JP2008139548A - Image forming apparatus - Google Patents

Abstract

An object of the present invention is to provide an image forming apparatus that reduces a space for projecting sideways from an apparatus main body.
First and second image forming units that are arranged across a substantially vertical sheet conveyance path and transfer images onto both sides of a sheet conveyed through the sheet conveyance path, and transferred onto both sides of the sheet A fixing unit for fixing an image; a first paper feeding unit disposed below the first image forming unit; a second paper feeding unit disposed below the second image forming unit; A first moving mechanism for slidingly moving the second image forming unit to the side of the apparatus main body.
[Selection] Figure 1

Description

  The present invention relates to an image forming apparatus.

  In recent years, in electrophotographic image forming apparatuses such as copying machines and printers, there is a growing need for forming images on both sides of a transfer material from the viewpoint of environmental considerations, and at the same time, it is required to improve productivity when forming double-sided images. ing.

  On the other hand, with conventional electrophotographic image forming apparatuses, when images are formed on both sides of a transfer material, an unfixed image is once formed on one side, heat-fixed, and then an unfixed image is formed on the other side. Then, heat fixing was performed again. Therefore, the heat curl and moisture content of the transfer material due to the first heat fixing affect the second image formation, and one surface is fixed once and the other surface is fixed. There are problems such as a difference in image quality between the front and back of the transfer material due to the two thermal fixings.

  In order to solve the above problems, various proposals have been made for the double-sided simultaneous image forming apparatus (see Patent Document 1 and Patent Document 2).

FIG. 7 is a schematic front view of a color double-sided simultaneous image forming apparatus main body with high duplex productivity. The toner image forming apparatus V is disposed symmetrically. Each of the photoconductors PRY, PRM, PRC, PRK is uniformly charged by the respective charging rolls CRY, CRM, CRC, CRK, and then laser light LY,
An electrostatic latent image is formed on the surface by LM, LC, and LK. The electrostatic latent image is stored in the developing units GY, GM,
The toner image is developed by GC and GK. The developed toner images are transferred to the first intermediate transfer belt B1 and the second intermediate transfer belt B2 in the primary transfer areas Q3Y, Q3M, Q3C, and Q3K, respectively.

Further, a secondary transfer device (double-sided simultaneous transfer device) T2 is constituted by the backup roll T2a, the contact roll T2b, and the secondary transfer roll T2c. The secondary transfer roll T2c is grounded, and a secondary transfer voltage having the same polarity as the toner charging polarity is applied to the backup roll T2a via the contact roll T2b.

The color toner images that are primarily transferred in sequence on the intermediate transfer belt B1 are conveyed to the secondary transfer device T2. On the other hand, similarly, the color toner image primarily transferred onto the intermediate transfer belt B2 is reversed in polarity by the polarity reversal corotron CB of the second image forming unit, and the color toner image on the first intermediate transfer belt B1 At the same timing, it is conveyed to the secondary transfer device T2. The polarity reversal corotron CB is disposed downstream of the primary transfer regions Q3Y, Q3M, Q3C, and Q3K in the belt moving direction.

  The transfer material conveyed from the paper feed tray TR1 or TR2 is sent to the secondary transfer device T2 in accordance with the timing of the toner images on the intermediate transfer belts B1 and B2. Then, the toner images are simultaneously transferred onto both surfaces of the transfer material. The transfer material onto which the toner image has been transferred passes through the fixing device F, and after being fixed on the toner image, is discharged to the paper discharge tray TRh.

FIG. 8 is a schematic front view of the double-sided simultaneous image forming apparatus main body for downsizing the apparatus.
JP 2000-352889 A JP 2003-287939 A

  However, in the case of the prior art as described above, the following problems have occurred.

In recent years, image forming devices have further space savings, reduced FCOT (First Copy Out Time),
Higher functionality and improved user operability are desired.

As shown in the example of FIG. 7, since the toner image forming apparatus V is arranged horizontally, the entire width of the apparatus is widened, and accordingly, an installation space is required. Further, the distance from the paper feed roller Rp to the transfer portion T2 is long, and the time for transporting the distance affects the FCOT. In addition, since the space of the sheet feeding units TR1 and TR2 is sacrificed, when a large number of recording sheets S are used in large quantities, the trouble of frequently setting the recording sheet bundle in the sheet feeding units TR1 and TR2 occurs. Furthermore, since there is only one paper discharge port, when using it as a multifunction machine, it is not possible to select a paper discharge port according to the user's usage such as copying, faxing, and printing, which makes it difficult to identify discharged paper.

