FIG.
OM21, RAM22, host interface 23,
Input interface 24, output interface 2
5, a motor drive circuit 26, a clutch drive circuit 27 and the like. Further, as input information, the above-described paper detection sensor 9 and height detection sensor 11 are connected to the input interface 24. On the other hand, the output interface 25 includes a lifting motor 28 to be controlled through a motor driving circuit 26 and a clutch driving circuit 27,
The paper feed motor 29 and the paper feed clutch 30 are connected.

The CPU 21 performs a processing operation according to a control program read from the ROM 21 and controls the operation of each drive system. ROM21 is CPU
The control program and control data necessary for the first processing operation are stored. The RAM 22 is for temporarily storing data necessary for the processing operation of the CPU 1. The host interface 23 is for exchanging so-called control information such as a paper feed start instruction and a paper feed end instruction with the main control unit on the apparatus main body (image forming apparatus main body) 1 side. . The input interface 24 is for providing the CPU 1 with the sensor signals output from the paper detection sensor 9 and the height detection sensor 11. The output interface 25 is for giving a control signal output from the CPU 1 to the motor drive circuit 26 and the clutch drive circuit 27. It should be noted that, among the drive systems listed as control targets, the lifting motor 28 is the paper feed unit 2
Paper source motor 29 for driving the paper stacking table 10
Serves as a drive source for the nudger roll 5 and the feed roll 6, and the paper feed clutch 30 connects and disconnects the power transmission from the paper feed motor 29 to the feed roll 6.

Next, the operation function of the sheet feeding device having the above-mentioned structure will be described with reference to the flow charts of FIGS. In the present embodiment, the processing procedure of the CPU 1 will be described mainly when the paper is fed to the image forming unit by manual paper feeding. First, prior to the paper feeding operation,
It is confirmed via the host interface 23 whether or not the setting on the apparatus main body 1 side is "manual feed" (step: S1). When "manual feed" is designated by the operator's input operation, a control signal is output to the motor drive circuit 26 via the output interface 25,
The raising / lowering motor 28 is reversely rotated by a predetermined amount in the direction in which the wire of the raising / lowering mechanism is fed out, and the sheet stacking table 1 of the sheet feeding unit 2 is rotated.
0 is lowered by several mm (S2). As a result, it becomes possible to supply the paper from the manual paper feed tray 3 to the paper call position F.

Next, while the elapsed time after the paper stacking table 10 is lowered is measured by a timer or the like, it is determined whether or not the paper is supplied (set) to the manual paper feed table 3 within a specified time. Judgment is made based on the ON / OFF signal output from 9 (S3). Here, when the output signal of the paper detection sensor 9 is switched from the off state to the on state (or vice versa) within the specified time, and thereby the paper supply to the manual paper feed tray 3 is confirmed, then the lifting mechanism is moved. The elevating motor 28 is normally rotated in the direction for winding the wire to raise the sheet stacking table 10 (S4). Then, the height detection sensor 1
While monitoring the output signal from 1 (S5), the lifting motor 2
When the output signal of the height detection sensor 11 is switched from the off state to the on state (or vice versa), the drive of the lifting motor 28 is stopped (S6). As a result, the paper supplied from the manual paper feed table 3 to the paper call position F is lifted together with the paper P stacked on the paper stack 10 and the paper height detected by the height detection sensor 11, that is, The nudger roll 5 and the uppermost sheet are positioned at a height position where an appropriate contact pressure is obtained, and the paper feeding operation from the manual paper feed tray 3 is in a standby state.

Next, when the start button on the apparatus main body 1 side is pressed, the main control section causes the host interface 2
When a paper feed start instruction is issued via 3, the control signal is output to the motor drive circuit 26 and the clutch drive circuit 27,
The paper feed motor 29 and the paper feed clutch 30 are driven to start the paper feed operation from the manual paper feed tray 3 (S7). As a result, the sheets fed from the manual feed tray 3 to the sheet calling position F are called by the nudger roll 5 in order from the uppermost position, and the image is formed from the feed roll 6 and the lead roll 7 via the takeaway roll 8. It will be sent to the department.

