JPH06191702A - Sheet reversing device - Google Patents

Abstract

PURPOSE:To perform sheet discharging without sheet jamming regardless of deformation such as sheet-folding, by discharging a sheet retained at a sheet retaining part by a pair of separating rollers in which a rotation direction is controlled in an introduction direction and a rotation direction by means of a control means. CONSTITUTION:In a compound machine, a switch-carrying part 22 and a reversing device 23 are arranged on the downstream side in the sheet carrying direction of a fixing apparatus 21 in a picture image forming part, and nonreversing discharge rollers 24 are arranged on the downstream side end of the switch- carrying apparatus 22. A sheet, having passed the discharge rollers 24, and a sheet, having passed the reversing device 23, are discharged to first and second sheet discharge trays 26 and 27 respectively. In this case, the reversing device 23 is provided with a main roller 35, in which plural feeding members 35a composed of elastic members are provided on a surface, introduction and discharge rollers 36 and 37, pressure contacted to the feeding members 35a to be drivenly rotated, and upper and lower handling rollers 47 and 48, arranged on a sheet retaining part 38; and sheets are discharged by the separating rollers 47 and 48.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet reversing device, and more particularly to a sheet reversing device for reversing the front and back sides of a fed sheet.

[0002]

2. Description of the Related Art Recently, multifunction machines having a facsimile function, a printer function and a copying function have been provided. In many cases, such a multifunction machine is equipped with a paper reversing device that reverses the front and back of the paper in order to stack continuous pages of paper in the paper ejection tray in the order of pages.

For example, in the reversing device shown in Japanese Patent Laid-Open No. 61-119551, a main roller and two rollers that rotate in pressure contact with the main roller are provided.
In this reversing device, one of the rollers and the main roller picks up the paper obliquely upward, holds the taken-in paper on the paper holding unit by inclining it toward the discharge side, and holds it by its own weight between the other roller and the main roller. After being guided in between, the paper held by the other roller and the main roller is discharged.

[0004]

SUMMARY OF THE INVENTION In the above conventional configuration,
In the sheet holding unit, the sheet is guided by its own weight between the main roller and the other roller and ejected. Therefore, if the retained sheet is deformed such as bent, the other sheet is ejected during ejection. It may not be properly guided between the roller and the main roller. If the paper is not properly guided, the paper will be jammed in the paper holder and the inverted paper cannot be ejected.

An object of the present invention is to prevent clogging of the sheet holding portion.

[0006]

A sheet reversing device according to the present invention is a device for reversing the front and back sides of a fed sheet, and includes a sheet holding portion for holding the sheet and one end of the sheet holding portion. The main roller arranged, the introduction roller that holds the fed sheet between the main roller and introduces it into the sheet holding unit, and the sheet in the sheet holding unit that is inserted between the main roller and A discharge roller that discharges from the rear end side, a pair of separation rollers that are rotatably provided in the sheet holding portion in the introduction direction and the discharge direction, and that sandwich a sheet to be introduced and discharged, and a pair of separation rollers. And a control means for controlling the rotation direction.

[0007]

In the sheet conveying apparatus according to the present invention, the fed sheet is nipped between the main roller and the introduction roller and introduced into the sheet holding portion. The sheet introduced into the sheet holding unit is introduced into and held by the sheet holding unit by a pair of separating rollers whose rotation direction is controlled by the control unit to be the introducing direction. The sheet held by the sheet holding portion is guided from the rear end side at the time of introduction between the main roller and the discharge roller by a pair of separating rollers whose rotation direction is controlled in the discharge direction,
The sheet is nipped by both rollers and discharged from the sheet holding unit.

In this case, the sheet held in the sheet holding portion is discharged by the pair of separating rollers whose rotation direction is controlled by the control means in the introducing direction and the discharging direction.
Compared with the case where the sheet is discharged by its own weight, the sheet can be reliably guided and discharged regardless of deformation such as bending of the sheet, and clogging of the sheet holding portion can be prevented.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic vertical sectional view showing the construction of a multi-function peripheral adopting an embodiment of the present invention. A document table 2 is provided on top of the multifunction device
And a reading device 3 are provided. The reading device 3 has a conveyance unit for feeding a document placed on the document table 2 and a sensor for reading image information of the document. A document discharge tray 4 for receiving a document that has passed through the reading device 3 is attached to the side of the reading device 3 on the side of the multifunction machine 1.

A laser device 5 is arranged in the upper part of the inside of the multifunction machine 1. The laser device 5 has a laser diode, a toroidal lens, an f-θ lens, or the like that emits light according to the image information read by the reading device 3 or according to the image information or the like transmitted from another computer device or the like. is doing. An image forming unit 6 is arranged below the laser device 5, and the image forming unit 6 is further provided.
A paper supply unit 7 for supplying paper to the image forming unit 6 is arranged below the.