  In the example shown in FIG. 8, space saving of the image forming apparatus is achieved. However, in order to perform double-sided simultaneous transfer, after the toner image is transferred from the first transfer belt 3 to the second transfer belt 15, the first image is transferred to the first transfer belt 3. Therefore, it is necessary to match the leading edge of the image on the second transfer belt 15 with the leading edge of the image on the first transfer belt 3. In such an image forming process, productivity on both sides is the same as that of a conventional image forming apparatus having a reverse path for both sides. In addition, in order to perform large-size double-sided transfer, the circumference of the second transfer belt is required to be longer than the length of the paper, resulting in an increase in the size of the apparatus, so there are few merits for simultaneous transfer on both sides for the user. .

On the other hand, in recent image forming apparatuses, even when a paper jam (JAM) occurs due to the curling of the recording material due to use in a poor environment beyond the specifications, or the frictional force between the roller and the recording material is reduced,
It is necessary to perform JAM processing quickly and restore the device. For this purpose, it is necessary to configure the apparatus so that it is possible to easily determine where the recording material subjected to JAM is, and to achieve both visibility and operability of the apparatus.

  In the double-sided simultaneous image forming apparatus in which image forming units are provided on both sides of the paper conveyance path as in Patent Document 1, the visibility of JAM paper and the operability of the apparatus are deteriorated, so that improvement in JAM processability is required. Further, there is an image forming apparatus having a configuration in which a paper conveyance path can be visually recognized by rotating one image forming unit (see FIG. 5 of Patent Document 2). In order to visually recognize the paper conveyance path, the rotation fulcrum must be arranged below and the rotation angle must be large, so that a large space for projecting to the side is required. In addition, the rotating mechanism also deteriorates the visibility during JAM processing.

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus that reduces a space for projecting sideways from an apparatus main body. To do.

  In order to achieve the above object, the present invention provides a first and second image forming unit that is arranged with a substantially vertical sheet conveying path interposed therebetween, and that transfers images onto both sides of the sheet conveyed through the sheet conveying path, Fixing means for fixing the image transferred on both sides, a first paper feeding unit arranged below the first image forming unit, and a second paper feeding unit arranged below the second image forming unit And a first moving mechanism for slidably moving the second image forming unit to the side of the apparatus main body.

  A space for projecting sideways from the apparatus main body can be reduced.

  Exemplary embodiments of the present invention will be described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. Absent.

<First embodiment>
FIG. 1 is a schematic front view of the image forming apparatus main body. The first image forming unit 101 and the second image forming unit 201 are disposed with a substantially perpendicular sheet conveyance path sandwiched therebetween. The first image forming unit 101 and the second image forming unit 201 transfer images to both sides of the sheet conveyed through the sheet conveyance path. Each photoreceptor 102Y, 102M, 102C, 102K, and 202Y
202M, 202C, and 202K are uniformly charged by a charging roller (not shown), and then electrostatic latent images are formed on the surfaces thereof by the laser beams from the exposure means 131 and 231. Thereafter, the electrostatic latent image is developed into a toner image by a developing device (not shown). The developed toner images are transferred to the first intermediate transfer belt 105 and the second intermediate transfer belt 205 by the primary transfer rollers 106Y, 106M, 106C, 106K, and 206Y, 206M, 206C, 206K, respectively. . The first intermediate transfer belt 105 and the second intermediate transfer belt 205 each correspond to the intermediate transfer member of the present invention.

  Further, a secondary transfer device (double-sided simultaneous transfer device) 120 is configured by the backup roll 121, the contact roll 122, and the secondary transfer roll 123. The secondary transfer roll 123 is grounded, and a secondary transfer voltage having the same polarity as the toner charging polarity is applied to the backup roll 121 via the contact roll 122.

