JPH10250943A - Sheet loading device, and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate jam processing in a device in which a sheet after first image formation is completed is temporarily stacked in the case of executing a multiple mode in which image formation is performed for plural times to the same surface in a single sheet, and a double surface mode in which image formation is performed to both surfaces of a single sheet. SOLUTION: In a device, an upper guide 211 and a horizontal carrier part 212 are pivotally supported by shafts 214, 215 at one end part of a tray 210 on which plural sheets after first image formation is performed can be stacked, these are composed to be separately rotatable to a tray upper surface covering position and an opening position, and in the case of jam on the tray 210, a hook 222 (222-1, 222-2) is driven by a solenoid 219 for integrally rotating the upper guide 211 and the horizontal carrier part 212 to open a tray upper surface. In the case of jam in the horizontal carrier part 212, engagement of the hook 222 is released to rotate the upper guide 211 only, so the horizontal carrier part is largely opened on the upper side to easily and securely perform jam processing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile, and the like.

[0002]

2. Description of the Related Art An image forming apparatus such as a copying machine, a printer, and a facsimile, which has an electrophotographic system, for example, has a multiplex mode in which an image is formed a plurality of times on the same surface of one sheet;
Some devices have a double-sided mode in which image formation is performed on both the front and back surfaces of one sheet.

[0003] Sheets such as paper on which images are formed in the multiplex mode and the duplex mode are placed on an intermediate tray (re-feeding stacking means) installed in the image forming apparatus main body after the first image formation. And then re-fed from the intermediate tray to the image forming section. In this case, the sheet on which the first image formation has been performed in the multiplex mode is stacked on the intermediate tray with the image forming surface facing down, and the sheet on which the first image formation has been completed in the double-sided mode has the image formation surface. It is stored on the intermediate tray in the state facing upward.

FIG. 6 shows the overall configuration of a conventional image forming apparatus (copier) having a multiplex mode and a duplex mode.

First, the configuration of the image forming apparatus of Conventional Example 1 shown in FIG. 6 will be described. Here, the overall configuration will be described along the flow of the sheet.

The image forming apparatus 1A is provided with a plurality of front loading type paper feed cassettes 1 to 4. Sheets S1 to S4 of different sizes are stacked and stored in each of the paper feed cassettes 1 to 4. For example, cassette 1
Inside is A5 size or statement size sheet S
1 is stored in the cassette 2, an A4 size, a B5 size, or a letter size sheet S2 is stored in the cassette 2, and an A4R size or a B5 size is stored in the cassette 3.
An R size or letter R size sheet S3 is loaded and stored, and a B4 size or legal size sheet S4 is loaded and stored in the cassette 4.

In the image forming apparatus 1A, the sheets S1 to S4 in the sheet cassettes 1 to 4 are selectively fed. The sheets S1 to S4 stacked and stored in the respective sheet cassettes 1 to 4 are sequentially fed from the top sheet by the sheet feeding roller 5 rotating counterclockwise in the drawing. The sheet S fed out by the paper feed roller 5 has only the uppermost sheet of 1 by the separation roller pair 6.
The sheet is separated and sent to the registration roller pair 13 in the rotation stopped state via the conveyance roller pairs 7 to 12.

The pair of conveying rollers 7 to 11 convey the sheet S until the leading end of the sheet strikes the nip of the pair of range rollers 13 to form a predetermined amount of loop. The skew state of the sheet S is corrected by the formation of the loop.

In the sheet S whose skew state has been corrected, an electrostatic latent image on a photosensitive drum 14 such as an electrophotographic photosensitive member rotating clockwise in the drawing is developed by a developer of a developing means. A pair of registration rollers 13 that starts rotating at the timing of aligning the position of the toner image with the front end of the sheet
Accordingly, the sheet is sent to a transfer section between the photosensitive drum 14 and the transfer charger 15. While passing through the transfer section, the toner image on the photosensitive drum 14 is sequentially transferred to the sheet surface by a transfer charger 15 as a transfer unit. The sheet S on which the transfer of the toner image has been completed is sent to the fixing roller pair 17 by the transport belt 16. Then, this fixing roller pair 1
The toner image is heated and pressed while passing through the nip 7 to fix the transferred toner image on the sheet surface.

