JP2000086019A - Paper feeding device for image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve image quality by releasing the recording paper holding state of a feeding roller when a lateral register roller moves in the cross direction of paper. SOLUTION: Simultaneously with the start of rotatory driving and axial (lateral) movement of a lateral register roller 51, a driving solenoid 50a constituting a roller release means is put in an ON state. A refeeding driven roller 41b is therefore lifted upward and spaced from recording paper, so that the held state of recording paper by a refeeding roller 41 is released into a freely moving state. With this constitution of moving the lateral register roller in the freely moving state released from restraint by a feeding roller the recording paper can be moved for alignment always desirably regardless of the size or the like of recording paper, and the quality of a formed image can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electrophotographic copying machine,
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device of an image forming apparatus, such as an electrostatic recording apparatus, provided with a horizontal registration roller for positioning a recording sheet fed to a transfer area in a paper width direction.

[0002]

2. Description of the Related Art In general, in various image forming apparatuses such as an electrophotographic copying machine, a document is placed on a document glass table and an illumination lamp or the like constituting an image reading means is scanned with respect to the document. An image is read, an electrostatic latent image corresponding thereto is formed on an image carrier, development is performed, and the obtained toner image is transferred onto a recording paper to form an image.

In such an image forming apparatus, in each device such as a tiled device for forming an image on both sides of a recording sheet, the recording sheet is moved in the paper width direction and aligned when feeding the sheet to the transfer area. That is being done. For example, the above-described tiled device guides a recording sheet on which an image is formed on one side through transfer, separation, and fixing to a lower conveyance path, and forwards and reverses a predetermined number of recording sheets to a lower conveyance path by forward / reverse rotation of a setback roller. The recording papers stacked in the tile shape are stacked one by one by the normal rotation operation of the set-back roller, the operation of the lower conveyance flapper, and the rotation operation of the re-feeding roller.
Separated sheets are fed back to the transfer area, and an image can be formed on the opposite side of the recording sheet.However, the leading edge of the recording sheet nipped and sent out by the re-feeding roller is ,
It is re-nipped by the horizontal registration rollers for alignment. The horizontal registration roller moves in the paper width direction while rotating while holding the recording paper, thereby aligning the recording paper in the paper width direction, and forming images on both sides of the recording paper in appropriate positions. It will be.

[0004]

However, an alignment sheet feeder using a horizontal registration roller as described above has been proposed.
If an attempt is made to apply the recording medium to a small-sized recording paper, the lateral registration roller and the paper supply roller are arranged close to each other in accordance with the length of the recording paper. When the paper is fed, when the horizontal registration roller moves in the paper width direction while nipping the recording paper, the recording paper is held at a predetermined position by the paper feed roller immediately behind the horizontal registration roller, Even if the registration roller moves, the recording paper may not be able to move due to the restraining force of the paper feed roller. Therefore, in the conventional apparatus, good alignment cannot be performed, and an image may not be formed at a predetermined position.

Accordingly, the present invention solves such a problem and an image forming apparatus capable of constantly and satisfactorily performing a positioning operation by a lateral registration roller and improving image quality. It is an object of the present invention to provide a paper feeding device.

[0006]

In order to achieve the above object, according to the first aspect of the present invention, a recording sheet nipped and fed by a paper feed roller is re-nipped by a horizontal registration roller,
In a sheet feeding device of an image forming apparatus in which the horizontal registration roller is moved in the paper width direction and the recording paper is fed to the transfer area while being aligned in the paper width direction, the horizontal registration roller moves in the paper width direction. At that time,
There is provided a roller releasing means for releasing the recording paper holding state of the paper feed roller.

[0007] According to the second aspect of the present invention, the first aspect is provided.
The described sheet feeding roller is a sheet re-feeding roller provided in a lower conveyance path for double-sided image formation.

Further, according to the third aspect of the present invention, the roller releasing means includes a solenoid driving mechanism for moving the paper feed roller so as to separate it from the recording paper.

According to the paper feeder of the image forming apparatus according to the first aspect, when the recording paper is moved in the paper width direction by the horizontal registration roller, the state in which the paper is nipped by the paper supply roller is released from the roller. The lateral registration roller is moved in a free state in which the restraining force of the paper feed roller is released, and the recording paper positioning movement is always good regardless of the size of the recording paper. Is to be performed.

