JPH0590521U - Image forming device - Google Patents

Abstract

(57) [Summary] [Purpose] It is not necessary to provide separate paper guides on the upstream side and the downstream side of the transfer device, the number of parts is reduced, manufacturing cost is reduced, and the paper guide is provided to the transfer device. Enable accurate positioning. [Structure] A base 25 made of synthetic resin is fixed on the upper surface of a support plate 23, and a permanent magnet 27 is mounted on the base 25.
Attach. The transfer device 8 is detachably attached to the permanent magnet 27 and is arranged along the axial direction so as to face the photosensitive drum 2. A paper guide 11 for guiding the recording paper P is provided between the photosensitive drum 2 and the transfer device 8 on the upstream side of the transfer device 8. A paper guide 17 for guiding the recording paper P after transfer to the heat fixing device 14 on the downstream side is provided on the downstream side of the transfer device 8. The lower paper guide 32 and the paper guide 17 of the paper guide 11 are integrally molded with the base 25,
One synthetic resin molded body S is used.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an image forming apparatus in which a toner image on a photoconductor is transferred onto a sheet by a transfer device, and more specifically, to a configuration including a paper guide provided upstream and downstream of the transfer device. Is.

[0002]

[Prior Art]

 In this type of image forming apparatus, the transfer device and the guide roller are arranged so as to face the photosensitive drum, and the paper is guided by the paper guide and fed between the photosensitive drum and the guide roller. There is. Then, the sheet is brought into close contact with the photosensitive drum by the guide roller, and a predetermined potential is applied to the close contact portion by the transfer device, so that the toner image on the photosensitive drum is transferred onto the sheet. Then, the paper after transfer is guided to a paper guide provided on the downstream side of the transfer device and sent to a heat fixing device, and the toner image on the paper is heat fixed.

By the way, generally, the transfer device is detachably mounted on the base in the main body of the apparatus for maintenance or the like, but in the conventional image forming apparatus, it is arranged on the upstream side and the downstream side of the transfer device. The formed paper guide was manufactured separately from the base.

[0004]

[Problems to be solved by the device]

 Therefore, it is necessary to separately manufacture these paper guides separately from the base, and it is also necessary to separately attach each paper guide manufactured separately, which increases the number of parts. There is a problem that the manufacturing cost rises because the number of assembling steps increases.

Further, in order to reliably guide the paper to the image forming portion between the photosensitive drum and the transfer device, or to reliably guide the paper after the transfer to the downstream side, each paper guide is used. Must be accurately positioned with respect to. However, as described above, if each paper guide is attached separately from the base that supports the transfer device, it becomes difficult to accurately position the paper guide with respect to the transfer device, which may hinder the guide of the paper. Jam may occur or the quality of the transferred image may deteriorate.

The present invention has been made in order to solve the above problems, and its purpose is to reduce the number of parts because it is not necessary to separately provide the paper guides on the upstream side and the downstream side of the transfer machine. Therefore, it is an object of the present invention to provide an image forming apparatus capable of reducing the manufacturing cost and accurately positioning the paper guide with respect to the transfer device.

[0007]

[Means for Solving the Problems]

 In order to achieve the above object, in the present invention, a transfer device is supported on a base so as to face the photoconductor, and a paper guide guides the paper between the photoconductor and the transfer device. An image forming apparatus configured to transfer a toner image on a photoconductor onto a sheet and to guide the transferred sheet to a downstream side by another sheet guide. At least one of them is molded integrally with the base.

[0008]

[Action]

 Therefore, according to the present invention, since at least one of the upstream and downstream paper guides of the transfer device is integrally formed with the base supporting the transfer device, the paper guides can be manufactured independently. In addition, the positional relationship with the transfer device supported on the base is accurate.

[0009]

【Example】

 Hereinafter, an embodiment embodying the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, a photosensitive drum 2 as a photosensitive member is rotatably supported on the apparatus frame 1. The charger 3 uniformly charges the outer peripheral surface of the photosensitive drum 2 to a predetermined potential. The exposure device 4 forms an electrostatic latent image of a predetermined potential on the photosensitive drum 2 by irradiation of light. The developing device 5 has a toner case 6 for containing the toner T and a developing roller 7. Then, a predetermined potential is applied to the toner T by the developing roller 7, and the toner T is attached to the electrostatic latent image based on the difference between the potential and the potential of the electrostatic latent image, and the electrostatic latent image is attached. The image is visualized.

