JP2003246502A - Sheet member feeder, and image forming device equipped therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To align the side end of a sheet member having different size by a simple structure. <P>SOLUTION: A right end reference surface 19a to regulate the right end position of a large sheet member (for example, A4 size) is provided on the outer side along the paper passing width direction of the sheet member of a right end reference plate 19, and a right end reference surface 19b to regulate the right end position of a small sheet member (for example, A5 size) is provided on the inner side thereof. The right end reference surface 19a and right end reference surface 19b are provided at higher/lower positions than a sheet member feeding surface 19d, respectively. The large sheet member is abutted on the feeding reference surface 19a by feeding rollers 20a, 21a and skew feeding rollers 20b, 21b, and the small sheet member is abutted on the right end reference surface 19b by the feeding roller 21a and skew feeding roller 21b. Even though the size is different, a mechanism to move the right end reference plate 19 is no more required. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet material conveying device that conveys a sheet material with one end of the sheet material along the conveying direction as a reference, and an image forming apparatus including the same.

[0002]

2. Description of the Related Art A conventional sheet material conveying device will be described with reference to FIGS. 8, 9, 10, and 11.

Of these, FIG. 8 shows a vertical cross section as seen from the front side of an image forming apparatus having an automatic double-sided printing function (automatic double-sided image forming function). A paper feed cassette 2 is detachably attached to the lower portion of the image forming apparatus main body 1. In the paper feed cassette 2, a plurality of sheet materials 3 are stacked on the intermediate plate 4 in a stacked state.

The sheet material 3 in the paper feed cassette 2 is fed by a paper feed roller 5, separated one by one by a separation pad 6, and then conveyed by a conveyance roller 7a and a conveyance roller 7b. The leading edge of the conveyed sheet material 3 is brought into contact with the nip portion between the registration roller 7a and the registration roller 7b that are stopped, the skew is corrected, and the sheet material 3 is once stopped.

On the other hand, in the process cartridge 10 which constitutes a part of the image forming section, a photosensitive drum 9 rotatable in the clockwise direction in the figure is arranged. This photosensitive drum 9
Is a charging / exposure device 12 using a primary charger (not shown).
A toner image is formed on the surface by exposure by (for example, a laser scanner) and development by a developing device (not shown). This toner image is transferred by the transfer roller 11 to the recording material 3 sent from the above-mentioned registration rollers 8a and 8b at the same timing. After the transfer of the toner image, the residual toner remaining on the surface of the photosensitive drum 9 is removed by a cleaning device (not shown), and the photosensitive drum 9 is used for the next image formation.

On the other hand, the sheet material 3 after the toner image transfer is conveyed to the fixing device 14 by the conveyor belts 13a and 13b, where it is heated and pressed to fix the toner image on the surface. The sheet material 3 on which the toner image has been fixed is conveyed upward by the lower paper ejection roller 15 and the lower paper ejection roller 16, and is formed on the upper portion (upper surface) of the image forming apparatus main body 1 by the paper ejection rollers 17a and 17b. The paper is ejected onto the ejected paper ejection tray. As a result, the image formation on one side (first side) of the sheet material 3 is completed.

On the other hand, when images are formed on both surfaces (first surface and second surface) of the sheet material 3, the rear end of the sheet material 3 after the toner image is fixed is the lower discharge roller 15. After passing through the lower discharge roller 16, the discharge roller 17a and the discharge roller 17
Before passing through b, these paper discharge rollers 17a and paper discharge rollers 1
The rotation direction of 7b is reversed and the conveying direction is reversed, and the sheet is conveyed downward.

The sheet material 3 conveyed downward is further conveyed to the re-feeding conveyance path under the image forming apparatus main body 1 by the above-described lower paper discharge roller 15 and the conveyance roller 18.

In this way, the sheet material 3 conveyed to the re-feeding conveying path is conveyed by the conveying rollers 20a, 21a and the oblique conveying rollers 20b, 21 which are in contact with the conveying rollers 20a, 21a at a constant angle.
It is conveyed diagonally rightward by b. At this time, the sheet material 3 is conveyed while the right end of the sheet material 3 is in contact with the right end reference plate 19 and is guided, so that the skew feeding is corrected.

