JP2898486B2 - Conveyance drive for sheet reversing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transport driving device for transporting a sheet in a sheet reversing device provided in an image forming apparatus such as a copying machine or a printing machine, or another sheet handling device.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine or a printing machine, or other sheet handling apparatuses, a sheet printed on one side by a printing apparatus main body is reversed during conveyance and re-fed to the printing apparatus main body. Some include a so-called sheet reversing device. This type of sheet reversing device is generally provided at the lower portion of the printing device main body, carries in a single-sided printing sheet discharged from the printing device main body from one end of the present device, passes through a reversing path, and after reversing the sheet. The sheet is once fed to the aligning section, the sheets are aligned by the aligning section, and then sent to the re-feeding path to be fed again from the other end of the apparatus to the printing apparatus main body.

[0003]

In this type of sheet reversing apparatus, sheet conveyance in the reversing path and the re-feeding path, and sheet feeding and discharging in the aligning section when the sheet is reversed are carried out. Various transport driving systems for performing the operation, a driving force transmission unit for transmitting a driving force to these transport driving systems, and the like are provided. However, while the sheet is always conveyed in the same direction in the sheet conveyance in the reversing pass and the re-feeding path, the sheet feeding and discharging in the alignment unit is performed when the sheet is fed into the alignment unit. It is necessary to perform forward / reverse switchable sheet conveyance, for example, when the sheet is discharged from the matching unit to the re-feed path, the conveyance direction is reversed. Therefore, in order to achieve downsizing of the sheet reversing device and to facilitate maintenance of the transport driving system, the layout when the transport driving system and the driving force transmission unit are arranged in the sheet reversing device is a major problem. Become.

[0004]

Accordingly, a first object of the present invention is to provide a forward drive system and a forward / reverse drive system in consideration of the arrangement of a transport drive system and a drive force transmission unit in a sheet reversing device. The split arrangement facilitates maintenance, and the overall size of the sheet reversing device is reduced by achieving compactness.

A second object of the present invention is to dispose a space in the apparatus formed by laying out the arrangement of the transport driving system and the driving force transmission unit, and to arrange a drive control circuit of the driving force transmission unit. By using the space as a space, it is possible to further reduce the size of the sheet reversing device as well as to reduce noise.

That is, the transport driving device of the sheet reversing device according to the present invention is, firstly, provided with a casing portion for carrying a sheet printed on one side by a printing device main body from one end of the device, and a drawer capable of being pulled out to the casing portion. A sheet reversing unit that feeds the loaded sheet carried into the casing unit to a reversing path, passes the reversing path, reverses the sheet, passes the refeeding path, and re-feeds the sheet from the other end of the apparatus to the printing apparatus main body. In the sheet reversing device, a driving system for conveying the sheet to the reversing path and the re-feeding path is divided into two, and a forward driving system for always conveying the sheet in one direction is provided on one side of the sheet reversing unit. A forward / reverse drive system capable of switching the sheet conveyance direction is disposed on the other side of the sheet reversing unit, and the forward drive system and the forward drive system are provided at a rear position of one of these drive systems. During loading of the sheet reversing unit for any BiTadashi reverse drive system is characterized in that during withdrawal of and sheet reversing unit transmits a driving force to place the driving force transmission unit to cut off the driving force to the casing portion,

Secondly, a driving system for conveying the sheet to the reversing path and the re-feeding path is divided into two parts, and a normal rotation driving system for always conveying the sheet in one direction is provided on one side of the sheet reversing unit. In addition, a forward / reverse drive system capable of switching the sheet conveyance direction is disposed on the other side of the sheet reversing unit, and the forward drive system and the forward / reverse drive system are provided at a rear position of one of these drive systems. In any case, a driving force transmission unit that transmits a driving force when the sheet reversing unit is loaded and blocks the driving force when the sheet reversing unit is pulled out is disposed on the casing portion side, and is opposite to the driving force transmission unit. Wherein a drive control circuit of the driving force transmission unit is disposed in the casing portion of the control device.

