JPH0349862B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sheet feeding device that is attached to a sheet intake port provided in an image forming apparatus such as a copying machine, a laser printer, a liquid crystal printer, or a printing machine.

[Conventional technology]

Generally, in image forming devices such as copying machines,
A paper feed set is attached to the sheet intake port to supply sheets such as copy paper, tracing paper, synthetic resin film, etc., but when copying a large amount at once, it is necessary to replenish the sheets frequently during copying. There must be.

Therefore, a sheet feeding device that accommodates a large amount of sheets is attached to the sheet intake port for a normal paper cassette installed in a copying machine, or to a specially provided sheet intake port to reduce the number of times sheets are replenished. ing.

Such a sheet supply device includes a stacking section that stacks sheets, and a lifting device that raises the stacking section according to the amount of sheet reduction.

[Problem to be solved by the invention]

In such a sheet feeding device, each time the sheets are fed out, the sheets rub against each other, which generates static electricity and paper dust.
Therefore, when this static electricity accumulates and discharges,
The noise may cause the microcomputer in the control unit to malfunction or be damaged. Therefore, the frame is grounded to eliminate static electricity. However, the loading section moves up and down relative to the frame, and paper dust accumulates on it, so
It is difficult to conduct electricity between the loading section and the frame, and the static electricity in the loading section cannot be removed reliably.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet feeding device that can stably eliminate static electricity generated in a stacking section at all times without being disturbed by the movement of the stacking section or paper dust generated from the sheets.

[Means to solve the problem]

In order to achieve the above-mentioned object, the present invention provides a conductive part on the surface of a frame that vertically movably supports a support part provided on a stacking part for stacking sheets, on the opposite side to the side facing the stacking part. At the same time, a conductive contact member that makes sliding contact with the conductive part is provided on the support part.

〔Example〕

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

<Configuration> As shown in FIG. 1, an image forming apparatus 3 such as a copying machine is placed on a mounting table 1.
The image forming apparatus 3 copies on sheets supplied from a sheet supplying device 5 attached to the image forming apparatus 3.

The mounting table 1 has openings 7 and 9 on the sides and top.
It has a large-capacity accommodating section 11 that accommodates the sheet feeding device 5 equipped with the above, and a multi-tiered cassette accommodating section 15 that accommodates a plurality of small-capacity paper feed cassettes 13 that accommodate sheets of different sizes.

The sheet feeding device 5 includes a sheet storage section 17 that stores sheets as shown in FIGS. 2 and 3.
, a feeding section 19 that guides the sheet sent out from the sheet storage section 17 to the image forming apparatus 3 , a support guide 21 having recesses 20 provided on both sides of the feeding section 19 , and a sheet storage section 17 . The pin 32 provided in the center of both sides and the seat accommodating part 17
and a back cover 27 rotatably attached to the back of the seat accommodating section 17 via a hinge.

Note that the pin 23 is provided in consideration of the position of the center of gravity of the sheet feeding device 5 at a position where the center of gravity does not fluctuate even if the size of the sheets to be accommodated changes.

Further, as shown in FIG. 3, the sheet storage section 17 includes a stacking section 29 such as a hopper whose tip abuts against a tip regulating plate 28 to support the sheet, and this stacking section 29 is attached to metal frames (chassis) 32 on both sides. An elevating device 31 is provided that moves up and down along a guide portion 30 such as a provided guide. The lifting device 31 includes a roller 35 rotated by a motor 33, and a belt 3 connecting the roller 35 and the loading section 29.
7. A roller 39 supporting this belt 37 is provided. Note that electric parts such as the lifting device 31 are electrically connected to the image forming apparatus 3 through a connector.

The stacking unit 29 includes a pair of support rollers 36 attached to a pair of support units 26 on the rear left and right sides of the center of gravity in the sheet taking-in direction when the sheets are loaded.
38 is provided, and the guide part 3 is tilted forward.
It is supported by 0. Note that the loading section 29 and the supporting section 26 are electrically connected.

On the outside of the metal frame 32 on one side, a conductive part 141 such as a nickel-plated metal plate is attached along the guide part 30 as shown in FIG. Further, a conductive contact member 145 such as a metal static elimination brush that slides into contact with the conductive part 141 is attached to the support part 26 via a metal arm 143.