The sheet material 3 in which the skew is corrected is guided by the sheet-metal conveying guide 23 and is fed by the re-feeding roller 22.
a, and the sheet is re-supplied to the image forming unit by the re-feeding roller 22b. Then, similarly to the above-mentioned first surface, the toner image is transferred and fixed on the second surface. The sheet material 3 on which the toner image has been fixed is discharged onto the discharge tray by the discharge rollers 17a and the discharge rollers 17b. As a result, image formation on both surfaces (first surface and second surface) of the sheet material 3 is completed.

FIG. 9 is a view of a horizontal cross section of the re-feeding conveyance path under the image forming apparatus main body 1, as viewed from above, and the upper side in the figure is the traveling direction of the sheet material 3. Reference numeral 1 in the figure
Reference numeral 9a is a rack portion provided on the right end reference plate 19, 24 is a motor (driving source) for moving the right end reference plate 19, and 25a, 2
5b is an idler gear, 26 is a guide shaft of the right end reference plate 19, and 27a and 27b are drive pulleys attached to the conveying rollers 20a and 21a.

FIG. 10 is a view taken along the line AA of FIG. 9 and 10 show a case where the A4 size sheet material 3 is conveyed. In the sheet material 3, the right end reference plate 19 is moved to a predetermined position P for A4 size by the motor 24.
4, the sheet feeding from the sheet material storage cassette 2 is started, and after the image formation on the first side is completed, the sheet is conveyed to the re-feeding conveyance path and is skewed by the right end reference plate 19. Then, the second side image formation is performed.

FIG. 11 shows the case where an A5 size sheet material is conveyed. As in the case of FIG. 9, the right end reference plate 19 is moved by the motor 24 to a predetermined position P5 for A5 size.

[0014]

However, according to the above-mentioned conventional example, the right end reference plate 19, the conveying roller 20a,
21a and the oblique feed rollers 20b, 21b are required to have a motor 24, an idler gear 25a, a rack 19a, and the like, and a sensor for detecting the position of the right end reference plate 19 is required. There was a problem of becoming.

Further, there is a problem that it takes a predetermined time to move the right end reference plate 19 and the like.

Therefore, the present invention simplifies the device configuration,
Further, it is an object of the present invention to provide a sheet material conveying device that does not require time for moving the right end reference plate and the like, and an image forming apparatus including the sheet material conveying device.

[0017]

The invention according to claim 1 is
The sheet material is provided with a side end reference surface that regulates the position of one side end along the conveyance direction, and a conveyance mechanism that conveys the sheet material while bringing one side end of the sheet material into contact with the side end reference surface. In the sheet material conveying device, at least two side end reference surfaces arranged at different positions in the sheet passing width direction of the sheet material, and at least two side end reference surfaces arranged at different positions in the sheet passing width direction of the sheet material. And a transport mechanism, wherein one of the two transport mechanisms is arranged between the outer side end reference surface on the outer side and the inner side end reference surface along the sheet passing width direction of the sheet material, The remaining 1 is further inside than the inner side end reference surface.
A plurality of the above-mentioned transport mechanisms are arranged.

According to a second aspect of the present invention, in the sheet material conveying device according to the first aspect, the conveying force of the sheet material by the outer conveying mechanism is larger than the conveying force of the sheet material by the inner conveying mechanism. It is set so that

According to a third aspect of the present invention, in the sheet material conveying apparatus according to the first or second aspect, the conveying mechanism conveys the sheet material to the downstream side, and is inclined with respect to the conveying roller. And a skew feed roller that skews and feeds the sheet material that is abutted against and is transported between the transport roller and the transport roller.

The invention according to claim 4 relates to claims 1 to 3.
In the sheet material conveying device according to any one of claims 1 to 3, the inner side end reference surface is provided at a position lower than the sheet material transfer surface, and the outer side end reference surface is higher than the sheet material transfer surface. It is provided in.

