JP2009126696A - Paper carrying guide and document feeding device and image forming device mounted with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper carrying guide reducing the number of assembling man-hours while performing secure grounding, and a document feeding device and image forming device mounted with the paper carrying guide. <P>SOLUTION: The paper carrying guide is provided with a resin guide member (41) having, on the side face (46), a boss (48) protruded toward a metallic casing (38), supported by the casing (38) via the boss (48) and having a carrying face (44) of paper; an antistatic member (60) provided on the end face (43) of the guide member (41) and removing electric charges charged on paper; and a metallic compression coil spring (80) having larger natural length than the length of the boss (48), surrounding the boss (48) and grounding the antistatic member (60) by interconnecting the casing (38) and the antistatic member (60). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a sheet conveyance guide for guiding a sheet conveyance direction, and a document feeding apparatus and an image forming apparatus equipped with the sheet conveyance guide.

This type of image forming apparatus is equipped with a document feeding device and an image reading unit, and the document set on the supply tray of the document feeding device is conveyed toward the image reading position of the image reading unit. The image is read by the image reading unit (see, for example, Patent Documents 1 and 2).
In an image forming apparatus using an electrophotographic process, a photosensitive drum is charged in advance and an electrostatic latent image is formed by irradiating the surface of the drum with laser light. Next, the developed toner image is transferred and fixed on a sheet.

  Here, the document conveyed from the supply tray is sent to the discharge tray of the document feeder via the guide. If the guide is made of resin so as to have various shapes, Electric charges are accumulated in the guide due to the friction of, and static electricity is generated. This static electricity attracts the paper and becomes a factor that hinders the conveyance of the paper. Therefore, a static eliminating member is installed in this guide (see, for example, Patent Document 3).

JP 2001-83749 A JP 2001-217988 A JP 2006-315826 A

By the way, in the above conventional technique, the static elimination member and the metal casing are electrically connected, and static electricity generated in the guide is released to the casing via the static elimination member.
However, in these prior art guides, a plurality of members are interposed between the static elimination member and the housing, and this increases the number of places that hinder conduction, and there is a concern that reliable grounding cannot be performed. is there.

In addition, when a plurality of members are interposed between the static elimination member and the housing as in the above technique, another problem arises in that the man-hour for assembling the guide increases.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-described problems, and to provide a paper transport guide that reduces assembly man-hours while performing reliable grounding, and a document feeding device and an image forming apparatus equipped with the paper transport guide.

  According to a first aspect of the present invention for achieving the above object, a resin having a boss projecting toward a metal casing on a side surface thereof, supported by the casing via the boss, and having a sheet conveying surface It is provided on the end face of the guide member made of the metal and the guide member intersecting the side surface, and has a neutralizing member for removing the electric charge charged on the paper, and a natural length larger than the length of the boss, and surrounds the boss. And a metal compression coil spring that connects the case and the charge removal member to ground the charge removal member.

According to the first aspect of the invention, the resin guide member has a paper conveyance surface and has a boss projecting toward the metal housing on its side surface, and the housing via the boss. It is supported by. Further, a neutralizing member is provided on the end surface of the guide member, and the charge charged on the paper is removed.
Here, the metal compression coil spring surrounds the boss, connects the housing and the charge removal member, and grounds the charge removal member. Therefore, mechanically more positive and reliable grounding is possible than in the past.

  Moreover, since the compression coil spring has a natural length larger than the length of the boss, the operator holds the guide member in a state where the compression coil spring is surrounded by the boss with his / her hand, and determines the position with respect to the casing. Then, when the boss is engaged with the casing and the hand is released, the guide member can be assembled to the casing by the urging force of the compression coil spring. Therefore, the number of assembly steps can be reduced as compared with the conventional case.

