JPH0524676A - Image forming device - Google Patents

Abstract

PURPOSE:To always carry out the separating work oppositely to the uppermost placed transfer paper sheet with a separating roller and a pressing roller even in the case where the height of the transfer paper sheet changes, by giving the property to tend to shift toward the uppermost placed transfer paper sheet, to the separating roller and the pressing roller. CONSTITUTION:A pressing roller 115A and a separating roller 116 are set so that the generation of the aslant traveling of a transfer paper sheet is prevented, and supporting shafts 115A1 and 1161 for each roller are applied with the tendency for the shift toward a tray 113 side by springs 1151 and 1162. Accordingly, the pressing roller 115A and separating roller 116 are constituted so as to always contact the uppermost paper sheet among the transfer paper sheets, and the engagement on the front side in the driving-out direction for the transfer paper sheet in the separating work by the separating roller is made sure by the all- time contact of the pressing roller 115A. Accordingly, the driving-out work for the transfer paper sheet by the frictional force of the large diameter part 116A of the separating roller 116 can be carried out surely.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus,
More specifically, it relates to a transfer paper separating structure in a paper feeding device.

[0002]

2. Description of the Related Art As is well known, in a sheet feeding device of an image forming apparatus such as a copying machine, a transfer sheet placed on a sheet feeding tray is fed toward a transfer position with a photoconductor. It has the structure of.

FIG. 12 shows an example of the above-mentioned feeding structure. This structure is provided with a separating roller a which is composed of a friction member whose peripheral surface is a flat portion. When a is rotated once, the peripheral surface other than the flat portion is brought into contact with the transfer paper b, so that the transfer paper is delivered through the frictional force between the transfer paper b and the peripheral surface.

[0004]

However, in the paper feeding device having the above-mentioned structure, it is necessary to prevent the double feeding of the transfer paper b when the transfer paper b is fed out by the rotation of the separation roller a. However, since the circumferential surface of the separation roller a is simply brought into contact with the uppermost transfer paper b,
In some cases, double feeding could not be reliably prevented. That is, when the circumferential surface of the separation roller a comes into contact with the transfer paper b, and when the transfer paper b is double-fed along the rotation direction of the separation roller A, the transfer paper b is more than frictional force between the transfer papers b. By increasing the frictional force between the separation roller a and the separation roller a, only the transfer paper b that is in contact with the separation roller a is fed out. If the abutting relationship is not normally maintained, the above-mentioned feeding cannot effectively apply the frictional force to the transfer paper,
As a result, the transfer paper cannot be separated accurately. In particular, when separating the transfer paper by the separation roller a,
This is performed on the premise that the uppermost transfer paper is always in contact, but in the case where a plurality of transfer papers are simultaneously separated by a plurality of rotations of the separation roller a, When the separation is completed, a gap corresponding to the number of separated sheets is opened between the transfer paper and the separation roller a, and when the separation work by the separation roller a is performed next, the separation roller a
There is a risk that proper separation work may not be possible due to the fact that they do not abut.

Therefore, in view of the above-mentioned problems in the conventional paper feeding device, an object of the present invention is to transfer the transfer paper in the stacked state to the transfer roller regardless of the number of separated sheets when the transfer paper in the stacked state is separated by one rotation of the feeding member. An object of the present invention is to obtain an image forming apparatus including a paper feeding device having a structure capable of properly maintaining a contact relationship with paper.

[0006]

In order to achieve this object, the present invention provides an image forming apparatus having a sheet feeding device having a structure in which the uppermost transfer sheets in a sheet stack are sequentially fed out. The transfer roller is provided with a separation roller that can be brought into contact with the transfer paper and can rotate in the feeding direction of the transfer paper. The separation roller has a large diameter portion that can contact the transfer paper in the circumferential direction and a small diameter portion that does not contact the transfer paper. The small-diameter portion is provided with a claw portion into which the rear end of the transfer paper can be dropped, and the position of the claw portion is at a position corresponding to the opposite side of the large-diameter portion with respect to the center of rotation. It is characterized in that it is provided with a paper feeding device that is set and supported so as to be displaced toward the topmost one of the transfer papers.

Further, according to the present invention, in an image forming apparatus equipped with a sheet feeding device having a structure in which the uppermost transfer sheet in the sheet feed stack is sequentially fed out, the uppermost transfer sheet can be brought into contact with the uppermost transfer sheet. A pressing roller rotatable in the feeding direction and a separation roller arranged upstream of the pressing roller in the feeding direction of the transfer paper are provided, and the pressing roller is
It is characterized in that it is provided with a sheet feeding device that is supported by being given the habit of displacing toward the topmost transfer sheet.

Further, the present invention is characterized in that the supporting portions of the separating roller and the pressing roller are provided with a sheet feeding device in which an elastic body is biased toward the uppermost one of the transfer sheets.

[0009]

According to the present invention, the separating roller and the pressing roller can be opposed to the uppermost one of the transfer papers by the displacement habit toward the uppermost one of the transfer papers.

Therefore, even when the height of the uppermost transfer paper stacked is changed, the separating roller and the pressing roller always face the uppermost transfer paper to perform the separating operation at the time of feeding. .

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the embodiments of the present invention will be described below with reference to FIGS.

FIG. 1 shows an example of an image forming apparatus according to an embodiment of the present invention. That is, the image forming apparatus 100 shown in FIG. 1 is provided with a copy processing unit A, a large-capacity paper feeding unit B, and a post-copy processing unit C, and is configured to enable mass copying.

