JP3836268B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus applied to a copying machine, a printer, a facsimile apparatus, and a composite device thereof using an electrophotographic process, and more particularly, to guide conveyance of recording paper conveyed to an image fixing apparatus. It relates to a transport structure.
[0002]
[Prior art]
In an electrophotographic apparatus equipped with an electrophotographic process, a recording sheet on which a toner image is fixed from a photoreceptor and an unfixed toner image is formed on an image surface is added to a fixing roller (heating roller) in the fixing apparatus. The image is fixed by heating and pressing with a pressure roller.
[0003]
FIG. 5 is an explanatory view showing the state of conveyance of the recording paper in the vicinity of the conventional fixing device. Reference numeral 1 denotes a fixing roller having a heating means (not shown) built therein, and 2 is in pressure contact with the fixing roller 1. A pressure roller, 3 is a fixing entrance guide plate that guides conveyance of the recording paper P, and 4 is a post-transfer guide that guides the recording paper P conveyed from the transfer means (not shown) side toward the fixing entrance guide plate 3. A post-transfer guide plate 4 is not shown in detail, but is provided in the apparatus main body so as to be openable and closable so that jammed paper generated in the conveyance path in this portion can be removed from the outside. It is provided in a part of the cover body.
[0004]
[Problems to be solved by the invention]
In the recording paper transport mechanism at the entrance portion of the conventional fixing device, as shown in FIG. 5, the fixing entrance guide plate 3 and the post-transfer guide plate 4 are separated, and a gap A is provided at the joint portion. This gap A is provided so as not to hinder the post-transfer guide plate 4 from opening and closing for the above-described reason.
[0005]
For this reason, as shown in FIG. 6 in particular, when the recording paper P with curl is conveyed so that the leading end faces the gap A, the leading edge of the recording paper P enters the gap A, and the recording paper P may cause jamming. Similarly, the presence of the gap A may cause a trouble in conveyance even on a recording sheet having a burr or a scratch at the leading end.
[0006]
The present invention solves the above-described conventional problems, and enables an image forming apparatus capable of satisfactorily transporting a curled recording paper or a recording paper having burrs or scratches at the leading end to a fixing device. The purpose is to provide.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a first guide portion for guiding recording paper, a second guide portion provided downstream of the first guide portion in the recording paper conveyance direction, and the second guide. In the image forming apparatus, the first image forming apparatus includes a cover body that is provided integrally with the image forming unit and that is configured to be openable and closable on the apparatus main body in order to remove jammed paper in the recording paper conveyance path. and a guide portion downstream with said second guide portion upstream of and arranged to cross the each other physician, in the intersection between the first guide portion and the second guide portion, said first The recording paper transport path surface side and the downstream end of the guide section of the first guide section protrude from the second guide section into the recording paper transport path . With this configuration, the first guide section and The second guide continuing to the first guide portion Since the side end portion is configured to overlap with, it is possible to eliminate the gap at the joint portion of the guide portion, trouble on the transport of the recording paper by a conventional Such gaps can be avoided in advance.
[0008]
Further, according to the present invention, the side ends of the first guide part or the second guide part have a comb-teeth shape, and with this configuration, the cover body can be easily opened and closed without any trouble by a simple structure. The overlapping state as described above can be achieved.
[0009]
In the present invention, any one of the first guide part and the second guide part is formed by a film body, and this configuration makes it easy to form the comb-tooth shape. At the same time, the sliding resistance of the recording paper can be reduced, and the transport movement at the seam becomes smooth.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
[0011]
FIG. 1 is a cross-sectional view showing a schematic configuration of a printer using an electrophotographic process for explaining an embodiment of the present invention. 10 is a printer main body, 11 is a drum-shaped photoconductor, 12 is a toner developing portion, transfer roller 14 is sheet cassette recording paper P _N which is cut to a predetermined size is accommodated, 15 paper feed roller, 16 is a resist roller, 17 is a heating means (not shown) is incorporated in the a fixing roller 1, which is a fixing device provided with a pressure roller 2 which is pressed against the fixing roller 1, 18 denotes a fixing entrance guide plate, 19 is a discharge roller, P ₁ is the conveyance of the recording sheet It is a route.
[0012]
21 is disposed under the printer body 10, to cut the roll paper P _R to any size a roll paper feeding device for feeding to the conveying path P ₁ of the printer body 10, 22 denotes a paper feed roller, 23 the cutter unit 24 is conveying roller installed in place, 25 denotes a guide plate, P ₂ is the conveying path of the recording paper.
[0013]
In this example, 27 is a cover body that covers the conveyance path P ₁ portion from the portion where the registration roller 16 is installed to the vicinity of the fixing device 17, and is provided on the printer main body 10 so as to be rotatable around the support shaft 28. This is a post-transfer guide plate part that is provided integrally with a part of the cover body 27 and constitutes a part of the transport path P ₁ .
[0014]
FIG. 2 is a configuration diagram showing a recording paper conveyance guide in the vicinity of the fixing device 17, and a post-transfer guide plate portion on the upstream side in the conveyance direction of the fixing entrance guide plate portion (second guide portion) 18 in the vicinity of the fixing device 17. (1st guide part) It installs so that it may overlap in the conveyance direction downstream side of 29. FIG. With this configuration, there is no gap at the joint between the fixing entrance guide plate portion 18 and the post-transfer guide plate portion 29, and the recording paper conveyance guide is smoothly performed across the guide plate portions 18 and 29.