The image forming section 6 has a photosensitive drum 10 on the surface of which an electrostatic latent image is formed by laser light from a laser device 5. In addition, around the photosensitive drum 10,
A main charging device 11 for charging the photoconductor drum 10,
A developing device 12 for developing an electrostatic latent image on the surface of the photoconductor drum 10, and the photoconductor drum 1 by the developing device 12.
0 transfer device 13 for transferring the toner image formed on the surface to the surface of the paper that has been sent, separating device 14 for separating the paper from the surface of the photoconductor drum, and remaining on the surface of photoconductor drum 10. And a cleaning device 15 for cleaning the removed toner. Also, the paper supply unit 7
Is a paper feed cassette 16 in which paper is loaded, and a paper feed roller 17 for feeding the paper in the paper feed cassette 16.
And a sheet feeding device 18 including a guide member and a transport roller.

Inside the multifunctional machine 1, a conveying device 20 and a fixing device 21 are provided on the downstream side of the image forming section 6 in the sheet conveying direction.
Are arranged. Further downstream of the fixing device 21,
The switching conveyance unit 22 and the reversing device 23 are arranged, and the non-reverse discharge roller 24 is provided at the downstream end of the switching conveyance unit 22.
Are arranged. Then, on the side of the multifunction machine 1, there are provided a first paper discharge tray 26 for receiving the paper discharged from the non-reverse discharge roller 24 and a second paper discharge tray 27 for receiving the paper discharged from the reversing device 23. It is arranged.

FIG. 2 shows the switching conveyance unit 22 and the reversing device 2.
3 is shown enlarged. The switching conveyance unit 22 is the fixing device 2
It has a non-reverse discharge path 42 for guiding the sheet from 1 to the non-reverse discharge roller 24 side, a reverse discharge path 43 for guiding the sheet to the upper reversing device 23 side, and a switching claw 41. The downstream end (the left end in FIG. 2) of the switching claw 41 is rotatably supported below the reversing device 23, and can take a reversing posture shown by a solid line and a non-reversing posture shown by a chain line. . The other end extends to the vicinity of the outlet of the fixing device 21. Such a switching claw 41, together with the lower guide member 44, in the non-inverted posture, the non-inverted discharge path 4
2, and the upper guide member 45 in the posture shown by the solid line.
Together with this, the reverse discharge path 43 is formed. A plurality of switching claws 41 are arranged in the front-rear direction of the device.

The reversing device 23 has a main roller 35, an introduction roller 36, a discharge roller 37, an upper separating roller 47, a lower separating roller 48, and a sheet holding section 38. Main roller 3
5 is rotatable counterclockwise as shown by the arrow in FIG. 2, and has a plurality of feeding members 35a formed of an elastic member such as resin on the surface. The introduction roller 36 is the main roller 3
5 is arranged on the fixing device 21 side. Then, it can rotate in the clockwise direction in FIG. 2 while being pressed against the feed member 35a of the main roller 35. The discharge roller 37 is the main roller 3
It is arranged on the opposite side of the introduction roller 36 across the sheet 5, and is located at the left end of the multifunction machine 1. Then, like the introduction roller 36, the discharge roller 37 can rotate clockwise while being in pressure contact with the feed member 35a. A plurality of rollers 35 to 37 are arranged at a predetermined interval in the front-rear direction of the device.

The sheet holder 38 holds the sheet taken into the reversing device 23. The sheet holder 38 is curved from above the main roller 35 to the image forming section 6 side and extends below the laser device 5. ing. The upper separation roller 47 and the lower separation roller 48 are arranged in the middle of the curved portion of the sheet holding unit 38 so as to be capable of pressure contact. The upper separating roller 47 includes a torque limiter, and can rotate clockwise in FIG. 2 when the torque is less than a certain torque allowed by the torque limiter.
When a torque of a certain level or more is applied, it can rotate counterclockwise. The lower separating roller 48 is provided with a clutch 53 (FIG. 3) and can rotate clockwise in FIG. 2 when the clutch 53 is turned on.
When is turned off, it can rotate freely.

