JP3181389B2 - Paper feeder - Google Patents

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 for an image forming apparatus such as a copying machine, a facsimile, a printer, etc., and more particularly to a sheet feeding device suitable for a large-volume sheet feeding.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication (Kokai) No. 56-7843 (1) relates to a large-volume sheet feeding device, in which a table for setting sheets is substituted by sheet transfer means (transfer pressing plate) fixed to a main body. The technology that has been shown
Japanese Unexamined Patent Application Publication No. 3-56334 (3) discloses a technique for feeding a large amount of sheets in a bundle and feeding the auxiliary paper container with a screw screw fixed to the main paper container. A driving connection technique is disclosed in Japanese Patent Laid-Open No. 3-124.
Japanese Patent Application Laid-Open No. 633 (4) discloses a technique in which the auxiliary paper container is drivingly connected to a screw screw fixed to the main paper container. A possible technology is disclosed,
JP-A-23031 (6) discloses a technique in which a transport belt for transporting a sheet bundle is stretched from a sub-sheet accommodating section to a main sheet accommodating section, and JP-A-3-232629 (7) discloses an operator. Japanese Patent Laid-Open Publication No. 4-28634 (8) discloses a technique for pulling out two empty paper storage units. A transfer belt for transferring a bundle of papers is stretched from a sub paper storage unit to a main paper storage unit. Japanese Patent Laying-Open No. 4-28635 (9) discloses a technique in which a transport belt for transporting a bundle of sheets is stretched from a sub-sheet storage section to a main sheet storage section. JP-A-4-4502
Japanese Patent Publication No. 2 (10) discloses a technique in which a transfer belt is provided in each of a sub-paper storage unit and a main paper storage unit.

[0003]

The technique shown in (1) is:
Since the table for setting the paper is replaced by a paper transfer means (transfer pressing plate) fixed to the main body, when setting the paper, the operator sets the paper on the main body 100 as shown in FIG. It is necessary to insert the paper into the paper transporting means 101, and there is a drawback that the paper replenishing performance is extremely poor. In the technique shown in (2), since a large amount of paper is stacked and fed, the paper becomes long in the vertical direction, so that a paper storage unit cannot be arranged in the main body, and a large space is provided next to the main body. There were drawbacks needed. In addition, in order to load a sheet with this feeder, it is necessary to temporarily stop the sheet feeding operation and further lower the elevator tray to secure a replenishing space. Therefore, there was a drawback that continuous paper feeding was not possible and productivity was poor. In the techniques shown in (3) and (4), the auxiliary paper container is driven and connected to a screw screw fixed to the main paper container. It is necessary to pull out the main paper container including Therefore, it is impossible to load paper into the sub-paper container while paper is being supplied from the main paper container. That is, since the paper feeding operation is temporarily stopped in order to load the paper, continuous paper feeding cannot be performed, so that there is a disadvantage that productivity is poor. In the technique shown in (5), only the sub-sheet storage section can be pulled out. Therefore, when all the sheets are used up, the sheet is set in the sub-sheet storage section once and waits for the sheet to move to the main sheet storage section. Then, the sheets are loaded again by setting the sheets again. That is, there is a disadvantage that sheets cannot be fully loaded by one sheet loading operation. In the techniques shown in (6), (8), and (9), since a transport belt for transporting a sheet bundle is stretched from the sub-sheet storage section to the main sheet storage section, it is difficult to load sheets. It is necessary to temporarily stop the sheet feeding operation and pull out the entire tray. That is, there is a drawback that continuous feeding cannot be performed and productivity is poor.
In the technique shown in (7), the operator pulls out two empty paper storage units, so that two pull-out operations are required, which is troublesome.

[0004] Further, if foreign matter or the like is present in the transport path while the paper is being transported in both (5) and (7), the transportable loading table collides with the foreign material and stops, but there is no safety device. Power supply to the motor does not stop. Therefore, there is a problem such as burning of the motor or breakage of the drive system.

Further, if the operator turns off the machine by mistake while transferring the paper, the loading table stops across the main paper storage and the sub paper storage, and the paper storage as shown in (7) is reached. Is also released. If one of the paper storage units is pulled out in this state, the loading table stopped on the way will be caught and it will not only be impossible to pull out, but also if the alignment of the paper on the loading table is disturbed or the pulling output is strong. , The loading table will be damaged. In the technique shown in (10), a transfer belt is provided in each of the sub-paper storage section and the main paper storage section. However, since both transfer means are disposed in the large tray, it is difficult to load paper. It is necessary to temporarily stop the paper feeding operation and pull out the tray. That is, there is a drawback that continuous feeding cannot be performed and productivity is poor.