The sheet S conveyed by the conveying roller pair 18 after the toner image fixing process is completed is sent to the paper discharging roller pair 20 through the paper discharging path 19 in the normal mode.
The paper is discharged onto a paper discharge tray 21 outside the apparatus by the paper discharge roller pair 20. In the normal mode, the flapper 22 opens the discharge path 19 and closes the vertical path 23 as shown by the solid line.

The sheet S conveyed by the conveying roller pair 18 after the toner image fixing process is completed is sent to the vertical path 23 leading to the intermediate tray 29 in the case of the multiplex mode and the duplex mode. In this case, the flapper 22 closes the discharge path 19 and opens the vertical path 23 as shown by the dotted line.

In the case of the multiplex mode, the sheet S sent to the vertical path 23 is transported by the conveying roller pairs 24 to 26 into the carry-in path 2.
7 and the intermediate tray 29 by the carry-in roller pair 28.
The intermediate tray 2 is sent to the upper discharge path 60 and the image forming surface faces downward from one of the discharge roller pairs 61 to 64 installed in the sheet conveying direction of the discharge path 60.
9 is discharged.

When the sheet S having the maximum size in the transport direction is used, the first flapper 66 corresponding to the size is rotated upward, and the sheet S is discharged from the discharge port 41.
To discharge. When the next largest sheet S is used, the second flapper 67 rotates upward,
The sheet S is discharged from the first discharge roller pair 61. 3 when the next largest sheet S is used
The second flapper 68 rotates upward to discharge the sheet S from the second discharge roller pair 62. When the next largest sheet S is used, the fourth flapper 69 rotates upward and discharges the sheet S from the third discharge roller pair 63. When the sheet S of the minimum size is used, the fifth flapper 70 rotates upward and discharges the sheet S from the fourth discharge roller pair 64.

Sheet S discharged onto intermediate tray 29
Is an auxiliary roller 7 that rotates counterclockwise in the figure.
1, the rotary shutter 44 in which the leading end of the sheet is raised
Is transported until it comes into contact with. In this case, the leading end of the sheet is guided by a movable sheet guide 72 which is set in an inclined state as shown by a dotted line so that the curl is suppressed. The auxiliary roller 71 stands by at the position shown by the solid line when the sheet is discharged, and conveys the sheet S by descending as shown by the dotted line immediately after the sheet is discharged. Movable seat guide 7
An opening is formed in 2 to allow the auxiliary roller 71 to move up and down.

The sheets S stacked on the intermediate tray 29 are sequentially fed out from the uppermost sheet by an auxiliary roller 71 rotating counterclockwise in the drawing. In this case, the auxiliary roller 71 descends from the standby position shown by the solid line as shown by the dotted line to feed out the sheet S. Further, the movable shutter 44 guides the sheet S which has been fed out while falling down in an inclined state to the nip of the separation roller pair 47. Note that a side guide 80 that moves according to the size of the sheet S is provided on the intermediate tray 29 to prevent the sheet from being skewed.

The sheet S fed out by the auxiliary roller 71 has only the top sheet 1 by the separation roller pair 47.
The sheet is separated and sent to the registration roller pair 13 in the rotation stopped state via the conveyance roller pairs 9 to 12.

In the case of the double-side mode, the sheet S sent to the vertical path 23 is transported by the conveying roller pairs 24 to 16 into the input path 2.
7 and sent to the discharge path 60 by the carry-in roller pair 28. In the case of this double-sided mode, all the flappers 66 to 70 of the discharge path 60 are rotating downward. Then, the sheet S sent to the discharge path 60 is conveyed to the terminal U-turn portion 73 by each of the discharge roller pairs 61 to 65, and the image forming surface is turned upward by the discharge roller 74 and the discharge roller 75 on the intermediate tray 29. Is discharged to in this case,
The leading end of the sheet is guided by a movable sheet guide 72 which is set in an inclined state as shown by the solid line, so that the curl is suppressed.

Sheet S discharged onto intermediate tray 29
Is an auxiliary roller 7 that rotates counterclockwise in the figure.
By 1, the sheet is conveyed until the leading end (the trailing end of the sheet at the time of discharge) comes into contact with the movable shutter 44 that is standing up. In this case, the leading end of the sheet is guided by a movable sheet guide 72 which is set in an inclined state as shown by a dotted line so that the curl is suppressed. The auxiliary roller 71 stands by at the position shown by the solid line when the sheet is discharged, and conveys the sheet S by descending as shown by the dotted line immediately after the sheet is discharged. The sheets S stacked on the intermediate tray 29 are re-fed to the registration roller pair 13 in order from the uppermost sheet as in the multiplex mode.