According to a fifth aspect of the present invention, in the sheet material conveying device according to the fourth aspect, the side end portions of the sheet material are arranged so that the side edges of the sheet material come into contact with the inner side end reference surfaces. It is characterized by having a roller which pushes downward.

According to a sixth aspect of the present invention, in the sheet material conveying device according to the first aspect, the side end reference surface is provided further inside the inner conveyance mechanism, and the side end reference surface is provided further inside the side end reference surface. A transport mechanism is provided.

According to a seventh aspect of the present invention, there is provided an image forming section for forming an image on a sheet material, and a sheet material conveying device for carrying the sheet material into the image forming section or unloading the sheet material from the image forming section. In the image forming apparatus including the above, the sheet material conveying device is the sheet material conveying device according to any one of claims 1 to 6.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In addition, in each of the drawings, components denoted by the same reference numerals have similar configurations or actions, and repeated description thereof will be appropriately omitted.

<First Embodiment> FIG. 1 shows an example of an image forming apparatus provided with a sheet material conveying apparatus according to the present invention. The image forming apparatus shown in the figure is an electrophotographic printer, and has an automatic double-sided printing function (automatic double-sided image forming) for automatically forming an image on both sides (first side and second side) of a sheet material. Function). FIG. 1 is a vertical cross-sectional view showing the schematic configuration of the image forming apparatus as viewed from the front side.

In the printer shown in FIG. 1 (hereinafter referred to as "image forming apparatus"), a detachable paper feed cassette 2 is attached to the bottom of an image forming apparatus main body 1. Paper cassette 2
Inside, a plurality of sheet materials 3 are stacked on the intermediate plate 4 in a stacked state.

The sheet material 3 in the paper feed cassette 2 is fed by a paper feed roller 5, separated one by one by a separation pad 6, and then conveyed by a conveyance roller 7a and a conveyance roller 7b. The leading edge of the conveyed sheet material 3 is brought into contact with the nip portion between the stopped registration rollers 8a and 8b to correct skew, and the sheet material 3 is once stopped.

On the other hand, in the process cartridge 10 which constitutes a part of the image forming portion, the photosensitive drum 9 which can be rotated clockwise in FIG. This photosensitive drum 9
Is a charging / exposure device 12 using a primary charger (not shown).
A toner image is formed on the surface by exposure by (for example, a laser scanner) and development by a developing device (not shown). This toner image is transferred by the transfer roller 11 to the recording material 3 sent from the above-mentioned registration rollers 8a and 8b at the same timing. After the transfer of the toner image, the residual toner remaining on the surface of the photosensitive drum 9 is removed by a cleaning device (not shown), and the photosensitive drum 9 is used for the next image formation.

On the other hand, the sheet material 3 after the toner image transfer is conveyed to the fixing device 14 by the conveyor belts 13a and 13b, where it is heated and pressed to fix the toner image on the surface. The sheet material 3 on which the toner image has been fixed is conveyed upward by the lower paper ejection roller 15 and the lower paper ejection roller 16, and is formed on the upper portion (upper surface) of the image forming apparatus main body 1 by the paper ejection rollers 17a and 17b. The paper is ejected onto the ejected paper ejection tray. As a result, the image formation on one side (first side) of the sheet material 3 is completed.

On the other hand, when images are formed on both surfaces (first surface and second surface) of the sheet material 3, the sheet material 3 after the toner image is fixed has its rear end formed with the lower paper discharge roller 15. After passing through the lower discharge roller 16, the discharge roller 17a and the discharge roller 17
Before passing through b, these paper discharge rollers 17a and paper discharge rollers 1
The rotation direction of 7b is reversed and the conveying direction is reversed, and the sheet is conveyed downward.

The sheet material 3 conveyed downward is further conveyed to the re-feeding conveyance path under the image forming apparatus main body 1 by the lower paper discharge roller 15 and the conveyance roller 18.