The present invention solves the above-mentioned drawbacks of the conventional apparatus, and is a thin type which can be installed in the main body, and which can cope with an erroneous operation by an operator such as entry of foreign matter into the sheet storage section or stop of the power supply during sheet transfer. It is an object to provide a paper device.

[0007]

[0008]

[0009]

Means for Solving the Problems The upper Symbol object, a first sheet accommodating portion for stacking plural sheets, a sheet feeding means for feeding sheets one by one from the first sheet storage portion, the second A paper feeder having a second paper storage unit disposed horizontally and in parallel with one paper storage unit, and paper transfer means for collectively transferring the paper in the second paper storage unit to the first paper storage unit In the apparatus, a driving source of the paper transporting means is constituted by a motor capable of rotating forward and reverse, an overcurrent detecting means for detecting an overcurrent flowing in the motor, and an overcurrent detecting means for overcurrent to the motor by the overcurrent detecting means. Control means for temporarily stopping supply of current to the motor when it is detected that the current has flowed, and drive transmission of two systems having different reduction ratios for transmitting the driving force of the motor to the paper transfer means. And intermittent drive to each drive transmission means Drive intermittent means that normally controls the drive intermittent means to use the drive transmission means with the smaller reduction ratio, and when the overcurrent is detected by the overcurrent detection means, the drive with the larger reduction ratio is driven. It is achieved by controlling the drive intermittent means in order to use the transmission means.

[0010]

[0011]

[0012]

According to the present invention , the control means can discriminate and determine whether a foreign substance has entered or a skew of a sheet bundle. Therefore, when the foreign substance has entered, the control means stops the transfer of the sheet, and when the skew of the sheet bundle is carried out, the sheet transfer is reliably performed. I do.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram of a copying machine to which the present invention is applied, FIG. 2 is a top view of a sheet feeding device according to an embodiment of the present invention,
FIG. 3 is a front view of the same.

The sheet feeding section shown in FIG. 1 is of a two-stage sheet feeding type consisting of an upper stage a and a lower stage b. The lower tray b is supported by a rail 7 so that a conventional tray 3 for storing large-size sheets (about 500 sheets) such as A3 can be pulled out in the front direction of the drawing.

The upper section a is an example of a sheet feeding apparatus using the present invention. The sheet storage section is capable of storing 500 sheets of small size paper such as A4 in the short direction in the right tray 1 and the left tray 2 in total. The shape of the left and right trays is a box with an open tray wall serving as a transfer passage so that the sheets stacked on the left can be transferred to the right. The left and right trays 1 and 2 are supported by rails 4, 5 and 6 so that they can be pulled out toward the front of the drawing.

In FIGS. 2 and 3, a handle 2-1 is provided on the front surface of the left tray 2, and the handle 2-1 is used when pulling out the tray. A sheet take-out device 8 is provided at the front edge of the right tray 1 on the transport side. In the sheet take-out device 8, reference numeral 9 denotes a pick-up roller for pressing the loaded sheet P1 and sending out the sheet P1 from the storage section.
Reference numerals 10 and 11 denote separation rollers that separate and feed the sheet P1 one by one. The right tray 1 is provided with a pair of side fences 12, 13 and back fences 14, 15 for positioning the paper P1, and a bottom plate 16 on which the paper P1 is stacked.

FIG. 4 is a perspective view of the vicinity of the side fence. Although the side fence 12 is shown here, the same applies to the side fence 13.

The back fluence 14 is supported by a torsion spring 17 in a counterclockwise direction. The back fluence 14 in the biased state regulates the trailing edge of the sheet. Reference numeral 18 denotes a rotary solenoid supported on the bottom of the side fence 12, and a rotary disk 18
-1 is electromagnetically rotated by a fixed angle, and the torque causes the back fluence 14 to rotate against the urging force of the torsion spring 17, thereby instantaneously securing the sheet transfer area. . When the power supply is stopped, the pin 18-2 is returned to the initial position by a return spring (not shown) inside the rotary solenoid 18, and the backfence 14 is turned off.
Also returns to the position where the trailing edge of the sheet is regulated.

A lifting device 19 is provided below the bottom plate 16 to press the bottom plate 16 to urge the bottom plate 16 in the direction of the paper feed roller.

FIG. 5 is a structural view of a drive unit of the bottom plate lifting device.

