JP2003306249A - Paper feeding device and image forming device with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce cost by eliminating a carrying roller control clutch, to simplify a control sequence, and to realize accurate control by eliminating an operation delay of an electromagnetic clutch. <P>SOLUTION: In this paper feeding device, a carrying roller drive control clutch to be arranged between a feed roller and a resist roller is eliminated, and the carrying roller has two drive sequences for transmitting driving force from the feed roller through a one-way and for transmitting driving force from the resist roller through the one-way. <P>COPYRIGHT: (C)2004,JPO

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 in an image forming apparatus for recording an image on a sheet material such as a copying machine, a printer and a fax machine.

[0002]

2. Description of the Related Art Conventionally, as this type of apparatus, there is an image forming apparatus as shown in FIG.

The image forming apparatus comprises an image forming apparatus main body 10
A sheet feeding deck 102 in which a large amount of sheet materials S are stacked and stored is provided on one side of the sheet No. 1, and a plurality of sheet feeding cassettes 103 and 105 in which a predetermined amount of sheet materials S are stacked and stored in the lower portion of the image forming apparatus main body 101. Is equipped with.

Then, a sheet feeding deck 102 as a sheet feeding portion for feeding the sheet material S and each sheet feeding cassette 10
Respective paper feed devices 106, 201, and 109 of the retard separation type are provided at the installation sites of 3 and 105, respectively.

The paper feed deck 102, the paper feed cassette 103,
The sheet material S in 105 is the paper feeding device 106, 2
When the paper is fed by 01 and 109, it is first sent to the registration roller pair 233 whose rotation is stopped, and the skewed state is corrected there.

Next, the registration roller 23 is timed with the toner image formed on the photosensitive drum 111.
3 is rotated to rotate the photosensitive drum 111 and the transfer charger 1.
And the toner image on the photosensitive drum 111 is transferred (image formation).

Thereafter, the sheet material S is sent to the fixing device (fixing roller pair) 115 by the conveyor belt 113, and a fixing process for fixing the toner image transferred here to the sheet surface is performed.

The image forming apparatus has a double-sided copy mode for performing double-sided copy on the sheet material S and a multiplex copy mode for performing multiplex copy. In the normal copy mode, the sheet material S after the fixing process is discharged internally. Paper is ejected onto a paper ejection tray 119 outside the apparatus by a pair of paper rollers 117.

In the double-sided copy mode and the multiplex copy mode, the inner discharge roller pair 116 or the switchback roller pair 127 temporarily moves the sheet onto the intermediate tray 121 via the re-feeding path 120 and the double-sided conveying path 126. It is loaded and stored in.

Then, the sheet material S stored on the intermediate tray 121 is again conveyed to the registration roller pair 233 for image formation by the re-feeding device 130, and thereafter discharged through the same process as single-sided copying. It

FIG. 4 is a sectional view of a conventional sheet feeding device 201.
FIG. 5 shows a perspective view of a conventional drive transmission device 213. The sheet feeding device 201 supplies the sheet material S to the image forming apparatus shown in FIG. As shown in FIGS. 4 and 5, the sheet feeding device 201
Is a pickup roller 20 that feeds the uppermost sheet material S one by one from a sheet material storage device 203 in which a plurality of sheet materials S are stacked and stored on a stacking table (not shown).
5, a feed roller 206 that conveys the sheet material 202 fed from the sheet material storage device 203 by the pickup roller 205 into the image forming apparatus main body (direction of arrow b in the drawing), and is arranged so as to face the feed roller 206. When there are a plurality of sheet materials fed from the sheet material storage device 203, a retard roller 207 for separating the sheet material S into one sheet material by rotating in a direction opposite to the rotation direction of the feed roller 206, and image formation. It is provided with a conveying roller pair 209 arranged in front of the apparatus main body. Further, a guide 211 is arranged in the sheet material passing region 210 between the pickup roller 205 and the feed roller 206 and the retard roller 207. The guide 211 is arranged between the feed roller 206 and the retard roller 207 and the conveying roller pair 209, and the conveying roller pair. 209 and the image forming apparatus main body between the guide 2
12 are arranged so that the sheet material 202 is guided and conveyed. The feed roller 206 and the retard roller 207 are the drive transmission device 213 shown in FIG.
Driven by.