In this way, the sheet material 3 conveyed to the re-feeding conveying path is conveyed by the conveying rollers 20a, 21a and the oblique conveying rollers 20b, 21 which are in contact with the conveying rollers 20a, 21a at a constant angle.
It is conveyed diagonally rightward by b. At this time, the sheet material 3 is conveyed while the right end thereof is in contact with and guided by the right end reference plate (side end reference plate) 19, and the skew is corrected.

The sheet material 3 whose skew has been corrected is guided by a sheet-metal conveying guide 23 while being fed by the re-feeding roller 22.
a, and the sheet is re-supplied to the image forming unit by the re-feeding roller 22b. Then, similarly to the above-mentioned first surface, the toner image is transferred and fixed on the second surface. The sheet material 3 on which the toner image has been fixed is discharged onto the discharge tray by the discharge rollers 17a and the discharge rollers 17b. As a result, image formation on both surfaces (first surface and second surface) of the sheet material 3 is completed.

FIG. 2 is a view of a horizontal cross section of the re-feeding conveyance path at the bottom of the image forming apparatus main body 1 as seen from above, and the upper side in FIG. 2 is the conveyance direction of the sheet material 3. In addition, FIG.
FIG. 3 is a view of the vicinity of conveyance rollers 20a and 21a as viewed from below in FIG. 2, that is, from the upstream side in the conveyance direction of the sheet material 3.
The right end reference plate 19 is formed with two right end reference surfaces 19a and 19b which are selectively used according to the size of the sheet material 3 along the sheet material conveying direction. Of these, the right end reference surface 19a on the outer side in the sheet passage width direction of the sheet material (direction orthogonal to the sheet material conveying direction) projects from the sheet material conveying surface 19d that guides the lower surface of the sheet material 3. It is provided, and the right end of a large sheet material (for example, A4 size, letter size) 3 is brought into contact. On the other hand, the inner right end reference surface 19b is formed such that a recess is provided in the sheet material conveying surface 19d, and the right end of a small sheet material (for example, A5 size) 3 is brought into contact therewith.

In this embodiment, the transport rollers 20a, 2
1a is arranged at the same position in the sheet material conveying direction, of which the conveying roller 20a is arranged outside the right end reference surface 19b and inside the right end reference surface 19a. On the other hand, the transport roller 21a is arranged further inside than the above-mentioned right end reference surface 19b.

Oblique feed rollers 20b and 21b having axes inclined with respect to the axes of the conveying rollers 20a and 21a, respectively, are in contact with the conveying rollers 20a and 21a from above. Further, the oblique feed rollers 20b and 21b are pressed against the transport rollers 20a and 21a by springs 28a and 28b. The conveying rollers 20a and 20b are rotated by a driving means (not shown) via a fixed driving pulley 27 at the right end, while the oblique feeding rollers 21a and 21b are rotated.
Is the conveyance rollers 20a, 21a when there is no sheet material 3.
Directly, or when there is sheet material 3, sheet material 3
It is designed to be driven to rotate via.

Conveying rollers 20a, 21 slightly inside the right end reference surface 19b on the inner side and along the sheet conveying direction.
The springs 30a and 30 are provided on the upstream side and the downstream side of a, respectively.
Rollers 29a and 29b are provided which are urged downward by b. These rollers 29a and 29b are for pressing the right end portion of the sheet material 3 from above in order to bring the right end of the small sheet material 3 into contact with the right end reference surface 19b.

When a large sheet material 3 is conveyed in the above sheet material conveying device, the sheet material 3 is conveyed.
Is a pair of conveying rollers 20a and 21a and an oblique feeding roller 20.
It is conveyed while being pressed against the right end reference surface 19a of the outer right end reference plate 19 by b and 21b. As a result, the right end of the large sheet material 3 is aligned with the reference position. When the large sheet material 3 is conveyed, the rollers 29a and 29b described above are
By this, the springs 30a and 30b are pushed upward against the spring force.

