JP2001139183A - Image formation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the positioning accuracy between a photoreceptor drum and a conveyance guide and solve the problems such as lowering of picture quality and paper jam caused by the structure of the conventional image formation device that the photoreceptor drum is supported to an imaging frame fixed to a base member and the rotary shaft of the conveyance guide is supported by a sheet metal fixed to the base member. SOLUTION: The conveyance guide is supported (support point 20a) by the imaging frame 30 supporting (support point 14a) a photoreceptor drum. This constitution allows to position the conveyance guide and the photoreceptor drum by the same support member so as to hold the high positioning accuracy between the both and prevent the lowering of the picture quality and the paper jam caused by the positioning error.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus having an openable and closable conveyance guide for opening a conveyance path for transfer paper.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine or a printer, a transfer guide which constitutes one side of a transfer path is provided so that a transfer path of a transfer sheet is opened and a recovery operation at the time of paper jam can be easily performed. Are often attached to open and close. Incidentally, 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 form the basis of the apparatus main body. It was fixed to the base member. Further, the rotation axis of the transport guide is also supported by a support member (sheet metal or the like) fixed to the base member.

[0003]

However, in the above-described conventional image forming apparatus, for example, the photosensitive drum and the transport guide are, for example, three members such as an image forming frame, a base member, and a support member for the transport guide. Therefore, there is a problem that it is difficult to secure the positioning accuracy between the two. As more members are interposed between the members, positioning accuracy decreases due to accumulation of mounting errors of the 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 a deterioration in image quality and a paper jam. SUMMARY OF THE INVENTION 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. To provide.

[0004]

According to the present invention, there is provided an image forming apparatus comprising an openable and closable transport guide which forms one side of a transfer paper transport path. The image forming apparatus is configured to be supported by a support member that supports the photosensitive drum positioned on the transport path. This gives
Since the conveyance guide and the photosensitive drum are positioned by the same support member, the positioning accuracy between the two can be maintained high, and the deterioration of the image quality and the occurrence of paper jam due to the positioning error can be prevented. Further, when the transport guide is closed and the engaging portion that engages with the engaging claw attached to the transport guide and supports the transport guide is similarly attached to the support member, the transport guide can be mounted. Higher positioning accuracy between the conveyance guide and the photosensitive drum in the closed normal state can be further ensured. Further, if image forming means other than the photosensitive drum, for example, a transfer roller and a fixing roller, are attached to the support member, each image forming means is compared with a case where each image forming means is supported by an individual frame. The positioning accuracy between the transfer guide and the transfer guide can be ensured with high accuracy, and the space efficiency can be improved. Furthermore,
If the support member is also used as a main body frame of the image forming apparatus, high positioning accuracy of the entire apparatus can be ensured and space efficiency can be improved.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments and examples of the present invention will be described below with reference to the accompanying drawings to provide an understanding of the present invention. The following embodiments and examples are examples embodying the present invention, and do not limit the technical scope of the present invention. Here, FIG. 1 is a diagram showing an appearance of an 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 an internal configuration of the copying machine Z1,
FIG. 3 is an external perspective view of the copying machine Z1.

A copying machine Z1 according to the present embodiment is a small-sized copying machine as an example of an image forming apparatus according to the present invention, and as shown in FIG. In this configuration, a transfer sheet discharge section 2 is formed in the middle of the first and second sections. The internal configuration of the image forming section 1 of the copying machine Z1 will be briefly described with reference to FIG. At the bottom of the image forming section 1, a transfer paper tray 11 for storing transfer paper is provided. When the copying operation is started, the uppermost transfer paper on the transfer paper tray 11 is transferred to the paper feed roller 1.
2 and a pair of conveying rollers 13, 13, when passing between the photosensitive drum 14 and the transfer roller 15,
After the toner image formed on the photosensitive drum 14 is transferred by the developing device 18 and the like, and further the toner image is fixed by the fixing roller 16, the sheet is discharged onto the sheet discharging unit 2 by the sheet discharging roller 17. You. Here, the above copying machine Z
In FIG. 1, the photosensitive drums 14 and
The image forming means such as the developing device 18 and the fixing roller 16 are all shown in FIG.
Are positioned on one image forming frame 30 (an example of a supporting member) as shown in FIG. In FIG. 1, 14a is a support point of the photosensitive drum, 15a is a support point of the transfer roller,
17a is a support point of the fixing roller. Further, since the image forming frame 30 also serves as a main body frame of the copying machine Z1, high positioning accuracy of the entire apparatus can be secured and space efficiency is good.