[0010] Such positioning of the recording paper by the lateral registration rollers is particularly effective in a double-sided image forming apparatus as described in the second aspect of the present invention.

Further, if the paper feed roller is separated from the recording paper by a roller releasing means comprising a solenoid driving mechanism, a reliable operation can be obtained with a simple configuration.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Prior to this, an outline of an image forming apparatus will be described using an electrophotographic copying machine as an example.

In the electrophotographic copying machine shown in FIG. 1, an original glass table 2 as an original table is provided on an upper surface of an apparatus main body 1 and a part immediately below the original glass table 2 is provided. Is provided with a scanner (scanning optical device) 3 constituting image reading means. The scanner 3 has an illumination lamp 3a for irradiating scanning light to a document (not shown) on the document glass table 2, and reflects light reflected from the document on an image carrier (hereinafter referred to as a photosensitive member). A reflection mirror 3b and a projection lens 3c for guiding the light onto a drum 4).

An original supply device 5 is provided on the original glass table 2 so as to cover the original glass table 2 so as to be openable and closable. The original supply device 5 includes the illumination lamp 3
a is stopped at a predetermined position, and a document feeder (DF) 5a for reading a document (sheet through) for reading while transporting the document, and the illumination lamp 3a is moved after stopping the document at a predetermined position. And an automatic document feeder (AF) 5b for reading while reading.

A photosensitive drum 4 is provided below the scanner 3 so as to rotate clockwise in the drawing. Around the photosensitive drum 4, a charger 6 for uniformly charging the photosensitive drum 4, and a toner is applied to the electrostatic latent image formed on the photosensitive drum 4 by exposing the reflected light from the scanner 3 to light. A developing device 7 for supplying and visualizing the image; a transfer charger 8 arranged in the middle of the paper transport path for transferring the toner image on the photosensitive drum 4 to the recording paper; and a separating device for separating the transferred recording paper. A separation charger 9 and a cleaning device 10 for removing, collecting, and discharging toner remaining on the photosensitive drum 4 after transfer are sequentially arranged along the rotation driving direction of the photosensitive drum 4.

Further, the toner image on the recording paper is thermally fixed to the exit side end of a belt-like paper transport path 11 extending from the transfer charger 8 and the separation charger 9 to the exit of the apparatus main body 1. A fixing device 12 for performing the fixing operation is provided, and a discharge conveyance path 22 extends from an exit portion of the fixing device 12 toward a discharge tray 13 mounted on an exit portion of the apparatus main body 1.

A first discharge roller 23 is disposed near the exit of the fixing device 12 in the discharge conveyance path 22, and a second discharge roller 23 is disposed near the exit of the apparatus main body 1. Rollers 24 are arranged, and the recording paper is conveyed toward the discharge tray 13 by the rotational driving force of each roller. Further, a paper discharge sensor 25 for monitoring the paper conveyance state is arranged near the first paper discharge roller 23.

Below the belt-shaped paper transport path 11, there is provided a lower transport section 30 constituting a main part of the tile stacking device. Below the lower transport section 30, cut recording paper is provided. Is provided so as to form a two-stage paper feed unit. The detailed configuration and operation of the above-mentioned tiled device will be described later.

At the outlet on the right side in the drawing of the paper feed cassette 14, paper feed rollers 15 for feeding out the recording paper placed on the paper feed cassette 14 are arranged, respectively. The transport paths 16 extend from the paper feed roller 15 to the transfer area of the photosensitive drum 4. Each of these transport paths 16 merges into a single transport path 17. Near the transfer area in the merged transport path 17, a registration roller 18 that feeds the recording paper to the transfer area in synchronization with the image forming process Is provided. Further, a registration sensor 26 for monitoring the paper conveyance state is disposed upstream of the registration roller 18 in the conveyance direction.

On the side of the apparatus main body 1 opposite to the paper discharge tray 13, a manual feed tray 19 is attached so as to project obliquely upward from the main body 1. At the lower end exit of the manual feed tray 19, a manual feed roller 20 for feeding out recording paper of an arbitrary size placed on the manual feed tray 19 is arranged.
, A manual feed path 21 extends toward the transfer area. The distal end portion of the manual feed path 21 is connected so as to be connected to the above-described convey path 17 to the registration roller 18.