As shown in FIG. 5, the drive transmission device 213 is connected to a feed roller shaft 215, which supports the feed roller 206, a retard roller shaft 216, which supports the retard roller 207, and the retard roller shaft 216. The retard roller drive shaft 217 is provided substantially in parallel. The retard roller shaft 216 is supported by a swingable support member (not shown) and can come into contact with and separate from the feed roller shaft 215 in parallel. A coupling 219 and a torque limiter 220 are arranged between the retard roller shaft 216 and the retard roller drive shaft 217. Further, at the end of the feed roller shaft 215, an electromagnetic clutch 222 for transmitting the driving force transmitted from the main driving means (not shown) of the main body of the image forming apparatus via the drive input belt 221 to the feed roller shaft 215 is provided. There is. Further, a retard drive belt 223 is wound between the feed roller shaft 215 and the retard roller drive shaft 217 to transmit the rotational drive force transmitted to the feed roller shaft 215 to the retard roller drive shaft 217. The coupling 219 is for transmitting the drive from the retard roller drive shaft 217 to the retard roller shaft 216 even if the retard roller 207 is displaced. The driving of the feed roller 206 and the retard roller 207 by the drive transmission device 213 will be described. The rotational driving force given from the main driving means of the main body of the image forming apparatus (not shown) is transmitted to the driving input belt 221, and the pulley 225 provided on the armature portion of the electromagnetic clutch 222 which is ON / OFF controlled according to the sheet feeding timing. Entered in. Here, since the feed roller shaft 215 that rotates integrally with the rotor portion of the electromagnetic clutch 222, the retard roller drive shaft 217, and the retard roller shaft 216 are connected by the retard drive belt 223, the feed roller shaft 215 and the retard roller shaft 216 are connected. Also, the retard roller drive shaft 217 rotates in the same direction, and the feed roller 2
06 and the retard roller 207 are rotationally driven in synchronization with the paper feed timing ON. By the drive transmission means 213, the sheet material S is fed in the sheet feeding direction (arrow b shown in FIGS. 4 and 5).
Direction), the retard roller 207 rotates in a direction opposite to the drive rotation direction of the retard roller drive shaft 217 because the torque limiter 220 idles due to the frictional force between the feed roller 206 and the sheet material 202. To do. Further, when a plurality of sheet materials 202 are fed,
Since the frictional force between the plurality of sheet materials 202 is smaller than the frictional force between the retard roller 207 and the sheet material 202, the torque limiter 220 does not idle and the retard roller 207 rotates the retard roller drive shaft 217. It rotates in the same direction as the driving direction. This separates the sheet material 202 on the feed roller 206 side, that is, the uppermost sheet material 202 and the other sheet material 202 among the plurality of fed sheet materials 202, and multi-feeds the sheet material 202 into the main body of the image forming apparatus. It is designed to prevent

In this way, when the sheet material S separated one by one and sent out from the feed roller 206 reaches a predetermined position, the conveying roller control clutch 231 is turned on.
The signal is transmitted, and the transport roller shaft 230 supporting the transport roller 209 is rotated by the drive transmitted from the main motor via the belt 232.

Then, the leading end of the sheet material S conveyed to the re-registration roller 233 by the conveyance roller 209 is abutted against the nip portion of the registration roller pair, and a predetermined amount of loop is formed on the sheet material S to perform the skew feeding. After the correction, the ON signal is transmitted to the registration roller control clutch 234, and the registration roller shaft 236 supporting the registration roller 233 is rotated by the drive transmitted from the main motor via the belt 235. In this way, the sheet material S is conveyed to the image forming unit by the registration rollers 233.

[0015]

As described above, in the conventional paper feeding device, in order to control ON / OFF of the driving of the feed roller, the conveying roller and the registration roller, a clutch mechanism is used as a drive transmission means for each roller. I need. Usually, an electromagnetic clutch is often used, but it is relatively expensive and has a problem that it is ON due to its controllability and a malfunction may occur due to an operation delay or noise with respect to a signal.

In consideration of the above-mentioned problems, an object of the present application is to provide a sheet feeding device which realizes cost reduction and accuracy improvement of sheet material conveyance control with a simple structure.

[0017]

In a sheet material conveying device having three or more pairs of rollers for conveying a sheet material in the sheet material conveying path direction, a conveying roller 2 located in the middle is a conveying roller upstream of the sheet material conveying path. The drive is transmitted from 1 to the conveying roller 2 via the one-way rotating clutch member, and the drive is transmitted from the conveying roller 3 on the downstream side of the sheet material conveying path to the conveying roller 2 via the one-way rotating clutch member. It is characterized by

A sheet feeding device having a feed roller for sending out a pair of sheets, a conveying roller for conveying the sheet load conveyed from the feed roller to a registration roller, and a sheet material conveyed by the conveying roller to an image forming section. In the image forming apparatus provided with a registration roller for carrying, the carrying roller is driven by each of the feed roller and the registration roller via a one-way rotation clutch member.