When a jam occurs around the intermediate tray, the intermediate tray is pulled out of the image forming apparatus, and jam processing is performed.

FIG. 4 shows the re-feeding stacking means including the intermediate tray.

The intermediate tray 210 is pulled out from the front of the image forming apparatus along the intermediate tray left rail 213 together with the upper guide 211 and the horizontal transport section 212 above the intermediate tray (front loading method).

FIG. 7 shows a state in which the upper guide 211 is pivotally opened. The upper guide 21 is used when performing jam processing.
When 1 is lifted, the horizontal transport unit 212 rotates leftward about the rotation center 215. The horizontal transport unit 212 is connected to the upper guide 211 via a belt 230, and interlocks with the rotation of the upper guide 211 to move the horizontal transport unit 21.
2 also rotates about the rotation center 214. In this state of FIG. 7, the paper staying between the horizontal transport unit 212 and the upper guide 211 or between the horizontal transport unit 212 and the intermediate tray 210 is removed.

[0023]

However, in the above-mentioned prior art, when a jam occurs in the horizontal conveying section on the intermediate tray or the sheet stacking section on the intermediate tray, the sheet is re-fed from the image forming apparatus for the jam clearance. When the stacking means is pulled out and the upper guide is rotated and opened, both the upper guide and the intermediate tray sheet stacking portion are opened at the same time, so that the opening angle is limited.

Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide a method for clearing a sheet where a sheet is stagnant when opening a horizontal transport unit during jam processing of an intermediate tray. Correspondingly, by selectively opening either the upper guide or the intermediate tray sheet stacking part, the angle of the opening is made about twice as large as that of the conventional one, so that an image forming mechanism having a mechanism for improving jam clearance is provided. It is intended to provide a device.

[0025]

According to a first aspect of the present invention, an upper guide having a plurality of conveying rollers provided at one end of a tray capable of stacking a plurality of sheets, and a plurality of flappers are provided. And a horizontal conveying unit having a position for covering the upper surface of the tray and a position for opening the tray, each of which is rotatably pivotally supported, and a sheet conveyed by a conveying roller between the upper guide and the horizontal conveying unit is sized. In the sheet stacking apparatus configured to drop on the tray by opening the flapper selected according to the above, a connecting means for selectively connecting and disconnecting both the upper guide and the horizontal transport unit is provided. And

According to a second aspect of the present invention, a driving means is attached to the connecting means, and a sheet detecting sensor for detecting a sheet between an upper guide and a horizontal conveying portion is provided. The driving means is operated to release the connection of the connecting means.

A third aspect of the present invention is characterized in that the connecting means is a hook member and the driving means is a solenoid coil.

According to a fourth aspect of the present invention, there is provided any one of the above-described sheet stacking apparatuses, and an image forming section for forming an image on a sheet fed from the sheet stacking apparatus.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 5 shows an example of a cross section of an image forming apparatus according to the present invention.

The image forming apparatus of this embodiment is of a front loading type, in which an upper part of the apparatus is provided with at least an image forming section 100A having a photosensitive drum 102 and an optical reading section 100B for optically reading information of a document. A registration roller 101 on the upstream side of the photosensitive drum, a transport unit 103 and a fixing unit 104 on the downstream side, a primary charger around the photosensitive drum, an exposure unit for forming an electrostatic latent image on the photosensitive drum, A developing unit for developing the latent image with the toner of the developer, a transfer unit for transferring the developed image to a sheet, a cleaning unit for removing the transfer residual toner on the photosensitive drum, and the like are provided.

Below the two paper storage cassettes 1
Cassette rails 123, 124, 125, and 126 for mounting the upper and lower parts 21 and 122 from the front of the apparatus in the upper and lower stages are provided. A sheet (P), which is a sheet through 106, is conveyed. The sheets are stacked on a sheet stacking device that once stacks the sheets, that is, the re-feeding stacking unit 200A.

