JPH07144768A - Sheet feeder and image forming device - Google Patents

Abstract

PURPOSE:To heighten parallelism between a feed roller and a sheet loading means, and prevent the occurrence of printing failure or a jam by a skew by arranging a positioning member to connect a feed roller shaft of the feed roller and the sheet loading means to each other. CONSTITUTION:At paper feeding time, a lock mechanism of a front cover 1 of an image forming device B is released, and a paper feeding tray 2 is rotated up to a sheet setting possible condition with a rotary center shaft 2a as its center. At this time, a positioning member 6 is also rotated by interlocking with the tray 2, and is fitted to a U shaped groove 6a, and the thrust direction is regulated. Parallelism with a paper feeding roller 3 to feed plural sheets one by one is reliably produced. Next, when paper feed is started, a pressing member 4 added to the roller 3 side is pushed up by a pressing spring, and presses the roller 3 through the plural sheets 10. The sheets 10 are fed up to a separating pad 5 by the rotating roller 3. In this way, since the paper feeding tray 2 and the feeding roller 3 are directly positioned by the positioning member 6, carrying accuracy is easily produced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device used in an image forming apparatus such as a copying machine or a laser beam printer.

[0002]

2. Description of the Related Art Conventionally, in a sheet feeding apparatus such as a copying machine, a sheet stacking unit for stacking sheets, a sheet feeding roller for feeding the sheets on the sheet stacking unit one by one, and a sheet for the sheet feeding roller. 2. Description of the Related Art There is known a sheet feeding device including a pressing member that presses and urges a pair of width regulating plates that regulate the position of stacked sheets in the width direction.

In such a sheet feeding device, the sheet stacking means is supported by the main body or the outer cover, and a projection is provided on the circumference of the central axis of rotation of the sheet stacking means. The sheet stacking means is positioned in the thrust direction with respect to the main body or the outer cover by abutting against each other.

[0004]

However, in the above-mentioned conventional example, the sheet stacking means having the width regulating plate for regulating the width direction of the sheet, and the main body or the outer cover supporting the sheet stacking means are provided. Although the positioning in the thrust direction is performed, the rollers for feeding the sheets one by one are positioned through the main body or the outer cover, so that the parallelism between the feeding roller and the sheet stacking means cannot be surely obtained.

For this reason, the sheets on the sheet stacking means, which are fed one by one by the feeding roller, are skewed depending on the accuracy of the parts such as the main body frame and the outer cover, and print defects and jams may occur. there were.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a sheet feeding device and an image forming apparatus capable of increasing the parallelism between the feeding roller and the sheet stacking means. To provide.

[0007]

In order to achieve the above object, according to the present invention, a sheet stacking unit mounted on the apparatus main body for stacking a plurality of sheets, and rotatably supported by the apparatus main body. A sheet feeding device having a sheet feeding roller shaft for feeding the sheets stacked on the sheet stacking unit one by one, and a sheet feeding roller shaft of the sheet feeding roller. It has a positioning member for connecting with the sheet stacking means.

A sheet stacking means having a rotating shaft, which is openably and closably attached to the apparatus main body for stacking a plurality of sheets, and a feeding roller shaft rotatably supported by the apparatus main body are provided. A sheet feeding device, comprising: a feeding roller configured to feed the sheets stacked on the sheet stacking unit one by one, wherein one end of a connecting member is fixed to a rotation shaft of the sheet stacking unit. At the other end of the connecting member, there is provided a fitting portion that fits into the feeding roller shaft when the sheet stacking means is opened and separates from the feeding roller shaft when the sheet stacking means is closed. Then, the connecting member can form a positioning member.

Further, the sheet stacking means includes a sheet stacking means rotatably mounted on the apparatus body for stacking a plurality of sheets, and a feeding roller shaft rotatably supported by the apparatus body. A sheet feeding device including a feeding roller that feeds stacked sheets one by one, wherein the sheet stacking unit is rotatably attached to a feeding roller shaft of the feeding roller. The sheet stacking means itself may form the positioning member.

Further, a sheet stacking unit having a rotary shaft and rotatably attached to the apparatus main body for stacking a plurality of sheets, and a feeding roller shaft rotatably supported by the apparatus main body are provided. A sheet feeding device comprising: a feeding roller configured to feed the sheets stacked on the sheet stacking unit one by one, wherein the sheet stacking unit includes a pair of sheets movably in a sheet width direction. A width regulating member is attached, and the sheet width regulating member is provided with a guide hole that is fitted to the feeding roller shaft of the feeding roller to guide the opening and closing of the sheet stacking means. The regulating member may be a positioning member.

Further, the sheet feeding device and an image forming section for forming an image on the sheet fed by the sheet feeding device may be provided.