Further, in the copying machine Z1, if a paper jam or the like occurs during the transfer of the transfer paper, the transfer path is opened so that the recovery operation can be easily performed by opening the transfer path. The guide 20 (shaded portion in FIG. 2) is configured to be openable and closable toward the outside of the main body. Here, the support point of the transport guide 20 is also changed to the photosensitive drum 14.
And the like (the reference numeral 20a in FIG. 1). Further, a swingable engagement claw 20b (FIG. 1) is attached to the conveyance guide 20, and when the conveyance guide 20 is closed, the engagement claw 20b is brought into contact with an engagement portion 31 (FIG. 1). Although the closed state is locked by engagement, the engagement portion 31 is also mounted on the image forming frame 30. That is, the swing support point of the transport guide 20, the engaging portion 31 with which the engaging claw 20b is engaged, the photosensitive drum 14, and other image forming portions are all the same image forming frame 30.
Since it is supported above, the positioning accuracy between the transport guide 20 and the photosensitive drum 14 and other image forming units can be kept high, and it is possible to prevent image quality deterioration and paper jam due to positioning errors.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS 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.
The present invention is applicable to any image forming apparatus such as a large-sized copying machine and a printer.

[0009]

As described above, the present invention relates to an image forming apparatus including an openable and closable conveyance guide which forms one side of a transfer paper conveyance path, wherein the conveyance guide is positioned on the conveyance path. The image forming apparatus is configured to be supported by a supporting member that supports the photosensitive drum, and thus the transport guide and the photosensitive drum are positioned by the same supporting member, and the The positioning accuracy can be maintained high, and the deterioration of image quality and the occurrence of paper jam due to the positioning error can be prevented. Further, when the transport guide is closed and the engaging portion that engages with the engaging claw attached to the transport guide and supports the transport guide is similarly attached to the support member, the transport guide can be mounted. Higher positioning accuracy between the conveyance guide and the photosensitive drum in the closed normal state can be further ensured. Further, if image forming means other than the photosensitive drum, for example, a transfer roller and a fixing roller, are attached to the support member, each image forming means is compared with a case where each image forming means is supported by an individual frame. The positioning accuracy between the transfer guide and the transfer guide can be ensured with high accuracy, and the space efficiency can be improved. Further, if the supporting member is also used as a main body frame of the image forming apparatus, high positioning accuracy of the entire apparatus can be secured and space efficiency is improved.

[Brief description of the drawings]

FIG. 1 is a view showing an 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 schematically showing an internal configuration of the copying machine Z1.

FIG. 3 is an external perspective view of the copying machine Z1.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 14 ... Photoreceptor drum 15 ... Transfer roller 16 ... Fixing roller 18 ... Developing device 20 ... Transport guide 20b ... Engagement claw 30 ... Image forming frame (an example of a support member) 31 ... Engagement part

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kenichi Tanabe 1-2-28 Tamazo, Chuo-ku, Osaka Mita Kogyo Co., Ltd. (72) Inventor Naoki Mizutani 1-2-28 Tamazo, Chuo-ku, Osaka Mita Kogyo Co., Ltd. (72) Inventor Hirotaka Kawakita 1-2-28 Tamazuki, Chuo-ku, Osaka-shi Mita Kogyo Co., Ltd. (72) Inventor Tetsuro Tomoe 1-2-28 Takuma-zo, Chuo-ku, Osaka Mita Kogyo Co., Ltd. F term (reference) 2H071 AA13 AA42 BA04 BA14 BA16 BA36 DA08 DA09 DA12 DA15 DA22 DA23 DA24 EA04 EA06 3F049 AA04 DA12 DB02 LA02 LB03 3F101 FB04 FE02 FE08 LA02 LB03

Claims (4)

[Claims] 1. An image forming apparatus comprising: an openable and closable conveyance guide forming one side of a transfer paper conveyance path;
An image forming apparatus, wherein the transport guide is supported by a support member that supports a photosensitive drum positioned on the transport path. 2. The method according to claim 1, further comprising: an engaging portion that engages with an engaging claw attached to the conveyance guide to support the conveyance guide when the conveyance guide is closed. The image forming apparatus according to claim 1. 3. The image forming apparatus according to claim 1, wherein an image forming means other than the photosensitive drum is further attached to the support member. 4. The image forming apparatus according to claim 1, wherein said support member also functions as a main body frame of said image forming apparatus.