Furthermore, as shown in FIG. 3, a feeding means 101 is provided at the top of the sheet storage section 17 to feed out the sheets stacked on the stacking section 29 one by one.
This feeding means 101 includes a feeding roller 103, a sprocket 105, a lurch chain 107, a sprocket 109, gears 111 and 113, and a pulley 1.
15, belt 117, pulley 119, motor 12
1, etc., and a feeding roller 103 feeds out the sheet by rotation of a motor 121. Note that the feeding roller 103 is a one-way roller that rotates in one direction.

The feeding unit 19 includes a separation claw 122 that separates the sheet sent out by the feeding roller 103 into one sheet, a guide unit 123 that guides the separated sheet, and a shaft 12.
a pressing plate 127 (pressing means) rotating around 5;
Solenoid 129 that rotates this pressing plate 127
is provided.

Note that the feeding section 19 is provided with a sheet detection sensor S having a light emitting element and a light receiving element in the sheet setting section.

On the other hand, a sheet intake port 41 is provided at the bottom of the image forming apparatus 3, facing the large-capacity storage section 11 of the mounting table 1, as shown in FIG. The sheet intake port 41 is open at the bottom and at the insertion side of the sheet feeding device 5.

Furthermore, a pin 43 that engages with the support guide 21 of the sheet feeding device 5 and a notch 45 that engages with the pin 23 are provided on the inner surface of the sheet intake port 41 .

Therefore, the sheet feeding device 5 is attached to the sheet intake port 41 as follows.

After confirming that the image forming apparatus 3 is placed in the correct position on the mounting table 1, the sheet supply device 5 is inserted into the large capacity storage section 11 and the sheet intake port 41.

At this time, the pins 2 provided on both sides of the lifting device 31
3 and a notch 4 provided inside the image forming apparatus 3.
5 so that the weight of the sheet feeding device 5 is supported by the notch 45. At this time, the lifting device 3
A pin 43 provided deep inside the sheet intake port 41 is engaged with the recessed portion 20 of the support guide 21 provided on both sides of the sheet feeding device 5, so that the sheet feeding device 5 supported by the notch 45 does not rotate around the pin 23. This is prevented by the support guide 21.

In the sheet intake port 41, as shown in FIG. 1, a sheet intake means, such as a intake roller 47, which is engaged with the pressing plate 127 of the sheet supply device 5 is provided.

Further, a support plate 49 such as a steel plate bent into an L-shape is provided at the bottom of the image forming apparatus 3, and the sheet supply device 5 is fixed to this support plate 49 via a mounting portion 25 with screws.

Furthermore, the image forming apparatus 3 includes a paper feed cassette 13.
An intake port 51 is provided to which a holder is attached.
Note that a take-in roller 53 is provided within this take-in port 51 .

Registration rollers 55 and a conveyor belt 57 are provided ahead of the take-in rollers 47 and 53 to feed the sheet to an image forming section 58.

The image forming section 58 is provided with a photosensitive drum 59. Around this photosensitive drum 59, a charging device 61, an unnecessary charge eraser 63, a developing device 6
5, a transfer device 67, a separation charge device 69, a separation claw 71, and a drum cleaner 73 are arranged.

An automatic document feeder 75 is attached to the document setting section so that its rear side can be opened and closed by a hinge.

A platen 77 made of contact glass is provided below the automatic document feeder 75, and a slit illumination device 79 is provided below the platen 77 so as to be movable in the left-right direction along the platen 77.

In addition, two movable reflecting mirrors 81 and 83 and a lens 8
5 and two fixed reflecting mirrors 87 and 89 transmits a light image of the original image illuminated by the slit illumination device 79 to the photosensitive drum 59, and performs exposure. There is.

The photosensitive drum 59 forms an electrostatic latent image corresponding to the image of the document on its outer peripheral surface, and this latent image is transferred to the developing device 6.
Visualization with toner is performed by 5.

The visible image formed on the photosensitive drum 59 in this way is captured by the capture roller 51 or 53, and the paper feeding timing is adjusted by the registration roller 55.
The image is transferred onto the sheet P sent between.

The sheet with the visible image transferred in this way is
The photosensitive drum 59 is separated from the photosensitive drum 59 by the discharging action by the separation charging device 69 and the mechanical separation action by the separating claw 71, and is sent to the fixing device 93 by the conveyance roller 91.