According to a second aspect of the present invention, in the configuration of the first aspect, the static eliminator member is fixed at the boundary between the end surface and the side surface while fixing the static eliminator brush extending toward the transport surface and fixing the static eliminator brush to the end surface. And a conductive plate in contact with the compression coil spring.
According to the second invention, in addition to the action of the first invention, the static elimination member is further composed of a static elimination brush and a conductive plate, and the conductive plate fixes the static elimination brush to the end face, while the guide member It is bent at the boundary between the end face and the side face of and contacts the compression coil spring. Therefore, grounding can be performed in a small space.

According to a third aspect of the present invention, in the configuration of the first or second aspect, the compression coil spring has a diameter-expanded end portion that is formed to expand from the housing toward the guide member and abuts against the charge removal member. It is characterized by being.
According to the third invention, in addition to the effects of the first and second inventions, the compression coil spring has a divergent shape from the housing toward the guide member, and the enlarged diameter end portion thereof contacts the static elimination member. It touches. Therefore, as compared with the case where the compression coil spring is configured with the same diameter as the diameter facing the casing, the contact width with the static elimination member is increased, and a more reliable grounding can be performed. In addition, as compared with the case where the compression coil spring is configured with the same diameter as the diameter facing the guide member, the assembly position of the guide member with respect to the housing is easily determined and is influenced by the surrounding shape of the housing. And a desired biasing force can be obtained.

A fourth invention is characterized in that, in the configurations of the first to third inventions, the guide member is rotatably supported by the housing via a boss.
According to the fourth invention, in addition to the effects of the first to third inventions, the guide member is rotatably supported by the housing via the boss. It is also possible to apply pressure to the paper, and the convenience of the paper transport guide is improved.

According to a fifth aspect of the present invention, there is provided a document feeding device having the first to fourth paper conveyance guides mounted thereon. The sixth invention is an image forming apparatus having the first to fourth paper conveyance guides mounted thereon. It is characterized by being.
According to the fifth and sixth inventions, in addition to the effects of the first to fourth inventions, reliable grounding is performed, and the conveyance of the paper is hardly hindered. Contributes to improved reliability.

  According to the present invention, it is possible to provide a paper transport guide that can reliably perform grounding without causing an increase in cost and deterioration in assembling ability, and a document feeding device and an image forming apparatus on which the paper transport guide is mounted.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a multifunction device 1 as an example of an image forming apparatus from the upper right front, and the front of the multifunction device 1 facing the operator and the right side surface of the multifunction device 1 can be seen. The multifunction machine 1 includes an apparatus main body 2, and in this embodiment, has an in-body discharge type apparatus main body 2, and a discharge tray 15 is formed inside the main body 2.

A document feeder 8 is mounted on the upper side of the apparatus main body 2. When the multifunction machine 1 is used as a copying machine, a facsimile machine, or a network scanner, a document is conveyed from the feeder 8 and its image surface is an optical type. Optically read by the scanner unit 9.
An operation display unit 20 is installed on the front side of the scanner unit 9. The operation display unit 20 is provided with a display screen 21 on which a plurality of operation keys and switches for various user operations are arranged and various information is displayed.

  A front loading type paper supply device 3 is disposed at the lower part of the apparatus main body 2. Specifically, the supply device 3 is provided with two upper and lower sheet feed cassettes 4 along the height direction of the main body 2. Each cassette 4 is configured to be detachable with respect to the main body 2, and the inside of the cassette 4 is opened to the outside by being drawn toward the front side of the multifunction device 1, while the rear surface of the multifunction device 1. The inside is closed by being pushed toward the side.

The inside of the multifunction machine 1 is shown in FIG. Note that arrows indicated by solid lines in the drawing represent a sheet conveyance path and its conveyance direction.
As shown in the figure, various papers P before image formation are accommodated in each cassette 4 in a stacked state, and the papers P are separated one by one from the cassette 4 and sent leftward.

  A paper transport unit 6 is disposed on the left side of the supply device 3, and the paper P delivered from the cassette 4 is transported upward along the left side surface of the device body 2. In addition, an openable manual feed tray 5 is provided on the right side surface of the main body 2, and the paper fed from the tray 5 is also conveyed leftward from the right side of the main body 2, and then conveyed upward. Is done.

