JPH06239502A - Paper sheet conveying device of picture image forming apparatus - Google Patents

Abstract

PURPOSE:To give different conveying actions depending on the positions in paper sheet width direction in a conveying roller device, in response to resistant members provided in trays in the case of feeding paper sheets from plural trays whose positions of conveying action to the paper sheets are different from each other and conveying them by means of conveying roller device after placing them in a confluent flow at a confluent part. CONSTITUTION:In a device in which a confluent part 20 to be arranged in a paper sheet conveying line of an electrophotographic copying machine and a conveying roller device 30 in its downstream area are combinated together, the confluent part 20 is provided with a conveying passage 24 from paper sheet feeding trays and a conveying passage 23 from hand feeding trays. In an inner guide member 25 to be arranged between the two conveying passages, a tip part having thickness in anti-reference line side is formed, paper sheets to be fed through an upper conveying passage 23 are passed over a small radius roller 35, the paper sheets are fed by being nipped only reference at its line side part, so that skew, etc., may not be generated in the paper sheets.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet conveying device in an image forming apparatus such as an electrophotographic copying machine, and more particularly, to a conveying roller arranged downstream of a confluence portion of a sheet feeding path from a manual feed tray and a sheet feeding tray. The present invention relates to a sheet conveying device of an image forming apparatus that prevents skewed feeding (skew) of a sheet due to an imbalance in a sheet conveying action between the apparatus and a sheet feeding member provided on a tray.

[0002]

2. Description of the Related Art In an image forming apparatus such as an electrophotographic copying machine, a plurality of paper feed trays are arranged in a paper feed section, and papers of different sizes are accommodated in the respective trays so that the originals It uses a mechanism that feeds paper of a suitable size according to the size and reduction ratio. Further, the electrophotographic copying machine is provided with a manual feed tray for feeding special paper such as postcards, sheets such as OHP film, and paper of special size, and cannot be accommodated in the paper feeding tray. I am able to make copies on paper. As an electrophotographic copying machine provided with the above-mentioned paper feeding means, for example, one disclosed in Japanese Patent Laid-Open No. 3-267230 is known.

The sheet feeding means arranged in the conventional electrophotographic copying machine is constructed as shown in FIG. 11, for example, with respect to the photosensitive drum 2 of the electrophotographic copying machine 1. A transfer / separation corotron 3 for transferring a toner image to a sheet is arranged. Then, after transferring the toner image formed on the photoconductor drum 2 by using the electrophotographic method to the paper fed from the paper feed tray 15 or the like, the toner image is fixed by the fixing device arranged in the downstream portion. , I try to eject the copy. An aligning unit 7 for the sheet is arranged upstream of the image transfer unit, and in the aligning unit,
Between the registration roller device 8 and the pre-registration roller device 9, a loop is formed on the sheet to align the leading edge of the sheet, and the sheet is formed on the photosensitive drum in a state of being accurately positioned with respect to the sheet. It also constitutes a mechanism for transferring the toner image.

In order to feed the paper toward the aligning section 7, the paper feed path 5 from the paper feed trays 15, 15a.
And a sheet conveying path from the manual feed tray 10 are arranged, and the sheet conveying paths are joined at the joining section 20 and fed toward the aligning section 7. Further, as shown by the upper paper feed tray 15, a paper feed roller member 16 and a paper separating device 17 are arranged in the paper supply tray to constitute a mechanism for supplying paper while separating the paper one by one. The fed-out paper is sent out toward the merging unit 20 via the paper transport path 5. Further, the paper feeding means from the manual feed tray 10 constitutes a mechanism for performing the feeding and feeding by the paper feed roller member 11 and the paper separating member 12, and even when a plurality of sheets or the like are set in the manual feed tray. , Papers 1
It is designed to be able to feed sheets one by one.

At the merging portion 20 of the sheet conveying path, as shown in FIG.
The paper guiding member configured as shown in FIG. 3 is arranged, and the conveying roller device 30 is arranged in the downstream portion of the joining portion. Then, in a state where the lower conveyance path 24 connected to the paper conveyance path from the paper feed tray and the upper conveyance path 23 connected to the paper feed path from the manual feed tray are joined at the tip of the joining portion 20, A mechanism for guiding the paper toward the transport roller device 30 is configured. The guide member arranged in the merging portion 20 is composed of an upper guide plate 21, a lower guide plate 22, and an intermediate guide member 25 arranged between both guides, and an upper conveying path 23 and a lower conveying member are provided between the respective guide members. And the path 24. Then, the sheet fed through the upper and lower conveying paths 23 and 24 is nipped by the conveying roller device 30 configured as a pre-registration roller device and can be fed toward the downstream portion. It Further, in the transport roller device 30, a mechanism for transporting the paper by nipping the paper between the drive roller 31 and the pinch roller 32 is configured, and by driving the drive roller as in the case of a general transport roller device. The paper nipped between the upper and lower rollers is conveyed.