The transfer sheet is discharged from a discharge port 97 with the visible image facing upward by a discharge roller 95, and is stored in a sheet storage device 99.

The sheet storage device 99 reverses the front and back of the sheets supplied from the image forming apparatus 3 and stores the sheets in page order.As shown in FIG. 151, a switchback path 153 that conveys the sheet in the opposite direction to the input direction, a reversal path 155 that turns the sheet in a U-turn and reverses it, a sheet discharge sensor S2 that detects sheet discharge, and a sheet discharge roller 157 that discharges the sheet. , 159, and a storage tray 161 on which discharged sheets are stacked.

The conveyance path switching device 151 includes first and second rotating bodies, such as conveyance rollers 163 and 165, which are in pressure contact with each other and rotate in the feeding direction, and a conveyance roller above the sheet sent out by these conveyance rollers 163 and 165. A third rotating body, for example, a conveying roller 167, which is provided in pressure contact with the conveying roller 165 and rotates in a direction opposite to the sheet feeding direction;
The rear end in the feeding direction of the sheet sent out by the conveyance rollers 163 and 165 is provided below the switchback path 153 between the conveyance rollers 16 and 165.
3, 165, for example, an intermediate roller 169, and an elastic material 17, such as a synthetic resin sheet, that presses the sheet against this intermediate roller 169.
1, and a deflecting means 173 that presses the rear end of the sheet sent out by the transport rollers 163 and 165 in the feeding direction against the transport roller 167.

Although the driving force of the relay roller 169 is obtained from the drive motor via a transmission mechanism, an auxiliary roller that is in contact with both the conveyance roller 163 and the intermediate roller 169 is provided, and the rotational force of the auxiliary roller driven by the conveyance roller 163 is transmitted. may be transmitted to the relay roller 169.

The deflection means 173 is configured so that the entrance sensor S1
After a predetermined time T1 after detecting the rear end of the sheet (sheet P
The shift lever 179 is provided with a solenoid 175 that is energized after the time when the rear end passes the relay roller 169 after being detected by the entrance sensor S1, and a shift lever 179 that is rotated about a shaft 177 by the solenoid 175.

The rollers 157, 165, and 169 are driven by a drive motor (not shown) (rotates when the entrance sensor S1 detects the leading edge of the sheet, and stops when the discharge sensor S2 detects the trailing edge of the sheet).

The automatic document feeder 75 includes a document tray 201 on which a document is set as shown in FIG. 203
The document sent out from the platen is conveyed onto the platen 77, set at the reference position, and after copying is completed,
It includes a conveyance section 205 that sends out from above the platen 77, a discharge section 207 that reverses and discharges the document sent from the conveyance section, and a storage tray 209 that stores the sheet discharged from the discharge section 207.

<Operation> With the above configuration, this device operates as follows.

First, the back cover 27 of the sheet feeding device 5 is opened, and sheets are set on the stacking section 29. Since the stacking section 29 is inclined, the leading edge of the sheet abuts against the leading edge regulating plate 28. In addition, the loading section 29
Since the support position of is located behind the center of gravity,
The weight of the sheet causes the stacking section 29 to further tilt forward. Therefore, the sheet does not shift toward the rear of the stacking section 29.

In this state, when the back cover 27 is closed, the motor 33 is automatically driven and the roller 35 is
is rotated to raise the loading section 29. When the sheet pushes up the feeding roller 103 and a sensor (not shown) turns on, the feeding roller 103 stops. And motor 121
is driven, and the feeding roller 103 rotates. For this reason, the sheet is sent out and separated by the separation claw 122.
It is separated into sheets and sent to the set position. When the leading edge of this sheet is detected by the sensor S, the motor 12
1 stops, the rotation of the feeding roller 103 is stopped, and the solenoid 129 is energized to rotate the pressing plate 127, so that the sheet is pressed against the taking-in roller 47.

On the other hand, the document tray 20 of the automatic document feeder 75
1 and press the copy button (not shown), the document is separated into one sheet by the separating and feeding unit 203 and sent out, and the conveying unit 205 transfers the document to the platen 7.
It is set to the reference position on 7. Note that when copying is completed, the original is ejected to the storage tray 209 via the ejection unit 207, and the next original is supplied from the separation/feed separation 203.