The above-mentioned copy processing section A is a copy step executing section including a step of transferring a visible image formed on a photoconductor to a transfer sheet, and the large-volume sheet feeding section B supplies a large amount of transfer sheets of the same size. The post-copy processing section C is a section for binding the transfer paper carrying the transfer image, for example, using the stapler C1.

The above-mentioned copy processing section A is a section for executing a normal copy process. Specifically, the automatic document feeder 101 for feeding the placed document toward the exposure position is provided in the main body casing. A charging device 103, an exposure device 104, and a developing device 1 for executing a copying process are provided around a belt-shaped photosensitive member 102 arranged in an upper portion and inside a main body housing.
05, a transfer device 106 and a cleaning device 107 are provided. In addition, a registration roller pair 108A for setting a feeding timing of a transfer sheet fed from a sheet feeding unit 108, which will be described later, is arranged near the transfer position on the belt-shaped photoreceptor 102, and behind the transfer position. Is a fixing device 109 that fixes the image on the transfer paper that has received the image transfer.
Has been placed. In the case of the present embodiment, the exposure device 104 described above is composed of a lamp 104A for illuminating the original set at the exposure position, a plurality of mirrors 104B for setting the exposure path, and a projection lens 104C, and exposes the original image. It is designed to be projected and exposed on the body.

Further, the paper feeding section 108 is provided with a plurality of paper feeding cassettes 1081 and 1010 for accommodating transfer sheets of different sizes.
82 and 1083 are provided, and from the selected paper feed cassette, the paper is fed out in order from the uppermost one by the feeding mechanism described later, and the paper feed timing is set by the above-mentioned registration roller pair 108A. ing. Further, a transfer paper conveyance path 110 is provided behind the above-described fixing device 109, and the conveyance path 110 is provided in the copy processing section A in the direction toward the sheet discharge tray 111 and in the post-copy processing section C. The conveyance direction of the transfer paper can be switched between the forward direction and the forward direction. Further, in the middle of the above-mentioned transport path 110, specifically, in front of the switching position and in the middle of the post-copy processing section C, the transfer sheet passing through this transport path is detected and the discharge tray in the copy processing section A is detected. 111 or a discharge sensor 1 for detecting the number of transfer sheets stacked on the discharge tray C2 of the post-copy processing section C
12 are arranged.

In the copy processing unit A having such a configuration, the belt-shaped photosensitive member 102 is uniformly charged by the charging device 103, and then the exposure position is adjusted by the automatic document feeder 101 via the exposure device 104. A latent image corresponding to the original set on the sheet is formed on the belt-shaped photoconductor 102, and the latent image is subjected to visible image processing by the developing device 105 to be fed to the sheet feeding unit 1.
The transfer sheet is transferred from 08. Then, the transfer sheet having undergone the visible image transfer is fixed by the fixing device 109 and then conveyed toward the paper discharge tray 111 or the post-copy processing section C.

On the other hand, the above-mentioned large-volume sheet feeding section B is a section used when feeding a large amount of transfer sheets, and is provided with a sheet feed tray B1 for placing a large amount of transfer sheets, A delivery mechanism having the same structure as that of the paper feed unit 108 is provided above the transfer paper located at the top of the tray B1.

As shown in FIG. 2, the transfer paper feeding mechanism described above is, for example, a tray 113 that can be moved up and down to stack and store the transfer paper, and is located above the tray 113 to transfer the transfer paper. Paper feeding roll in the feeding direction
Pickup roller 11 located upstream of LA pair 108B
4 and further upstream of the pickup roller 114, in other words, a separating device 115 located on the rear end side of the transfer paper in the feeding direction. The separation device 115 described above is
It is composed of a pressing roller 115A and a separation roller 116 that rotate in a direction in which the uppermost one of the transfer sheets is brought into contact with the transfer sheet and can be fed out. That is, the separation roller 11
Reference numeral 6 is a unit for counting the number of sheets fed by a counter (not shown) by rotating in conjunction with the feeding of the transfer paper. As a concrete structure, as shown in FIG. The small-diameter portion 116B is formed into a cam shape, and the large-diameter portion 116A has a peripheral surface formed of a material such as rubber having a friction coefficient higher than that between transfer sheets. , In the circumferential direction of the small diameter portion 116B forming a base circle.
The large-diameter portion 116A described above is set to have a fan-shaped angle of 60 to 90 degrees with reference to the rotation center of the separation roller 116 in FIG.

The large diameter portion 11 of the separating roller 116
6A, the upstream edge portion in the rotational direction indicated by the arrow in FIG. 4 is the counter front end portion 116A1 and the downstream edge portion in the rotational direction is the counter rear end portion 116A2, which is the home position, which is the initial position. As a posture,
In FIG. 4, the counter tip portion 116A1 is the separation roller 1
It is positioned upstream from the position immediately below in the direction of rotation of 16, and a small distance (G) can be set between the counter leading end 116A1 and the uppermost transfer sheet in the sheet stack.

Further, the small diameter portion 116B of the separation roller 116 has a large diameter portion 116A based on the center of rotation.
The position corresponding to the opposite side, specifically, the position where the phase is reversed by approximately 180 degrees with respect to the counter tip portion 116A1.
16C is provided, and this claw portion 116C is formed with a concave fitting portion 116C1 which is bent toward the downstream side in the rotational direction and into which the rear end of the transfer sheet can be inserted.

