JP2004240376A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize space saving, compaction and the reduction of cost, to facilitate jamming disposal, to improve safety in such disposal and to improve maintenance and the easiness of the exchange of parts. <P>SOLUTION: In the image forming apparatus, an image formed by an image forming device is transferred to an intermediate transfer belt 12, and the 1st image is transferred to a transfer belt 17 by a transfer roller 18. Thereafter, a 2nd image is carried on the belt 12 and transferred to the 1st surface of transfer paper S, and the 1st image is transferred to the other surface thereof by a transfer charger 20. The transfer paper S is separated from the belt 17 by a separation corona charger 80. A side cover 61 is provided so as to be able to turn with a shaft 62 as a supporting point. When the cover is opened, the belt 17 is moved integrally with the cover 61 and the charger 20 and the charger 80 remain in the device main body 2. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile, and a plotter, and more particularly, to an image forming apparatus capable of forming an image on both sides of a sheet-shaped recording medium simultaneously or simultaneously.
[0002]
[Prior art]
2. Description of the Related Art In recent electrophotographic apparatuses such as copiers and printers, image formation by double-sided transfer onto a sheet-shaped recording medium has been common. However, as a method of transferring to a sheet-shaped recording medium, the first image is transferred and fixed to one surface of the sheet-shaped recording medium, and then the sheet-shaped recording medium is reverse-fed using a double-sided reversing device or the like, and the sheet is fed back. This is a process of transferring and fixing the second image to the other surface (second surface) of the recording medium.
In double-sided printing on a sheet-like recording medium by such a method, a double-sided reversing device or the like is indispensable, and it cannot be denied that the first print time in double-sided image formation is delayed by the double-sided reversing operation (switchback).
[0003]
Japanese Patent Application Laid-Open No. 2000-352889 discloses an image forming apparatus that performs double-side printing without using a double-side reversing device or the like. In this apparatus, an image forming device such as a photoreceptor is provided for each of a first surface and a second surface of a sheet-shaped recording medium.
However, in a configuration in which an image forming device is provided for each surface of a sheet-shaped recording medium, space saving, compactness, and cost reduction are desired, and inevitably the device size is inevitably increased. However, the increase in equipment cost could not be suppressed.
[0004]
[Patent Document 1]
JP 2000-352889 A
[Problems to be solved by the invention]
For example, an image formed on one image forming means (including a tandem method) is carried on a primary image carrier, and the first image is transferred to a belt-like secondary image by the primary transfer means at a primary transfer position. After the image is transferred onto the image carrier, a second image is separately carried on the primary image carrier, and the first image is transferred to the first image by the primary transfer means at the primary transfer position. Is transferred to the sheet-shaped recording medium by the secondary transfer means at the secondary transfer position, and an image is formed on both sides of the sheet-shaped recording medium. Compactness and low cost can be realized.
[0006]
In the case of such a method, the secondary transfer means or the recording medium separating means for separating the sheet-shaped recording medium having the image transferred on both sides from the conveying means is provided outside the belt of the secondary image carrier. However, the sheet-shaped recording medium passes as a conveyance path between the secondary transfer unit or the recording medium separating unit and the secondary image carrier.
Therefore, if the secondary transfer means or the recording medium separating means is formed integrally with the secondary image carrier, the processing work becomes troublesome when a jam occurs.
Further, when a static elimination needle, a static elimination brush, or the like is used as the recording medium separating means, there is a risk that the user directly touches the recording medium separating means when the jam processing work area is narrow, and the toner is easily stained or damaged from the shape, There has been a problem such as functional deterioration of the recording medium separating means.
In addition, there is a problem regarding ease of maintenance and replacement.
[0007]
Therefore, the present invention can realize space saving, downsizing, and cost reduction, and can easily perform jam processing, improve safety in the processing, and improve easiness of maintenance and parts replacement. The main purpose is to provide an image forming apparatus that can be used.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, the first image transferred from the image forming means and carried on the primary image carrier is subjected to secondary transfer at the primary transfer position by the primary transfer means. After the image is transferred onto the image carrier, a second image is separately carried on the primary image carrier, and the first image is transferred to the first image by the primary transfer means at the primary transfer position. Is transferred to a sheet recording medium by a secondary transfer unit at a secondary transfer position, and an image is formed on both sides of the sheet recording medium. In the image forming apparatus, the secondary transfer unit and the secondary image carrier are The configuration is such that it is provided so as to be separable.