On the other hand, when the small sheet material 3 is conveyed, the right end portion of the sheet material 3 is first pressed downward by the roller 29a, and then the conveying roller 21a.
The sheet is conveyed while being pressed against the right end reference surface 19b inside the right end reference plate 19 by the oblique feed roller 21b. As a result, the right end of the small sheet material 3 is aligned with the reference position.

The above-mentioned small sheet material 3 is larger than the large sheet material 3 in the conveying guide 30 and the sheet material conveying surface 19d.
Since the area of contact with the carriage is small, the carrying resistance received from the carrying guide 30 or the like is small. Therefore, the small sheet material 3
Can change the conveying posture with a smaller force, so that the contact pressure between the oblique feed rollers 20b and 21b is the same.
Can be made smaller. As a result, when the large sheet material 3 is conveyed, the conveyance rollers 20a,
It can be obliquely fed by the obliquely feeding roller 20b.

<Second Embodiment> FIGS. 4 and 5 show the present embodiment. FIG. 4 is a diagram corresponding to FIG. 2 in the above-described first embodiment, and FIG. 5 is a diagram corresponding to FIG. In the present embodiment, as shown in these figures, the set of the transport roller 20a and the skew feed roller 20b and the set of the transport roller 21a and the skew feed roller 21b are set at different positions along the sheet material transport direction. And transport rollers 20a and 21a, respectively.
Are rotationally driven by pulleys 27a and 27b fixed to different drive shafts.

Therefore, the transport roller 21a and the oblique feed roller 21 are
The rotation speed of b can be made higher than the rotation speeds of the transport roller 20a and the oblique feed roller 20b. Therefore, when a large sheet material 3 is conveyed, it can be more efficiently obliquely fed. The transport rollers 20a, 2
The number of rotations of 1a is set to be the same, and the conveyance rollers 20a, 2
The same effect as described above can be obtained by changing the radius of 1a and setting the diameter of 21a in the carrying roller to be larger than the diameter of the carrying roller 20a.

In the present embodiment, as shown in FIGS. 4 and 5, the sheet material conveying surface 19f on which the right end portion of the large sheet material 3 is placed is the sheet on which the right end portion of the small sheet material 3 is placed. By setting the position higher than the material conveying surface 19e, the roller 29, which is necessary in the above-described first embodiment, can be obtained.
Even if the a, 29b and the springs 30a, 30b are omitted, the right end of the small sheet material 3 can be brought into good contact with the inner right end reference surface 19b.

<Third Embodiment> FIGS. 6 and 7 show the present embodiment. In the present embodiment, in the above-described first embodiment, the right end reference surfaces 19a and 19b are separately used in two cases, that is, when the sheet material 3 is large and when the sheet material 3 is small. Another right end reference surface 19c is provided further inside the right end reference surface 19b, and the right end reference surfaces 19a, 19b, and 19c are selectively used depending on three cases of large, medium, and small sizes of the sheet material 3.
As the constitution, the right end reference surface 19c, the conveyance roller 31a,
Oblique feed rollers 31b, rollers 32a, 32b, springs 30c, 3
0d is added.

In the present embodiment, the right end of the large sheet material 3 (for example, A3 size) is brought into contact with the outermost right end reference surface 19a, and the medium sheet material 3 (for example, A3 size).
The right end of the size 4 and letter size is brought into contact with the middle right end reference surface 19b, and the small sheet material 3 (for example, A5 size) is brought into contact with the innermost right end reference surface 19c. .

As described above, by increasing the number of right end reference surfaces, it is possible to increase the size of the sheet material 3 that can be supported.

In each of the above-described first to third embodiments, the case where the right end of the sheet material 3 is brought into contact with the right end reference surface has been described as an example, but the left end of the sheet material 3 contacts the left end reference surface. The basic configuration is the same for the case of contact.

[0048]

As described above, according to the present invention,
Since it is possible to align the position of one side end of sheet materials of various sizes without moving the reference plate with which one side end of the sheet material abuts, a mechanism for moving the reference plate is provided. The configuration can be simplified because it is not necessary, and the image forming time can be shortened by eliminating the time for moving.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a schematic configuration of an image forming apparatus according to a first embodiment.