Then, every time one sheet of paper is fed out, it is judged whether or not the number of processed sheets designated by the apparatus main body 1 side has been reached (S8), and when the designated number of processed sheets is reached, the manual feed tray 3 Then, the sheet feeding operation from is ended (S9). When the paper feed is completed in this way, it is determined whether there is paper on the manual paper feed tray 3 based on the output signal of the paper detection sensor 9 (S10). Outputs a control signal to the motor drive circuit 26 to rotate the elevating motor 28 in the reverse direction by a predetermined amount to move the sheet stacking table 10 by several meters.
It is lowered by about m (S11). As a result, the pressure contact state of the sheet at the sheet call-up position F is released, and the remaining sheets can be easily taken out from the manual feed tray 3.

On the other hand, until the sheet is removed from the manual paper feed tray 3 by the operator, the presence / absence of paper on the manual paper feed tray 3 is continuously detected based on the output signal of the paper detection sensor 9 ( S12) If the paper is not removed even after the lapse of a predetermined time, the main control unit on the apparatus main body 1 side is caused to perform a display process to the effect that there is paper on the manual paper feed tray 3, and the paper is fed. A notification that the sheet feeding operation from the unit 2 is prohibited is given (13). Further, it is determined whether or not the start button on the apparatus body 1 side has been pressed (turned on) by the operator (S14), and the same processing (S12, S13) is repeated until the start button is pressed. . On the other hand, when the start button is pressed, the process proceeds to step S4 at that point and the paper feeding operation from the manual paper feed tray 3 is restarted in the same procedure as described above.

If it is determined in step S3 that the paper has not been supplied within the specified time, or if the operator has taken out the paper and determined that there is no paper in step S12, Step S1
Move to 5. In step S15, a control signal is output to the motor drive circuit 26 to rotate the elevating motor 28 in the forward direction and raise the sheet stacking table 10. Further step S1
6, the output signal from the height detection sensor 11 is monitored while the elevation motor 28 continues to rotate forward, and the height detection sensor 1
1 output signal from OFF state to ON state (or vice versa)
The drive of the lifting motor 28 is stopped at the time of switching to (S17). As a result, the sheets stacked on the sheet stacking table 10 are positioned at the sheet height detected by the height detection sensor 11, and the sheet feeding operation from the sheet feeding unit 2 is in a standby state. That is, when the image forming process is manually specified and the operator removes the paper from the manual paper feed tray 3, the manual paper feed is automatically canceled at that point and the paper feeding operation from the paper feeding unit 2 is continued. Ready to start. Also, in step S10, if it is determined that there is no paper when the paper feed operation from the manual paper feed tray 3 is completed, the process returns to step S1.

On the other hand, in step S8, if the actual number of processed sheets has not reached the designated number of processed sheets, the process proceeds to step S18. In step S18, the presence / absence of paper on the manual paper feed tray 3 is detected by the paper detection sensor 9
If it is determined that there is paper, the operation returns to step S7 and the paper feed operation from the manual paper feed tray 3 is repeated.

On the other hand, if it is determined in step S18 that there is no paper, the main controller of the apparatus body 1
The notification that the NO-PAPER display is performed is given via the host interface 23 (S19), and a control signal is output to the motor drive circuit 26 to rotate the lifting motor 28 in the reverse direction by a predetermined amount (S20). As a result, a message is displayed to the operator to supply paper to the manual paper feed tray 3, and the reverse rotation of the lifting motor 28 lowers the paper stacking tray 10 by several millimeters. It becomes possible to supply the sheet from the sheet 3 to the sheet calling position F.

