JP2006084780A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of obtaining a high-quality image without being affected by the deformation of a main frame. <P>SOLUTION: An intermediate transfer belt 1 and image forming units 8, 9, 10 and 11 are supported in a sub frame 6. The sub frame 6 is supported in the main frame 7 via an elastic body 12. Therefore, even when the main frame 7 is affected and finely deformed by the state of a floor and vibration or heat or the like in the image forming apparatus, the deformation of the main frame 7 is not transmitted to the sub frame 6 by the elastic body 12, so that misregistration (color slurring) is not caused and the high-quality image is obtained on paper P. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus that obtains one image by superimposing images formed by a plurality of image forming units.

  Among image forming apparatuses such as copiers and printers, there is a color image forming apparatus that forms a multicolor image using an endless intermediate transfer belt.

In addition, in this type of color image forming apparatus, a so-called tandem type color image forming apparatus is provided that includes, on the intermediate transfer belt, image forming units individually corresponding to, for example, yellow, magenta, cyan, and black. (For example, Patent Documents 1 to 3).
JP 2000-233843 A Japanese Patent Application Laid-Open No. 10-078734 JP 09-016051 A

  In a conventional image forming apparatus, a paper feed mechanism, a fixing mechanism, and the like are positioned on the main frame of the apparatus, and the main frame also serves as a support when installing on the floor. There was a problem that minute deformation occurred depending on the state.

  In the conventional image forming apparatus, since the exposure device and the photosensitive member are attached to the main frame, even if the main frame is slightly deformed, the light beam is misaligned, which causes color registration misalignment.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide an image forming apparatus that can obtain a high-quality image without being affected by deformation of the main frame.

  The invention according to claim 1 includes a plurality of image forming units that form toner images on the image carrier and an intermediate transfer member that sequentially superimposes the toner images formed on the image carrier. An image forming apparatus for fixing a toner image by a fixing unit after transferring a toner image of a member to a recording medium, and a main frame mounted on an installation portion, and a subframe disposed apart from the main frame And an elastic body that elastically supports the sub-frame with respect to the main frame, and the intermediate transfer member and the image forming unit are supported by the sub-frame.

  Next, the operation of the image forming apparatus according to the first aspect will be described.

  In the image forming apparatus according to claim 1, the toner images formed on the image carrier are sequentially superimposed on the intermediate transfer member, the toner image on the intermediate transfer member is transferred to the recording medium, and the toner image is fixed by the fixing unit. Done.

  Since the image forming apparatus includes a plurality of image forming units that form toner images on the image carrier, the color of the toner image can be changed for each image forming unit, thereby obtaining a color image. .

  Since the image forming unit is supported by the subframe, and the subframe is supported by the main frame via an elastic body, for example, the mainframe may be minute due to the installation state, vibration of the apparatus itself, heat, etc. Even when deformation occurs, the elastic body does not transmit the deformation of the main frame to the sub-frame, so that the positional relationship between the image forming units is prevented from shifting, and an image without color misregistration is intermediate transferred. Can be obtained on the body.

  According to a second aspect of the present invention, the image carrier includes a plurality of image forming units that form toner images on the image carrier, the toner images formed on the image carrier are sequentially superimposed on a recording medium, and the toner image is formed by a fixing unit. An image forming apparatus that fixes the main frame, a main frame mounted on an installation unit, a subframe that is spaced apart from the main frame, and the subframe that elastically supports the main frame. And an elastic body, and the image forming unit is supported by the sub-frame.

  Next, the operation of the image forming apparatus according to claim 2 will be described.

  In the image forming apparatus according to the second aspect, the toner images formed on the image carrier are sequentially superimposed on the recording medium, and the toner image is fixed by the fixing unit.

  Since the image forming apparatus includes a plurality of image forming units that form toner images on the image carrier, the color of the toner image can be changed for each image forming unit, thereby obtaining a color image. .

  Since the image forming unit is supported by the subframe, and the subframe is supported by the main frame via an elastic body, for example, the mainframe may be minute due to the installation state, vibration of the apparatus itself, heat, etc. Even when deformation occurs, the elastic body does not transmit the deformation of the main frame to the sub-frame, so that the positional relationship between the image forming units is prevented from shifting, and an image without color misregistration is intermediate transferred. Can be obtained on the body.

  As described above, according to the image forming apparatus of the present invention, a high-quality image can be obtained even when the main frame is slightly deformed by the state of the floor on which the apparatus is installed, the vibration of the apparatus, heat, or the like. , Has an excellent effect.

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic diagram showing a configuration example of an image forming apparatus 5 to which the present invention is applied.

  As shown in FIG. 1, an intermediate transfer belt 1 composed of an endless belt is supported on the subframe 6 by a driving roll 2, a secondary transfer roll 3, and a plurality of driven rolls 4 with a predetermined tension.

  The drive roll 2 is rotated by power transmission from a motor (not shown), and the intermediate transfer belt 1 travels in the X direction in the drawing by the rotation of the drive roll 2.

  In the sub-frame 6, image forming units 8 and 9 corresponding to the respective colors of yellow (Y), magenta (M), cyan (C), and black (K) are arranged below the intermediate transfer belt 1 according to the belt running direction. , 10, 11 are arranged and supported in order.

  As shown in FIG. 2, the image forming units 8, 9, 10, and 11 expose and scan the photosensitive drums 8a, 9a, 10a, and 11a and the surfaces of the photosensitive drums 8a, 9a, 10a, and 11a, respectively. Exposure devices 8b, 9b, 10b, and 11b.