[0008]

According to the above-mentioned means, by mounting the sheet reversing unit on the casing, the forward drive system and the forward / reverse drive provided respectively on the left and right sides of the driving force transmitting unit and the sheet reversing unit attached to the casing. The driving force is transmitted to both the forward rotation drive system and the forward / reverse rotation drive system by the drive of the drive system transmission unit. Driving force in the forward and reverse directions is transmitted to the system.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 and FIG. 2 show a printer P as an image forming apparatus. The printer P includes a printer main body 100 for forming an image, a transport unit 200 disposed downstream of the printer main body 100, a main body mounting paper feed unit 300 incorporated in a lower part of the printer main body 100, and a lower part thereof. The sheet reversing device 400 is provided. Note that the main unit-mounted paper feeding unit 300 can be formed by appropriately stacking a plurality of the units in two or three stages, on the contrary, by directly stacking the printer main body 100 and the sheet reversing device 400 without mounting them, It is also possible to freely combine a sheet distributing unit (not shown) at the lower part of the table. Main unit paper feed unit 3
00 and the sub-control means 301 of the sheet reversing device 400,
Reference numeral 401 is electrically connected to the main control unit 101 of the printer main body 100 via each connector, and the main control unit 101 recognizes the configuration state of each of the mounted units and individually controls the units appropriately. In particular, the sub-control unit 301 of the main body-mounted paper feeding unit 300 that can be stacked in a plurality of stages is configured to output a signal to the printer main body 100 so as to be able to recognize the order of the stage. Lock means (not shown) are provided to prevent the drawer cassette from being pulled out during operation of the lower unit. Further, the printer main body 1 is provided in the main body-mounted sheet feeding unit 300 and the sheet reversing device 400.
Positioning means 302 and 402 for mounting and positioning with the upper unit or the upper unit and mounting error preventing means 303 and 403 for preventing an error in the mounting order are provided. Further, a main body storage paper feed unit 500 is integrated with the bottom of the printer main body 100.

The printer main body 100 includes an image forming unit 102 for printing a sheet fed from a paper feeding unit such as the main body storage paper feeding unit 500 or the main body mounted paper feeding unit 300. In the image forming unit 102, the sheet guide 10
3 is fed to the registration roller 105 by the conveying roller 104 and the registration roller 10
After temporarily waiting at 5, the image is transferred onto the sheet by the image forming drum 106. Then, the image is further fixed on the sheet by passing between a pair of fixing rollers 107, and is sent to the transport unit 200 via a sheet discharging roller 108 disposed downstream of the sheet. A switchable sheet reversing guide 1 is provided near the downstream side of the discharge roller 108.
09 is provided, and by switching the sheet reversing guide 109, the sheet can also be discharged to a sheet reversing tray 110 provided separately from the transport unit 200 in a state where the sheet is reversed.

The sheet sent to the conveying unit 200 is conveyed to the sheet discharging roller 203 via the sheet discharging relay roller 202 after the leading end of the sheet is detected by the sheet discharging sensor 201, and the sheet is turned upside down. The paper is discharged onto a paper discharge tray 204. Further, the transport unit 200 has a re-feeding path in addition to the sheet discharging path. The refeed path includes a switchable refeed guide piece 205 disposed between the discharge relay roller 202 and the discharge roller 203, and a refeed guide 206 following the refeed guide piece 205. ,
A refeed sensor 207 for detecting the passage of the leading edge of the sheet at the tip of the refeed guide 206, and a refeed discharge roller 20
8. And the re-feeding guide piece 2
The sheet is fed into the refeeding guide 206 by opening the passage of the refeeding path by switching 05. After the leading edge of the sheet is detected by the sheet re-feed sensor 207 and the trailing edge of the sheet passes through the fixing roller 107,
The rotation speed of the sheet is increased, and the sheet conveying speed is increased. The sheet that has passed through the re-feeding guide 206 passes through a lower transport guide 304 provided at the rear of the main unit-mounted sheet feeding unit 300, and is then sent into the sheet reversing device 400.