[0009]
According to the second aspect of the present invention, after the first image transferred from the image forming means and carried on the primary image carrier is transferred onto the secondary image carrier by the primary transfer means at the primary transfer position. A second image is separately carried on the primary image carrier, and the second image is secondarily transferred at the secondary transfer position by the primary transfer means at the primary transfer position. In an image forming apparatus for transferring images onto both sides of a sheet-shaped recording medium by a transfer unit and forming images on both sides of the sheet-shaped recording medium, recording that separates the sheet-shaped recording medium from a recording-medium conveying unit that conveys the sheet-shaped recording medium It has a medium separating means, and the recording medium separating means and the recording medium conveying means are provided so as to be separable.
[0010]
According to a third aspect of the present invention, in the image forming apparatus according to the second aspect, the recording medium conveying means is the secondary image carrier.
[0011]
According to a fourth aspect of the present invention, in the image forming apparatus according to the second or third aspect, the recording medium separating means is a separation corona charger.
[0012]
According to a fifth aspect of the present invention, in the image forming apparatus according to the second or third aspect, the recording medium separating means is a discharging needle.
[0013]
According to a sixth aspect of the present invention, in the image forming apparatus according to the second or third aspect, the recording medium separating unit is a discharging brush.
[0014]
According to a seventh aspect of the present invention, in the image forming apparatus of the first aspect, the secondary image carrier is provided so as to be openable and closable with respect to the image forming apparatus main body by rotating or linearly moving the secondary image carrier. When the carrier is opened, the secondary transfer unit remains on the image forming apparatus main body side.
[0015]
According to an eighth aspect of the present invention, in the image forming apparatus of the second aspect, the secondary image carrier is provided so as to be openable and closable with respect to the image forming apparatus main body by rotating or linearly moving the secondary image carrier. When the carrier is opened, the recording medium separating means remains on the image forming apparatus main body side.
[0016]
According to a ninth aspect of the present invention, in the image forming apparatus according to the first aspect, the secondary transfer unit is unitized integrally with the primary image carrier or other image forming-related members, and the unit is used for image forming. The configuration is such that it is provided so as to be freely drawn out from the apparatus main body.
[0017]
According to a tenth aspect of the present invention, in the image forming apparatus of the first aspect, the recording medium separating unit is unitized integrally with the primary image carrier or other image forming-related members, and the unit is used for image forming. The configuration is such that it is provided so as to be freely drawn out from the apparatus main body.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described below with reference to FIGS.
As shown in FIG. 1, an apparatus main body (image forming apparatus main body) 2 of a full-color printer 1 as an image forming apparatus is provided with a front cover 45 as an exterior cover rotatable in the direction of arrow F on its operation surface side. A side cover 61 is provided on the right side of the operation surface as an exterior cover rotatable in the direction of arrow R. On the upper surface of the apparatus main body 2, a discharge stack unit 29 for discharging and stacking a sheet-shaped recording medium on which an image has been formed is formed.
[0019]
The full-color printer 1 has a configuration capable of printing almost simultaneously on both sides in a so-called tandem system. An outline of the configuration will be described with reference to FIG.
An image forming device 42Y, 42M, 42C, 42Bk for forming an image for each color according to the image information is disposed at a substantially central portion of the device main body 2, and each of the image forming devices 42Y, 42M, 42C, 42Bk is provided. An intermediate transfer belt 12 as a primary image carrier is disposed to face the intermediate transfer belt 12.
An optical writing unit 8 is disposed below each of the image forming devices 42Y, 42M, 42C, and 42Bk, and a transfer belt 17 as a secondary image carrier is provided on the right side of the primary image carrier 12 in the drawing. The transfer surface is arranged so as to extend in a substantially vertical direction.
Sheet feed cassettes 23 and 24 are provided below the optical writing means 8 as sheet feeding means for supplying transfer paper S as a sheet-shaped recording medium. The transfer paper S, which has been separated and fed one by one from the paper feed cassettes 23 and 24 by the paper feed rollers 25 and 26 in order from the uppermost one, is transported by a transport roller pair to a transport path 27 toward a registration roller pair 28 by a transport roller pair. It is supposed to be.
[0020]
Each of the image forming devices 42Y, 42M, 42C, and 42Bk performs development of each color of yellow, magenta, cyan, and black, and uses a different color of toner. The configuration of 42Y will be described as a representative example of each of the image forming devices 42Y, 42M, 42C, and 42Bk, and the other components will be denoted by the corresponding reference numerals and description thereof will be omitted.
The image forming device 42Y includes a photosensitive drum 3Y as an electrostatic latent image carrier, a charging device 4Y and a developing sleeve 5Y that are sequentially arranged around the photosensitive drum 3Y along the rotation direction (the direction of the arrow). A known configuration including a developing device 6Y and a cleaning device 7Y, and receiving exposure light 8Y from the optical writing unit 8 between the charging device 4Y and the developing device 6Y is used.