[0006]

In the sheet feeding means of the electrophotographic copying machine configured as described above, the sheet feeding device arranged on the sheet feeding tray depends on the size of the sheet accommodated in the tray. It is arranged so that the feeding action of the sheet feeding roller member is applied to the substantially central portion of the sheet to be fed. Then, the sheet sent out from the tray can be sent out toward the merging section without causing skew due to the action of the sheet feeding roller member. In the sheet feeding device from the sheet feeding tray, as shown in FIG. 13, when feeding the sheet P, a position where a feeding action is performed by a sheet feeding roller member 16 provided in the tray,
A line F connecting the centers of the transport action of the transport roller device 30 is
Since the sheet is arranged so as not to cause the deviation, the sheet can be fed in a state where the sheet is not skewed even if the resistance Fa in the sheet feeding roller member 16 or the sheet separating mechanism is added.

Further, in the paper feeding means from the manual feed tray,
For example, it is required that a single sheet feeding device feeds various types of sheets having different sizes from small sheets such as postcards to large sheets. And
As shown in FIG. 14, in the sheet feeding device provided in the manual feed tray, the separating member 12 is arranged at a position close to the reference line 28, and the position where the separating member 12 exerts the conveying action is the conveying roller device. It is configured such that a shift occurs with respect to the central portion of the carrying action at 30. Therefore, when the sheet is nipped between the sheet feeding device of the manual feed tray and the transport roller device 30, the separating member 1
The resistance Fb added by 2 is displaced from the line of action in the transport roller device 30 by the distance H.

As described above, when the sheet is nipped by the two conveying members, the action lines of both conveying members do not coincide with each other, so that a force in the direction of rotating the sheet acts and the sheet acts. However, there is a problem that skew tends to occur. Then, as shown in FIG. 14, when the sheet fed from the tray is skewed, the aligning portion arranged downstream thereof cannot sufficiently exert the action of correcting the sheet position. The problem arises. Therefore, there arises a problem that the toner image transferred onto the paper is not formed at an accurate position on the paper and the quality of copy deteriorates.

In order to solve the above problems,
For example, as disclosed in Japanese Patent Application Laid-Open No. 2-18243, it may be possible to control the nip pressure in the transport roller device according to the type of tray by using a means for adjusting the nip pressure in the transport roller device. To be However,
Providing a means for controlling the nip pressure with respect to the transport roller device complicates the configuration of the transport roller device and provides a control device for controlling the nip pressure according to the type of tray. Will be needed. Therefore,
Providing the means for adjusting the nip pressure as described above not only increases the manufacturing cost of the electrophotographic copying machine, but also causes a serious problem in terms of maintenance.

[0010]

It is an object of the present invention to solve the above-mentioned problems of the conventional sheet conveying apparatus, and it is possible to feed the sheet from the sheet feeding tray to the conveying roller apparatus arranged at the downstream side of the joining section. Arrange the reference line side feeding section and the non-reference line side paper feeding section that does not affect the paper sent from the manual feed tray,
An object of the present invention is to provide a sheet conveying device of an image forming apparatus in which skew is not generated in a sheet by causing a conveying roller device to perform a conveying action in accordance with a resistance state in each tray.

[0011]

According to the present invention, a plurality of sheet feeding means are arranged in a sheet feeding portion, and the sheet feeding paths from these sheet feeding means are joined at the joining portion. The present invention relates to a device in which a conveyance roller device is arranged on the downstream side and a sheet is fed toward the next step. In the present invention, the roller member that constitutes the transport roller device is arranged such that the drive roller and the pinch roller face each other on the side of the reference line, and the reference line is used to sandwich and convey the paper in the nip portion of the roller member. On the side conveying section and the side away from the reference line, an anti-reference-line side sheet feeding section that presses the sheet against the drive roller is arranged. And
The roller member on the side distant from the reference line constitutes a mechanism for conveying the sheet to the sheet fed through one sheet feeding path only by the reference line side conveying section, and the other sheet feeding path. With respect to the sheet fed through the sheet feeding mechanism, a mechanism for feeding the sheet by using all the driving rollers of the conveying roller device is configured.