A sector gear 19-2 fixed to the shaft end of the pressure shaft 19-1 is driven by a bottom plate lifting motor 19-3 which can be rotated forward and backward. The pressure shaft 19-1 is supported below the tray base,
The pressure plate 19-4 (FIGS. 2 and 3) is installed at the other shaft end. When the pressure shaft 19-1 rotates clockwise, the pressure plate 19-4 lifts the bottom plate 16 from below below the hole 20 (FIG. 2) on the tray base, so that the loaded paper P1
Is pressed upward, and the uppermost sheet comes into contact with the pick-up roller 9 [If necessary, an ascending detection sensor 9-1 (FIG. 3) for detecting the height of the uppermost sheet may be provided).

In FIG. 3, reference numeral 21 denotes a pressure plate 19-4.
Is a lowering detection sensor that detects that the lowering part is not in contact with the bottom plate 16. 22 is a sheet P1 in the right tray 1
Is a paper empty detection sensor that detects the presence or absence of
When there is no sheet P1 in the right tray 1, the filler portion of the empty detection sensor 22 is notched 16-1 of the bottom plate 16.
It is detected that there is no sheet P1 by falling into (FIG. 2).

The right tray 1 is provided with a locking mechanism supported by the tray.

FIG. 6 is a configuration diagram of the tray lock mechanism.

A locking claw 32 is provided rotatably around a shaft 32-1 fixed to the right tray 1 as a fulcrum. The locking claw 32 is constantly urged clockwise by a torsion spring 32-3. Therefore, the lock hole 2 of the left tray 2
Since the locking claw 32 is held so that the distal end 32-2 of the locking claw 32 is fitted to 3, the right tray 1 can be pulled out integrally by pulling the left tray 2. However, when the lock release solenoid 31 supported by the main body operates, the pulling force of the solenoid 31 rotates the release lever 31-2 to the position shown by the dotted line in the figure against the spring force of the return spring 31-1. Let it. Accordingly, since the tip 32-2 of the locking claw 32 is opened from the locking hole 2-3 of the left tray 2, even if the left tray 2 is pulled, no pulling force acts on the right tray 1.

FIG. 7 is a configuration diagram of the tray lock mechanism.
More specifically, it is a detailed view of a locking mechanism when the left tray 2 is stored in the main body when the release solenoid 31 is not operated.

Edge 2-4 of left tray 2 and locking claw 3
2 are cam-shaped with respect to each other as shown in the figure, so that the locking claw 32 rotates counterclockwise against the force of the torsion spring 32-3 to allow the left tray 2 to enter. I do.

A bottom plate 23 on which sheets P2 are stacked is provided on the left tray 2 in FIG. 3, and a movable back fence 24 for pressing a substantially central portion of the stacked sheets P2 and transferring the sheets P2 collectively in the right tray 1 direction. Is provided. The required pressing force is
In the experiment, the weight is about 800 gf for 500 sheets of A4 size.

The movable back fluence 24 is movable in the sheet transport direction along a guide member (not shown) fixed to the left tray 2.

The bottom plate 23 and the ascending bottom plate 16 have a smooth surface or a rib or a bead to reduce the conveyance resistance so that the sheet bundle can be easily slid and transported.
The bottom plate 23 is fixed to the left tray 2 and has a hole 23-1 on the bottom plate so that the pressing portion 24-1 of the movable back fence 24 can move. Since the pressing portion 24-1 protrudes from the connecting portion 24-2 with the wire (which may be a timing belt) 25 below the bottom plate 23 in the transport direction, the paper P2 can be transported to the position P1.

As shown in FIG. 2, the wire 25 connected to the movable back fluence 24 is connected to pulleys 26, 27, 2 as shown in FIG.
The movable back fluence 24 reciprocates by rotating the pulley 27 in a forward and reverse direction by a transfer motor 30 which is stretched between the positions 8 and 29 and can be rotated forward and reverse by a transfer motor 30 which can be rotated forward and backward. For positioning of the reciprocating motion, the projecting piece 24-3 is provided on the movable back fence 24, and the projecting piece 24-3 is attached to the home sensor 47.
Is detected by the positioning sensor 48.

In FIGS. 2 and 3, reference numeral 33 denotes a sheet bundle detection sensor.

The force by which the back fluence 24 presses the sheet bundle P2 is generated by the driving torque of the transfer motor 30. However, when a load force greater than the driving torque of the transfer motor 30 is generated due to the entry of foreign matter during the transfer of the sheet bundle P2, the transfer motor 30 locks and stops. In this state, the transfer motor 30
An overcurrent flows inside and burns in.

FIG. 10 is a block diagram of the motor control circuit.