[0012]

According to the present invention having the above-mentioned structure, since the sheet feeding means has the positioning member for connecting the feeding roller shaft of the feeding roller and the sheet stacking means, the sheet stacking means feeds the sheet through the apparatus main body. Like the conventional one, which is positioned at
It is possible to prevent that the parallelism between the sheet stacking unit and the feeding roller is not exerted due to the accuracy of the parts of the apparatus main body.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1, 2 and 3 show a first embodiment of the present invention, and FIGS. 1 and 2 are drawings which best show the features of the present invention. 3 shows a vertical sectional front view of the sheet feeding device.

In FIG. 1, a front cover 1 as an apparatus main body of the sheet feeding apparatus A is configured to be rotatable around a rotation fulcrum shaft 1a on a main body frame 13 of the image forming apparatus B.

In FIG. 1, the front cover 1 of the sheet feeding device A holds a sheet feed tray 2 as a sheet stacking unit on which a plurality of sheets 10 are stacked. Is provided with a pair of sheet width regulation plates 11a and 11b for regulating the width direction of the sheet 10.

The pinion 1 is provided on the back surface of the paper feed tray 2.
2 is rotatably supported by the boss 9. Pinion 12
A pair of racks 15 and 16 mesh with each other at opposite positions. The racks 15 and 16 are slidably supported in the width direction of the paper feed tray 2, and the width regulating plates 11a and 11b are provided through holes provided in the width direction of the paper feed tray 2.
Are respectively linked to. As a result, the width regulating plates 11a and 11b are configured to interlock with each other and move in the width direction of the sheet to guide the width direction of the sheet.

The paper feed tray 2 is pivotally supported by a rotation center shaft 2a as a rotation shaft of the front cover 1 of the sheet feeding device A,
When the normal paper feed tray 2 is not used, it is fixed and held by the lock mechanism of the front cover 1 of the sheet feeding device A (not shown) as shown in FIG. 2, and when the paper feed tray 2 is used, as shown in FIG. The sheet feed tray 2 is rotated about the rotation center shaft 2a until the sheet is set in a proper state.

At both ends of the sheet feed tray 2, the sheets 10 on the sheet feed tray 2 are fitted one by one with a sheet feed roller shaft 3a as a sheet feed roller shaft of a sheet feed roller 3 as a sheet feed roller. A connecting member (positioning member) 6 having a U-shaped groove 6a as a fitting portion to be fitted is provided. Thrust restricting members 14a and 14b are provided on the paper feed roller shaft to abut the positioning member 6 to determine the position in the thrust direction, and the paper feed tray 2 is rotated about the rotation center shaft 2a. As the sheet is set, the sheet feeding roller shaft 3a of the sheet feeding roller 3 and the U-shaped groove 6a of the positioning member 6 are fitted to each other when the sheet is set, as shown in FIG.

At this time, since the rotation center shaft 2a of the sheet feeding tray 2 is fitted in the round long hole so as to have a play with respect to the front cover 1 of the sheet feeding apparatus A, the sheet feeding tray 2 is positioned by the positioning member 6 And the paper feed roller shaft 3a of the paper feed roller 3 is positioned.

On the downstream side of the paper feed tray 2, a pressing member 4 for pressing the sheet 10 against the paper feed roller 3 is pivotally supported at a position coaxial with the rotation center shaft 2a of the paper feed tray 2, and a pressing spring (not shown) is provided. Pushes up the back surface of the pressing member 4, so that the pressing member 4 is biased by the sheet feeding roller 3.

At this time, the central axis of rotation of the pressing member 4 may be provided in the main body frame 13 of the image forming apparatus B or may be provided on the paper feed tray 2.

A plurality of sheets 1 are provided on the downstream side of the pressing member 4.
A separation pad 5 having a rubber material having a high friction coefficient for separating 0 is provided on the body frame 13 and a pressing spring (not shown) pushes up the back surface of the separation pad 5 to urge the paper feed roller 3. .

The paper feed roller 3 is adhered or press-fitted into a substantially central portion of the paper feed roller shaft 3a, and the paper feed roller shaft 3a is held by the main body frame 13 via a bearing. The paper feed roller 3 is an image forming apparatus B (not shown).
It receives a driving force from the driving gear transmitted from the motor and rotates only in the clockwise direction.

The sheet 1 is provided on the downstream side of the feeding roller 3.
A conveying roller pair 18 including a guide member 17 for guiding 0 and a pinch roller 7 in pressure contact with the conveying roller 8 is provided.