Next, the configuration of the tile stacking device will be described. The paper discharge transport path 22 branches at a position on the upstream side of the second paper discharge roller 24, and from the branch point toward the above-described left entrance of the lower transport unit 30, the entrance transport path 3.
One is extended. In the vicinity of the exit of the entrance conveyance path 31, a lower conveyance entrance roller 32 for conveying the recording paper to the lower conveyance section 30 is arranged. A lower transport entrance sensor 33 for monitoring the paper transport state is disposed downstream of the lower transport entrance roller 32 in the transport direction.

The lower transport section 30 includes a lower transport path 36 connected to the entrance transport path 31.
The lower transport path 36 is configured to be sandwiched between the upper transport guide 34 and the lower transport guide 35 as shown in FIGS. 2 and 3. This lower transport path 3
6, first and second setback rollers 37 and 38 for performing a setback operation described below are arranged from the upstream side to the downstream side in the transport direction (from left to right in the drawing). .

The first setback roller 37 includes a transport roller 37a driven by a drive source (not shown),
A pressure roller 3 that sandwiches the recording paper between the transport roller 37a and transports the recording paper together with the transport roller 37a.
7b, a plurality of pairs of the transport roller 37a and the pressure roller 37b are arranged in the axial direction. The second setback roller 38 is similar to the first setback roller 37, and includes a plurality of pairs of transport rollers 38a and pressure rollers 38b arranged in the axial direction. At this time, the pressure rollers 37b and 38b are supported by leaf springs, and can apply a predetermined pressure to the plurality of recording sheets even when the plurality of recording sheets are sandwiched between the conveyance rollers. It is configured as follows.

A lower transport flapper 39 rotatable around one axis is provided on the lower transport path 36 further downstream than the second setback roller 38 in the transport direction. By rotating so as to appear on the transport path 36 (rotating counterclockwise in the figure), the lowermost recording paper of the stacked recording papers is moved with respect to the other stacked recording papers. And are separated. Further, a lower transport outlet sensor 40 for monitoring the paper transport state is disposed upstream of the lower transport flapper 39 in the transport direction.

Further, near the exit of the lower transport path 36, a paper re-feed roller 41 for re-sending the recording paper to the above-mentioned transfer area is arranged. The re-feeding roller 41 includes a lower re-feeding drive roller 41a driven by a drive source (not shown), and a lower re-feeding drive roller 41a.
a, and the re-feeding drive roller 41a is interposed between the recording paper and the re-feeding driving roller 41a to sandwich the recording paper (one recording paper because the recording paper tiled by the above-described lower conveyance flapper 39 is separated one by one). Driven re-feed roller 41b for conveying
Consisting of The refeed driving roller 41a and the refeed driven roller 41b are arranged in pairs in the axial direction.

The re-feed follower roller 41b disposed on the upper side is pressed downward by a pressing force of a spring member (not shown) with a rotating shaft 41c protruding from both ends of the re-feed follower roller 41b. The refeeding driven roller 41b is configured to be pressed against the refeeding drive roller 41a by the pressing force.

Further, the refeeding driven roller 41b is provided with a roller release mechanism 50 that lifts the refeeding driven roller 41b upward to release the roller. As shown in FIG. 4, the roller release mechanism 50 includes a solenoid 50a as a drive source on the upper transport guide 34. The output shaft 50b of the drive solenoid 50a is connected to the plate-like link member 50c. Is rotatably connected to the base end portion of the swing lever 50d through the lever. The swing lever 50d is rotatably mounted on a support plate 50e provided to rise from the transport upper guide 34, and extends from the rotation support shaft 50f toward the re-feed driven roller 41b. The swing end portion is in contact with the rotation shaft 41c of the re-feed driven roller 41b from below. When the drive solenoid 50a is turned on and the output shaft 50b is retracted as shown by the arrow, the swing end portion of the swing lever 50d rises, and the refeeding driven roller 41b is raised by a predetermined amount. The recording paper is separated from the recording paper side.