  The exposure apparatuses 8b, 9b, 10b, and 11b of the present embodiment are LED arrays, but may be of other types.

  As shown in FIG. 1, around each photosensitive drum 8a, 9a, 10a, 11a, charging units 8c, 9c, 10c, 11c, developing units 8d, 9d, 10d, 11d, Primary transfer rolls 8e, 9e, 10e, and 11e, a cleaner (not shown), and the like are sequentially disposed.

  In the image forming apparatus 5 of the present embodiment, the sub-frame 6 is supported via the elastic body 12 with respect to the main frame 7 installed on the floor surface.

  The elastic body 12 is of course less rigid than the main frame 7 and the subframe 6, and for example, a spring such as metal or synthetic resin, or an elastomer such as rubber can be used. The material, shape, and the like of the elastic body 12 are not limited as long as the minute deformation of 7 is not transmitted to the subframe 6.

Further, the paper P to be image-formed is accommodated in the paper feed cassette 13, and the paper P fed out of the paper feed cassette 13 is transported along a transport path constituted by a predetermined number of roll pairs 16, and is transferred to a secondary transfer roll. 3 is sent to the pressure contact position.
(Function)
An operation procedure when a color image is formed using the image forming apparatus 5 having the above configuration will be described.

  First, the intermediate transfer belt 1 is caused to run in the X direction by the rotation of the drive roll 2, and image writing is sequentially started in each of the image forming units 8, 9, 10, 11.

  On the intermediate transfer belt 1, each color image of yellow, magenta, cyan, and black is successively transferred (primary transfer), thereby forming a single color image.

  Thereafter, the color image is fed to the secondary transfer roll 3 side along with the running of the intermediate transfer belt 1, and the color image on the intermediate transfer belt 1 is collectively transferred (secondary transfer) onto the paper P.

  The sheet P on which the color image has been transferred is sent to the fixing device 18 where the image is fixed (heating, pressing, etc.) and then discharged to a tray at the top of the apparatus.

  Since the image forming units 8, 9, 10, and 11 are supported by the sub-frame 6, and the sub-frame 6 is supported by the main frame 7 through the elastic body 12, the flatness and horizontalness of the floor surface is improved. The elastic body 12 does not transmit the deformation of the main frame 7 to the sub-frame 6 even if the main frame 7 is slightly deformed due to the vibration or heat in the apparatus. (Color misregistration) does not occur, and a high-quality image can be obtained on the paper P.

  In addition, the manufacturing accuracy and rigidity of the main frame 7 can be reduced. For example, a synthetic resin can be used as the material, and the material cost of the main frame 7 can be reduced.

  Further, since the fixing device 18 as a heat source is provided on the main frame 7 side and supported by a member different from the image forming units 8, 9, 10, and 11, the heat of the fixing device 18 is transferred to the image forming unit 8, Transmission to 9, 10, and 11 is prevented, and the light quantity of the LED array, the sensitivity of the photosensitive material, the toner charge amount, and the like can be improved.

  Further, it is difficult for vibrations of the conveyance system of the paper P (the roll pair 16 and a motor (not shown) that drives the roll pair 16) to be transmitted to the image forming units 8, 9, 10, and 11, and good image quality can be maintained.

  The sub frame 6 only needs to support the image forming units 8, 9, 10, 11, the intermediate transfer belt 1, and the conveyance system of the intermediate transfer belt 1, so that the sub frame 6 can be made compact and easy to increase rigidity, thereby reducing cost materials. Can also improve the image quality.

  Further, since the image forming units 8, 9, 10, and 11 are supported by the subframe 6, the distance accuracy between the photosensitive drum and the exposure device (focus accuracy) and the distance accuracy between the photosensitive drum and the developing device are manufactured. It becomes easy to improve.

  In the image forming apparatus 5 of this embodiment, the toner images on the photosensitive drums 8a, 9a, 10a, and 11a are transferred onto the paper P through the intermediate transfer belt 1, but the toner images are directly transferred onto the paper P. It is good also as composition to do.

1 is a side view illustrating a schematic configuration of an image forming apparatus. It is a bottom view of a subframe.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Intermediate transfer belt 5 Image forming apparatus 6 Sub frame 7 Main frame 8 Image forming unit 9 Image forming unit 10 Image forming unit 11 Image forming unit 12 Elastic body P Paper (recording medium)

Claims (2)

A plurality of image forming units that form toner images on the image carrier, and an intermediate transfer member that sequentially superimposes the toner images formed on the image carrier, and transfers the toner images on the intermediate transfer member to a recording medium After that, an image forming apparatus that fixes the toner image with a fixing unit,
A mainframe mounted on the installation section;
A subframe that is spaced apart from the main frame;
An elastic body that elastically supports the sub-frame with respect to the main frame;
With
An image forming apparatus, wherein an intermediate transfer member and an image forming unit are supported by the subframe. An image forming apparatus that includes a plurality of image forming units that form toner images on an image carrier, sequentially superimposes the toner images formed on the image carrier on a recording medium, and fixes the toner image by a fixing unit. And
A mainframe mounted on the installation section;
A subframe that is spaced apart from the main frame;
An elastic body that elastically supports the sub-frame with respect to the main frame;
With
An image forming apparatus, wherein an image forming unit is supported by the subframe.

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