Inside the main body 2, a registration roller 7, an image forming unit 10, and a transfer unit 11 are sequentially arranged on the downstream side when viewed in the sheet conveyance direction. An optical unit 14 is provided on the right side of the image forming unit 10, and laser light is irradiated from the optical unit 14 toward the photosensitive drum of the image forming unit 10.
In addition, a fixing unit 12 having a roller pair 19 and a discharge branching unit 13 are sequentially arranged on the downstream side of the transfer unit 11 when viewed in the paper conveyance direction. In the case of single-sided printing, the fixing unit 12 is discharged from the fixing unit 12. The discharged paper is discharged to the paper discharge tray 15 through the discharge branching section 13.

On the other hand, a duplex printing unit 16 is disposed between the discharge branching unit 13 and the sheet conveying unit 6. The unit 16 returns the sheet discharged from the fixing unit 12 to the sheet conveying unit 6 to form an image. The data is sent again toward the unit 10.
Here, the above-described document feeder 8 is configured to include a sheet conveyance guide 40 (FIG. 3). Specifically, the document feeder 8 includes a supply tray 32, and the tray 32 is configured to be rotatable to the main body 30 via a shaft 36 (FIG. 4) and is read by the scanner unit 9. The previous document is set on the tray 32.

Further, a discharge tray 34 is provided on the lower surface side of the tray 32, and the document after the reading is discharged to the tray 34 via the conveyance roller 72. The roller 72 is also configured to be rotatable to the main body 30 via the rotating shaft 70 (FIG. 4).
The paper transport guide 40 of this embodiment is disposed between the supply tray 32 and the delivery roller 72.

  Specifically, the transport guide 40 has a guide member 41 having a substantially rectangular parallelepiped shape made of resin, and the guide member 41 of the present embodiment faces two transport surfaces, that is, the lower surface of the supply tray 32. The upper conveying surface 42 and a lower conveying surface (conveying surface) 44 facing the conveying roller 72 are provided. The lower transport surface 44 is a surface that guides when the document read by the scanner unit 9 is discharged to the discharge tray 34.

  On the other hand, the upper conveying surface 42 is a surface that guides when both sides of the original are read by the scanner unit 9. Specifically, in this case, when one side of the original set on the supply tray 32 is read, a part of the original reaches the upper conveyance surface 42. Next, the sheet is sent again toward the scanner unit 9 by reversing a roller (not shown). Then, the document whose both sides are read is guided to the lower conveyance surface 44 and discharged to the discharge tray 34.

  Each of the transport surfaces 42 and 44 is continuous with the end surface 43 as viewed in the document transport direction, and is continuous with the side surface 46 in the front-rear direction of the multifunction machine 1. The side surface 46 faces a sheet metal housing (housing) 38, and the housing 38 is fixed to the main body 30 and grounded via the apparatus main body 2. A boss 48 projecting in the front-rear direction of the multi-function device 1 is formed at an appropriate position of the side surface 46, and the guide member 41 is rotated through a hole (not shown) of the housing 38 via the boss 48. It is supported freely.

Accordingly, when the guide member 41 is rotated by a drive motor (not shown), the guide member 41 can apply a predetermined pressure to the document that has reached the upper conveyance surface 42 when both sides of the document are read by the scanner unit 9. .
On the other hand, the above-described end surface 43, specifically, the guide member 41, is provided with a charge removal member 60 on the end surface 43 positioned on the downstream side in the document transport direction. The static elimination member 60 is composed of a conductive tape (conductive plate) 62 and a static elimination brush 68. The static elimination brush 68 is formed on the lower conveyance surface 44 as shown in FIGS. In other words, it protrudes from the end face 43 toward the tray 34.

The conductive tape 62 is a single tape composed of a width surface 64 and a depth surface 66, and the width surface 64 fixes the static elimination brush 68 to the end surface 43, and further, this tape is connected to the end surface 43 and the side surface 46. The end portion of the depth surface 66 is disposed in the vicinity of the boss 48 (FIG. 5).
Instead of this tape, a metal plate capable of fixing the brush 68 may be used.