Incidentally, the above-mentioned main body mounting paper supply unit 30
0 and the main body storage paper feed unit 500 are both on the front side of the printer P (the right side of the printer main body 100 in FIG. 2).
The paper feed cassettes 306 and 506 can be pulled out from the printer. The cassettes 306 and 506 basically have sheet hoppers 307 and 50 for placing sheets.
7, separation claws 308 and 508 for locking both front corners of the sheets placed on the sheet hoppers 307 and 507, and the sheet hoppers 307 and 507 which are arranged on the front bottom of the sheet hoppers 307 and 507 and keep the sheet hoppers 307 and 507 upward. The springs 309 and 509 to be urged, the sheet feeding rollers 310 and 510 which contact the uppermost sheet by the spring pressure, and the sheet feeding guide 3 formed on the front side of the separation claws 308 and 508.
11 and 511. Then, at the time of sheet feeding, the sheet feeding rollers 310 and 510 selectively rotate on the sheet, and the uppermost sheet is fed out in the sheet feeding direction by the frictional force, and the sheets are separated one by one from the separation claws 308 and 508. Sheet feeding guides 311 and 511
To send it into the image forming unit 102 of the printer body 100.

As shown in FIGS. 2 to 5, the sheet reversing device 400 has a rectangular parallelepiped casing section 406 having a rear end portion formed with a carry-in port 405 for a sheet printed on one side by the printer body 100. The sheet reversing unit 40 is mounted on the casing portion 406 so as to be able to be pulled out in the front direction.
7 is comprised. A sheet conveyance path 408 extending forward from the carry-in port 405 is formed in the casing unit 406, and a rear cover 409 of the casing unit 406 is openable so that a paper jam near the carry-in port 405 can be reduced. It has a configuration that can be removed.

On the other hand, a sheet reversing unit 407 includes a reversing path 410 connected to the conveying path 408 of the casing unit 406, a aligning unit 411 for aligning the inverted sheet in the width direction, and a unit for aligning the aligned sheet. And a re-feed path 413 for feeding the sheet again to the printer main body 100 from a sheet discharge port 412 formed at the front end of the printer.

The reversing path 410 includes a horizontal guide 414 coupled to the leading end of the transport path 408 when the casing 406 is loaded, and a pair of upper and lower opening / closing pivotally mounted on the other end of the horizontal guide 414. Guides 415 and 416,
The opening / closing guides 415 and 416 are formed by a U-shaped guide 417 that bends downward from the other end and continues to the alignment portion 411. The horizontal guides 414 and the opening / closing guides 415 and 416 are provided with conveying rollers 418 and 419 as means for conveying the sheet in the reversing path 410, respectively. These transport rollers 418, 4
Reference numeral 19 denotes a sheet for nipping and conveying the sheet between the pinch rollers 431 and 432 arranged facing each other. As shown in FIG.
A pair of right and left sides is attached to the drive shaft 435 and the driven shaft 436 which are bridged over the side frames 433 and 434, respectively. A belt 437 is stretched on one end side of the drive shaft 435 and the driven shaft 436, and when the transport roller 418 rotates, the transport roller 419 also rotates. Further, the driven shaft 43 of the transport roller 419
A belt 439 is also stretched between one end of the side frame 6 and a rotation transmitting section 438 provided near the front end of the side frame 434. The rotation transmitting portion 438 is connected via an electromagnetic clutch 444 to one end of a driven shaft 440 of a discharge roller 441 disposed on a re-feed path 413, and the driven shaft 436 is interposed therebetween. Thus, the rotation of the drive shaft 435 is transmitted.

As described above, the transport rollers 418 and 419 before and after the reversing path 410 and the re-feeding path 4134
Are rotated only in one direction (the rotation direction of the discharge roller 441 is opposite to the rotation direction of the transport rollers 418 and 419), and a belt for driving these transport units is used. The forward drive system such as 437 and 439 and the rotation transmission section 438
Is provided on one side of the sheet reversing unit 407 along the outside of the sheet.