[0021]
The intermediate transfer belt 12 is stretched around the driving roller 9, the driven roller 10, and the tension roller 11, and a cleaning device 14 is provided at a position outside the belt facing the tension roller 11.
The images formed by the respective image forming devices 42Y, 42M, 42C, and 42Bk are bias rollers 13Y, 13M, 13C, and 13Bk provided at belt inner positions facing the photosensitive drums 3Y, 3M, 3C, and 3Bk. Is transferred onto the intermediate transfer belt 12 in a superimposed manner.
The full-color toner image transferred onto the intermediate transfer belt 12 is transferred onto a transfer belt 17 by a transfer bias applied to a transfer roller 18 as a primary transfer unit provided opposite to the drive roller 9. As a result, on the transfer belt 17, a full-color toner image (first image) for one side of the transfer paper S is maintained and transported.
The surface of the intermediate transfer belt 12 is cleaned by a cleaning device 14 to prepare for the next image formation and transfer.
[0022]
The transfer roller 18 is urged toward the drive roller 9 by a spring 22. The transfer belt 17 is looped between the drive roller 15, the driven roller 16, the tension roller 19, and the transfer roller 18, and a cleaning device 21 is provided at a position outside the belt facing the drive roller 15.
After the transfer of the first image to the transfer belt 17, when the intermediate transfer belt 12 moves to a predetermined position, an image forming process for the other surface on the transfer paper S is started. The image forming process in this case is the same as that for forming the full-color toner image for one surface, and the full-color toner image (second image) is carried on the intermediate transfer belt 12.
[0023]
After the image forming process of the second image is completed, the transfer paper S is transferred to the transfer roller 18 by the registration roller pair 28 at a predetermined timing (timing at which the leading end of the second image coincides with the predetermined position in the transport direction of the transfer paper S). Is conveyed toward the primary transfer position.
At the primary transfer position, the full-color toner image (second image) on the intermediate transfer belt 12 is transferred to the other side of the transfer sheet S. Subsequently, a full-color toner image on the transfer belt 17 is transferred onto one surface of the transfer paper S conveyed by the transfer belt 17 as a recording medium conveying means by a transfer charger 20 as a secondary transfer means disposed at a secondary transfer position. (First image) is transferred.
[0024]
That is, double-sided printing is performed on one transfer sheet S at the primary transfer position and the secondary transfer position almost simultaneously. The transfer paper S on which the full-color toner images have been transferred almost simultaneously on both surfaces is separated from the transfer belt 17 by a separation corona charger 80 as a recording medium separating means arranged near the downstream of the transfer charger 20 and passes through the transport path 30. The sheet is conveyed to the fixing device 31.
The transfer sheet S on which the full-color toner image has been fused and fixed on both sides by heat and pressure by the fixing device 31 is discharged to the discharge stack unit 29 by the discharge roller pair 32.
The surface of the transfer belt 17 after transferring the first image to the transfer paper S is cleaned by the cleaning device 21.
[0025]
Above the intermediate transfer belt 12, a supply toner tank 33 is disposed. The replenishment toner tank 33 includes a yellow toner tank 33a, a magenta toner tank 33b, a cyan toner tank 33c, and black toner tanks 33d and 33e.
The side cover 61 is rotatably supported at its lower end by a shaft 62 and is provided to be rotatable in the arrow R direction as described above. The transfer belt 17, the drive roller 15, the driven roller 16, the tension roller 19, the transfer roller 18, the spring 22, the cleaning device 21, and the like are integrally provided on the side cover 61 to form one unit.
[0026]
FIG. 3 shows a state where the side cover 61 is opened. When the side cover 61 is rotated outward, the transfer belt 17 is displaced integrally with the side cover 61, and the transfer charger 20 as the secondary transfer unit and the separation corona charger 80 as the recording medium separating unit are connected to the apparatus main body 2. Deferred inside.
As a result, the transfer path of the transfer paper S extending in the substantially vertical direction is opened, and when a jam occurs, the jammed paper can be easily taken out by opening the side cover 61. In FIG. 3, reference numeral 63 denotes a protective cover of the secondary transfer unit including the transfer belt 17 and the like.
[0027]
FIG. 4 shows a state where the front cover 45 is opened. When the front cover 45 is opened, the supply toner tank 33 is exposed, and the drawer units 44, 41, and 43 are exposed. An inner cover 46 that protects the drawer units 44, 41, and 43 is provided on the inner surface of the front cover 45.