When the original is set at the reference position on the platen 77, a sheet take-in command is issued from the image forming apparatus 3, the take-in roller 47 rotates, and the sheet is taken into the image forming apparatus 3. Then, when the rear end of the sheet is detected by the sensor S, the solenoid 1
29 is de-energized and the press plate 127 separates from the take-in roller 47, the motor 121 rotates and the feed roller 103 feeds out the next sheet.

Note that when a predetermined amount of sheets are taken in, the stacking section 2
9 rises by a certain amount, and the sheet always reaches the feed roller 10.
It borders on 3.

By the way, when the loading section 29 moves up and down, the conductive contact member 145 contacts and slides on the conductive section 141. Therefore, no matter where the loading section 29 is located, the static electricity charged on the loading section 29 is always removed from the supporting section 2.
6. It flows to the conductive part 141 via the arm 143 and the conductive contact member 145, spreads to the metal frame 32, and is neutralized.

The image of the sheet taken into the image forming device 3 is copied in the image forming section 58, and the sheet is transferred to the sheet storage device 99.
is supplied to

When the entrance sensor S1 detects the leading edge of the sheet, the drive motor is activated by the signal, and the rollers 159,1
65,169 rotates. Therefore, the sheet is gripped by transport rollers 163 and 165 and sent to switchback path 153. Note that the sheet is conveyed while being pressed against the relay roller 169 by the elastic material 171. When the rear end of the sheet is detected by the entrance sensor S1, a timer for exciting the solenoid 175 is activated.

When the trailing edge of the sheet passes through the conveyance rollers 163 and 165, it is further conveyed by the intermediate roller 169 and the elastic material 171, and when the trailing edge of the sheet comes off the intermediate roller 169, the sheet fed to the switchback path 153 loses its conveying force and stops. do. When time T1 has elapsed since the entrance sensor S1 detected the rear end of the sheet, the solenoid 175 is energized.
The shift lever 179 rotates as shown in the eleventh example, and presses the sheet end against the conveying roller 167.

Therefore, this sheet end is switched back by the conveying force of the conveying roller 167, and
5,167 and supplied to the reversing path 155. Note that the solenoid 175 is demagnetized after a predetermined time T2 after being energized.

The sheet supplied to the reversing path 155 is ejected with the sheet end, which was the trailing edge when ejected from the image forming apparatus 3, becoming the leading edge. Then, when the trailing edge of the sheet is detected by the paper discharge sensor S2, the drive motor is stopped unless the next sheet is detected by the entrance sensor S1. If the entrance sensor S1 detects a sheet, the drive motor continues to rotate.

The sheets discharged by the paper discharge rollers 157 and 159 are stacked on a storage tray 161.

The conveyance rollers 163 and 165 are pressed against each other and rotate in the feeding direction, and the conveyance roller 165 is provided above the sheet sent out by these conveyance rollers 163 and 165, and is in pressure contact with the conveyance roller 165, and rotates in the feeding direction of the sheet. A conveyor roller 167 that rotates in the opposite direction to the conveyor roller 167 is provided below the conveyor roller 167 across the switchback path 153, and the rear end of the sheet sent out by the conveyor rollers 163, 165 in the feeding direction is connected to the conveyor rollers 163, 165. an intermediate roller 169 that moves away from the conveyor roller 163;
a shift lever 17 that presses the rear end in the feeding direction of the sheet sent out by the sheet feeding roller 165 against a conveying roller 167;
9, the sheet is sent out by the relay roller 196 even after the trailing edge of the sheet comes off the conveyance rollers 163, 165 as shown in FIG. be pushed away. Therefore, when the sheet is biased and pressed against the conveying roller 167 by the shift lever 179 and the sheet is switched back in the opposite direction to the feeding direction, the edge of the sheet is not bent by the conveying roller 165.

<Effects of Example> According to this example described above, the following effects can be obtained.

(1) When the stacking section 29 is loaded with sheets or moves up and down, it vibrates around the support section 26, but since the conductive contact member 145 is attached to the support section 26 of the stacking section 29, the stacking section 29 does not vibrate. However, the vibration of the conductive contact member 145 is small. Therefore, the movable loading section 29 can be stably and reliably neutralized.