In the circuit as shown in FIG.
Control 0. That is, when a current equal to or more than a specified amount flows through the transfer motor 30, the comparator 40
The power is supplied to the transfer motor 30 by turning off the transistor 42 according to a command from the CPU 41. FIG. 10 shows a circuit for stopping the transfer motor 30 when a current of, for example, 0.7 A flows.

FIG. 11 is an explanatory diagram showing characteristics of the motor.

It is assumed that the transfer motor 30 is used at a rotation speed of 1500 rpm in order to satisfy the specifications of "the movement distance of the back fluence 250 mm, the transfer time is within 3 seconds, and the required pressing pressure of the back fluence 800 gf". Hereinafter, an estimate of the reduction ratio and the transfer time required for the design of the drive unit is calculated (here, the gear efficiency is not taken into account, but is calculated at the time of actual design).

Reduction ratio = necessary pushing pressure ÷ (motor torque /
Pulley radius) = 800 gf ÷ 50 gf = 16 (1 cm radius of pulley) Transfer speed = (circle of output pulley × revolution) ÷ (60 × reduction ratio) = 20π × 1500/60 × 16 = 98 mm / se
c Transfer time = Moving distance / Transfer speed = 250/98 =
2.5 sec Here, assuming that the above-described circuit is used, the load force on the back fluence 24 is 1200 gf (at 0.7 A).
Then, the transfer motor 30 stops.

As described above, since the transfer motor 30 does not lock due to the entry of foreign matter, there is no fear of burning of the transfer motor 30. However, when the sheet bundle is skewed and strongly contacts the side fences 12 and 13 during the transfer of the sheet bundle, the sheet bundle moves slowly and the load force is reduced to one.
It may be 200 gf. In this case, if the motor 30 is simply stopped by the above-described circuit, a jam occurs during transfer even though there is no foreign matter on the tray.

Therefore, as shown in FIG. 12, the drive path from the transfer motor 30 to the wire 25 is a drive mechanism having two systems with different reduction ratios. The reduction ratios of the first and second drive paths are set to 16, 24, respectively, and both drive paths have clutches 50, 51. Normally, the first clutch 50 is turned on and the second clutch 51 is turned off so that the drive is transmitted through the first drive path. Then, after detecting a load force of 1200 gf and stopping the forward / reverse rotation motor 30, the first clutch 50 is turned off and the second clutch 5 is turned off.
Turn 1 on.

Accordingly, the safety device does not operate up to a load force of 1800 gf, so that even a skewed sheet bundle can be transferred. When foreign matter is mixed, the load force is 180
Since it becomes 0 gf or more, the safety device operates and the transfer motor 30 stops. Therefore, the jam being transferred is displayed on the display unit to prompt the operator to perform the jam processing.

If the second drive path is used from the beginning, no skewing of the sheet bundle occurs, but the drive path with a large reduction ratio is used, so that the transport time of the sheet bundle becomes longer. Therefore, usually, the first path having a short transfer time is used.

Next, the control contents of the present invention will be described based on the flowchart of FIG.

When the start signal is input, the bottom plate raising motor 19-3 starts to rotate forward (S1). When the completion of the ascent is detected by the ascent sensor 9-1 (Y in S22), the motor 19-3 stops (S3). If it is confirmed by the empty detection sensor 22 that the sheet on the right tray 1 is left (Yes in S4), the sheet feeding operation is started (S5). However, if it is detected that the paper has been consumed and becomes empty (No in S4), and furthermore, at this time, if the paper bundle detection sensor 33 detects that there is a paper in the left tray 2 (Yes in S6), The bottom plate raising motor 19-3 is reversed by instructing the bottom plate raising device 19 (S7), and the bottom plate 16 is returned to the release position. Then, the back fluence 14,1 on the right tray 1
5 is retracted from the paper bundle transfer path (rotary solenoid 18 is turned on) (Y, S9, S10 in S8). Next, after operating the first drive path (the first clutch 50 is turned on) (S
11) The mobile back fluence 24 is driven (S1).
2) The sheet bundle P2 is transferred to the right tray 1. Before the sheet transfer is completed (N in S13), if the above-mentioned circuit detects that the load force has become 1200 gf or more (S14).
N), and temporarily stops the transfer motor 30 (S1).
5) The second drive path is activated (S16), and the movement of the sheet bundle is started again (S17). Here, the transfer motor 30 is stopped when switching from the first drive path to the second drive path. However, there is no problem even if the drive path is switched while the transfer motor 30 is rotating. Then, before the transfer is completed (N in S18), when the load force becomes 1800 gf or more (N in S19), the transfer motor 30 is stopped as the jam during the transfer (S20), and the jam is displayed (S21).