Further, as shown in FIG. 5, the pressing roller 115A and the separation roller 116 described above are arranged along the width direction of the transfer sheet to be fed out, and the transfer sheet is skewed in the width direction of the transfer sheet. Is prevented from occurring, and the support shafts 115A1 and 1161 of each roller are given the habit of being displaced toward the tray 113 side by the springs 1151 and 1162 arranged at both axial ends thereof. Therefore, the pressing roller 115A and the separation roller 116
Can always come into contact with the uppermost one of the transfer papers, and the pressing roller 115A always comes into contact with the transfer roller to securely lock the transfer paper at the front side in the feeding direction during the separation work. Then, the transfer paper can be reliably fed out by the action of the frictional force of the large diameter portion 116A of the separation roller 116. In FIG. 5, reference numerals 117 and 118 denote optical sensors facing each other across the bottom plate of the tray 113, and the optical sensors 117 and 118 detect the presence or absence of the transfer paper on the tray 113. ing.

The separation roller 116 having the above-mentioned relationship is configured to separate the transfer paper by the operation shown in FIG.

That is, FIG. 6 (A) shows the separation roller 116 in the home position, in which the pressing roller 115A abuts on the uppermost one of the transfer sheets, and Counter tip 116 of separation roller 116
A1 is stopped facing the transfer paper side. Then, as shown in FIG. 6 (B), when only the separation roller 116 starts to rotate in the clockwise direction in the figure, the counter tip portion 116A1 of the separation roller 116 comes into contact with the surface of the transfer paper, and the rotation direction thereof In synchronism with the movement to, the frictional force between the uppermost transfer sheet and the transfer sheet located below it is overcome, and the uppermost sheet of the transfer sheet is dragged and moved to the left side in the figure. As shown in FIG. 6 (C) and FIG. 6 (D), the transfer paper whose uppermost one is displaced by the rotation of the separation roller 116 is stopped in one of the feeding directions by the pressing roller 115. In accordance with the rotation of the separation roller 116, the swelling is directed upward and the swelling amount is increased. Then, the rotation of the separation roller 116 progresses and the rear end of the transfer sheet in the feeding direction is dragged to face the counter rear end portion 116A2 of the separation roller 116.
As shown in (E), by this time, the uppermost transfer paper is separated from the transfer paper positioned below it, and the rear end is separated from the lower transfer paper. When the separation roller 116 further rotates in this state, as shown in FIG. 6 (F), the trailing edge of the transfer paper enters the concave fitting portion 116C1 of the claw portion 116C of the separation roller 116 as shown in FIG. G)
As shown in, the rear end is pushed up as the separation roller 116 rotates. Then, when the claw portion 116C is positioned upward due to the rotation of the separation roller 116, the transfer paper comes off the claw portion 116C of the separation roller 116, and as shown in FIG. In addition, it is in a position to ride on the upper peripheral surface of the separation roller 116. When the separation roller 116 further rotates once and rotates once, as shown in FIG. 6 (I), the transfer paper is placed on the upper portion of the claw portion 116C of the separation roller 116, so that the separation between the lower transfer paper and the separation paper is performed. Will be completed.

FIG. 7 shows a state after the above separating operation is repeated a plurality of times. In this case, the separating roller 1
16 is rotated 5 times and 5 sheets of transfer paper are separated. In addition, in order to enable separation of a plurality of transfer sheets, the tray 1
Either or both of the 13 side and the separation roller 116 are moved so that the separation roller 116 and the uppermost one of the transfer sheets can come into contact with each other.

On the other hand, the separating operation by the separating roller 116 described above is controlled by the control unit 119 described later. That is, the control unit 119 in FIG.
Although not shown in detail, the main part is constituted by a microcomputer 119A for performing sequence control 9 for image formation of a copying machine, and a basic program for sequence control and arithmetic control processing are provided. It is provided with a ROM 119B for storing basic data for storing data and a RAM 119B for reading and writing various data, and is connected to an external device via an I / O interface 119D. On the input side of the above-mentioned I / O interface 119D, as related to the separation operation of the transfer paper, the operation unit 120 described later and the light-receiving side sensor 118 of the optical sensors shown in FIG. A transfer number sensor (not shown) is connected to detect the number of rotations of the separation roller 116, and the display unit 12 provided on the operation unit 120 is provided on the output side.
1 and the drive unit 122 are connected. The operation unit 120 described above is configured by an operation panel, as shown in FIG. 9, and the panel is related to the separating operation.
Number of sheets setting selection switch 120A, number of sheets setting switch 12
0B set number confirmation switch (data entry switch)
120C is provided, and as the configuration of the display unit 121, a number display lamp 121A and a message display lamp 121B for displaying the difference between the number set by the number setting switch 120B and the actual number of separated sheets as the remaining number. It is provided. In the case of this embodiment, the content of the message is "please supply paper" when the number of transfer sheets accommodated on the tray 113 is insufficient with respect to the set number. Is displayed.

Further, in the case of the present embodiment, the above-mentioned drive section 122 is the rotation drive section of the separation roller 116 and the tray 1.
13 or an up-and-down drive unit for the separation roller 116. In the control unit 119 having the above-described configuration, turning on of the number setting switch 120A is accepted as an interrupt process, and normally, for example, a predetermined number of 10 sheets is set in advance, and this number of sheets is set in advance. The separation can be done. Therefore, the number setting switch 1
When 20A is turned on, the separation operation state for a predetermined number of sheets is released, and the separation work is executed based on the number setting by the sheet number setting switch 120B.

Since the present embodiment is constructed as described above,
Now, the operation of the controller 119 will be described with reference to the flowchart shown in FIG.