Since the above-mentioned inversion path 410 has a U-shape, a space 420 is necessarily formed inside the bent portion as shown in FIGS. In the present embodiment, a sheet feeding unit 421 is provided by utilizing the inner space 420. The paper feeding means 421 is provided near the entrance of the aligning section 411 and is capable of rotating forward and reverse.
And a pickup roller 424 connected to the paper feed roller 422 by an arm member 423. As shown in FIG. 4, a compression spring 445 that presses against the arm member 423 is wound around the drive shaft 447 of the paper feed roller 422. When the paper feed roller 422 rotates, the compression spring 445 is rotated. The arm member 423 is rotated in the rotation direction of the paper feed roller 422 by the pressing force of the arm. The upward rotation of the arm member 423 is restricted by a stopper 425 protruding from the lower surface of the lower cover 416 of the opening / closing guide. When rotating, this stopper 4
The rotation of the feed roller 422 is restricted by the contact of the distal end of the arm member 423 with the feed roller 25.
It is possible to rotate. The drive shaft 447 of the paper feed roller 422 has both ends supported by the side frames 433 and 434 of the sheet reversing unit 407, and one end protrudes outside the side frame 433. Driven gear part 449 constituting a reverse rotation drive system
Is attached.

A driving force transmission unit 450 for transmitting a driving force to the forward rotation drive system and the forward / reverse rotation drive system is disposed behind the driven gear portion 449. The driving force transmission unit 450 is attached to the casing unit 406 and has a motor 451 for moving the aforementioned driving system.
And a forward / reverse rotation power unit 452 for generating power of the forward / reverse rotation drive system, and a forward rotation power unit 4 for generating power of the forward rotation drive system.
53. A rotary encoder 454 is attached to a drive shaft of the motor 451, and controls a rotation amount of the paper feed roller 422. Forward / reverse power unit 4
The belt 4 is provided between the rotation shaft 455 of the first shaft 52 and a power transmission gear portion 456 disposed in front of the casing portion 406.
As shown in FIG. 4, when the sheet reversing unit 407 is loaded in the casing 406, the driven gear 449 of the forward / reverse drive system meshes with the power transmission gear 456 as shown in FIG. 451 is transmitted.

On the other hand, the forward rotation power unit 453 is connected to the rotation shaft 455 of the forward / reverse rotation power unit 452. However, even if the rotation direction of the rotation shaft 455 is switched, a mechanism that always produces only the forward rotation is used. Has become. Then, as shown in FIG. 4, when the sheet reversing unit 407 is loaded in the casing 406, the output side power transmission gear 45
The driven gear portion 459 provided at the other end of the drive shaft 435 of the transport roller 418 meshes with the transmission gear 8 to transmit the driving force of the motor 451.

In this embodiment, the above-described motor 451 is utilized by utilizing a space 460 formed at a rear end corner of the casing 406 facing the driving force transmission unit 450.
And a control circuit board 461 for controlling the normal / reverse rotation of the motor and for controlling the matching operation in the matching unit 411. As shown in FIGS. 5 and 6, the control circuit board 461 includes a pair of ribs 463 protruding from the frame 462 of the casing 406 and a rib 465 protruding from the cover 464 in the same manner. It is sandwiched in a state of being put in between. The ribs 463 and 465 are provided with grooves 466 and 467 for holding the control circuit board 461 therebetween. The control circuit board 461 includes the forward drive system, the forward / reverse drive system, and the driving force transmission unit 45.
Since it is arranged at a position away from 0, it is also effective in terms of noise suppression.

As shown in FIGS. 2 and 3, the alignment section 411 includes a pair of left and right alignment guide members 427 for supporting both sides of the inverted sheet, and the alignment guide member 42.
Drive control unit 42 for moving the same 7 by the same distance in the left and right opposite directions
And 8. The alignment guide member 427 moves to a home position, a plurality of evacuation positions slightly retreating from both side ends of the sheet so as not to hinder sheet conveyance, and a position corresponding to substantially both ends of the sheet from the evacuation position. And an alignment position for sandwiching both sides of the sheet. Then, when the sheet is fed to the alignment section 411, the alignment guide member 427 moves from the home position to one retreat position corresponding to the sheet size to support both sides of the sheet, while feeding the sheet to a predetermined position. When this is done, the alignment guide member 427 slides to the alignment position, sandwiches both sides of the sheet, and aligns the sheet in the width direction.