The first-stage drawer unit 44 includes an intermediate transfer belt 12, a driving roller 9, a driven roller 10, a tension roller 11, a cleaning device 14, bias rollers 13Y, 13M, 13C, 13Bk, a transfer charger 20, a separation corona charger 80, and the like. Are provided integrally.
[0028]
The image forming apparatuses 42Y, 42M, 42C, 42Bk and the like are integrally provided in the second-stage drawer unit 41.
The third-stage drawer unit 43 is provided integrally with the optical writing means 8 and the like. These drawer units 44, 41, 43 are provided so as to be able to be pulled out in front of the operation surface side, so that maintenance and replacement work of each of the above-described elements can be easily performed.
FIG. 5 shows a state where the first-stage drawer unit 44 is pulled out. The drawer unit 44 is provided via a slide rail 59 so as to be freely taken in and out. As shown in the drawing, when the drawer unit 44 is pulled out, the transfer charger 20 and the separation corona charger 80 are pulled out separately from the transfer belt 17 inside the apparatus main body 2.
In FIG. 5, reference numeral 56 denotes a protective cover for the intermediate transfer unit including the intermediate transfer belt 12 and the like, and reference numeral 57 denotes a handle for replacing the intermediate transfer unit.
[0029]
In the above-described embodiment, the separation corona charger 80 is used as the recording medium separating means. However, a configuration may be employed in which a static elimination needle having a known configuration is provided, or a configuration in which a static elimination brush having a known configuration is provided.
[0030]
【The invention's effect】
According to the first aspect of the present invention, the first image transferred from the image forming means and carried on the primary image carrier is transferred onto the secondary image carrier by the primary transfer means at the primary transfer position. After that, a second image is separately carried on the primary image carrier, and the first image is transferred at the secondary transfer position by the primary transfer means at the primary transfer position. In an image forming apparatus in which images are formed on both sides of a sheet-shaped recording medium by transferring images onto respective sheet-shaped recording media by secondary transfer units, the secondary transfer unit and the secondary image carrier are provided so as to be separable. With this configuration, the conveyance path of the sheet-shaped recording medium can be opened, and the jam clearing operation can be easily performed. Further, it is possible to suppress the danger that the secondary transfer means is damaged when the jammed paper is removed.
[0031]
According to the second aspect of the present invention, the first image transferred from the image forming means and carried on the primary image carrier is transferred onto the secondary image carrier by the primary transfer means at the primary transfer position. After that, a second image is separately carried on the primary image carrier, and the first image is transferred at the secondary transfer position by the primary transfer means at the primary transfer position. In an image forming apparatus in which images are formed on both sides of a sheet-shaped recording medium by transferring images onto the sheet-shaped recording medium by secondary transfer means, the sheet-shaped recording medium is separated from a recording medium conveying means for conveying the sheet-shaped recording medium. Recording medium separating means, and the recording medium separating means and the recording medium conveying means are provided so as to be separable, so that the conveying path of the sheet-shaped recording medium can be opened, and the jam processing can be performed. Work can be performed easily. In addition, it is possible to reduce the risk of damage to the recording medium separating means or the possibility of toner contamination or injury to the operator when the jammed paper is removed, and to facilitate maintenance and replacement of parts.
[0032]
According to the third aspect of the present invention, in the image forming apparatus according to the second aspect, the recording medium transport unit is configured to be the secondary image carrier, so that the transport path of the sheet-shaped recording medium is opened. And a jam clearing operation can be easily performed. In addition, it is possible to reduce the risk of damage to the recording medium separating means or the possibility of toner contamination or injury to the operator when the jammed paper is removed, and to facilitate maintenance and replacement of parts.
[0033]
According to the fourth aspect of the present invention, in the image forming apparatus according to the second or third aspect, the recording medium separating means is a separation corona charger, so that the separation corona charger is damaged when jammed paper is removed. In addition, it is possible to reduce the risk of toner contamination or injury to the operator, and to facilitate maintenance and replacement of parts.
[0034]
According to the fifth aspect of the present invention, in the image forming apparatus according to the second or third aspect, the recording medium separating means is configured as a static elimination needle. It is possible to reduce the risk of toner contamination or injury to the user, and to facilitate maintenance and replacement of parts.
[0035]
According to the sixth aspect of the present invention, in the image forming apparatus according to the second or third aspect, the recording medium separating means is configured to be a static elimination brush. It is possible to reduce the risk of toner contamination or injury to the user, and to facilitate maintenance and replacement of parts.