  Further, in the boss 48 described above, specifically, in the guide member 41, a metal compression coil spring 50 is provided on the boss 48 positioned on the back side when viewed in the front-rear direction of the multifunction machine 1. The coil spring 50 has an end portion 52 that abuts the casing 38, and the length (natural length) from the end portion 52 to the end portion 54 is made larger than the length of the boss 48. The coil spring 50 surrounds the boss 48, and its end 54 is in contact with the depth surface 66 of the conductive tape 62.

As a result, the static elimination member 60, the compression coil spring 50, and the casing 38 are conducted, and the charge charged on the original is released to the casing 38.
In the document feeder 8 having the above-described sheet conveyance guide 40, the document is set on the supply tray 32 and conveyed toward the image reading position of the scanner unit 9 by pressing a predetermined button of the operation display unit 20. And is discharged to the discharge tray 34 after being discharged by the charge removal member 60.

  On the other hand, in the multi-function machine 1 equipped with the document feeder 8, the sheets are separated and sent one by one from the cassette 4 and the tray 5, and the sheets reach the registration rollers 7 via the sheet transport unit 6. The roller 7 feeds the paper to the transfer unit 11 while correcting the oblique feeding of the paper and timing the toner image formed by the image forming unit 10.

Further, based on image data from a controller (not shown), the multifunction device 1 controls the irradiation of the laser beam by the optical unit 14. As a result, an electrostatic latent image of the original image is formed on the drum in the image forming unit 10, and then a toner image is formed on the drum from the latent image and transferred to a sheet.
Thereafter, the sheet is fed toward the fixing unit 12 with an unfixed toner image carried thereon, and the toner image is fixed. Next, the paper discharged from the fixing unit 12 is discharged to the tray 15 through the discharge branching unit 13.

When double-sided printing is performed in contrast to this single-sided printing, the paper discharged from the fixing unit 12 is pulled back to the unit 16 immediately before being discharged to the tray 15, and this paper joins the paper transport unit 6. It is sent again toward the transfer unit 11. In this case, the toner image is transferred to the surface of the paper that has not been printed.
By the way, as for the metal compression coil spring mentioned above, each edge part may be comprised by a different diameter.

  Specifically, the compression coil spring 80 shown in FIG. 6 also surrounds the boss 48 located on the back side when viewed in the front-rear direction of the multi-function device 1, as in the above-described embodiment. However, the compression coil spring 80 of this embodiment is formed in a shape that widens toward the guide member 41 from the housing 38, and its enlarged diameter end portion 84 is compared to the above embodiment. Thus, it contacts the depth surface 66 of the conductive tape 62 with a sufficient margin.

Note that the length (natural length) from the end portion 82 of the spring 80 to the enlarged diameter end portion 84 is made larger than the length of the boss 48 as in the above-described embodiment.
As described above, according to the present embodiment, the resin guide member 41 has at least the lower conveyance surface 44 of the document, and the boss 48 protruding toward the metal sheet metal housing 38 on the side surface 46. And is rotatably supported by the casing 38 via the boss 48.

Further, a neutralizing member 60 is provided on the end face 43 located on the downstream side of the guide member 41 in the document transport direction to remove the electric charge charged on the document.
Here, the metal compression coil springs 50 and 80 surround the boss 48 and directly connect the housing 38 and the charge removal member 60 to ground the charge removal member 60. Therefore, compared to the conventional configuration in which a plurality of members are interposed between the casing and the charge removal member, mechanically positive and reliable grounding is possible.

  In addition, since the compression coil springs 50 and 80 have a natural length larger than the length of the boss 48, the operator guides the guide member 41 in a state where the compression coil springs 50 and 80 are surrounded by the boss 48 with their hands. , Determine the position of both bosses 48 with respect to the housing 38, and then engage the boss 48 on the side having the compression coil springs 50, 80 with the holes in the housing and release the hand to guide the boss 48. The member 41 can be assembled to the housing 38 by the urging force of the compression coil springs 50 and 80. Therefore, the number of parts and the number of assembly steps can be reduced as compared with the conventional configuration that requires connection of a plurality of members, which contributes to a reduction in manufacturing cost.