  The color toner images that are primarily transferred in sequence on the intermediate transfer belt 105 are conveyed to the secondary transfer device 120. On the other hand, similarly, the color toner image primarily transferred onto the intermediate transfer belt 205 is the polarity of the second image forming unit disposed downstream of the primary transfer rollers 206Y, 206M, 206C, and 206K in the belt moving direction. The polarity is inverted by the inversion corotron 220. Thereafter, the color toner image on the intermediate transfer belt 205 is conveyed to the secondary transfer device 120 at the same timing as the color toner image on the first intermediate transfer belt 105.

The transfer material is fed to the feeding cassettes 132a to 132d (corresponding to the “first paper feeding unit” of the present invention), the manual paper feeding unit 136, or the paper deck 137 (the “second paper feeding unit” of the present invention). From the equivalent). By disposing the manual paper feed unit 136 between the second image forming unit and the paper deck 137, an image forming apparatus capable of passing a large number of recording materials in a small space can be realized. The transferred transfer material is sent to the secondary transfer device 120 in accordance with the timing of the toner image on the intermediate transfer belts 105 and 205. Then, the toner images are simultaneously transferred onto both surfaces of the transfer material. The transfer material onto which the toner image has been transferred passes through a fixing device 133 (corresponding to the “fixing means” of the present invention), and after fixing the toner image, the transport direction is determined by a flapper (not shown), and the discharge tray 134 or 234 is transferred. To be discharged. By providing at least one or more paper discharge ports at the top of each of the first and second image forming units, it becomes possible to select a paper discharge port according to the user's usage such as copying, FAX, and printing.

Here, since the photosensitive members 102 and 202 are disposed below the intermediate transfer belts 105 and 205, the primary transfer onto the intermediate transfer belts 105 and 205 performed by the primary transfer rollers 106 and 206 is transferred to the transfer material. The distance to the secondary transfer device 120 that performs the secondary transfer is made as close as possible. As a result, a series of operations from feeding the transfer material to image formation, transfer to the transfer material, fixing, and discharging to the discharge tray can be performed in a short time, greatly contributing to the improvement of device productivity. is doing. Further, since the photoconductors 102 and 202 are arranged obliquely, the space in the width direction of the image forming units 101 and 201 can be narrowed. As a result, it greatly contributes to space saving of the entire image forming apparatus. Yes.

  The photoconductors 102 and 202, the charging roller, and the developing device are integrated to form a process cartridge.

  Next, the operation of the image forming apparatus during JAM processing will be described with reference to FIG.

When a paper jam occurs due to paper moisture absorption, charging, adhesion of foreign matter, curling, or an error in the apparatus, the second image forming unit 201 of this embodiment uses a paper deck 137 that supports a plurality of sheets. Is moved to the side of the apparatus main body (direction A in the figure) by a slide rail 140 (corresponding to the “first moving mechanism” of the present invention) disposed above the apparatus. The slide rail 140 is slidably attached to the side using rollers, balls, or the like. When the second image forming unit 201 is slid in the direction A in the drawing, the sheet conveyance path is opened. Here, even if the heavy second image forming unit 201 moves, the center of gravity of the entire image forming apparatus is stable because the second image forming unit is arranged on the paper deck 137. . In addition, since the sheet conveyance path can be visually recognized even with a small slide amount because the structure is not rotated, it is easy to check and take out the JAM paper.

As shown in FIG. 2, the manual sheet feeder 136 slides integrally with the second image forming unit 201. The manual sheet feeding unit 136 slides integrally with the second image forming unit 201, so that the JAM processing generated in the paper deck 137 is facilitated. The JAM generated between the paper deck 137 and the secondary transfer device 120 is caused by the slide deck 160 (corresponding to the “second moving mechanism” of the present invention) provided in the lower part of the paper deck 137 to be used by the paper deck 137. JAM processing is possible by moving to the side of the main unit. The slide rail 160 is slidably attached to the side using rollers, balls, or the like. In this case, the JAM generated from the downstream side of the manual paper feed unit 136 to the upstream side of the secondary transfer unit 120 is detected by the manual paper feed unit 13.
If the transfer paper remains on the outside of the paper 6, the paper can be visually recognized from the outside when the second image forming unit 201 slides even when no paper remains on the outside of the manual paper feed unit. is there.