A sheet feeding device having a feed roller for feeding the sheet material, a feeding roller for feeding the sheet material fed from the feed roller to a registration roller, and a sheet material fed by the feeding roller to an image forming section. In an image forming apparatus including a registration roller for conveying, and the feed roller and the registration roller are driven at different conveyance speeds, the conveyance roller is driven from the feed roller and the registration roller via a one-way rotation clutch member. It is characterized by being transmitted.

A sheet feeding device having a feed roller for feeding the sheet material, a feeding roller for feeding the sheet material fed from the feed roller to a registration roller, and the sheet material fed by the feeding roller to the image forming section. In an image forming apparatus equipped with a registration roller for carrying, a driving force is transmitted through the one-way rotation clutch member so that the carrying roller carries the sheet material from the feed roller at a constant speed with the feed roller, and Drive is transmitted from a registration roller via a one-way rotation clutch member so as to convey the sheet material at the same speed as the registration roller.

A sheet feeding device having a feed roller for feeding a sheet material, a feeding roller for feeding the sheet material fed from the feed roller to a registration roller, and a sheet material fed by the feeding roller to an image forming section. In an image forming apparatus including a registration roller for carrying, and the feed roller being driven at a carrying speed different from that of the registration roller, the carrying roller carries the sheet material at a constant speed from the feed roller. Drive is transmitted through the one-way rotation clutch member, and the drive is transmitted through the one-way rotation clutch member so as to convey the sheet material from the registration roller at the same speed as the registration roller. And

The present invention is characterized by including the above-mentioned conveying devices 1 to 5 and an image forming means for forming an image on a sheet material fed from the conveying device.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) A first embodiment of the present invention will be described in detail with reference to FIG.

FIG. 1 is a perspective view showing a first embodiment of the present invention, and FIG. 2 is a drive development view thereof. This figure shows an image forming apparatus having a cross section similar to that of FIG. 6 showing a conventional example, in which a sheet material S stacked in a sheet material storage portion is separated from the sheet material storage portion by a pickup roller 301 of a sheet feeding device. When a plurality of sheet materials are sent out at this time, by the action of the feed roller 302 and the retard roller 303 which constitute the sheet material separating mechanism-after separating each sheet, the conveyance provided in the sheet conveyance path An apparatus that conveys the sheet material S to the re-registration roller 305 by the roller 304, corrects the skew of the sheet material S by the registration roller pair, and conveys the sheet material S toward the image forming unit is shown.
The drive of the pickup roller 301 of the sheet feeding device is transmitted from the feed roller via the belt 306, and ON / OFF of contact of the pickup roller 301 with the sheet material S is controlled by a solenoid (not shown).
The retard roller 303 is a feed roller shaft 307.
The feed roller 3 via the torque limiter 308
Drive is transmitted so as to rotate in the opposite direction to 02. Here, the drive of the feed roller 302 is transmitted from a main motor 309 which is a drive source, and ON / OFF control is performed by a paper feed control clutch 310.

Similarly, the registration roller 305 is also driven by the main motor 309, which is a drive source, and is ON / OFF controlled by the registration control clutch 311.

The conveying roller 304 between the feed roller 302 and the registration roller has two drive transmission paths and does not have an electromagnetic clutch or the like as a clutch mechanism for ON / OFF control. The first drive transmission path A is performed by a gear train from the feed roller shaft 307, which is ON / OFF controlled by the general control clutch 310, via the transport roller shaft 312 and the one-way 313. At this time, the one-way 31 is mounted so as to be locked when the gear train rotates the transport roller shaft 312 in the direction A of FIG. The second drive transmission path B is performed from the registration roller shaft ON / OFF controlled by the registration control clutch 311 to the conveyance roller shaft 312 via the one-way 314 by a gear train. One way 31 at this time
No. 4 is attached so that the gear train locks when the transport roller shaft 312 is rotated in the direction A of FIG.

Thus, the paper feeding operation of the paper feeding device of the present invention is as follows.