That is, when the copy mode is set by a switch (not shown) in the operation unit 120, the control unit 119 takes in 10 sheets, which is a predetermined value as the number of sheets to be separated, as data, and For the number of sheets, it is determined whether or not there is an interruption due to the turning on of the number of sheets setting selection switch 120A, and if there is an interruption, the new set number of sheets by the number of sheets setting switch 120B is fetched when the number of sheets setting confirmation switch 120C is turned on, and this value is set to this value. Based on this, the separation work is started. That is, the process in this case is as shown in FIG.
As shown in, the paper feed tray 11 according to the copy mode setting
3 is selected, the newly set number of sheets is read, and the selected paper feed tray 113 is selected.
The presence or absence of the transfer sheet above is determined based on the detection of the optical sensor 118, and when the transfer sheet remains, the separation roller 116 is rotated via the drive unit 122. In other words, separation roller 1
When the transfer paper remains on the tray 113, the tray 16 continues to rotate until the set number of sheets is reached.
As shown in FIG.
As shown in, load on the peripheral surface. Further, when it is detected that there is no transfer sheet on the tray 113, the difference between the rotation speed data of the separation roller 116 and the set number of sheets is obtained, and when the transfer sheet is insufficient during copying, which will be described later, Move to processing. That is, the separation roller 116 that matches the set number of sheets
Determines if the rotation has been completed, and if so, that is,
When the transfer sheets according to the set number of sheets are separated from the tray 113, copying is started and the separation roller 116 is rotated once so that the transfer sheets corresponding to the set number of sheets are always stacked on the peripheral surface. And while this action is repeated,
If there is a transfer sheet on the tray 113, it is determined whether or not the number of times of copying matches the set number of sheets, and if they match, the process ends.

On the other hand, in the above process, the separation roller 1
When it is detected that there is no transfer sheet on the tray 113 at the stage before the number of times of copying is equal to the set number of sheets by repeating 16 rotations, the number of rotations of the separating roller 116 up to that time is changed.
The difference between the set number and the set number is obtained, and the difference is displayed as the unseparated number with respect to the set number on the number display lamp 121A, and the message display lamp 121B is turned on. The message in this case means that when the number of transfer sheets stacked on the separation roller 116 is copied, there is no transfer sheet to be copied thereafter, and the operator is
For example, by seeing this display and supplying the transfer paper onto the tray 113, copying can be performed without interruption.

When the transfer paper is not replenished as described above, copying is performed while the display is continued, and the number of remaining sheets displayed is decreased by one each time copying is performed. .

[0031]

As described above, according to the present invention, between the large diameter portion of the separation roller in the home position and the transfer sheet, and the pressing roller in the transfer sheet separating mechanism in the sheet feeding device. Since the relationship between the transfer paper and the transfer paper is set so that it can always come into contact with each other due to the displacement habits of both rollers, it is possible to reliably perform the pressing processing of the transfer paper by the pressing roller during the separation work by the separation roller. Further, in the separation roller, it is possible to surely perform the feeding operation of the transfer paper via the frictional force of the large diameter portion. Therefore, regardless of the change in the number of separated sheets, it is possible to prevent a situation in which a gap is left between each roller and the uppermost transfer sheet, and the transfer sheet can be separated.

[Brief description of drawings]

FIG. 1 is a layout diagram showing an overall configuration of an image forming apparatus according to an embodiment.

FIG. 2 is a model diagram for explaining a structure of a sheet feeding unit in the image forming apparatus shown in FIG.

FIG. 3 is a perspective view showing a separation roller used in the paper feeding unit shown in FIG.

FIG. 4 is a model diagram for explaining a positional relationship between a large diameter portion, a small diameter portion, and a claw portion in the separation roller shown in FIG.

5 is a perspective view for explaining an arrangement state of separation rollers in the sheet feeding unit shown in FIG.

FIG. 6 is a model diagram for explaining a procedure for separating transfer paper by the separation roller shown in FIG.

FIG. 7 is a model diagram for explaining one mode of action by the separation roller shown in FIG.

8 is a block diagram illustrating a configuration of a control unit in the image forming apparatus illustrated in FIG.

9 is a schematic diagram showing an operation unit connected to the control unit shown in FIG.

10 is a flowchart for explaining the operation of the control unit shown in FIG.

FIG. 11 is a flowchart for explaining the operation of the control unit shown in FIG.

FIG. 12 is a schematic diagram for explaining a conventional structure of a transfer paper feeding mechanism.

[Explanation of symbols]

100 image forming apparatus 102 photoconductor 108 paper feeder 115 Separation mechanism 115A holding roller 115A1 Support roller shaft 1151 Spring as biasing member 116 separation roller 116A large diameter part 116A1 Counter tip 116A2 Counter rear end 116B small diameter part 116C claw 116C1 recess 1161 Separation roller support shaft 1162 Spring as a biasing member

[Procedure amendment]

[Submission date] September 4, 1991

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction content]

[Document name] Statement

Image forming apparatus

[Claims]

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus,
More specifically, it relates to a transfer paper separating structure in a paper feeding device.

[0002]

2. Description of the Related Art As is well known, in a sheet feeding device of an image forming apparatus such as a copying machine, a transfer sheet placed on a sheet feeding tray is fed toward a transfer position with a photoconductor. It has the structure of.

FIG. 20 and FIG. 21 show an example of the above-mentioned feeding structure, which is provided with a separating roller a composed of a friction member whose peripheral surface is a flat portion. By rotating the separation roller a once, the peripheral surface other than the flat portion is brought into contact with the transfer paper b, so that the transfer paper is delivered through the frictional force between the transfer paper b.