  In the case of this configuration, it is possible to adopt a configuration that can accommodate a user who does not need the paper deck 137 or a plurality of paper feed cassettes (see FIGS. 3 and 4).

In addition, you can select the paper discharge port for copying, faxing, and printing, and whether the image surface of the sheet to be discharged when forming a single-sided image is the top or bottom surface. It is possible to select according to the use form of the user by the printer setting. An image forming apparatus capable of selecting a single-sided output paper and a paper discharge port according to the user's preference by making it possible to select whether the image surface at the time of paper discharge is the upper surface or the lower surface during single-sided image formation realizable.

<Second embodiment>
5 and 6 show the JAM processing of the double-sided simultaneous image forming apparatus in which the manual paper feed unit 136 is slidable integrally with the paper deck 137 and is slidable independently of the second image forming unit 201. It is a figure of time. The second image forming unit 201 may be moved to the side of the apparatus main body by providing a slide rail on the manual sheet feeding unit 136.

In this configuration, when a paper jam occurs between the manual paper feed unit 136 and the secondary transfer unit 120, the manual paper feed unit 136 and the paper deck 137 are manually moved by the slide movement or the second image forming unit 201 slide movement. The conveyance path of the paper feeding unit can be visually confirmed. Note that the slide movement of the manual paper feed unit 136 and the paper deck 137 facilitates JAM processing that occurs downstream of the manual paper feed unit 136 and upstream of the image forming unit.

  As described above, in the first and second embodiments, the image reading unit 150 and the second image forming unit are arranged on the right side of the first image forming unit. However, the same effect can be obtained even when the left and right are reversed. It goes without saying that it can be obtained.

1 is a schematic front view of an image forming apparatus main body of the present invention. FIG. 6 is a diagram of the image forming apparatus main body of the present invention during JAM processing. It is a figure of the other form of Example 1. FIG. It is a figure of the other form of Example 1. FIG. FIG. 10 is a diagram at the time of JAM processing in the form of Example 2. FIG. 10 is a diagram at the time of JAM processing in the form of Example 2. It is a figure of the image forming apparatus which concerns on a prior art. It is a front schematic diagram of an image forming apparatus according to a conventional technique.

Explanation of symbols

11... Drive input means 101, 201... Toner image forming apparatus 102, 202... Photoconductor 105, 205... Intermediate transfer belt 106, 206. 210 ... Process cartridge 120 ... Secondary transfer device 121 ... Backup roll 122 ... Contact roll 123 ... Secondary transfer roll 131, 231 ... Exposure means 132, 232... Feeding cassette 133... Fixing device 134, 234... Discharge tray 135 235. 140... Moving rail 150... Image reading unit 220.

Claims (8)

First and second image forming units that are arranged across a substantially vertical sheet conveying path and transfer images onto both sides of the sheet conveyed through the sheet conveying path;
Fixing means for fixing the image transferred on both sides of the sheet;
A first paper feed unit disposed below the first image forming unit;
A second paper feed unit disposed below the second image forming unit;
An image forming apparatus comprising: a first moving mechanism for slidingly moving the second image forming unit to the side of the apparatus main body.   The image forming apparatus according to claim 1, wherein the first moving mechanism is provided above the second sheet feeding unit.   3. The image forming apparatus according to claim 1, wherein at least one paper discharge port is provided at an upper portion of each of the first and second image forming units.   The image forming apparatus according to claim 1, wherein a manual sheet feeding unit is disposed between the second image forming unit and the second sheet feeding unit.   The image forming apparatus according to claim 4, wherein the manual sheet feeding unit moves integrally with the second image forming unit by the first moving mechanism. A second moving mechanism for moving the second paper feeding unit to the side of the apparatus body;
The image forming apparatus according to claim 4, wherein the manual sheet feeder is moved integrally with the second sheet feeder by the second moving mechanism.   Each of the first and second image forming units includes a plurality of photosensitive members and an intermediate transfer member, the plurality of photosensitive members are arranged obliquely, and the intermediate transfer member is disposed above the plurality of photosensitive members. The image forming apparatus according to claim 1, wherein the image forming apparatus is disposed obliquely.   The image forming apparatus according to claim 1, wherein, when forming a single-sided image, it is possible to select whether an image surface when discharging a sheet is an upper surface or a lower surface.

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