(2) Conductive part 1 with which the conductive contact member 145 makes sliding contact
41 is provided on the outer surface of the metal frame 32, no matter how much paper dust is generated inside the conductive part 141 as sheets are fed, it is difficult for the paper dust to adhere to the outer conductive contact member 154 or the conductive part 141. . Therefore, conductivity is maintained even after long-term use, and static electricity is removed reliably.

[Modified example]

Although one embodiment of the present invention has been described above,
The present invention is not limited to the above-mentioned embodiment, and for example, the following modifications are possible.

(1) Conductive part 141 in contact with conductive contact member 145
may be provided only at the top. This is because discharge is more likely to occur when the number of sheets decreases.

(2) In the embodiment described above, a metal plate is attached to the surface of the metal frame 32 to form the conductive portion 141, but the conductive contact member 145 may be brought into direct contact with the metal frame 32. That is, the surface of the metal frame 32 may be used as the conductive portion 141.

(3) The support section 26 may be a shaft or a roller that supports the loading section 29. Further, the support section 26 is connected to the loading section 2.
It may be placed on the front and back of 9 instead of on both sides.

(4) The frame 32 that supports the support portion 26 does not need to be made of metal, as long as the conductive portion 141 is grounded.

〔Effect of the invention〕

As explained above, according to the present invention, the frame includes the stacking section 29 for stacking sheets, the supporting section 26 attached to the stacking section 29, and the guide section 30 for vertically movably supporting the supporting section 26. 3
2, an elevating device 31 that moves the stacking section 29 up and down along the guide section 30, and a sending means 101 that sends out the sheets stacked on the stacking section 29 to a sheet intake port 41 of the image forming apparatus 3. In the sheet feeding apparatus, a conductive part 141 provided on the surface of the frame 32 on the opposite side to the side facing the stacking section 29; and a conductive part 141 attached to the support part 26,
Since the conductive contact member 145 is provided in sliding contact with 41, the following effects can be obtained.

That is, even if vibration or rocking occurs due to the vertical movement of the loading portion 29, the support portion 26 becomes the center of the vibration or rocking, and there is substantially less vibration or rocking, and the conductive portion 141 and the conductive contact member 145 There is no contact or separation, and static electricity can be removed stably.

Further, the conductive portion 141 is connected to the loading portion 2 of the frame 32.
Since it is provided on the side opposite to the side facing 9, paper dust generated as the sheet is fed does not adhere to the conductive part 141 and the conductive contact member 14 due to paper dust.
5, and stable static elimination can be performed over a long period of time.

[Brief explanation of drawings]

1 to 6 are diagrams showing one embodiment of the present invention, in which FIG. 1 is a cross-sectional view showing the overall configuration of an image forming apparatus, and FIG. 2 is a large-capacity storage section of a mounting table and an image forming apparatus 3 is a schematic diagram showing the structure of the sheet feeding device, FIG. 4 is a diagram showing the structure of the container, and FIG. 5 is a diagram showing the sheet storage device. FIG. 6 is a cross-sectional view showing the structure of the sheet storage device, and FIG. DESCRIPTION OF SYMBOLS 1... Mounting table, 3... Image forming device, 5... Sheet supply device, 11... Large capacity storage part, 17... Loading part, 1
9... Feeding section, 26... Supporting section, 29... Loading section, 30
...Guide part, 32...Metal frame, 36, 38...Support roller, 41...Sheet intake port, 47...Take-in roller, 58...Image forming unit, 99...Sheet storage device, 101...Feeding means, 141...Conductive part, 143 ...Arm, 145...Conductive contact member.

Claims (1)

[Scope of Claims] 1. A frame 32 having a stacking section 29 for stacking sheets, a support section 26 attached to the stacking section 29, a guide section 30 that supports the support section 26 in a vertically movable manner; The loading section 29 is connected to the guide section 3.
an elevating device 31 that moves up and down along 0, and a sending unit 1 that sends out the sheets stacked on the stacking section 29 to the sheet intake port 41 of the image forming apparatus 3.
01, the conductive part 141 is provided on the surface of the frame 32 opposite to the side facing the stacking section 29;
41. A sheet feeding device characterized by comprising a conductive contact member 145 in sliding contact with 41.