Here, when the upper separating roller 47 and the lower separating roller 48 are in pressure contact with each other and the clutch 53 is turned on, a torque above a certain level acts on the upper separating roller 47 from the lower separating roller 48, and The separating roller 47 rotates counterclockwise in FIG. Further, when the paper is nipped between the upper separation roller 47 and the lower separation roller 48 with the clutch 53 being turned on, the upper separation roller 47 is inserted through the paper.
A certain torque is applied to the sheet, and the sheet is conveyed upward in FIG. Subsequently, when the clutch 53 is turned off, torque above a certain level does not act on the upper separating roller 47, so that the upper separating roller 47 rotates clockwise in FIG. 2 and the sheet is conveyed downward. Further, when two sheets are sandwiched between the upper separating roller 47 and the lower separating roller 48 with the clutch 53 turned on, since the frictional force between the two sheets is small, a torque of a certain level or more is generated. Does not act on the upper loosening roller 47, and the paper contacting the upper loosening roller 47 faces downward in FIG.
The sheets in contact with the lower separating roller 48 are conveyed upward in FIG.

Between the introduction roller 36 and the upper guide member 45, there is provided a timing switch 46 for detecting the leading edge and the trailing edge of the introduced sheet in order to switch the sheet introducing and discharging operations in the sheet holding section 38. It is arranged. Further, the multifunction machine 1 is provided with a control unit 50 as shown in FIG. The control unit 50 includes a CPU, RAM, ROM
It is equipped with a microcomputer including the above. Control unit 5
At 0, an operation panel 51 in which a transmission / copy key for instructing facsimile transmission or a copy operation and an inversion key for switching the ejection mode between an inversion mode and a non-inversion mode are arranged, a timing switch 46, In order to drive a sheet detection switch 55 for detecting that the sheet has been conveyed from the conveyance device 20, a drive unit 52 for rotationally driving rollers including the main roller 35, a clutch 53, and a switching claw 41. Drive unit 54 and other input / output units are connected.

Next, the operation of the above embodiment will be described. In the multi-function device 1, printing processing is performed by operating a transmission / copy key provided on the operation panel 46 or by a command from another computer device. Further, by pressing the reverse key, the discharge mode can be changed between the reverse mode and the non-reverse mode. The control in these cases is shown in FIGS. 4 and 5.

In step S1 of FIG. 4, it is determined whether a print command has been issued. In step S2, it is determined whether the reverse key has been pressed. If it is determined that the print command is issued, the process proceeds from step S1 to step S3. In step S3, the printing process shown in FIG. 5 is performed. If it is determined that the reverse key is pressed in step S2, the process proceeds to step S4. In step S4, it is determined whether or not the discharge mode is set to the reverse mode. If the reverse mode has already been set, the process proceeds to step S5. In step S5, the discharge mode is set to the non-inversion mode, and the switching claw 41 is controlled to the non-inversion posture shown by the one-dot chain line in FIG. Further, when the discharge mode is set to the non-reversal mode, steps S4 to S6
Move to. In step S6, the discharge mode is set to the reverse mode, and the switching claw 41 is controlled to the reverse posture shown by the solid line in FIG.

In the printing process of step S3, the image is transferred onto the surface of the sheet by the image forming section 6, and the sheet on which the image is transferred is conveyed to the fixing device 21 via the conveying device 20 and subjected to the fixing process. When the sheet is transported to the transport device 20,
The paper detection switch 55 detects the paper. In step S10 of FIG. 5, it is determined whether the paper detection switch 55 has detected a paper. If it is determined in step S10 that a sheet has been detected, the process proceeds to step S11. Step S11
Then, the main roller 35 and the rollers 36, 37, 47, 48
To drive. Since the clutch 53 is off at this time, the lower separating roller 48 is in a free state. Further, the upper separating roller 47 rotates clockwise in FIG.

In step S12, it is determined whether the discharge mode is the reverse mode. When it is determined in step S12 that the mode is the reverse mode, the process proceeds to step S13. When the reverse mode is set, the sheet subjected to the fixing process is guided to the reverse discharge path 43 by the switching claw 41. In step S13, the process waits until the timing switch 46 detects the leading edge of the sheet guided to the reverse discharge path 43. When the timing switch 46 comes into contact with the leading edge of the sheet and is turned on, the process proceeds to step S14. In the step S14 waits for the lapse of the time T _1. This time T ₁ is
In the timing chart shown in FIG. 6, it is the time from when the timing switch 46 is turned on to when the clutch 53 is turned on. Specifically, as shown in FIG.
Paper P ₁ nipped by main roller 35 and introduction roller 36
Is the time until just before the tip of the roller reaches the separating rollers 47, 48.

When the time T ₁ has elapsed, the process proceeds to step S15. In step S15, the clutch 53 is turned on.
As a result, the lower separating roller 48 rotates clockwise as shown in FIG. 7B, and the upper separating roller 47 and the paper P ₁
The paper P ₁ is introduced into the paper holding unit 38 by sandwiching the paper. In step S16, it waits until the timing switch 46 is turned off. When the timing switch 46 is turned off, the process proceeds to step S17. In step S17, the process waits for the time T ₂ to elapse. This time T ₂ is, as shown in FIG.
This is the time from when the timing switch 46 is turned off to when the clutch 53 is turned off. Specifically, as shown in FIG. 7C, the trailing edge of the paper P ₁ is the main roller after the timing switch 46 is turned off. It is the time until the sheet 35 passes through the sandwiching position between the sheet 35 and the discharge roller 37.

