JP3633838B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus provided with an openable / closable conveyance guide for opening a transfer sheet conveyance path.
[0002]
[Prior art]
In image forming apparatuses such as copiers and printers, the conveyance guides that make up one side of the conveyance path are attached so that they can be opened and closed easily so that the transfer paper conveyance path can be opened to facilitate recovery work when a paper jam occurs. It is often done.
By the way, in such a conventional image forming apparatus, image forming means such as a photosensitive drum, a developing device, and a fixing device are supported by one or more image forming frames, and these image forming frames are the basis of the apparatus main body. It was fixed to the base member. Further, the rotation axis of the conveyance guide is also supported by the image forming frame fixed to the base member.
[0003]
[Problems to be solved by the invention]
However, the conventional image forming apparatus as described above, for example, a photosensitive drum and conveying guides, image forming frame, to be positioned through the base member, and referred to as the transport guide for example three members, both There is a problem that it is difficult to ensure positioning accuracy. As more members are interposed, the positioning accuracy decreases due to the accumulation of attachment errors of the respective members. If the positioning accuracy between the conveyance guide and the photosensitive drum is low, the transfer paper cannot be accurately conveyed to the transfer unit or the like, which causes image quality degradation or paper jam.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an image forming apparatus capable of ensuring positioning accuracy between a conveyance guide and a photosensitive drum or other image forming means. Is to provide.
[0004]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention , an image reading unit is provided on the entire upper surface, and the transfer paper stored in a transfer paper tray provided at the lowermost part is passed through an image forming unit having a vertical conveyance path. The image forming process is performed, and the image-formed transfer sheet is discharged to a paper discharge unit provided above the image forming unit and below the image reading unit.
The vertical conveyance path has a fixed-side conveyance guide provided in an image forming frame including a photosensitive drum, and a movable-side conveyance guide that can be opened and closed by rotating with respect to the fixed-side conveyance guide. In an image forming apparatus formed between
A rotation support point of the movable conveyance guide is provided at an end of the movable conveyance guide on the transfer paper tray side, and the movable conveyance guide supports the photosensitive drum. The image forming apparatus is configured to be supported by an image forming frame .
As a result, since the conveyance guide and the photosensitive drum are positioned by the same image forming frame , the positioning accuracy between the two can be maintained high, and image quality degradation and paper jam caused by positioning errors can be prevented.
Further, in a state where the conveyance guide of the movable side is closed, the same applies to the engaging portion for supporting the conveyance guide of the movable-side engaged with the engaging claw which is attached to the conveying guide of the movable above If it is attached to the image forming frame , the positioning accuracy between the movable conveyance guide and the photosensitive drum in the normal state with the conveyance guide closed can be further ensured.
Further, in the image forming frame, further said image forming means other than the photosensitive drum, such as transcription by attaching a roller or a fixing roller or the like, each image forming as compared with the case those supported by each individual frame of each image forming means In addition to ensuring high positioning accuracy between the means or the movable conveyance guide, space efficiency is also improved.
Further, the image forming frame, if also used as a main frame of the image forming apparatus, the positioning accuracy of the entire device can be secured high, space efficiency is also improved.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments and examples of the present invention will be described below with reference to the accompanying drawings for understanding of the present invention. It should be noted that the following embodiments and examples are examples embodying the present invention and do not limit the technical scope of the present invention.
FIG. 1 is a diagram showing the appearance of the image forming frame 30 of the copying machine Z1 according to the embodiment of the present invention, FIG. 2 is a diagram showing an outline of the internal configuration of the copying machine Z1, and FIG. 3 is the copying machine. It is an external appearance perspective view of Z1.
[0006]
The copying machine Z1 according to the present embodiment is a small-sized copying machine as an example of the image forming apparatus according to the present invention. As shown in FIG. A transfer paper discharge section 2 is formed in the middle.
The internal configuration of the image forming unit 1 of the copying machine Z1 will be briefly described with reference to FIG. A transfer paper tray 11 in which transfer paper is stored is provided at the bottom of the image forming unit 1. When the copying operation is started, the uppermost transfer paper on the transfer paper tray 11 is transported by the paper feed roller 12 and the transport roller pairs 13 and 13 and passes between the photosensitive drum 14 and the transfer roller 15. When the toner image formed on the photosensitive drum 14 is transferred by the developing device 18 and the like, and the toner image is fixed on the fixing roller 16, the paper discharge roller 17 moves the toner image onto the paper discharge unit 2. The paper is discharged.
Here, in the copying machine Z1, the image forming means such as the photosensitive drum 14, the developing device 18, the fixing roller 16 and the like are all in one image forming frame 3 as shown in FIG. Positioned on 0 . In FIG. 1, reference numeral 14a is a support point for the photosensitive drum, 15a is a support point for the transfer roller, and 17a is a support point for the fixing roller. Furthermore, since the image forming frame 30 also serves as the main body frame of the copying machine Z1, the positioning accuracy of the entire apparatus can be ensured with high space efficiency.