[0004]

However, in the paper feeding device having the above-mentioned structure, it is necessary to prevent the double feeding of the transfer paper b when the transfer paper b is fed out by the rotation of the separation roller a. However, since the circumferential surface of the separation roller a is simply brought into contact with the uppermost transfer paper b,
In some cases, double feeding could not be reliably prevented. That is, when the circumferential surface of the separation roller a comes into contact with the transfer paper b, and when the transfer paper b is double-fed along the rotation direction of the separation roller A, the transfer paper b is more than frictional force between the transfer papers b. By increasing the frictional force between the separation roller a and the separation roller a, only the transfer paper b that is in contact with the separation roller a is fed out. If the abutting relationship is not normally maintained, the above-mentioned feeding cannot effectively apply the frictional force to the transfer paper,
As a result, the transfer paper cannot be separated accurately. In particular, when separating the transfer paper by the separation roller a,
This is performed on the premise that the uppermost transfer paper is always in contact, but in the case where a plurality of transfer papers are simultaneously separated by a plurality of rotations of the separation roller a, When the separation is completed, a gap corresponding to the number of separated sheets is opened between the transfer paper and the separation roller a, and when the separation operation is performed by the separation roller a, the separation roller a does not contact. Therefore, proper separation work may not be performed.

Therefore, in view of the above-mentioned problems in the conventional paper feeding device, an object of the present invention is to transfer the transfer paper in the stacked state to the transfer roller regardless of the number of separated sheets when the transfer paper in the stacked state is separated by one rotation of the feeding member. An object of the present invention is to obtain an image forming apparatus including a paper feeding device having a structure capable of properly maintaining a contact relationship with paper.

[0006]

In order to achieve this object, the present invention provides an image forming apparatus having a sheet feeding device having a structure in which the uppermost transfer sheets in a sheet stack are sequentially fed out. The transfer roller is provided with a separation roller that can be brought into contact with the transfer paper and can rotate in the feeding direction of the transfer paper. The separation roller has a large diameter portion that can contact the transfer paper in the circumferential direction and a small diameter portion that does not contact the transfer paper. The small-diameter portion is provided with a claw portion into which the rear end of the transfer paper can be dropped, and the position of the claw portion is at a position corresponding to the opposite side of the large-diameter portion with respect to the center of rotation. It is characterized in that it is provided with a paper feeding device that is set and supported so as to be displaced toward the topmost one of the transfer papers.

Further, according to the present invention, in an image forming apparatus equipped with a sheet feeding device having a structure in which the uppermost transfer sheet in the sheet feed stack is sequentially fed out, the uppermost transfer sheet can be brought into contact with the uppermost transfer sheet. A pressing roller rotatable in the feeding direction and a separation roller arranged upstream of the pressing roller in the feeding direction of the transfer paper are provided, and the pressing roller is
It is characterized in that it is provided with a sheet feeding device that is supported by being given the habit of displacing toward the topmost transfer sheet.

Further, the present invention is characterized in that the supporting portions of the separating roller and the pressing roller are provided with a sheet feeding device in which an elastic body is biased toward the uppermost one of the transfer sheets.

[0009]

According to the present invention, the separating roller and the pressing roller can be opposed to the uppermost one of the transfer papers by the displacement habit toward the uppermost one of the transfer papers.

Therefore, even when the height of the uppermost transfer paper stacked is changed, the separating roller and the pressing roller always face the uppermost transfer paper to perform the separating operation at the time of feeding. .

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the embodiments of the present invention will be described below with reference to FIGS.

FIG. 1 shows an example of an image forming apparatus according to an embodiment of the present invention. That is, the image forming apparatus 100 shown in FIG. 1 is provided with a copy processing unit A, a large-capacity paper feeding unit B, and a post-copy processing unit C, and is configured to enable mass copying.

The above-mentioned copy processing section A is a copy step executing section including a step of transferring a visible image formed on a photoconductor to a transfer sheet, and the large-volume sheet feeding section B supplies a large amount of transfer sheets of the same size. The post-copy processing section C is a section for binding the transfer paper carrying the transfer image, for example, using the stapler C1.

The above-mentioned copy processing section A is a section for executing a normal copy process. Specifically, the automatic document feeder 101 for feeding the placed document toward the exposure position is provided in the main body casing. A charging device 103, an exposure device 104, and a developing device 1 for executing a copying process are provided around a belt-shaped photosensitive member 102 arranged in an upper portion and inside a main body housing.
05, a transfer device 106 and a cleaning device 107 are provided. In addition, a registration roller pair 108A for setting a feeding timing of a transfer sheet fed from a sheet feeding unit 108, which will be described later, is arranged near the transfer position on the belt-shaped photoreceptor 102, and behind the transfer position. Is a fixing device 109 that fixes the image on the transfer paper that has received the image transfer.
Has been placed. In the case of the present embodiment, the exposure device 104 described above is composed of a lamp 104A for illuminating the original set at the exposure position, a plurality of mirrors 104B for setting the exposure path, and a projection lens 104C, and exposes the original image. It is designed to be projected and exposed on the body.

Further, the paper feeding section 108 is provided with a plurality of paper feeding cassettes 1081 and 1010 for accommodating transfer sheets of different sizes.
82 and 1083 are provided, and from the selected paper feed cassette, the paper is fed out in order from the uppermost one by the feeding mechanism described later, and the paper feed timing is set by the above-mentioned registration roller pair 108A. ing. Further, a transfer paper conveyance path 110 is provided behind the above-described fixing device 109, and the conveyance path 110 is provided in the copy processing section A in the direction toward the sheet discharge tray 111 and in the post-copy processing section C. The conveyance direction of the transfer paper can be switched between the forward direction and the forward direction. Further, in the middle of the above-mentioned transport path 110, specifically, in front of the switching position and in the middle of the post-copy processing section C, the transfer sheet passing through this transport path is detected and the discharge tray in the copy processing section A is detected. 111 or a discharge sensor 1 for detecting the number of transfer sheets stacked on the discharge tray C2 of the post-copy processing section C
12 are arranged.