Next, the operation of the above configuration will be described. When a user turns on a copy button (not shown), document size information from a document size detection sensor (not shown) arranged in the optical reading unit 100B, and user copy mode information (magnification, magnification, etc.) from an operation panel (not shown). Double-sided, multiple, number of sheets, paper size, etc.) and paper storage cassette 121,
The sheet (P), which is a sheet, is sent from the selected sheet storage cassette based on the storage sheet size information from 122,
Registration roller 101, photosensitive drum 102, transport unit 10
3. The sheet is transported through the fixing unit 104 and the sheet reversing unit 105. (i) In the case of the normal copy mode, the discharge roller 107
Is discharged onto the paper discharge tray 108.

(Ii) In the case of double-sided, multiplex, the sheet is sent to the left vertical path section 106 and is stacked on the re-feeding stacking means 200A.
The sheet is fed again, and the registration rollers 1
01, the image forming unit 100A, the paper discharge reversal unit 10
5 from the right vertical pass unit 110 to the registration rollers 1
01, the image forming unit 100A, the paper discharge reversal unit 10
5 is conveyed and discharged out of the apparatus by the discharge roller 107, thereby ending a series of operations.

The features of the present invention in the image forming apparatus that performs the above-described series of operations will be specifically described.

The image forming apparatus according to the present invention is provided with a double-sided or multiplex refeed unit shown in FIG.
In FIG. 1, a re-feeding stacking unit as a sheet stacking device includes an intermediate tray 210, an upper guide 211, and a horizontal transport unit 21.
The upper guide 211 is provided with a handle 225 for rotating only the upper guide or the upper guide 211 and the horizontal transport unit 212 at the time of jam clearance. Upper guide 21
1 and the horizontal transport unit 212 are provided with a discharge roller (corresponding to the discharge rollers 61 to 65 in FIG. 6) and a flapper (corresponding to the flappers 66 to 70 in FIG. 6) corresponding to the sheet size. , And the description thereof will be omitted.

A shaft 223 disposed on the upper guide 211
L-shaped hooks 221 and 222 are provided at both ends of
The hook 222 is connected to driving means such as a solenoid 219 via a solenoid arm 220.

The solenoid 219 is connected to sheet detection sensors 216 and 217 on the lower surface of the upper lid via a control circuit (not shown). The solenoid 219 operates in conjunction with the ON / OFF operation of the sensor, and the hooks 221 and 221 operate. 222
Rotates. When neither of the sheet detection sensors 216 and 217 detects a sheet, that is, in the OFF state, the solenoid 219 is not energized, and the hook 22
1, 222 are located at 221-1 and 222-1. Axis 2
The hooks 23 and the hooks may be provided on the horizontal transport unit.

When one or both of the sheet detection sensors 216 and 217 detect a sheet and are in an ON state, a control circuit (not shown) receives a signal from the sheet detection sensor and energizes the solenoid 219. Solenoid 21
9 is energized and operates, so that the solenoid arm 2
20 is pulled in the direction of arrow C in the figure, and the hooks 221 and 222 are located at the rotations 221-2 and 222-2 about the shaft 223. Also, by displaying the detection signal on an operation panel or the like, the location where the jam has occurred is displayed.

When a sheet stays on the intermediate tray 210, a sheet detection sensor on the intermediate tray (not shown) detects the sheet and sends a signal to a control circuit (not shown). The sheet staying position is displayed on the operation unit of the image forming apparatus. After confirming the sheet staying position on the display of the operation unit, the operator pulls out the sheet re-feed unit in FIG. 1 along the intermediate tray left rail 213 toward the image forming apparatus (in the direction of arrow A in FIG. 1). At this time, the horizontal transport unit 21
2, there is no sheet, and the sheet detection sensors 216, 2
17 is in the OFF state, so the solenoid 219 does not operate, and the hooks 221 and 222 are connected to 221-1 and 222-1.
In the position.

After pulling out the sheet re-feeding unit, the operator lifts the handle 225 in the direction of arrow B, and
15 is rotated. At this time, the horizontal transport unit 212
Is rotated about the hinge 214 by the hooks 221 and 222 in conjunction with the upper guide 211 to form an opening α between the horizontal transport unit 212 and the intermediate tray 210 as shown in FIG. The staying sheet can be removed.