  The static elimination member 60 includes a static elimination brush 68 and a conductive tape 62. The tape 62 fixes the static elimination brush 68 to the end face 43, while the corner portion of the guide member 41, that is, the end face 43 and the side face. 46 is in contact with the compression coil springs 50 and 80. Therefore, grounding can be performed in a small space.

Further, as shown in FIG. 6, the compression coil spring 80 has a shape that widens toward the guide member 41 from the housing 38, and its enlarged diameter end 84 has a margin in the static elimination member, specifically, the depth surface 66 of the tape 62. Are in contact.
Therefore, as compared with the case where the compression coil spring 80 is configured with the same diameter as the diameter facing the casing 38, the contact width with the static elimination member 60 is increased, and a more reliable grounding can be performed. On the other hand, the assembly position of the guide member 41 with respect to the housing 38 is easily determined as compared with the case where the compression coil spring is configured with the same diameter as the diameter facing the guide member 41, and around the hole of the housing 38. A desired urging force can be obtained without being affected by the shape.

Furthermore, since the guide member 41 is rotatably supported by the casing 38 via the boss 48, for example, the pressure is applied to the document that has reached the upper conveyance surface 42 by the rotation of the guide member 41. This also makes it possible to improve the convenience of the paper transport guide 40.
Further, as described above, reliable grounding is performed, and it is difficult for paper jam due to static electricity to occur. This contributes to improving the reliability of the document feeder 8 and the multifunction device 1.

The present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the claims.
For example, in the above-described embodiment, an example in which the image forming apparatus is embodied in a multifunction machine is shown. However, the present invention can naturally be applied to a copying machine, a printer, and the like having a sheet conveyance guide.

1 is a perspective view of a multifunction machine according to an embodiment. FIG. 2 is a front view of a vertical section schematically showing the multifunction machine of FIG. 1. FIG. 2 is a perspective view of the document feeder in FIG. 1. FIG. 4 is a perspective view around a guide member in FIG. 3. It is a principal part enlarged view of FIG. It is a principal part enlarged view in the other Example.

Explanation of symbols

1 MFP (image forming device)
8 Document Feeder 30 Main Body 38 Sheet Metal Case (Case)
40 Paper transport guide 41 Guide member 43 End face 44 Lower transport surface (transport surface)
46 Side surface 48 Boss 50 Compression coil spring 60 Static elimination member 62 Conductive tape (conductive plate)
68 Static elimination brush 80 Compression coil spring 84 Expanded end

Claims (6)

A resin-made guide member having a boss projecting toward the metal housing on its side surface, supported by the housing via the boss, and having a paper transport surface;
A neutralizing member that is provided on an end surface of the guide member that intersects the side surface, and that removes electric charges charged in the paper;
A metal compression coil spring having a natural length larger than the length of the boss, surrounding the boss, connecting the casing and the charge removal member, and grounding the charge removal member; A paper transport guide featuring: The paper transport guide according to claim 1,
The static elimination member is
A static elimination brush extending toward the conveying surface;
A paper conveyance guide comprising: a conductive plate that fixes the static eliminating brush to the end surface and is bent at a boundary between the end surface and the side surface to contact the compression coil spring. The paper conveyance guide according to claim 1 or 2,
The paper conveyance guide according to claim 1, wherein the compression coil spring has a diameter-increased end portion that is formed to expand from the housing toward the guide member and abuts against the charge removal member. A paper conveyance guide according to any one of claims 1 to 3,
The paper transport guide, wherein the guide member is rotatably supported by the housing via the boss.   An original feeding apparatus comprising the paper conveyance guide according to any one of claims 1 to 4. An image forming apparatus comprising the paper conveyance guide according to claim 1.

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