In the copy processing unit A having such a configuration, the belt-shaped photosensitive member 102 is uniformly charged by the charging device 103, and then the exposure position is adjusted by the automatic document feeder 101 via the exposure device 104. A latent image corresponding to the original set on the sheet is formed on the belt-shaped photoconductor 102, and the latent image is subjected to visible image processing by the developing device 105 to be fed to the sheet feeding unit 1.
The transfer sheet is transferred from 08. Then, the transfer sheet having undergone the visible image transfer is fixed by the fixing device 109 and then conveyed toward the paper discharge tray 111 or the post-copy processing section C.

On the other hand, the above-mentioned large-volume sheet feeding section B is a section used when feeding a large amount of transfer sheets, and is provided with a sheet feed tray B1 for placing a large amount of transfer sheets, A delivery mechanism having the same structure as that of the paper feed unit 108 is provided above the transfer paper located at the top of the tray B1.

As shown in FIG. 2, the transfer paper feeding mechanism described above is, for example, a tray 113 that can be moved up and down to stack and store the transfer paper, and is located above the tray 113 to transfer the transfer paper. Paper feeding roll in the feeding direction
Pickup roller 11 located upstream of LA pair 108B
4 and further upstream of the pickup roller 114, in other words, a separating device 115 located on the rear end side of the transfer paper in the feeding direction. The separation device 115 described above is
It is composed of a pressing roller 115A and a separation roller 116 that rotate in a direction in which the uppermost one of the transfer sheets is brought into contact with the transfer sheet and can be fed out. That is, the separation roller 11
Reference numeral 6 is a unit for counting the number of sheets fed by a counter (not shown) by rotating in conjunction with the feeding of the transfer paper. As a concrete structure, as shown in FIG. The small-diameter portion 116B is formed into a cam shape, and the large-diameter portion 116A has a peripheral surface formed of a material such as rubber having a friction coefficient higher than that between transfer sheets. , In the circumferential direction of the small diameter portion 116B forming a base circle.
The large-diameter portion 116A described above is set to have a fan-shaped angle of 60 to 90 degrees with reference to the rotation center of the separation roller 116 in FIG.

The large diameter portion 11 of the separating roller 116
6A, the upstream edge portion in the rotational direction indicated by the arrow in FIG. 4 is the counter front end portion 116A1 and the downstream edge portion in the rotational direction is the counter rear end portion 116A2, which is the home position, which is the initial position. As a posture,
In FIG. 4, the counter tip portion 116A1 is the separation roller 1
It is positioned upstream from the position immediately below in the direction of rotation of 16, and a small distance (G) can be set between the counter leading end 116A1 and the uppermost transfer sheet in the sheet stack.

Further, the small diameter portion 116B of the separation roller 116 has a large diameter portion 116A based on the center of rotation.
The position corresponding to the opposite side, specifically, the position where the phase is reversed by approximately 180 degrees with respect to the counter tip portion 116A1.
16C is provided, and this claw portion 116C is formed with a concave fitting portion 116C1 which is bent toward the downstream side in the rotational direction and into which the rear end of the transfer sheet can be inserted.

Further, as shown in FIG. 5, the pressing roller 115A and the separation roller 116 described above are arranged along the width direction of the transfer sheet to be fed out, and the transfer sheet is skewed in the width direction of the transfer sheet. Is prevented from occurring, and the support shafts 115A1 and 1161 of each roller are given the habit of being displaced toward the tray 113 side by the springs 1151 and 1162 arranged at both axial ends thereof. Therefore, the pressing roller 115A and the separation roller 116
Can always come into contact with the uppermost one of the transfer papers, and the pressing roller 115A always comes into contact with the transfer roller to securely lock the transfer paper at the front side in the feeding direction during the separation work. Then, the transfer paper can be reliably fed out by the action of the frictional force of the large diameter portion 116A of the separation roller 116. In FIG. 5, reference numerals 117 and 118 denote optical sensors facing each other across the bottom plate of the tray 113, and the optical sensors 117 and 118 detect the presence or absence of the transfer paper on the tray 113. ing.

The separation roller 116 having the above-mentioned relationship is configured to separate the transfer paper by the operation shown in FIGS. 6 to 14.

That is, as shown in FIG.
In this state, the pressing roller 115A abuts on the uppermost one of the transfer papers, and the counter tip 116A1 of the separation roller 116 is shown.
Is stopped facing the transfer paper side. Then, as shown in FIG. 7, when only the separation roller 116 starts to rotate in the clockwise direction in the figure, the counter tip portion 116A1 of the separation roller 116 contacts the surface of the transfer paper and moves in the rotation direction. In conjunction with, the uppermost transfer sheet is dragged by overcoming the frictional force between the uppermost transfer sheet and the transfer sheet located below it, and is moved to the left side in the figure. As shown in FIGS. 8 and 9, the transfer paper whose topmost sheet is displaced by the rotation of the separation roller 116 is pressed by the pressing roller 115.
As a result, the movement of one of the feeding directions is stopped, so that as the separating roller 116 rotates, it rises upward, increasing the amount of rise. Then, the rotation of the separation roller 116 progresses, the rear end of the transfer paper in the feeding direction is dragged, and the counter rear end portion 1 of the separation roller 116
16A2, the uppermost transfer sheet is separated from the transfer sheet located below it and the rear end is separated from the lower transfer sheet as shown in FIG. When the separation roller 116 further rotates in this state, as shown in FIG. 11, the trailing end of the transfer paper enters the concave fitting portion 116C1 of the claw portion 116C of the separation roller 116 as shown in FIG. The rear end is pushed up as the separation roller 116 rotates. Then, by rotating the separation roller 116, the claw portion 11
When 6C is positioned above, the transfer paper comes off the claw portion 116C of the separation roller 116, and is placed on the upper circumferential surface of the separation roller 116 by the resilience due to the strength of the waist of the separation roller 116, as shown in FIG. To be done. When the separation roller 116 further rotates once, as shown in FIG. 14, the separation roller 116 is rotated.
When the transfer paper is placed on the upper part of the claw portion 116C, the separation from the lower transfer paper is completed.