Further, in the present invention, one of the plurality of paper feeding means is a paper feeding means from the manual feed tray, and the other paper feeding means is configured as a paper feeding means from the paper feeding tray. At the same time, it is possible to configure a mechanism in which all of the drive rollers of the carry roller device carry out a carry action for the paper that is fed through the paper feed path from the paper feed tray. Further, in the present invention, the member that presses the sheet against the drive roller in the sheet feeding unit on the side opposite to the reference line of the transport roller device can be configured by a pressure plate member.

With the above construction, in the present invention, the means for pressing the sheet against the drive roller of the conveying roller device is arranged corresponding to the tray, so that the structure of the sheet conveying device is simplified. As well as
It is possible to suppress an increase in the manufacturing cost of the device. Then, since the conveyance action of the conveyance roller device can be exhibited in correspondence with the conveyance resistance of the tray for the paper fed from an arbitrary tray, the paper is not skewed and directed toward the alignment section. It is possible to feed the paper while maintaining a good posture of the paper. Therefore, the aligning portion arranged upstream of the image transfer portion can easily perform the aligning action, and can improve the copy quality even for the paper fed from the manual feed tray.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A sheet conveying device of an image forming apparatus of the present invention will be described with reference to the illustrated example. The example shown in FIG. 1 relates to the merging unit 20 arranged upstream of the sheet aligning unit of the image forming apparatus, like the device shown in FIG.
In the example shown in FIG. 1, the merging portion 20 is arranged upstream of the conveying roller device 30 including the driving roller 31 and the pinch roller 32, and the upper conveying path 23 and the lower conveying path 23 provided in the merging portion 20 are arranged. The paper feed path from the paper feed tray and the paper feed path from the manual feed tray are connected via the paper feed path 24. The merging portion 20 includes upper and lower guide plates 21 and 22.
And the middle guide member 25 are combined to guide the paper supplied through the upper and lower transport paths 23 and 24 toward the nip position of the transport roller device 30.

In the merging section 20, as shown in FIG. 2, an intermediate guide member 25 disposed between the upper and lower guide plates 21 and 22 has two conveyance paths on the reference line side, which are substantially knife-edge shaped. The leading end portion 26 of the middle guide member 25 is formed as a portion having a predetermined thickness at a position apart from the reference line. Further, in the conveying roller device 30 arranged downstream of the merging portion 20, the pinch roller 32 is arranged in the reference line side conveying portion 37 so as to face the drive roller 31 arranged in the entire width of the sheet conveying path. In the non-reference line side sheet feeding section 38, the small-diameter rollers 35, 3
5a is arranged to be pressed.

As shown in FIG. 3, with respect to the paper fed through the lower transport path 24 in the apparatus in which the transport roller device and the middle guide member are arranged as shown in FIG. 2, as shown in FIG. The feeding action of the feeding roller member 16 provided on the feeding tray and the feeding roller device 30 is performed. And
As shown in FIG. 3, the paper P supplied through the lower transport path 24 is pressed by the pinch roller and the small-diameter roller with respect to the drive roller in the transport roller device 30. In all of the transport units, the action of transporting the paper while nipping the paper is exhibited. Therefore, in the example shown in FIG. 3, the line of action for applying a sheet-conveying action to the sheet by the sheet-feeding roller member 16 provided in the sheet-feeding tray and the line of action of the conveying roller device are straight lines F.
Set on.

In the carrying roller device 30 shown in FIG. 3, a plurality of roller members 31 provided in the carrying roller device 30.
Of these, the line of action F of the sheet feeding roller member is positioned with respect to the central roller member, and the line of action F coincides with the center line of the sheet feeding roller member 16. Then, with respect to the line of action F, in the transport roller device 30, the transport action by the roller members on both sides is performed at equal intervals L on both sides, so that the sheet is transported by the paper feed roller member 16 by the transport roller device. Even if the brake action is applied to the sheet conveyance, the sheet will not be skewed. Therefore, in the state as shown in FIG. 1 and FIG.
When the paper fed from the paper feed tray is conveyed, the paper is nipped between the drive roller pinch roller on the reference line side conveyance section 37 side and the drive roller on the non-reference line side paper feed section 38 side. By nipping with the small-diameter roller, the paper can be conveyed in a normal state without causing skew in the paper along the reference line 28.