When the time T ₂ has elapsed, the process proceeds to step S18. In step S18, the clutch 53 is turned off. As a result, as shown in FIG. 7 (D), the driving force of the lower separating roller 48 does not apply a torque above a certain level that has been acting on the upper separating roller 47, and thus the upper separating roller 4
7 rotates clockwise. Therefore, the separation rollers 47, 4
The sheet P ₁ nipped by 8 is conveyed downward in FIG. 7, and its leading end is nipped by the main roller 35 and the discharge roller 37,
The sheet is discharged to the second sheet discharge tray 27.

During this discharge, as shown in FIG.
Paper P₂When the paper is ejected from the fixing device 21,
When the main roller 3
5 and the introduction roller 36. And timing
Time T after the switch 46 is turned on₁After the clutch 53
Turns on. At this time, the upper separating roller 47 and the lower separating roller
Paper P that is being ejected and is sandwiched between₁Is once upward
But the newly ejected paper P₂Is low
When it is pinched between the la 47 and the lower separating roller 48,
As shown in (F), since the frictional resistance between the sheets is small,
Paper P being ejected ₁Is turned downward again by the upper handling roller 47.
Paper P discharged and introduced into₂Is the lower handling roller 48
Is introduced into the paper holding section 38 by the.

On the other hand, when the discharge mode is the non-reverse mode in step S12, the processes of steps S13 to S18 are skipped. Here, the sheet discharged from the fixing device 21 is guided to the non-inversion discharge path 42 by the switching claw 41 controlled to the posture shown by the one-dot chain line in FIG.
The sheet is discharged to the first sheet discharge tray 26 by the non-reverse discharge roller 24.

As described above, in the reversing device 23, when a sheet is nipped between the main roller 35 and the discharge roller 37, the next sheet is guided into the reversing device 23 by the main roller 35 and the introducing roller 36. Can be captured. Therefore, the interval between the conveyed sheets can be shortened, and high-speed processing can be performed. Further, since the sheet can be reliably guided and ejected in the direction of the ejection roller 37 by the upper separating roller 47, the sheet can be reliably ejected from the sheet holding portion. Therefore, it is possible to prevent a paper jam in the paper holding unit 38.

Further, in this embodiment, the separating rollers 47,
Since the sheet can be reliably held by 48, the sheet holding portion 38 can be bent downward, for example. Therefore, the degree of freedom in design is increased when the space for disposing the sheet holding unit 38 is secured.

[0028]

As described above, according to the present invention, by controlling the rotation directions of the pair of separating rollers, the sheet in the sheet holding portion can be surely guided to the discharge roller side, so that the sheet is slightly deformed. Paper can be reliably discharged, and paper jams in the sheet holding unit can be prevented.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional schematic configuration diagram of a multifunction machine that employs an embodiment of the present invention.

FIG. 2 is an enlarged view of the discharging section.

FIG. 3 is a control block diagram thereof.

FIG. 4 is a control flowchart thereof.

FIG. 5 is a control flowchart thereof.

FIG. 6 is a timing chart thereof.

FIG. 7 is a schematic diagram showing an operation during discharging.

[Explanation of symbols]

 23 Reversing Device 35 Main Roller 36 Introducing Roller 37 Ejecting Roller 38 Paper Holding Unit 47, 48 Upper / Lower Separation Roller 50 Control Unit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor ▲ Sat ▼ Ya Mao 1-22-28 Tamazo, Chuo-ku, Osaka City Mita Engineering Co., Ltd. (72) Inventor Keimi Okada 1-2 2-chome, Chuo-ku, Osaka No. 28 Mita Industrial Co., Ltd.

Claims (1)

[Claims] 1. A sheet reversing device for reversing the front and back of a fed sheet, comprising: a sheet holding portion for holding the sheet; and a main roller arranged at one end of the sheet holding portion. A sheet that is inserted between the main roller and the main roller, and a sheet inside the sheet holder that is sandwiched between the main roller and the sheet and is discharged from the rear end side when the sheet is introduced. And a pair of separating rollers that are rotatably provided in the sheet holding portion in the sheet introducing direction and the sheet ejecting direction, respectively, and sandwich the sheet to be introduced and discharged, and the rotation directions of the pair of separating rollers. A sheet reversing device including: a control unit that controls the sheet.