At this time, the drive solenoid 50a is turned on when the lateral registration roller 51 described below starts rotating. The lateral registration roller 51
The lower drive is provided in the middle of an exit conveyance path 42 extending from the re-feed roller 41 toward the transfer area, and is connected to the output side of the main motor via a clutch mechanism (not shown). An upper driven lateral roller that sandwiches the recording paper sent from the re-feed roller 41 and conveys the recording paper together with the driving lateral registration roller 51a between the lateral registration roller 51a and the driving lateral registration roller 51a. It consists of a registration roller 51b. The driving lateral registration rollers 51a and the driven lateral registration rollers 51b are formed of roller members that are elongated in the axial direction.

As shown particularly in FIG. 3, the rotation shaft 51c of the lateral registration roller 51 is provided with a lateral movement motor 51e via a conversion mechanism 51d for converting rotational movement and linear movement between each other. The output shaft is connected, and the lateral registration roller 51 is reciprocated in the axial direction by the rotational driving force of the lateral movement motor 51e, whereby the recording paper P is moved by an appropriate amount in the paper width direction. I have.
Further, at one axial end portion (the lower end portion in FIG. 3) of the horizontal registration roller 51, a horizontal edge portion P of the recording paper P is provided.
A horizontal edge paper position sensor 51f for detecting the position of "a" is arranged in close proximity, and the position of the recording paper P in the paper width direction is confirmed by a detection signal from the horizontal edge paper position sensor 51f. .

Further, at a predetermined position on the upstream side of the lateral registration roller 51, a lateral registration paper feed sensor 51g for monitoring the state of paper conveyance with respect to the lateral registration roller 51 is arranged. The horizontal registration paper feed sensor 51g detects the leading end of the recording paper P in the paper feeding direction, and the paper feeding operation of the recording paper P is confirmed by a detection signal emitted from the horizontal registration paper supply sensor 51g. It has become.
The recording paper P is detected by the horizontal registration paper feed sensor 51g.
Is detected, the clutch mechanism of the lateral registration roller 51 described above is turned on to start the rotational drive, and at the same time, the rotational drive of the lateral movement motor 51e is started. As a result, while the recording paper P is sandwiched by the horizontal registration rollers 51 and the paper is fed,
By one axial movement, the recording paper P is moved in the paper width direction, for example, as indicated by the arrow in FIG. The horizontal edge portion Pa of the recording paper P is detected by the horizontal edge paper position sensor 51f, whereby the recording paper P is positioned at a predetermined position in the paper width direction.

At the same time as the rotation of the lateral registration roller 51 and the start of the shaft (lateral) movement, the drive solenoid 50a constituting the roller releasing means is turned on. As a result, the re-feeding driven roller 41b is lifted upward and separated from the recording paper P, and
1 is released and the recording paper P is released to a free movement state.

On the other hand, at the connection portion between the above-described entrance conveyance path 31 and the lower conveyance path 36, the trailing end of the recording paper that branches off at this position and deviates from the entrance conveyance path 31 during the setback operation is located at the lower left side in the figure. A recording paper rear end guide that guides toward the recording paper is provided. Although the recording paper trailing end guide is provided in the same manner in the related art, in the present embodiment, the recording paper trailing end guide is further extended so that the recording paper trailing end guide is disposed on the side of the apparatus main body 1 above the discharge tray 13. It is connected to a discharge port 45 opened at a lower position, and the recording paper discharge conveyance path 42 is connected to the recording paper rear end guide and the extended portion.
Is configured. In the discharge conveyance path 42, first and second discharge rollers 43 and 44 are arranged from the upstream side to the downstream side in the discharge direction (from the upper right side to the lower left side in the drawing).

The first discharge roller 43 includes a discharge drive roller 43a driven by a drive source (not shown), and a recording paper sandwiched between the discharge drive roller 43a and the discharge drive roller 43a. It is composed of a discharge driven roller 43b for conveying. Similarly, the second discharge roller 44 includes a discharge drive roller 44a and a discharge driven roller 44b.

The roofing apparatus thus constructed is provided with a roofing control device 60 as shown in FIG. The stacking control device 60 controls the operation of the stacking device, and has a central processing unit (microcomputer; hereinafter, referred to as CPU) 61 as a main part.