A re-feed path 413 extends from the front end of the alignment guide member 427 to a sheet discharge port 412 formed at the front end of the sheet reversing unit 407. In addition to the above-described paper discharge roller 441, a flapper 430 for switching paths and a paper discharge sensor 468 are provided at the branch from the U-shaped guide 417.

Therefore, in the sheet reversing device 400 having such a configuration, as shown in FIG. 4, when the sheet reversing unit 407 is loaded in the casing portion 406, the power transmission gear portion 456 rotates forward and reverse. The driven gear portion 449 of the drive system meshes with the power transmission gear portion 458 and the driven gear portion 459 provided at the other end of the drive shaft 435 meshes with the power transmission gear portion 458 so that the driving force of the motor 451 can be transmitted to each drive system. Becomes Therefore, when the sheet printed on one side by the printer main body 100 is conveyed to the sheet reversing device 400, the motor 451 rotates in the forward direction by the start signal from the control circuit board 461, and the power is transmitted to the forward rotation drive system. Conveyance rollers 418 and 419 and paper discharge roller 44
1 rotates, and the power is also transmitted to the forward / reverse drive system so that the paper feed roller 422 rotates forward. Therefore, the sheet conveyed into the apparatus from the rear entrance 405 at the rear end of the sheet reversing device 400 passes through the reversing path 410 by the rotation of the conveying rollers 418 and 419 in the forward direction, and the alignment guide is reversed. The sheet is fed to the member 427. Note that the sheet is fed into the alignment guide member 427 by the conveyance force of the sheet feeding roller 422 rotating in the forward direction. Then, when the leading edge of the sheet is detected by the stay sensor 469 located below the alignment section 411, the rotary encoder 454 switches, and after counting a predetermined number of rotations according to the sheet size, stops driving the motor 451. This motor 451
, The transmission of the driving force from the motor 451 is stopped in both the forward drive system and the forward / reverse drive system.

After a certain time lag from the stop of the drive, the motor 451 receives a start signal of the reverse rotation drive from the control circuit board 461 and rotates in the reverse direction. As a result, the rotating shaft 455 of the driving force transmission unit 450 rotates in the opposite direction to the above, and the driving shaft 447 of the sheet feeding roller 422 is rotated.
Is rotated in the opposite direction. With the rotation of the drive shaft 447, the arm member 423 rotates downward, moves down the pickup roller 424 and sandwiches the sheet with the pinch roller 426. Since the pickup roller 424 rotates in the same direction as the sheet feeding roller 422, sheet re-feeding from the alignment unit 411 is started by the pickup roller 424, and the sheet re-feeding path 413 is further fed by the conveying force of the sheet feeding roller 422. Sent inside. On the other hand, the forward power unit 453
However, despite the reverse rotation of the rotation shaft 455 of the driving force transmission unit 450, the rotation in the same direction as described above is ensured, so that the forward rotation drive system continues to rotate in the forward direction. As a result, the discharge roller 441 of the re-feeding path 413 also rotates in the sheet discharging direction, and the re-feeding path 4
13 can be conveyed. The sheet conveyed by the paper discharge roller 441 is discharged from a paper discharge port 412 formed at the leading end of the re-feed path 413, passes through the upper conveyance guide unit 305 of the main unit-mounted paper feed unit 300, and The image is then sent to the image forming unit 102 of the printer main body 100, printed on the opposite surface, and then conveyed to the conveyance unit 200 again. Note that the trailing end of the sheet sent from the alignment unit 411 is connected to the sheet ejection sensor 45
8 and the reverse rotation of the motor 451 is stopped based on the detection signal.