[0015]
In FIG. 1, a standard size recording sheet _PN is fed from the sheet feeding cassette 14 to the registration roller 16 one by one from the sheet feeding roller 15, and the toner image formed on the surface of the photosensitive member 11 is transferred to the recording sheet _PN. Then, the image is transferred by the transfer roller 13. After transfer, the recording sheet P _N having the unfixed toner image is fed to the fixing device 17, is the image fixing by receiving heat and pressure, then, it is discharged to the printer main body 10 outside the discharge roller 19.
[0016]
In roll paper feeding apparatus 21, pull out the roll paper P _R due feeding roller 22, to cut the roll paper P _R to the size specified by the cutter unit 23, the roll paper P _R was the cut, transport It is sent to the conveyance path P ₁ of the printer body 10 through the path P ₂ .
[0017]
In the printer body 10, the roll paper P _R is similar to the above is sent to the registration rollers 16, the toner image formed on the photosensitive member 11 surface is transferred by the transfer roller 13. After transfer, the roll paper P _R having the unfixed toner image is fed to the fixing device 17, is the image fixing by receiving heat and pressure, then, it is discharged to the printer main body 10 outside the discharge roller 19.
[0018]
When transporting the recording paper to the fixing device 17, since the joint portion between the fixing entrance guide plate portion 18 and the post-transfer guide plate portion 29 is overlapped and there is no gap, the recording paper is continuously spread over both the guide plate portions 18 and 29. Even if a roll paper P _R with a roll roll or a recording paper P _N with a burr or a flaw at the tip is conveyed, a post-transfer guide plate Smooth movement from the portion 29 to the fixing entrance guide plate portion 18 can eliminate troubles in conveying the recording paper.
[0019]
As described above, the fixing entrance guide plate 18 and the post-transfer guide plate 29 are overlapped with each other, and the cover body 27 having the post-transfer guide plate 29 is opened and closed without any trouble. In the embodiment, as shown in FIG. 3, comb-like portions 18 a having an uneven shape are formed on the side of the fixing entrance guide plate portion 18 on the upstream side in the conveyance direction, while the cover body is formed as shown in FIG. 4. 27, a post-transfer guide plate 29 is integrally formed with a rib structure 30 on the inner wall 27, and when the cover 27 is in a closed state, the comb-teeth 18a of the fixing entrance guide plate 18 is shown in FIG. The unevenness and the unevenness of the rib structure 30 which is the post-transfer guide plate portion 29 are alternately inserted.
[0020]
As shown in FIGS. 3 and 4, by forming the fixing entrance guide plate portion 18 and the post-transfer guide plate portion 29, a gap is formed at the joint portion between the fixing entrance guide plate portion 18 and the post-transfer guide plate portion 29. In addition, when the cover body 27 is opened and closed, the post-transfer guide plate portion 29 provided integrally with the cover body 27 can be moved from the fixing entrance guide plate portion 18 without any trouble.
[0021]
In this example, the fixing entrance guide plate portion 18 is formed of a plastic thin film body (for example, a film of polyethylene terephthalate resin), thereby forming the comb-like portion 18a in the fixing entrance guide plate portion 18. In addition, the sliding resistance between the guide member and the recording paper is reduced even if the leading edge of the recording paper being conveyed has burrs or scratches, so that the recording paper is guided smoothly.
[0022]
【The invention's effect】
As described above, according to the present invention, a first guide portion, have side edge portions overlapping engagement with the second guide part comprising communicating et to the first guide portion, and the first guide portion In this case, the end on the recording paper conveyance path surface side and the downstream side protrudes into the recording paper conveyance path from the second guide portion , so that a gap can be eliminated in the joint portion between the two guide portions, as in the prior art. It is possible to avoid troubles in conveying the recording paper due to a gap.
[0023]
In addition, since the first guide portion or the second guide portion is a comb-teeth shape or a film body, the overlapping state as described above can be achieved with a simple structure without hindering the opening / closing operation of the cover body. Can be.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a schematic configuration of a printer using an electrophotographic process for explaining an embodiment of the present invention. FIG. 2 is a configuration diagram showing a conveyance guide for recording paper in the vicinity of a fixing device in the present embodiment. FIG. 3 is a perspective view showing a fixing entrance guide plate part in the present embodiment. FIG. 4 is a perspective view showing a cover body and a post-transfer guide plate part in the embodiment. FIG. FIG. 6 is an explanatory diagram illustrating a state. FIG. 6 is an explanatory diagram for explaining a problem of a recording paper conveyance state in the vicinity of a conventional fixing device.
17 Fixing device 18 Fixing entrance guide plate portion 18a Comb-shaped portion 27 Cover body 29 Guide plate portion 30 after transfer Rib structure

Claims (3)

A first guide portion for guiding the recording paper; a second guide portion provided downstream of the first guide portion in the recording paper conveyance direction; and the recording paper provided integrally with the second guide portion. In an image forming apparatus provided with a cover body that can be opened and closed in the apparatus main body in order to be able to remove jammed paper in the conveyance path,
An upstream side of the downstream side of the second guide portion of said first guide section is arranged so as to intersect each other physician, in the intersection between the first guide portion and the second guide portion An image forming apparatus characterized in that an end of the first guide portion on the recording paper conveyance path surface side and on the downstream side protrudes into the recording paper conveyance path from the second guide portion . The image forming apparatus according to claim 1, wherein a side end of the first guide portion or the second guide portion has a comb-teeth shape. The image forming apparatus according to claim 1, wherein one of the first guide part and the second guide part is formed of a film body.

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