The transfer unit 8 and the guide roller 9 rotatably supported by the transfer unit 8 are arranged so as to face the photosensitive drum 2 with a sheet transfer path interposed therebetween. Then, the recording paper P, which is a paper that has been transported through the pair of feed rollers 10 and the pair of upper and lower paper guides 11, is brought into close contact with the photosensitive drum 2 by the guide rollers 9, and is also transferred by the transfer device 8. A predetermined potential is applied to the contact portion, and the toner image is transferred onto the recording paper P based on the difference between the potential and the potential of the toner image. The charge eliminating lamp 12 irradiates the outer peripheral surface of the photosensitive drum 2 after transfer with light to eliminate the charge on the outer peripheral surface. The cleaner 13 cleans the residual toner on the photosensitive drum 2.

The heating and fixing device 14 is disposed on the downstream side of the photosensitive drum 2, and has a heating roller 15 and a pressure roller 16 which comes into contact with the heating roller 15 with a paper transfer path interposed therebetween. Then, the recording paper P is fed between the heating roller 15 and the pressing roller 16 via the paper guides 17 and 18, and the toner image on the recording paper P is heated and fixed.

As shown in FIGS. 1 and 2, the device frame 1 has a pair of left and right support plates 21 and 22 made of a metal plate, and the support plates 21 and 22 have mounting pieces 21 a and 22 a, respectively. It is bent inward. The support plate 23 is installed between the mounting pieces 21a and 22a, and one side edge thereof is bent upward to form a mounting portion 23a. A substrate 24 is attached to the mounting portion 23a so as to extend along the axial direction of the photosensitive drum 2, and a large number of LEDs 12a are arranged side by side on the substrate 24 to form the charge eliminating lamp 12 described above. There is.

A base 25 made of synthetic resin is fixed to the upper surface of the support plate 23 with screws 26, and a pair of permanent magnets 27 are mounted on the base 25. Engagement recesses 21b and 22b that can engage with both ends of the transfer unit 8 are cut out at the upper edges of the support plates 21 and 22.

Then, when both ends of the transfer unit 8 are engaged with the engaging recesses 21 b and 22 b of the support plates 21 and 22 from above, the transfer unit 8 is attracted to the permanent magnet 27 and is attached to the apparatus frame 1. The transfer unit 8 is detachably attached, and the transfer unit 8 is arranged so as to extend along the axial direction of the photosensitive drum 2.

As shown in FIGS. 1 and 2, the lower paper guide 32 of the paper guide 11 is integrally formed at the upstream edge of the base 25, and the downstream edge of the base 25 is formed. The sheet guide 17 is integrally formed in the section via a pair of left and right connecting plates 33. The lower paper guide 32 is composed of a guide plate 32a and auxiliary plates 32b and 32c integrally formed in a bent state on the upstream and downstream edges of the guide plate 32a, and has a substantially U-shaped cross section as a whole. And has openings 32d at both ends. The lower edge of the auxiliary plate 32c on the downstream side of the guide plate 32a is integrally connected to the upstream edge of the base 25.

The paper guide 17 is composed of a guide plate 17a and an auxiliary plate 17b integrally formed in a bent state at a downstream edge of the guide plate 17a. The connecting plate 33 is integrally formed. The arm portion 33a of the connecting plate 33 is integrally connected to the downstream edge portion of the base 25.

That is, the base 25, the lower paper guide 32, and the paper guide 17 are integrally molded of synthetic resin to form a synthetic resin molded body S. As described above, the synthetic resin molded body S is a support plate. It is fixed by screws 26 on a support plate 23 that is erected between the mounting pieces 21a and 22a of the parts 21 and 22. The upper paper guide 31 of the paper guide 11 is fixed to the lower paper guide 32 or the mounting pieces 21a and 22a of the support plates 21 and 22 by screws (not shown) or the like.