First, from the main body of the image forming apparatus, the sheet material S
When a sheet feeding signal for conveying the sheet is generated, the pickup roller 301 first contacts the sheet material S, an ON signal is transmitted to the sheet feeding control clutch 310, and the drive of the main motor 309 is transmitted to the feed roller 302. Then, the drive is transmitted from the feed roller 302 to the pickup roller 301 by the belt 306, and the sheet material S is sent from the sheet material storage portion to the feed roller 302. At this time, when the sheet material S is sent out to the nip between the plurality of feed rollers 302 and the retard roller 303, it is separated into each sheet by the action of the retard roller 303 whose drive is transmitted from the feed roller shaft 307 and is conveyed to the conveying roller 304. Is transported.

When the sheet material S is sufficiently held in the nip of the feed roller 302, the pickup roller 301 is retracted from the sheet material S in the sheet material storage portion by the action of a solenoid (not shown), and the sheet material S is fed by the feed roller. Three
It is transported to the transport roller 304 by 02.

At this time, the conveying roller 304 is rotated by the drive transmitted from the feed roller shaft 307 which is the first drive transmission path (A). At this point, the registration roller 30
The second drive transmission path B does not operate because the drive transmission of No. 5 has not been performed yet. Further, since the one-way 314 is used, the drive is not transmitted from the transport roller 304 to the registration roller 305.

Then, the sheet material S is conveyed by the conveying roller 304 to the registration roller 305 which has been stopped in advance, and in order to form a loop and correct skew, a controller (not shown) controls a sheet feeding control clutch. 310
To the feed roller 302 and the feed roller 304 are stopped. Next, the ON signal is transmitted to the registration control clutch 311 at a timing with the toner image formed on the photosensitive drum, the drive of the main motor 309 is transmitted to the registration roller 305, and the sheet material S is rotated. The conveyance is started by 305.

Then, the transport roller 304 is rotated by the drive transmitted from the registration roller shaft 315 which is the second drive transmission path (B). One way 31 as before
Due to the effect of 3, the feed roller 3
No drive is transmitted to 02.

As described above, when the paper feeding device of the present invention is used, the electromagnetic clutch for ON / OFF control of the carrying roller 304 is not required, the cost can be reduced, and the carrying roller is mechanically controlled. As a result, the control software sequence can be simplified, and malfunctions of clutches and operation delays can be eliminated, and reliable and highly accurate control can be performed.

(Second Embodiment) A second embodiment of the present invention will be described in detail with reference to FIG.

FIG. 3 is a drive development view of the second embodiment of the present invention.

As shown in FIG. 3, in this embodiment, the reduction ratio C from the main motor 409 to the feed roller 402 is
And the reduction ratio D from the main motor to the registration roller is different, and the first conveyance speed (conveyance speed of the feed roller), which is the conveyance speed of the sheet material S from the sheet feeding device, is the sheet material S in the image forming unit. The sheet feeding device according to the first embodiment of the present invention is used in an image forming apparatus that is faster than the second transport speed (transport speed of the registration roller), which is the transport speed of.

Further, in the present embodiment, the speed reduction ratio of the first drive transmission path A is set so that the conveying roller 404 rotates so that the conveying speed of the feed roller 403 and the sheet material S becomes substantially the same speed. There is.

The speed reduction ratio of the second drive transmission path B is
The transport roller 404 is the registration roller 405 and the sheet material S.
It is set to rotate so that the conveyance speed of is approximately constant.

Therefore, until the leading edge of the sheet material S is conveyed from the feed roller 402 to the conveying roller 404 and reaches the registration roller to form a loop, the conveying roller 404 conveys the sheet pair S to the first conveying direction. The drive is transmitted by the first drive transmission path A so as to convey at a speed (conveyance speed of the feed roller).

When the sheet material S is conveyed by the registration rollers 405 after forming the registration loop, the conveyance rollers 404 convey the sheet material S at the second conveyance speed (conveyance speed of the registration rollers). The drive is transmitted to the second drive transmission path B.

The transport roller 404 is the first drive transmission path A.
The rotations of different speeds are drive-transmitted from the second drive transmission path B and the one-way provided in each drive transmission path. The drive is not transmitted to the second drive transmission path B, and conversely, the drive is not transmitted from the conveyance roller 404 to the first drive transmission path A when being driven from the second drive transmission path B. , It does not rotate each roller that is stopped.

As described above, when the feeding speed of the sheet material S is higher than the conveying speed at the time of image formation as in the second embodiment of the present invention, the first embodiment described above is used. In addition to the effect of the above, the feed roller 402 and the registration roller 40
The rotation speed of the transport roller 404 between the two speeds is automatically switched to the second speed.