In the above apparatus, as for the paper fed from the manual feed tray, as shown in FIG. 4, the paper is sent out toward the carrying roller device through the upper carrying path 23. It should be noted that the example shown in FIG.
9 illustrates a sheet conveyance state on the side of the reference line of 0. When the sheet is fed through the upper transport path 23, as shown in FIG. 2, at the portion where the reference line side transport section 37 of the upper transport path 23 merges with the lower transport path 24, the front end portion 27 is formed. Since it has no thickness, the paper is easily introduced at the nip position between the drive roller and the pinch roller. On the other hand, on the side of the non-reference line side sheet feeding portion 38, the leading end portion 26 of the middle guide member 25 is in a state of having a predetermined thickness, so that the upper transport path 23 is located relative to the drive roller. It is configured to guide the paper to the upper side of the pressed small diameter roller 35.

Therefore, as shown in FIG. 5, the paper fed from the manual feed tray corresponds to a small-sized paper, and the action line F of the separating member 12 arranged at a position close to the reference line 28. On the other hand, the central portions of the positions where the carrying action is applied in the reference line side carrying section 37 of the carrying roller device 30 are made to coincide with each other. On the side of the paper feed unit 38 on the side opposite to the reference line, since the large-sized paper is guided so as to pass through the portion above the small-diameter roller 35, the carrying action by the carrying roller device is not given, and the paper is not fed. Therefore, it is possible to prevent an extra conveying action from being applied to the.

[0020]

Another Embodiment of the Present Invention In addition to the merging portion as shown in FIGS. 1 to 5, in the present invention, a merging portion as shown in FIG. 6 can be constructed. In the merging portion 20 shown in FIG. 6, the tip end portion 27 of the middle guide member 25 arranged between the upper and lower guide plates 21 and 22 is formed in a straight line in parallel with the tip end portion of the guide plate. Has been done. In the example shown in FIG. 6, the upper and lower transport paths 23, 2
In order to give different conveyance actions to the sheet conveyed through the sheet 4, the pressure plate member 36 is arranged on the side of the paper feed unit 38 opposite the reference line, and the sheet is pressed toward the drive roller. Let it work. The pressure plate member 36 is
A plastic film member is attached to the upper surface of the middle guide member 25 so as to be pressed by the drive roller. Further, on the side of the reference line side transport unit 37 of the transport roller device, as in the case of the device of FIG. 2, the drive roller 31 and the pinch roller 32 are provided.
And are provided so as to face each other, and the conveying action can be given in a state where the sheet is nipped between the rollers.

In the sheet transporting device constructed as described above, it is possible to impart the transporting action to the sheet fed from the sheet feeding tray through the lower transporting path 24 as shown in FIGS. it can. For the paper fed from the paper feed tray, as shown in FIG. 7, the lower conveyance path 2 formed between the lower guide plate 22 and the lower surface of the middle guide member 25.
4 is introduced into the nip position of the transport roller device 30. In the state where the sheet is conveyed by the conveying roller device 30, as shown in FIG. 8, the reference line side sheet feeding section 37 performs the operation of nipping the sheet between the upper and lower roller members. On the other hand, on the side of the anti-reference-line side sheet feeding portion 38, the sheet is pressed against the driving roller by the pressure plate member 36, and the conveying action of the driving roller is added to the sheet.
The feeding operation of the feeding roller device 30 is performed by the feeding roller member 16
Can be made to coincide with the action line F. Therefore, in the example shown in FIG. 8, the sheet fed from the merging unit 20 via the transport roller device 30 is not provided with the oblique feeding action, and the skew of the sheet is prevented. .

In addition to the case where the paper is fed through the lower transport path, the paper fed from the manual feed tray through the upper transport path 23 is in the state as shown in FIGS. The carrying action is carried out. As shown in FIG. 9, the paper P guided from the manual feed tray through the upper transport path 23 is guided so as to pass through the upper surface of the pressure plate member 36 in the non-reference line side paper feeding section 38. Therefore, the carrying action is not given by the carrying roller device. On the other hand, on the side of the reference line side transport unit 37 of the transport roller device, the sheet is introduced between the drive roller and the pinch roller, and the transport action is imparted while being nipped between the both rollers. Therefore, as shown in FIG. 10, the conveying force acting on the sheet P is formed along the straight line F by the action line of the separating member 12 and the action line of the feeding roller device 30. Therefore, it is possible to prevent a force such as skewing the sheet from being applied.

In the sheet conveying apparatus of the present invention configured as described above, the widths of the reference line side conveying portion and the non-reference line side sheet feeding portion formed with respect to the conveying roller device are determined by the sheet feeding tray. It is possible to set an arbitrary interval according to the position of the sheet feeding means provided on the manual feed tray. Further, in the conveying roller device, as the small diameter roller or the pressure plate member arranged to press the paper against the driving roller, any member other than those shown in the embodiment can be used. The pressing force of the pressing member and the like can be configured according to the properties of the paper and sheets that are often used in electrophotographic copying machines.