In this embodiment, the sheet 1 having the above structure is used.
When 0 is set on the paper feed tray 2, the lock mechanism holding the paper feed tray 2 of the front cover 1 of the image forming apparatus B (not shown) is released, and the sheet as shown in FIG. 1 can be set. The paper feed tray 2 is rotated about the rotation center shaft 2a until the state.

At this time, the positioning member 6 also rotates in conjunction with the paper feed tray 2 and fits into the U-shaped groove 6a of the positioning member 6 and the paper feed roller shaft 6a of the paper feed roller 6, and the thrust regulating member 1
The thrust direction is restricted by 4a and 14b, and the parallelism between the paper feed tray 2 and the paper feed roller 3 that feeds a plurality of sheets on the paper feed tray 2 one by one can be surely obtained.

That is, the sheet 10 set on the paper feed tray 2 can be fed at a right angle to the axis of the paper feed roller 3,
The skew of the seat 10 can be prevented.

When the sheet 10 is set on the paper feed tray 2, it passes over the pressing member 4 which is pushed down by the cam provided on the body frame side of the image forming apparatus B (not shown) and before the separating pad 5. Push the sheet until it hits the surface of.

Next, when feeding is started, a cam provided on the body frame side (not shown) rotates, so that the pressing member 4 attached on the side of the feeding roller 3 becomes a pressing spring (not shown). Since it is pushed up, the pressing member 4 presses the sheet feeding roller 3 via the plurality of sheets 10. Further, the sheet feeding roller 3 which rotates in the clockwise direction by transmitting the driving force by the driving gear on the main body side not shown,
The sheet 10 is fed to the separating pad 5. The sheet 10 is squeezed between the separating pad 5 having a rubber material having a high friction coefficient and the sheet feeding roller 3 and is fed one by one from the top. The uppermost sheet fed from between the separating pad 5 and the paper feed roller 3 is guided by the guide member 17 and fed to the pair of transport rollers 18. The sheet fed by the pair of conveying rollers 18 is fed to the image forming unit 80 in the image forming apparatus B shown in FIG.

As described above, when a plurality of sheets 10 are set on the paper feed tray 2, the positioning member 6 of the paper feed tray 2 directly positions the paper feed tray 2 and the paper feed roller 3. Since there are no parts in the middle, it is easy to obtain accuracy.

That is, the paper feed roller shaft 3 of the paper feed roller 3
Since the sheet is fed at a right angle to the axis of a, the sheet does not skew.

Another embodiment of the present invention will be described below. The same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

Next, a second embodiment of the present invention will be described. The paper feed auxiliary tray 52 is configured so that it can be slid while being guided by the guide surface of the slide guide member 51a and stored in the paper feed tray 51 as a sheet stacking unit. Paper tray 5
1 is rotatable around a sheet feeding roller shaft 3a of a sheet feeding roller 3 that feeds the sheets 10 one by one. Normally, when the sheet 10 is not set, the sheet feeding tray 51 has a rotation center 3a.
It is rotated around the center and is fixed by the lock mechanism (not shown) of the front cover 1 drawing a locus as shown in FIG.

When the sheet 10 is set, the front cover 1 is unlocked as shown in FIG. 4, and the paper feed tray 51 is rotated to a predetermined position about the paper feed roller shaft 3a which is the center of rotation.
Pull out the paper feed auxiliary tray 52. At this time, the sheet feeding auxiliary tray 52 is positioned with respect to the sheet feeding tray 51.

In the above-described first embodiment, the paper feed tray is provided with the positioning member 6 having a U-shaped groove, and the paper feed roller shaft 3a and the positioning member 6 are fitted by rotating the paper feed tray. Although the parallelism with the paper feed roller is obtained by combining them, the same effect can be obtained even if the rotation center of the paper feed tray 51 is directly the paper feed roller shaft 3a.

That is, since there are few intervening parts from the paper feed auxiliary tray 52 to the paper feed roller 3 for feeding the sheets 10 one by one, the parallelism with the paper feed roller 3 can be improved by accumulating the precision of each part. Because there is no thing that you can not give it,
The sheet 10 is smoothly fed without skewing.

Next, a third embodiment is shown in FIG.

On the paper feed tray 2, a pair of sheet width restricting members 61 as a pair of sheet width restricting members having a sufficient thickness for restricting the width of the sheet 10 are provided. It fits through the long guide hole 61a.

A pinion 12 is fitted to the boss 9 on the back surface of the paper feed tray 2, and the pinion 12 is a pair of racks 1.
It meshes with 5,16. One of the racks 16 is connected to the sheet width regulating plate 61 via a hole provided in the width direction of the paper feed tray 2, and the pair of sheet width regulating portion plates 61 are
It is configured to work in the seat width direction.