The input ports of the CPU 61 include the above-described paper discharge sensor 25, registration sensor 26, lower transport inlet sensor 33, lower transport outlet sensor 40, and lateral registration paper feed sensor 5.
Each output side of 1g and the horizontal edge paper position sensor 51f is connected respectively.

A power switch 62 is also connected to the input port of the CPU 61 so as to detect whether or not power is turned on.

The input port of the CPU 61 is connected to a ROM 63 in which a control program such as a stacking control procedure is stored. The input / output port of the CPU 61 temporarily stores various data. The RAM 64 is connected.

On the other hand, the output port of the CPU 61
A drive motor driver 65a for the second paper discharge roller 24 and the lower transport entrance roller 32, which has a common drive source;
The first setback roller 37 having a common drive source
Driver 65 for the drive roller 37a of the second setback roller 38 and the transfer roller 37a of the second setback roller 38
b, a re-feeding driving roller 41a of the re-feeding roller 41 and a driving motor driver 65c of the registration roller 18, a driving solenoid driver 65d of the lower transport flapper 39, and a common driving source. The discharge drive roller 43a of the first discharge roller 43 and the second
The drive motor driver 65e of the discharge drive roller 44a of the discharge roller 44 is connected to each. As described above, the re-feed driving roller 41a and the registration roller 18 have a common drive source, but the registration roller 18 is driven by the main motor of the copier, and the re-feed driving roller 41a is The main motor is operated by being appropriately connected to the clutch.

Further, an output port of the CPU 61 has a driver 65f for a clutch solenoid for operating a clutch mechanism for rotating the above-described lateral registration roller 51, and a lateral movement motor 51e for performing axial movement of the lateral registration roller 51. 65g and a driver 64h for the drive solenoid 50a of the roller releasing means are connected to each other.

The CPU 61 is provided for each of the sensors 2 described above.
.. Based on the outputs of 5, 26, 33, 40, 51f, 51g,..., The aging of the built-in timer, and the presence or absence of power-on by the power switch 62 described above. Is transmitted.

Next, the operation of the copying machine having the above-described configuration will be described. The operation of the above-described laying apparatus when duplex copying is performed will be described below. When the paper feed cassette 14 is used, the recording paper is
5, the sheet is conveyed to the registration roller 18 via the conveyance path 16, the merged conveyance path 17, and the like, and when the manual tray 19 is used, the recording paper is fed by the manual paper feed roller 20, the manual conveyance path 21, The sheet is conveyed to the registration roller 18 via the above-mentioned operation. The recording paper is controlled by the registration roller 18 so as to coincide with the leading end of the image on the photosensitive drum 4, and is transferred by the transfer charger 8, separated by the separation charger 9, conveyed by the belt-shaped paper conveyance path 11, An image is formed on one side after fixing by the fixing device 12.

As shown in FIG. 6A, the recording paper P1 that has passed through the fixing device 12 is first and second discharge rollers 2 as shown in FIG.
The paper is conveyed by the sheets 3 and 24 so that a part of the paper (conveying tip side) is discharged to the paper discharge tray 13. At this time, the lower conveyance entrance roller 32 is rotating in the same direction because the driving source is common to the second paper ejection roller 24. When a predetermined time elapses after the detection of the passage of the trailing edge of the recording sheet P1 by the sheet ejection sensor 25, the rotation is stopped with the second sheet ejection roller 24 holding the trailing edge of the recording sheet P1. Thereafter, the second paper discharge roller 24 rotates in the reverse direction, and the rear end of the recording paper P1 (the right end in the figure).
Will enter the entrance transport path 31 as shown in FIG. At this time, the lower transport entrance roller 32 also rotates in the same manner as the second discharge roller 24,
The recording paper P1 is conveyed toward the lower conveyance path 36 as shown in FIG. Here, since the transport direction is reversed, the right end in the drawing is the leading end of the recording paper P1, and the left end in the drawing is the rear end of the recording paper P1.