[0024]

Since the sheet conveying device of the image forming apparatus of the present invention is configured as described above, a means for pressing the sheet against the driving roller of the conveying roller device is provided.
By arranging them in correspondence with the trays, it is possible to simplify the configuration of the sheet conveying device and suppress an increase in the manufacturing cost of the device. Then, for the paper fed from an arbitrary tray, it is possible to exhibit the carrying action in the carrying roller device in correspondence with the carrying resistance in the tray.
It is possible to feed the sheet toward the aligning section without skewing the sheet and keeping the sheet in a good posture.
Therefore, in the matching section arranged upstream of the image transfer section,
The aligning action can be easily performed, and the copy quality can be improved even for sheets of arbitrary size fed from the manual feed tray.

[Brief description of drawings]

FIG. 1 is a side view showing a configuration of a merging section of a sheet conveying apparatus of the present invention.

FIG. 2 is a perspective view showing a configuration of a transport roller device and a merging portion of the paper transport device of the present invention.

FIG. 3 is an explanatory diagram showing a state of a sheet conveying device in the device shown in FIG.

FIG. 4 is a side view showing a state of the paper on the side of the paper feed unit opposite to the reference line of the paper transport device.

FIG. 5 is an explanatory diagram of a transporting action on a sheet fed through an upper transporting path.

FIG. 6 is a perspective view of a member constituting a second embodiment of the present invention.

FIG. 7 is a side view in the case of feeding a sheet through a lower conveyance path.

FIG. 8 is an explanatory diagram of a transport operation for a sheet fed through a lower transport path.

FIG. 9 is a side view in the case of feeding a sheet through an upper conveyance path.

FIG. 10 is an explanatory diagram of a transport operation for a sheet fed through an upper transport path.

FIG. 11 is a side view showing the configuration of a general image forming apparatus.

FIG. 12 is a side view showing a configuration of a transport roller device and a merging portion in a conventional paper transport device.

13 is a side view of the apparatus shown in FIG. 12 in the case of feeding a sheet through a lower conveyance path.

FIG. 14 is a side view of the apparatus shown in FIG. 12 when a sheet is fed through an upper conveyance path.

[Explanation of symbols]

1 electrophotographic copying machine, 2 photoconductor drums, 5
Paper transport path, 7 alignment section, 10 manual feed tray, 11 paper feed roller member, 12 separating member,
15 paper feed trays, 16 paper feed roller members, 1
7 Paper sorting device, 20 Confluence part, 21
Upper guide plate, 22 Lower guide plate, 23 Upper transport path, 24 Lower transport path, 25 Middle guide member, 2
8 reference line, 30 conveying roller device, 31 drive roller, 32 pinch roller, 35 small diameter roller, 36 pressure plate member, 37 reference line side sheet feeding section, 38 anti-reference line side sheet feeding section

Claims (3)

[Claims] 1. A plurality of sheet feeding means are arranged in a sheet feeding section, sheet feeding paths from these sheet feeding sections are joined at a joining section, and a conveying roller device is arranged on the downstream side of the joining section. In a device for feeding a sheet toward the next step, a roller member that constitutes the transport roller device is arranged such that a drive roller and a pinch roller face each other on a reference line side, and a nip portion of the roller member is provided. A reference line side paper feed unit that sandwiches and conveys the paper and an anti-reference line side paper feed unit that presses the paper against the drive roller are arranged on the side away from the reference line. In the roller member, for a sheet fed through one sheet feeding path, a mechanism is configured to convey the sheet only by the reference line side conveying section, and the sheet is fed through another sheet feeding path. For the paper, all the drive rollers of the transport roller device are used for paper feeding. A sheet conveying device of an image forming apparatus, which is characterized in that 2. One of the plurality of paper feed means is a paper feed means from a manual feed tray, and the other paper feed means is configured as a paper feed means from a paper feed tray. 2. The sheet conveying device for an image forming apparatus according to claim 1, wherein all of the drive rollers of the conveying roller device perform a conveying action with respect to the sheet fed through the sheet feeding path from. 3. A member for pressing a sheet against a drive roller in a sheet feeding section on the side opposite to the reference line of the conveying roller device,
The sheet conveying device of the image forming apparatus according to claim 1, wherein the sheet conveying device is configured by a pressure plate member.