In the image forming apparatus of this embodiment, the lower sheet guide 32 and the sheet guide 17 arranged on the upstream side and the downstream side of the transfer device 8 support the transfer device 8 via the permanent magnet 27. It is molded integrally with the base 25 to form one synthetic resin molded body S. Therefore, since the lower paper guide 32 and the paper guide 17 are formed at the same time when the base 25 is manufactured, it is not necessary to separately manufacture the paper guides unlike the above-mentioned conventional method, and the labor required for the manufacture can be saved. In addition, the number of parts can be reduced, and the manufacturing cost can be reduced. The lower paper guide 32 and the paper guide 17 are attached to the apparatus frame 1 at the same time when the base 25 is mounted on the support plate 23. Therefore, the lower paper guide 32 and the paper guide 17 are attached separately. There is no need, and the labor required for its installation can be saved.

Further, as described above, since the lower paper guide 32 and the paper guide 17 are integrally formed with the base 25 supporting the transfer device 8, the lower paper guide 32 and the paper guide 17 are transferred to the transfer device 8. 8 can be accurately positioned. That is, unlike the case where the paper guide is manufactured separately and attached separately from the base that supports the transfer device, the arrangement positions of the lower paper guide 32 and the paper guide 17 with respect to the base 25 do not change. Therefore, the positional relationship among the transfer device 8 supported on the base 25 and the lower paper guide 32 and the paper guide 17 can be made accurate. Therefore, the recording paper P can be reliably guided between the photosensitive drum 2 and the transfer device 8, and the recording paper P after transfer can be reliably guided to the heat fixing device 14 on the downstream side. There is no possibility of causing any trouble in the above, and there is no fear of causing a jam or deteriorating the quality of the transferred image.

Further, although the synthetic resin molded body S is large in the sheet transfer direction by the above-mentioned integral molding, the molded body S is not a simple flat plate shape but a substantially inverted U-shaped cross section. A lower paper guide 32, a paper guide 17 including a guide plate 17a and an auxiliary plate 17b integrally formed on the guide plate 17a in a bent state, and a connecting plate 33 integrally formed on both sides of the paper guide 17 Since it has a three-dimensional shape that is bent up and down and left and right, it has excellent mechanical strength, and there is no risk of bending or distorting assembly accuracy.

The present invention is not limited to the above-described embodiment. For example, the upper paper guide 31 of the paper guide 11 is integrally formed with the base 25, or one of the lower paper guide 32 and the paper guide 17 is used. The configuration of each part is arbitrarily changed without departing from the spirit of the present invention, such as integrally molding only one side with the base 25 or appropriately changing the shapes of the base 25, the lower paper guide 32, and the paper guide 17. It is also possible to materialize by doing so.

[0022]

[Effect of the device]

 As described above in detail, according to the present invention, it is not necessary to separately provide the paper guides on the upstream side and the downstream side of the transfer device, the number of parts can be reduced, the manufacturing cost can be reduced, and the paper guide can be reduced. It has the excellent effect that it can be accurately positioned with respect to the transfer device.

[Brief description of drawings]

FIG. 1 is a partial sectional view showing an embodiment of an image forming apparatus embodying the present invention.

FIG. 2 is a partial plan view showing a state in which a transfer device is removed.

[Explanation of symbols]

2 ... Photosensitive drum as photoconductor, 8 ... Transfer device, 11 ... Paper guide, 17 ... Paper guide, 25 ... Base, 32 ... Lower paper guide, P ... Recording paper as paper, S ... Synthetic resin molding.

Claims (1)

[Scope of utility model registration request] 1. A transfer device is supported on a base so as to face the photoconductor, a paper guide guides the paper between the photoconductor and the transfer device, and the transfer device transfers the toner image on the photoconductor to the paper. In an image forming apparatus in which the transfer is performed on the upper side and the transferred sheet is guided to the downstream side by another sheet guide, at least one of the upstream side and downstream side sheet guides of the transfer device is integrated with the base. Image forming device molded into a.