In the above embodiment, the sheet reversing device 4
00, the sheet is fed one by one to the reversing path 410, and the sheet is reversed and aligned by the aligning unit 411 and then immediately re-fed to the printer main body 100. However, a plurality of sheets are sequentially sent to the aligning unit 411. The present invention can also be applied to a sheet reversing device of a type in which paper is fed, aligned together, and then re-fed to the printer main body 100 sequentially. By disengaging the electromagnetic clutch 444, the timing of refeeding the paper from the refeed path 413 to the printer main body 100 can be controlled separately from the sheet reversing operation of the sheet reversing device 400.

[0026]

As described above, according to the transport driving device for a sheet reversing device according to the present invention, the transport driving system for a sheet in the sheet reversing device is divided into a forward drive system and a forward / reverse drive system. Since these are arranged on the left and right sides of the sheet reversing unit, maintenance of these transport drive systems becomes easy, and the transport drive systems can be stored compactly.
The size of the sheet reversing device can be reduced.

Further, according to the present invention, the drive control circuit of the driving force transmission unit is arranged in the space formed in the apparatus by the arrangement of the conveyance driving system, so that the conveyance driving system and the driving force transmission unit can be connected to each other. The drive control circuit can be installed at a remote location, the space in the device can be used effectively, and noise control has been improved.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a printer including a sheet reversing device according to the present invention.

FIG. 2 is a schematic sectional view of a printer provided with a sheet reversing device according to the present invention.

FIG. 3 is a schematic sectional view when the sheet reversing unit is pulled out.

FIG. 4 is a schematic plan view when a sheet reversing unit is loaded in a casing portion.

FIG. 5 is a schematic plan view when a sheet reversing unit is pulled out from a casing portion.

FIG. 6 is a schematic sectional view taken along line AA in FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 Printer main body (printing apparatus main body) 400 Sheet reversing device 406 Casing unit 407 Sheet reversing unit 410 Reversing path 437 Belt (normal rotation driving system) 438 Rotation transmitting unit (normal rotation driving system) 439 Belt (normal rotation driving system) 449 Transmission gear unit (forward / reverse drive system) 450 Driving force transmission unit

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B65H 83/02 B65H 85/00

Claims (2)

(57) [Claims] 1. A casing section for carrying a sheet printed on one side of a printing apparatus main body from one end of the apparatus, and a sheet loaded removably into the casing section and carried into the casing section is sent to a reversing path, and the reversing path is performed. A sheet reversing unit comprising a sheet reversing unit for refeeding paper from the other end of the apparatus to the printing apparatus body through the refeeding path after reversing the path, and conveys the sheet to the reversing path and the refeeding path. The driving system is divided into two parts, a forward driving system for always conveying the sheet in one direction is provided on one side of the sheet reversing unit, and a forward / reverse driving system for switching the conveying direction of the sheet is provided for the sheet reversing unit. At the rear side of one of these drive systems, a seat reversing unit is provided for both the forward drive system and the forward / reverse drive system. Conveying drive of the sheet reversing device sometimes during withdrawal of and sheet reversing unit transmits a driving force, characterized in that a driving force transmitting unit to cut off the driving force to the casing side. 2. A casing section for carrying a sheet printed on one side of the printing apparatus main body from one end of the apparatus, and a sheet loaded removably into the casing section and carried into the casing section is sent to a reversing path. A sheet reversing unit comprising a sheet reversing unit for refeeding paper from the other end of the apparatus to the printing apparatus body through the refeeding path after reversing the path, and conveys the sheet to the reversing path and the refeeding path. The driving system is divided into two parts, a forward driving system for always conveying the sheet in one direction is provided on one side of the sheet reversing unit, and a forward / reverse driving system for switching the conveying direction of the sheet is provided for the sheet reversing unit. At the rear side of one of these drive systems, a seat reversing unit is provided for both the forward drive system and the forward / reverse drive system. Sometimes, a driving force transmission unit that transmits a driving force and shuts off the driving force when the sheet reversing unit is pulled out is arranged on the casing portion side, and the drive force transmission unit drive is mounted on the opposite casing portion facing the driving force transmission unit. A transport driving device for a sheet reversing device, comprising a control circuit.