FIG. 15 shows a state after the above-described separating operation is repeated a plurality of times. In this case, the separating roller 116 rotates 5 times to separate 5 sheets of transfer paper. In addition, in order to enable separation of a plurality of transfer sheets, the tray 1
Either or both of the 13 side and the separation roller 116 are moved so that the separation roller 116 and the uppermost one of the transfer sheets can come into contact with each other.

On the other hand, the separating operation by the separating roller 116 described above is controlled by the control unit 119 described later. That is, the control unit 119 in FIG.
Although not shown in detail, the main part is constituted by a microcomputer 119A for performing sequence control 9 for image formation of a copying machine, and a basic program for sequence control and arithmetic control processing are provided. It is provided with a ROM 119B for storing basic data for storing data and a RAM 119B for reading and writing various data, and is connected to an external device via an I / O interface 119D. On the input side of the above-mentioned I / O interface 119D, as related to the separation operation of the transfer paper, the operation unit 120 described later and the light-receiving side sensor 118 of the optical sensors shown in FIG. A transfer number sensor (not shown) is connected to detect the number of rotations of the separation roller 116, and the display unit 12 provided on the operation unit 120 is provided on the output side.
1 and the drive unit 122 are connected. The operation unit 120 described above is configured by an operation panel as shown in FIG. 17, and the number of sheets setting selection switch 120A and the number of sheets setting switch 120B set number determination switch (designation) -Entry switch) 120C is provided, and the display section 121 is configured to display a difference between the number set by the number setting switch 120B and the actual number of separated sheets as a remaining number display lamp 121A and a message. Indicator lamp 12
1B is provided. In the case of this embodiment, the content of the message is "please supply paper" when the number of transfer sheets accommodated on the tray 113 is insufficient with respect to the set number. Is displayed.

Further, in the case of the present embodiment, the above-mentioned drive section 122 is the rotation drive section of the separation roller 116 and the tray 1.
13 or an up-and-down drive unit for the separation roller 116. In the control unit 119 having the above-described configuration, turning on of the number setting switch 120A is accepted as an interrupt process, and normally, for example, a predetermined number of 10 sheets is set in advance, and this number of sheets is set in advance. The separation can be done. Therefore, the number setting switch 1
When 20A is turned on, the separation operation state for a predetermined number of sheets is released, and the separation work is executed based on the number setting by the sheet number setting switch 120B.

Since the present embodiment is constructed as described above,
Now, the operation of the controller 119 will be described with reference to the flowcharts shown in FIGS. 18 and 19.

That is, when the copy mode is set by a switch (not shown) in the operation unit 120, the control unit 119 deletes 10 sheets, which is a predetermined value as the number of separation works, as shown in FIG. Then, it is determined whether or not there is an interruption due to turning on of the number-of-sheets setting selection switch 120A for this number of sheets, and if there is an interruption, a new number of sheets set by the number-of-sheets setting switch 120B is set in the number-of-sheets setting confirmation switch 120C. It is taken in at the time of input and the separation work is started based on this value. That is, in the processing in this case, as shown in FIG. 19, the paper feed tray 113 is selected by setting the copy mode, and the newly set number of sheets is read and selected. The presence or absence of the transfer paper on the paper feed tray 113 is determined based on the detection of the optical sensor 118, and when the transfer paper remains, the separation roller 116 is rotated via the drive unit 122. That is, when the transfer paper remains on the tray 113, the separation roller 116 continues to rotate until the set number of sheets is reached, and the transfer paper on the tray 113 is sequentially separated from the topmost one. 6 to 14, the sheets are stacked on the peripheral surface.

When it is detected that there is no transfer sheet on the tray 113, the difference between the rotation speed data of the separation roller 116 and the set number of sheets is calculated, and the transfer sheet is insufficient during copying, which will be described later. The processing shifts to the case. That is, it is determined whether or not the rotation of the separation rollers 116 corresponding to the set number is completed, and when the rotation is completed, that is, when the transfer sheets according to the set number are separated from the tray 113, the copying is started. At the same time, the separation roller 116 is rotated once so that the transfer sheets of the set number are always stacked on the peripheral surface. While this operation is repeated, if there is the transfer sheet on the tray 113, the number of copying is set to the set number of sheets. It is discriminated whether or not, and the process is ended when they match.

On the other hand, in the above process, the separation roller 1
When it is detected that there is no transfer sheet on the tray 113 at the stage before the number of times of copying is equal to the set number of sheets by repeating 16 rotations, the number of rotations of the separating roller 116 up to that time is changed.
The difference between the set number and the set number is obtained, and the difference is displayed as the unseparated number with respect to the set number on the number display lamp 121A, and the message display lamp 121B is turned on. The message in this case means that when the number of transfer sheets stacked on the separation roller 116 is copied, there is no transfer sheet to be copied thereafter, and the operator is
For example, by seeing this display and supplying the transfer paper onto the tray 113, copying can be performed without interruption.