When a predetermined time elapses after the rotation of the second discharge roller 24 and the lower conveyance inlet roller 32 is reversed, the first recording paper P1 on which an image is formed on one side is formed as shown in FIG.
As shown in (d), the leading end of the first setback roller 37 enters the lower transport path 36 and is stopped.
And a loop is formed at the tip. At this time, as shown in FIG. 7A, the lower transport flapper 39 is lowered to appear on the lower transport path 36, and at the same time,
The first and second setback rollers 37 and 38 start rotating in the forward direction (the direction in which the recording paper is turned to the right in the drawing),
The recording paper P <b> 1 advances along the lower conveyance path 36 (moves toward the right side in the drawing), and the trailing end of the recording paper P <b> 1 exits the entrance conveyance path 31.

When a relatively short recording sheet such as A4 in the transport direction is used as in this embodiment, the first,
When the trailing end of the recording sheet P1 comes out of the entrance conveyance path 31 due to the rotation of the second setback rollers 37 and 38, as shown in FIG.
Never reach 1. When a relatively long recording paper is used in the transport direction such as A3, when the first and second setback rollers 37 and 38 rotate the trailing edge of the recording paper from the entrance transport path 31, The course of the leading end of the recording paper is changed upward by the lower transport flapper 39 which is lowered.

Now, the entrance conveyance path 31 at the rear end of the recording paper P1
7 is detected by the lower transport entrance sensor 33, the lower transport flapper 39 rises to open the lower transport path 36, as shown in FIG.
The rotation of the first and second setback rollers 37 and 38 is reversed. Then, the trailing edge of the recording paper P1 retreats while entering the discharge transport path 42 according to the transport. When a predetermined time elapses after the rotation of the first and second setback rollers 37 and 38 is reversed, the setback roller 3
The rotation of 7, 38 stops. At this time, the leading end of the recording paper P1 is at a position protruding rightward in the figure by a predetermined distance a from the first setback roller 37.

Subsequently, in the same manner as described above, the second recording sheet P2 having an image formed on one side is conveyed to the lower conveying path 36 as shown in FIG. 7C. This 2
As shown in FIG. 7D, the first setback roller 37 whose leading end is also stopped, as shown in FIG.
And a loop is formed at the tip. At this time, as shown in FIG. 8A, at the same time as the lower transport flapper 39 is lowered, the first and second setback rollers 37 and 38 start rotating in the forward direction, and the first recording is performed. Paper P
The first and second recording sheets P2 advance along the lower conveyance path 36 together with the rear end of the second recording sheet P2 to the entrance conveyance path 3.
Exit from 1.

The entrance conveyance path 3 at the rear end of the second recording paper P2
8 is detected by the lower transport entrance sensor 33, the lower transport flapper 39 is raised, and at the same time, the first and second setback rollers 37, 38 are raised, as shown in FIG. The rotation reverses, and the recording paper P1, P2 retreats while the trailing edge of the recording paper P1 enters the discharge conveyance path 42 according to the conveyance, and the first and second setback rollers 37, 38.
When a predetermined time has elapsed since the rotation of the setback rollers 37 and 38, the rotation of the setback rollers 37 and 38 stops. At this time,
The leading end of the second recording sheet P2 is located at a position protruding rightward in the drawing from the first setback roller 37 at a predetermined distance a similar to the case of the first recording sheet P1.

The same operation as described above is repeated for the third and subsequent recording papers, and a large number of recording papers are stacked on the lower transport path 36 in a tile shape. Here, in this embodiment, up to 20 recording sheets can be stacked in a tile shape.

When the final copy on one side is stacked in a tile pattern, the first and second setback rollers 37, 38
Starts rotating in the forward direction, and as shown in FIG. 8C, the lower conveyance outlet sensor 40 passes the leading end of the first recording paper (the lowermost recording paper) P1 (projects to the right in the drawing). Is moved forward until the is detected.

When the leading end of the first recording sheet P1 is detected by the lower conveyance exit sensor 40, as shown in FIG. 8D, the first and second setback rollers 37, 38 are provided.
Is reversed, and the entire stack of recording paper is retracted until the lower conveyance exit sensor 40 detects the passage of the leading end of the first recording paper P1 (pulling to the left side in the figure). The rotation of 37 and 38 stops. Thus, a double-sided copy standby state is set.

Here, when a copy start key (not shown) is pressed, the first and second setback rollers 37 and 3 are pressed.
8 starts to rotate in the forward direction, and as shown in FIG. Lower transport exit sensor 4
When a predetermined time elapses after the passage of the leading edge of the first recording sheet P1 is detected by “0”, the lower conveyance flapper 39 is moved to the state shown in FIG.
(B) As shown in FIG.
Setback rollers 37 and 38 temporarily stop.