Then, it is judged whether or not the paper is supplied by the operator based on the output signal of the paper detection sensor 9 (S21), and the motor drive circuit is operated at the time when the paper is supplied onto the manual paper feed tray 3. A control signal is output to 26, and the raising / lowering motor 28 is normally rotated (S22). Then, while monitoring the output signal from the height detection sensor 11, the lifting motor 2
8 continues to rotate normally (S23), and when the output signal of the height detection sensor 11 is switched from the off state to the on state (or vice versa), the drive of the lifting motor 28 is stopped (S24). As a result, the paper sheets supplied (supplied) to the manual paper feed tray 3 are the paper sheets P stacked on the paper stack tray 10.
It is lifted together with the height detection sensor 11
The sheet is positioned at the sheet height detected by, and the paper feed operation from the manual paper feed tray 3 is in a standby state. After that, the process proceeds from step S24 to step S7, and the paper feeding operation from the manual paper feed tray 3 is restarted as described above.

[0026]

As described above, according to the present invention, when the paper is fed from the paper feeding unit having the manual paper feeding tray and the vertically movable paper loading tray, the control means is based on the detection result of the height detecting means. By controlling the raising / lowering operation of the sheet stacking table, the sheets fed from either side are positioned at the same height at the sheet calling position, and the sheet is fed to the image forming section with the common sheet feeding means in order from the top. It will be possible to deliver it. As a result, in the paper feeding device of the image forming apparatus equipped with the manual paper feeding function and the paper feeding function having the vertically movable paper loading table, the paper feeding means corresponding to each function can be shared. A significant cost reduction is realized by simplifying the mechanical mechanism and the control form associated with.

[Brief description of drawings]

FIG. 1 is a schematic side sectional view showing an embodiment of a sheet feeding device of an image forming apparatus according to the present invention.

FIG. 2 is a functional block diagram showing a configuration of a drive control system of the sheet feeding device in the embodiment.

FIG. 3 is a flowchart (No. 1) for explaining the operation function of the paper feeding device according to the present invention.

FIG. 4 is a flowchart (No. 2) for explaining the operation function of the paper feeding device according to the present invention.

[Explanation of symbols]

 2 Paper Feeding Unit 3 Manual Paper Feeding Stand 4 Paper Feeding Mechanism (Paper Feeding Unit) 9 Paper Detecting Sensor (Paper Detecting Means) 10 Paper Loading Platform 11 Height Detecting Sensor (Height Detecting Means) 20 CPU (Control Means) 28 Elevating motor

Claims (4)

[Claims] 1. A paper feed unit for feeding the papers supplied to a predetermined paper call position toward the image forming section in order from the top, and a manual paper feed table for supplying the paper to the paper call position. And a paper stacking base that is capable of moving up and down below the manual paper feeding base, and a paper feeding unit that supplies the paper stacked on the paper stacking base to the paper loading position; Height detecting means for detecting the highest height of the paper, and when the paper is supplied from the manual paper feed tray and the paper feed unit, the paper stacking platform is moved up and down based on the detection result of the height detecting means. And a control unit that controls the sheet feeding device of the image forming apparatus. 2. A paper detection unit for detecting the presence / absence of paper on the manual paper feed tray is further provided, and the control unit is based on the detection result of the paper detection unit and the detection result of the height detection unit. The sheet feeding device of the image forming apparatus according to claim 1, wherein the raising / lowering operation of the sheet stacking table is controlled. 3. The sheet feeding device of the image forming apparatus according to claim 1, wherein an upper cover of the sheet feeding unit is configured as the manual sheet feeding table. 4. The apparatus further comprises designating means for designating that the paper is fed from the manual feed tray, and the control means is designated by the designating means to feed the paper from the manual feed tray. 2. The sheet feeding device of the image forming apparatus according to claim 1, wherein in this case, the raising / lowering operation of the sheet stacking table is controlled so that the sheets stacked in the sheet feeding unit are retracted from the sheet calling position.