[0007]
Further, in the copying machine Z1, when a paper jam or the like occurs during the transfer of the transfer paper, the transfer guide 20 (one side of the transfer path is configured so that the transfer path can be opened and the restoration work can be easily performed. 2 is configured to be openable and closable toward the outside of the main body. Here, for the support point 20a of the conveying guide 20, that is formed on the same said image forming frame 30 and the photosensitive drum 14 or the like. As shown in FIG. 1, the support point 20a is provided at the end of the transport guide 20 on the transfer paper tray 11 (see FIG. 2) side. Furthermore, a swingable engaging claw 20b (FIG. 1) is attached to the transport guide 20, and when the transport guide 20 is closed, the engaging claw 20b is engaged with the engaging portion 31 (FIG. 1). Although the closed state is locked by engaging, the engaging portion 31 is also mounted on the image forming frame 30. That is, the swing support point of the conveyance guide 20, the engaging portion 31 with which the engaging claw 20 b engages, and the photosensitive drum 14 and other image forming portions are all supported on the same image forming frame 30. Positioning accuracy between the conveyance guide 20 and the photosensitive drum 14 and other image forming units can be maintained high, and image quality degradation and paper jams caused by positioning errors can be prevented.
[0008]
【Example】
In the above embodiment, a small copying machine as shown in FIG. 3 has been described as an example. However, the present invention is not limited to this, and a large copying machine or printer can be used as long as it has an openable / closable conveyance guide. The present invention can be applied to any image forming apparatus.
[0009]
【The invention's effect】
As described above, according to the present invention , the image reading unit is provided on the entire upper surface, and the transfer paper stored in the transfer paper tray provided on the lowermost part passes through the image forming unit provided with the vertical conveyance path. The image forming process is performed and the image-formed transfer sheet is discharged to a paper discharge unit provided above the image forming unit and below the image reading unit.
The vertical conveyance path has a fixed-side conveyance guide provided in an image forming frame including a photosensitive drum, and a movable-side conveyance guide that can be opened and closed by rotating with respect to the fixed-side conveyance guide. In an image forming apparatus formed between
A rotation support point of the movable conveyance guide is provided at an end of the movable conveyance guide on the transfer paper tray side, and the movable conveyance guide is supported by the imaging frame. Therefore , the conveyance guide and the photosensitive drum are positioned by the same image forming frame, so that the positioning accuracy between them can be maintained high, and the positioning error can be reduced. It can prevent image quality degradation and paper jams.
Further, in a state where the conveyance guide of the movable side is closed, the same applies to the engaging portion for supporting the conveyance guide of the movable-side engaged with the engaging claw which is attached to the conveying guide of the movable above If it is attached to the image forming frame , the positioning accuracy between the movable-side conveyance guide and the photosensitive drum in the normal state in which the movable-side conveyance guide is closed can be further ensured.
Further, in the image forming frame, further said image forming means other than the photosensitive drum, such as transcription by attaching a roller or a fixing roller or the like, each image forming as compared with the case those supported by each individual frame of each image forming means The positioning accuracy between the means or the movable conveyance guide can be ensured high, and the space efficiency can be improved.
Further, the image forming frame, if also used as a main frame of the image forming apparatus, the positioning accuracy of the entire device can be secured high, space efficiency is also improved.
[Brief description of the drawings]
FIG. 1 is a diagram showing an external appearance of an image forming frame 30 of a copying machine Z1 according to an embodiment of the present invention.
FIG. 2 is a diagram showing an outline of the internal configuration of the copying machine Z1.
FIG. 3 is an external perspective view of the copying machine Z1.
[Explanation of symbols]
14 ... photosensitive drum 15 ... transfer roller 16 ... fixing roller 18 ... developing device 20 ... transport guide 20b ... engaging claws 30 ... imaging frames
3 1... Engaging portion

Claims (4)

An image reading unit is provided on the entire upper surface, and the transfer paper stored in the transfer paper tray provided at the lowermost part is subjected to image formation processing via an image forming unit having a vertical conveyance path, and an image has been formed. The transfer paper is discharged to a paper discharge unit provided above the image forming unit and below the image reading unit,
The vertical conveyance path has a fixed-side conveyance guide provided in an image forming frame including a photosensitive drum, and a movable-side conveyance guide that can be opened and closed by rotating with respect to the fixed-side conveyance guide. In an image forming apparatus formed between
Conveying guide of the rotation supporting point of the movable side, it becomes provided at the end of the transfer tray side of the conveyance guide of the movable side, the conveyance guide of the movable side is supported by the image forming frame An image forming apparatus comprising: Further, the state in which the conveyance guide is closed the movable side, the movable-side engaging portion above image forming frame supporting the conveyance guide of the conveyor engaging claw which is attached to the guide and engaged with the movable side of the The image forming apparatus according to claim 1, wherein the image forming apparatus is attached to the apparatus. The image forming apparatus according to claim 1, wherein image forming means other than the photosensitive drum is further attached to the image forming frame . The image forming frame is, the image forming apparatus according to claim 1 which also serves as the main frame of the image forming apparatus.

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