When the completion of the transfer of the sheet bundle is detected (Y in S13 and Y in S18), the movable back fence 24 is returned to the home position (detected by the home sensor 47) (S2).
(2, S23, S24, Y, S25), the paper empty of the left tray 2 is displayed on the operation unit or the like, and the operator is prompted to replenish the paper.

In the right tray 1, after the sheet bundle is transferred, the back edge of the sheet bundle is regulated by returning the back fluences 14 and 15 to the return position (the rotary solenoid 18 is turned off) (S26), and the bottom plate 16 is moved to a predetermined position. To perform the sheet feeding operation (Y in S27, S28, S29, S3
0). Lock release solenoid 31 when paper feeding operation is started
Turns on (S31), and the lock on the left and right trays is released. Accordingly, when the operator notices the paper empty of the left tray 2 during the paper feeding operation and pulls the handle 2-1 forward to replenish the paper, only the left tray 2 is pulled forward as shown in FIG. I can do it. That is, since the left tray 2 is at the front, the opter can easily supply paper. Further, the paper feeding operation on the right tray 1 is performed during paper supply, so that there is no time loss.

When the operator pulls the handle 2-1 forward when the sheets in the left and right trays are used up or when the power is turned off, the lock release solenoid 31 as shown in FIG.
Does not operate, the left and right trays are integrated and pulled out to the front, so that a total of 1000 sheets can be replenished by one pulling-out operation. Similarly, even if the operator turns off the power by mistake during the sheet transfer operation and pulls out the tray in that state, the lock release solenoid 31 does not operate. That is, even if the sheet being transported is stopped while straddling the left and right trays, there is no damage to the sheet bundle and the sheet transport drive unit due to the tray withdrawal operation. When the paper feeding operation is completed (S32), the lock release solenoid 31 is turned off (S32).
33).

[0049]

[0050]

[0051]

According to the present invention, the control means can discriminate and judge whether a foreign substance has been mixed or a skew of a sheet bundle. A transfer can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a copying machine to which the present invention is applied.

FIG. 2 is a top view of the sheet feeding device according to the embodiment of the present invention.

FIG. 3 is a front view of the sheet feeding device according to the embodiment of the present invention.

FIG. 4 is a perspective view near a side fence.

FIG. 5 is a configuration diagram of a drive unit of the bottom plate lifting device.

FIG. 6 is a configuration diagram of a tray locking mechanism.

FIG. 7 is a configuration diagram of a tray locking mechanism.

FIG. 8 is a plan view of the tray when the handle is pulled toward the front in the unlocked state of the tray.

FIG. 9 is a plan view of the tray when the handle is pulled toward the user in the locked state of the tray.

FIG. 10 is a block diagram of a motor control circuit.

FIG. 11 is an explanatory diagram showing characteristics of a motor.

FIG. 12 is a perspective view of a two-system drive transmission unit.

FIG. 13 is a flowchart showing control contents of the present invention.

FIG. 14 is a perspective view of a sheet feeding device according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Right tray (1st paper accommodation part) 2 Left tray (2nd paper accommodation part) 4,5,6 rail 8 Paper take-out device (paper supply means) 9 Pickup roller 10,11 Separation roller 12,13 Side fence 14, 15 Backfence 24 Mobile backfence (paper transfer means) 30 Transfer motor (drive source) 40 Comparator (overcurrent detection means) 41 CPU (control means)

Claims (1)

(57) [Claims] A first sheet storage unit for stacking a plurality of sheets; a sheet feeding unit for feeding sheets one by one from the first sheet storage unit; In a paper feeder having a second paper storage unit disposed in parallel and a paper transfer unit for transferring the paper in the second paper storage unit to the first paper storage unit, the driving of the paper transfer unit is performed. An overcurrent detecting means for detecting an overcurrent flowing in the motor, and an overcurrent detecting means for detecting an overcurrent flowing in the motor when the overcurrent is detected by the overcurrent detecting means. Control means for temporarily stopping the supply of current to the motor, and the driving force of the motor
Drive transmission means with different reduction ratios for transmission to the gears
Drive that can intermittently drive the stage and the respective drive transmission means
Intermittent means, and usually the drive transmission with the smaller reduction ratio
Controls the drive intermittent means to use the means and detects overcurrent
If an overcurrent is detected by the
The paper feed device controls the drive intermittent means to use the drive transmission means .