At this time, the paper feed tray 2 and the sheet width regulating plate 6
1, the paper feed tray 2 and the racks 15 and 16 are attached to the paper feed tray 2 with a certain gap, and the sheet width regulation plate 6
In No. 1, the perpendicularity to the axis of the paper feed roller shaft 3a is restricted by the paper feed roller shaft 3a and the round guide hole 61a.

As described above, the pair of sheet width regulating plates 6 for regulating the width direction of the plurality of sheets 10 on the paper feed tray 2.
Since a right angle with respect to the axis of one sheet feeding roller shaft 3a can be obtained, sheets fed one by one from above by the sheet feeding roller 3 can be fed without being skewed by being guided by the sheet width regulating plate 61. .

[0042]

As described above, according to the present invention,
Since the positioning member that connects the feeding roller shaft of the feeding roller and the sheet stacking unit is provided, the sheet stacking unit can be positioned on the sheet feeding roller via the apparatus body as in the conventional apparatus. It is possible to prevent that the parallelism between the sheet stacking unit and the feeding roller is not exerted due to the influence of component accuracy.

As a result, the sheet is fed smoothly without skewing, and printing defects and jams due to skewing can be prevented.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a sheet feeding apparatus according to a first exemplary embodiment of the present invention with a sheet stacking unit opened.

FIG. 2 is a schematic configuration diagram of the image forming apparatus according to the embodiment and a sheet stacking unit of the sheet feeding apparatus in a closed state.

FIG. 3 is a vertical sectional front view of the device.

FIG. 4 is a schematic configuration diagram of a sheet feeding device according to a second embodiment of the present invention.

FIG. 5 is a schematic configuration diagram of a sheet feeding device according to a third embodiment of the present invention.

[Explanation of symbols]

 1 Front Cover (Device Main Body) 2,51 Paper Feed Tray (Sheet Stacking Means) 2a Rotation Center Shaft (Rotation Shaft) 3 Paper Feed Roller (Feeding Roller) 3a Paper Feed Roller Shaft (Feeding Roller Shaft) 6 Connecting Member (Positioning member) 6a U-shaped groove (fitting portion) 10 Sheet 61 Sheet width regulating plate (sheet width regulating member) 61a Round guide hole (guide hole) 80 Image forming unit

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Masafumi Onishi 338-18 Kawadera, Hanno City, Saitama Prefecture (72) Inventor Hiroki Nomura 665-1 Shimokagemori, Chichibu City, Saitama Prefecture

Claims (5)

[Claims] 1. A sheet stacking means mounted on the apparatus main body for stacking a plurality of sheets, and a feeding roller shaft rotatably supported by the apparatus main body. In a sheet feeding device including a feeding roller that feeds sheets one by one, a positioning member that connects a feeding roller shaft of the feeding roller and the sheet stacking unit is provided. Sheet feeding device. 2. A sheet stacking unit that has a rotation shaft and is openably and closably attached to the apparatus main body for stacking a plurality of sheets.
A sheet feeding device comprising: a feeding roller shaft rotatably supported by the apparatus main body; and a feeding roller configured to feed the sheets stacked on the sheet stacking unit one by one. One end of a connecting member is fixed to a rotating shaft of the sheet stacking unit, and the other end of the connecting member is fitted to the feeding roller shaft when the sheet stacking unit is opened. The sheet feeding apparatus according to claim 1, wherein the connecting member forms a positioning member by providing a fitting portion that is detached from the feeding roller shaft when closing the sheet. 3. The sheet stacking means comprising a sheet stacking means rotatably attached to the apparatus main body for stacking a plurality of sheets, and a feeding roller shaft rotatably supported by the apparatus main body. A sheet feeding device including a feeding roller that feeds stacked sheets one by one, wherein the sheet stacking unit is rotatably attached to a feeding roller shaft of the feeding roller. The sheet feeding device according to claim 1, wherein the sheet stacking means itself constitutes a positioning member. 4. A sheet stacking unit that has a rotation shaft and is openably and closably attached to the apparatus main body for stacking a plurality of sheets.
A sheet feeding device comprising: a feeding roller shaft rotatably supported by the apparatus main body; and a feeding roller configured to feed the sheets stacked on the sheet stacking unit one by one. A pair of sheet width regulating members is attached to the sheet stacking means so as to be movable in the sheet width direction, and the sheet stacking member is fitted to the feeding roller shaft of the feeding roller to stack the sheets. The sheet feeding device according to claim 1, wherein the sheet width regulating member serves as a positioning member by providing a guide hole for guiding when the means is opened and closed. 5. An image forming apparatus, comprising: the sheet feeding device according to claim 1; and an image forming unit that forms an image on a sheet fed by the sheet feeding device.