Next, the first and second setback rollers 37 and 38 resume rotation in the forward direction, and the paper re-feed roller 41 starts rotating in the forward direction. Then, FIG. 9
As shown in (c), the lowermost recording sheet P1 is separated from the lowermost recording sheet P1 by the lower transport flapper 39, and the second and subsequent recording sheets P2 are separated by a setback roller. 37 and 38 and the re-feed roller 41 convey the outlet conveyance path 42, while the second and subsequent recording sheets P 2 are diverted upward by the lower conveyance flapper 39.

First and second setback rollers 37, 3
When a predetermined time elapses after the rotation of the first and second setback rollers 37 and 38 has been restarted, the rotation of the first and second setback rollers 37 and 38 is reversed, and the lower conveyance outlet sensor 40 detects the leading edge of the second recording sheet P2. Until the passage (retraction to the left side in the figure) is detected, all of the second and subsequent stacked recording papers are retracted.
At this time, the first recording paper P1 has already separated from the second setback roller 38, as shown in FIG. When the passage of the leading end of the second recording sheet P2 (pulling to the left side in the figure) is detected by the lower conveyance outlet sensor 40, the rotation of the setback rollers 37 and 38 is stopped and the lower conveyance flapper 39 is raised.

On the other hand, for the first sheet of recording paper P1 sent out to the exit conveyance path 42 by the re-feed roller 41, the following positioning control operation in the paper width direction is performed. That is, as shown in FIG. 11, when the recording paper P1 reaches the horizontal registration paper feed sensor 51g by the rotation of the re-feed roller 41 (step 1), the horizontal registration paper feed sensor 51g is used. Is turned on (Yes in step 2), a leading edge detection signal of the recording paper P1 is issued, and when the leading edge detection signal is maintained for a predetermined time,
It is determined that the recording paper P1 has reached the nip portion of the horizontal registration roller 51 (Yes in step 3).

Next, the clutch for rotating the horizontal registration roller 51 is turned on (step 4), and the horizontal registration roller 51 starts rotating. At the same time,
The drive solenoid 50a constituting the roller releasing means is turned on (step 5), whereby the re-feed roller 41 is lifted upward and separated from the recording sheet P1, and the re-feed roller 41 releases the recording sheet P1. The holding state is changed to the released state, and the recording paper P1 is set in the free moving state.

In this state, the lateral movement motor 51e starts rotating (step 6), and the lateral registration roller 51 reciprocates in the axial direction. This lateral (axial) movement continues while the lateral edge paper position sensor 51f is off (N in step 7).
o), when the lateral edge portion Pa of the recording paper P1 reaches the lateral edge paper position sensor 51f and the lateral edge paper position sensor 51f is turned on (Yes in step 7), the lateral movement motor 51e is turned off. The rotation stops (step 8). At the same time, the drive solenoid 50a constituting the roller releasing means is turned off (step 9), whereby the re-feed roller 41 returns to the original recording paper nipping state by the spring force.

The recording paper P1 thus aligned in the paper width direction is conveyed to the merging conveyance path 17, and as shown in FIG.
When the leading edge is detected by 6, the re-feeding operation of the second recording sheet P2 is started and executed in the same manner as the above-described first recording sheet P1. The refeeding operation for the third and subsequent recording sheets is performed in the same manner.

The transfer, separation, conveyance, and fixing of the recording paper which is prevented from being double-fed by the above-described stacking device and which is surely separated one by one and sequentially re-fed are performed in the same manner as in the case of one side. The image is formed on the back side, and the double-sided copy is completed.

As described above, in this embodiment, when the recording paper P is moved in the paper width direction by the horizontal registration roller 51, the nipping state of the recording paper P by the paper re-feed roller 41 is determined by the roller release means 50. Will be released
The lateral registration roller 51 is moved in a free movement state in which the restraining force of the re-feed roller 41 is released, so that the positioning movement of the recording paper P is always good regardless of the size of the recording paper P or the like. Done in

Such a positioning operation of the recording paper P by the lateral registration rollers 51 is particularly effective in the laying device of the double-sided image forming apparatus according to the present embodiment. Become.