FIG. 2 is a diagram of a horizontal cross section of a re-feeding conveyance path of the image forming apparatus according to the first embodiment as viewed from above.

FIG. 3 is a vertical cross-sectional view of the vicinity of a transport roller in FIG. 2 viewed from below.

FIG. 4 is a diagram corresponding to FIG. 2 in the second embodiment.

FIG. 5 is a diagram corresponding to FIG. 3 in the second embodiment.

FIG. 6 is a diagram corresponding to FIG. 2 in the third embodiment.

FIG. 7 is a diagram corresponding to FIG. 3 in the third embodiment.

FIG. 8 is a vertical sectional view showing a schematic configuration of a conventional image forming apparatus.

FIG. 9 is a diagram showing a mechanism for moving the right end reference plate and a state in which the right end reference plate is moved according to an A4 size sheet material in the conventional image forming apparatus.

10 is a view taken along the line AA of FIG.

FIG. 11 is a diagram showing a mechanism for moving the right end reference plate and a state in which the right end reference plate is moved in accordance with an A5 size sheet material in the conventional image forming apparatus.

[Explanation of symbols]

1 Image forming device body 3 sheet materials 10 Image forming unit (process cartridge) 19 Side edge reference plate (right edge reference plate) 19a, 19b, 19c side end reference surface (right end reference surface) 19d, 19e, 19f Sheet material conveying surface 20a, 21a, 31a transport rollers 20b, 21b, 31b skew feed rollers 29a, 29b, 32a, 32b rollers

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoshihisa Ibaraki             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation (72) Inventor Takaaki Kawade             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation F-term (reference) 2H072 CA01 HB10 JA02                 3F049 AA02 DA12 LA01 LB03                 3F100 AA01 CA15 EA03                 3F102 AA01 AB01 BA02 BB04 EA03                       EA06

Claims (7)

[Claims] 1. A side end reference surface that regulates the position of one side end of a sheet material in the conveyance direction, and a conveyance operation in which one side end of the sheet material is in contact with the side end reference surface. In a sheet material conveying device including a mechanism, at least two side end reference surfaces arranged at different positions in the sheet width direction of the sheet material, and at different positions in the sheet width direction of the sheet material. At least two of the transport mechanisms, and one of the two transport mechanisms between the outer side end reference surface on the outer side and the inner side end reference surface along the sheet passing width direction of the sheet material. The sheet material conveying device is characterized in that one piece is arranged, and the remaining one piece of the conveying mechanism is arranged further inside the inner side end reference surface. 2. The sheet according to claim 1, wherein a conveying force of the sheet material by the outer conveying mechanism is set to be larger than a conveying force of the sheet material by the inner conveying mechanism. Material transport device. 3. The transport reference surface for transporting the sheet material between the transport roller for transporting the sheet material downstream and the skew roller abutting against the transport roller and transporting the sheet material between the transport rollers. The sheet material conveying device according to claim 1 or 2, further comprising: an oblique feeding roller that obliquely feeds the sheet material. 4. The inner side end reference surface is provided at a position lower than the sheet material conveying surface, and the outer side end reference surface is provided at a position higher than the sheet material conveying surface. The sheet material conveying device according to any one of claims 1 to 3. 5. The roller according to claim 4, further comprising a roller that presses a side end portion of the sheet material downward so that a side end of the sheet material is brought into contact with the inner side end reference surface. Sheet material conveying device. 6. The sheet according to claim 1, wherein the side end reference surface is provided further inside the inner conveyance mechanism, and the conveyance mechanism is provided further inside the side end reference surface. Material transport device. 7. An image forming apparatus comprising: an image forming section for forming an image on a sheet material; and a sheet material conveying device for carrying in the sheet material to or unloading the sheet material from the image forming section. The image forming apparatus according to claim 1, wherein the sheet material conveying device is the sheet material conveying device according to any one of claims 1 to 6.