Next, when a sheet stays on the horizontal transport section 212, the sheet detection sensor 216 or 217 on the lower surface of the upper guide 211 detects the staying sheet. When the sheet detection sensors 216 and 217 detect the staying sheet, a control circuit (not shown) receives a signal from the sheet detection sensor and operates the solenoid 219. Solenoid 219 is ON
When the solenoid arm 220 is pulled in the direction of arrow C in FIG. 1, the hooks 221 and 222 rotate about the shaft 223 in the direction of arrow D in FIG.
2-2.

The operator pulls out the re-feeding unit in the same manner as described above, lifts the handle portion 225 in the direction of arrow B, and lifts the upper guide 2.
11 is rotated about the hinge 215. At this time, the hooks 221 and 222 are located at 221-2 and 222-2.
Only 1 rotates to form an opening β between the upper guide 211 and the horizontal transport unit 212 as shown in FIG. In this state of FIG. 3, the operator removes the staying sheet on the horizontal transport unit 212. The opening in this case is about twice as large as the conventional one.

In the above-described embodiment, the connecting means for connecting the horizontal conveying portion and the upper guide has been described as an example of a hook. However, the present invention is not limited to this. Can be used
Further, a stepping motor, a fluid actuator, or the like may be used instead of the solenoid as the driving means of the connecting means.

[0044]

As described above, according to the present invention,
When sheets stay in the intermediate tray or the horizontal transport unit, the upper guide and the horizontal transport unit may be connected by the connecting means, or the connection may be released, and only the upper guide may be rotated from the tray covering position to the open position. When the sheet jams on the tray, the upper guide and the horizontal transport unit are opened in a connected state to enable the processing, and when the jam occurs on the horizontal transport unit, The connection is released, only the upper guide is rotated, and the horizontal conveyance section is largely opened to perform the jam processing, thereby reducing a failure factor such as an erroneous operation. In addition, by operating the driving unit of the connecting unit based on the detection result of the sheet detection sensor that detects the staying sheet on the horizontal transport unit, the operation of the connecting unit can be automated, and the result is displayed. This makes it possible to clarify the location of the stay sheet and improve the operability of the user. At the same time, by minimizing the opening, failure factors such as erroneous operation when the user clears the jam are reduced, and the reliability is improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a re-feeding stacking unit according to an embodiment of the image forming apparatus of the present invention.

FIG. 2 is a side view 1 of the re-feeding stacking unit of the image forming apparatus of the present invention.

FIG. 3 is a side view 2 of the re-feeding stacking unit of the image forming apparatus of the present invention.

FIG. 4 is a side view 3 of the re-feeding stacking unit of the image forming apparatus of the present invention.

FIG. 5 is a sectional view of one embodiment of the image forming apparatus of the present invention.

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

FIG. 7 is a sectional view of a re-feeding stacking unit of the conventional image forming apparatus.

[Explanation of symbols]

100A Image forming unit 100B Optical reading unit 200A Reloading stacking means 210 Intermediate tray 211 Horizontal transport unit 212 Upper guide 213 Intermediate tray left rail 214, 215 Hinge 216, 217 Sensor 219 Solenoid 220: Solenoid arm 221: Hook (front) 222: Hook (back) 225: Hand

Claims (4)

[Claims] An upper guide provided with a plurality of conveyance rollers and a horizontal conveyance section having a plurality of flapper at one end of a tray capable of stacking a plurality of sheets are opened at a position where the upper surface of the tray is covered and opened. The sheets conveyed by the conveyance rollers between the upper guide and the horizontal conveyance unit are pivoted independently of each other so that the sheets fall onto the tray by opening the flapper selected according to the size. The sheet stacking apparatus according to claim 1, further comprising a connecting unit for selectively connecting and disconnecting both the upper guide and the horizontal transport unit. 2. A driving means is attached to the connecting means, a sheet detecting sensor for detecting a sheet between an upper guide and a horizontal conveying portion is provided, and the driving means is activated by detecting a sheet by the sheet detecting sensor. 2. The sheet stacking device according to claim 1, wherein the connection of the connection means is released. 3. The sheet stacking apparatus according to claim 1, wherein said connecting means is a hook member, and said driving means is a solenoid coil. 4. An image forming apparatus, comprising: the sheet stacking apparatus according to claim 1; and an image forming unit that forms an image on a sheet fed from the sheet stacking apparatus.