When the transfer paper is not replenished as described above, copying is performed while the display is continued, and the number of remaining sheets displayed is decreased by one each time copying is performed. .

[0032]

As described above, according to the present invention, between the large diameter portion of the separation roller in the home position and the transfer sheet, and the pressing roller in the transfer sheet separating mechanism in the sheet feeding device. Since the relationship between the transfer paper and the transfer paper is set so that it can always come into contact with each other due to the displacement habits of both rollers, it is possible to reliably perform the pressing processing of the transfer paper by the pressing roller during the separation work by the separation roller. Further, in the separation roller, it is possible to surely perform the feeding operation of the transfer paper via the frictional force of the large diameter portion. Therefore, regardless of the change in the number of separated sheets, it is possible to prevent a situation in which a gap is left between each roller and the uppermost transfer sheet, and the transfer sheet can be separated.

[Brief description of drawings]

FIG. 1 is a layout diagram showing an overall configuration of an image forming apparatus according to an embodiment.

FIG. 2 is a model diagram for explaining a structure of a sheet feeding unit in the image forming apparatus shown in FIG.

FIG. 3 is a perspective view showing a separation roller used in the paper feeding unit shown in FIG.

FIG. 4 is a model diagram for explaining a positional relationship between a large diameter portion, a small diameter portion, and a claw portion in the separation roller shown in FIG.

5 is a perspective view for explaining an arrangement state of separation rollers in the sheet feeding unit shown in FIG.

FIG. 6 is a model diagram for explaining a procedure for separating transfer paper by the separation roller shown in FIG.

FIG. 7 is a model diagram for explaining a stepwise aspect of a procedure for separating transfer paper by the separation roller shown in FIG.

FIG. 8 is a model diagram for explaining a stepwise aspect of a procedure for separating transfer paper by the separation rollers shown in FIG.

FIG. 9 is a model diagram for explaining one step mode of the procedure for separating the transfer paper by the separation roller shown in FIG.

FIG. 10 is a model diagram for explaining one step mode of the procedure for separating the transfer paper by the separation roller shown in FIG.

FIG. 11 is a model diagram for explaining one step mode of the procedure for separating the transfer paper by the separation roller shown in FIG.

FIG. 12 is a model diagram for explaining one step mode of the procedure for separating the transfer paper by the separation roller shown in FIG.

FIG. 13 is a model diagram for explaining one step mode of the procedure for separating the transfer paper by the separation roller shown in FIG.

FIG. 14 is a model diagram for explaining a stepwise aspect of a procedure for separating transfer paper by the separation rollers shown in FIG.

FIG. 15 is a model diagram for explaining one mode of action of the separation roller shown in FIG.

16 is a block diagram for explaining a configuration of a control unit in the image forming apparatus shown in FIG.

17 is a schematic diagram showing an operation unit connected to the control unit shown in FIG.

FIG. 18 is a flowchart for explaining the operation of the control unit shown in FIG.

FIG. 19 is a flowchart for explaining the operation of the control unit shown in FIG.

FIG. 20 is a schematic diagram for explaining a conventional structure of a transfer paper feeding mechanism.

FIG. 21 is a schematic diagram for explaining one aspect of a conventional structure of a transfer paper feeding mechanism.

[Explanation of symbols] 100 image forming apparatus 102 photoconductor 108 paper feeder 115 Separation mechanism 115A holding roller 115A1 Support roller shaft 1151 Spring as biasing member 116 separation roller 116A large diameter part 116A1 Counter tip 116A2 Counter rear end 116B small diameter part 116C claw 116C1 recess 1161 Separation roller support shaft 1162 Spring as a biasing member

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Fig. 2]

[Figure 3]

[Figure 6]

[Figure 7]

[Figure 8]

[Figure 4]

[Figure 5]

[Figure 9]

[Figure 10]

FIG. 11

[Fig. 12]

[Fig. 13]

FIG. 14

FIG. 15

FIG. 16

FIG. 17

FIG. 18

FIG. 19

FIG. 20

FIG. 21

Claims (3)

[Claims] 1. An image forming apparatus equipped with a paper feeding device having a structure in which the uppermost transfer paper in the paper feed stack is sequentially fed out, wherein the uppermost transfer paper can come into contact with the uppermost transfer paper in the feeding direction. A rotatable separation roller is provided, and the separation roller has a large diameter portion that can come into contact with the transfer paper in the circumferential direction and a small diameter portion that is not in contact with the transfer paper.
The structure is provided with a claw part that can drop the rear end of the transfer paper, and the position of the claw part is set to a position corresponding to the opposite side of the large diameter part with respect to the rotation center, and
An image forming apparatus equipped with a sheet feeding device that is supported by being given the habit of displacing toward the topmost transfer sheet. 2. An image forming apparatus equipped with a paper feeding device having a structure of sequentially feeding from the uppermost transfer paper in a paper feeding stack, wherein the uppermost transfer paper can come into contact with the uppermost transfer paper, and the transfer paper is fed in the feeding direction. A rotatable pressing roller and a separating roller arranged upstream of the pressing roller in the feeding direction of the transfer paper are provided. The pressing roller has a habit of displacing toward the uppermost one of the transfer paper. An image forming apparatus having a supported sheet feeding device. 3. The image forming apparatus according to claim 1 or 2, wherein the supporting portions of the separating roller and the pressing roller are provided with a sheet feeding device biased toward the uppermost one of the transfer sheets by an elastic body. Image forming device.