When the actual transport speed of the sheet material S is different from the actual transport speed of the feed roller 402 and the registration roller 405 due to the difference in the material such as the transport roller 404 and the applied pressure, the actual transport speed is different. The speed reduction ratios of the first and second drive transmission paths (A, B) may be set such that

[0044]

As described above, according to the present invention,
A clutch is not required to control the transport roller between the feed roller and the registration roller, and the transport roller is also driven when the feed roller or the registration roller is driven. Further, when the speed-up control at the time of feeding is being performed, it becomes possible to automatically switch the transport speed of the transport roller to the second speed. As a result, the cost of the device can be reduced and the control of the transport roller is mechanically performed.
The sequence of the control software is simplified, and malfunctions of the clutch and operation delays are eliminated, and reliable and highly accurate control is possible.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of the present invention.

FIG. 2 is a drive development view of the first embodiment of the present invention.

FIG. 3 is a drive development view of a second embodiment of the present invention.

FIG. 4 is a sectional view of a conventional paper feeding device.

FIG. 5 is a perspective view of a conventional paper feeding device.

FIG. 6 is a sectional view of a conventional image forming apparatus main body.

[Explanation of symbols]

201 paper feeder 203 sheet material stacking section 205, 301, 401 Pickup roller 206, 302, 402 Feed rollers 207, 303, 403 retard roller 209, 304, 404 Conveying rollers 305.405 Registration roller 215, 307 Feed roller shaft 216 retard roller shaft 231 Conveyor Roller Control Clutch 310,410 Paper feed control clutch 311 411 Registration control clutch 313,314 One way

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3F049 DA12 EA01 EA10 LA01 LB01                 3F102 AA02 AA10 AA11 AB01 BA02                       BB02 DA08 EA03                 3F343 FA02 FB02 FB03 FB04 GB01                       GC01 GD01 JA18 JD04 JD09                       JD33 KB05 KB06 KB17 KB19                       LA04 LA16 LC20 LC22 LC25                       LD29

Claims (6)

[Claims] 1. A sheet material conveying device having three or more pairs of rollers for conveying a sheet material in a sheet material conveying path direction,
The conveyance roller 2 located in the middle transmits drive from the conveyance roller 1 on the upstream side of the sheet material conveyance path to the conveyance roller 2 via the one-way rotation clutch member, and the conveyance roller 3 on the downstream side of the sheet material conveyance path. The sheet feeding device is characterized in that the driving force is transmitted from the sheet to the conveying roller 2 via the one-way rotating clutch member. 2. A feed roller for feeding a pair of sheets,
In an image forming apparatus including a sheet feeding device having a conveying roller that conveys a sheet load conveyed from the feed roller to a registration roller, and a registration roller that conveys the sheet material conveyed by the conveying roller to an image forming unit. A sheet feeding apparatus, wherein the conveying roller is driven by each of the feed roller and the registration roller via a one-way rotation clutch member. 3. A feed roller for feeding a sheet material,
A sheet feeding device having a conveyance roller that conveys the sheet material conveyed from the feed roller to the registration roller, and a registration roller that conveys the sheet material conveyed by the conveyance roller to the image forming unit. An image forming apparatus in which the registration rollers are driven at different conveyance speeds, wherein the conveyance rollers are driven by the feed rollers and the registration rollers via a one-way rotation clutch member. 1. The sheet feeding device described in 1. 4. A feed roller for feeding a sheet material,
In an image forming apparatus including a sheet feeding device having a conveying roller that conveys a sheet material conveyed from the feed roller to a registration roller, and a registration roller that conveys the sheet material conveyed by the conveying roller to an image forming unit. Drive is transmitted via the one-way rotation clutch member so that the conveying roller conveys the sheet material from the feed roller at the same speed as that of the feed roller, and at the same speed from the registration roller to the registration roller. A sheet feeding device, wherein drive is transmitted via a one-way rotation clutch member so as to convey a sheet material. 5. A feed roller for feeding a sheet material,
The sheet feeding device includes a sheet feeding device that conveys the sheet material conveyed from the feed roller to the registration roller, and a registration roller that conveys the sheet material conveyed by the conveyance roller to the image forming unit. In an image forming apparatus driven at a conveyance speed different from that of the registration roller, the conveyance roller is driven via a one-way rotation clutch member so as to convey the sheet material from the feed roller at the same speed as the feed roller. 5. The sheet feeding device according to claim 4, wherein the driving force is transmitted through the one-way rotation clutch member so that the sheet material is conveyed from the registration roller at the same speed as the registration roller. . 6. An image forming apparatus, comprising: the conveying device according to any one of 1 to 5 above; and an image forming unit that forms an image on a sheet material fed from the conveying device.