Further, if the re-feed roller 41 is separated from the recording paper P by the roller releasing means 50 comprising a solenoid driving mechanism as in the present embodiment, a reliable operation can be obtained with a simple configuration.

Although the invention made by the inventor has been specifically described based on the embodiment, the invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the invention. Needless to say, for example, the present invention is not limited to the stacking device of the double-sided image forming apparatus as in the above-described embodiment, and can be similarly applied to other sheet feeding devices.

That is, the paper feed roller according to the present invention
The present invention is not limited to the sheet re-feeding roller as in the above-described embodiment, and may be a sheet feeding roller of a sheet feeding device that forms a single-sided image.

It goes without saying that the present invention can be similarly applied to an image forming apparatus other than a copying machine.

[0065]

As described above, in the paper feeder of the image forming apparatus according to the first aspect, when the recording paper is moved in the paper width direction by the lateral registration rollers, the recording paper is sandwiched by the paper feed rollers. Roller releasing means for releasing the
Since the horizontal registration rollers are moved in a free movement state in which the restraining force of the paper feed rollers is released, the recording paper alignment movement is always performed satisfactorily regardless of the size of the recording paper. And the quality of the formed image can be improved.

At this time, when the present invention is applied to the double-sided image forming apparatus as described in the second aspect, the alignment of the double-sided images can be favorably performed, which is particularly effective.

Further, if the paper feed roller is separated from the recording paper by a roller releasing means comprising a solenoid drive mechanism as in the third aspect of the present invention, in addition to the above-described effects, a simple configuration is ensured. Operation is obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a copier as an example of an image forming apparatus having a tiled device to which a sheet feeding device according to the present invention is applied.

FIG. 2 is a partially enlarged side view illustrating a main transport path of the tiled device illustrated in FIG. 1;

FIG. 3 is an explanatory plan view of a transport path shown in FIG. 2;

FIG. 4 is a side view illustrating a roller release mechanism according to the embodiment of the present invention.

FIG. 5 is a block diagram illustrating a control system of the tiled device.

FIG. 6 is an explanatory cross-sectional view illustrating a control operation of the tiled device.

FIG. 7 is an explanatory cross-sectional view illustrating a control operation subsequent to FIG. 6;

FIG. 8 is an explanatory cross-sectional view illustrating a control operation subsequent to FIG. 7;

FIG. 9 is an explanatory cross-sectional view showing a control operation following FIG. 8;

FIG. 10 is an explanatory cross-sectional view showing a control operation following FIG. 9;

FIG. 11 is a flowchart illustrating a control procedure of a horizontal registration roller.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Apparatus main body 8 Transfer charger 31 Inlet conveyance path 36 Lower conveyance path 37, 38 Setback roller 39 Paper separation means 41 Refeeding roller 41a Refeeding driving roller 41b Refeeding driven roller 41c Rotating shaft 42, 46 Discharge conveyance Paths 43, 44 Discharge roller 45 Discharge port 47 Remaining paper storage unit 50 Roller release mechanism 50a Drive solenoid 50d Swing lever 51 Lateral registration roller 51a Drive lateral registration roller 51b Followed lateral registration roller 51e Lateral movement motor 51f Lateral paper position sensor 61 CPU P1, P2 Recording paper

Claims (3)

[Claims] 1. A recording sheet that has been nipped and sent out by a paper feed roller is re-nipped by a horizontal registration roller, and the horizontal registration roller is moved in the paper width direction so that the recording paper is positioned in the paper width direction and is transferred to the transfer area. In a paper feeding device of an image forming apparatus adapted to feed paper, a roller releasing means for releasing the recording paper nipping state of the paper feeding roller when the horizontal registration roller moves in the paper width direction is provided. Feeding device of the image forming apparatus. 2. A sheet feeding device for an image forming apparatus according to claim 1, wherein said sheet feeding roller is a re-feeding roller provided in a lower conveyance path for two-sided image formation. 3. The sheet feeding device according to claim 1, wherein the roller releasing unit includes a solenoid driving mechanism that moves the sheet feeding roller so as to separate the sheet feeding roller from the recording sheet.