[0036]
According to a seventh aspect of the present invention, in the image forming apparatus according to the first aspect, the secondary image carrier is provided so as to be openable and closable with respect to the image forming apparatus main body by rotating or linearly moving. Since the secondary transfer means remains on the image forming apparatus main body when the next image carrier is opened, the conveying path of the sheet-shaped recording medium can be easily opened, and the jam clearing operation can be easily performed. be able to. In addition, it is possible to reduce the risk of damaging the secondary transfer unit or removing toner contamination or injury from the operator when the jammed paper is removed, and to facilitate maintenance and replacement of parts.
[0037]
According to an eighth aspect of the present invention, in the image forming apparatus of the second aspect, the secondary image carrier is provided so as to be openable and closable with respect to the image forming apparatus main body by rotating or linearly moving. When the next image carrier is opened, the recording medium separating means remains on the image forming apparatus main body side, so that the conveying path of the sheet-shaped recording medium can be easily opened, and the jam clearing operation can be easily performed. be able to. In addition, it is possible to reduce the risk of damage to the recording medium separating means or the possibility of toner contamination or injury to the operator when the jammed paper is removed, and to facilitate maintenance and replacement of parts.
[0038]
According to the ninth aspect of the present invention, in the image forming apparatus of the first aspect, the secondary transfer unit is unitized integrally with the primary image carrier or other image forming-related members. Since the configuration is provided such that it can be pulled out from the image forming apparatus main body, it is possible to further improve the ease of maintenance and replacement of parts.
[0039]
According to a tenth aspect of the present invention, in the image forming apparatus of the first aspect, the recording medium separating unit is unitized integrally with the primary image carrier or other image forming-related members, and the unit is Since the configuration is provided such that it can be pulled out from the image forming apparatus main body, it is possible to further improve the ease of maintenance and replacement of parts.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view of a full-color printer as an image forming apparatus according to an embodiment of the present invention.
FIG. 2 is a schematic front view showing the entire configuration of the full-color printer.
FIG. 3 shows a side cover 61 opened to separate a transfer belt 17 as a secondary image carrier, a transfer charger as a secondary transfer unit remaining on the apparatus main body 2 side, and a separation charger as a recording medium separation unit. It is a schematic perspective view of a state.
FIG. 4 is a schematic perspective view showing a state where a front cover 45 is opened.
FIG. 5 is a schematic perspective view illustrating a state in which a front cover 45 is opened and a drawer unit 44 integrally including a primary image carrier, a transfer charger 20, a separation charger 80, and the like is drawn toward the user.
[Explanation of symbols]
42Y, 42M, 42C, 42Bk Image forming device 12 as image forming means Intermediate transfer belt 18 as primary image carrier Transfer roller 17 as primary transfer means Transfer belt 20 as secondary image carrier 20 Secondary transfer means Transfer charger S as a transfer sheet 17 as a sheet-shaped recording medium Transfer belt 80 as a recording medium conveying means Separation corona charger as a recording medium separating means

Claims (10)

After the first image transferred from the image forming means and carried on the primary image carrier is transferred onto the secondary image carrier by the primary transfer means at the primary transfer position, the first image is transferred onto the primary image carrier. The second image is separately carried on the sheet-shaped recording medium by the primary transfer means at the primary transfer position, and the second image is transferred by the secondary transfer means at the secondary transfer position. In an image forming apparatus that transfers images to both sides of a sheet-shaped recording medium,
An image forming apparatus, wherein the secondary transfer means and the secondary image carrier are provided so as to be separable. After the first image transferred from the image forming means and carried on the primary image carrier is transferred onto the secondary image carrier by the primary transfer means at the primary transfer position, the first image is transferred onto the primary image carrier. The second image is separately carried on the sheet-shaped recording medium by the primary transfer means at the primary transfer position, and the second image is transferred by the secondary transfer means at the secondary transfer position. In an image forming apparatus that transfers images to both sides of a sheet-shaped recording medium,
A recording medium separating unit that separates the sheet-shaped recording medium from a recording medium conveying unit that conveys the sheet-shaped recording medium, wherein the recording medium separating unit and the recording medium conveying unit are provided so as to be separable; An image forming apparatus comprising: The image forming apparatus according to claim 2,
An image forming apparatus, wherein the recording medium conveying means is the secondary image carrier. The image forming apparatus according to claim 2, wherein
An image forming apparatus, wherein the recording medium separating means is a separating corona charger. The image forming apparatus according to claim 2, wherein
An image forming apparatus, wherein the recording medium separating means is a static elimination needle. The image forming apparatus according to claim 2, wherein
An image forming apparatus, wherein the recording medium separating means is a charge removing brush. The image forming apparatus according to claim 1,
The secondary image carrier is provided so as to be openable and closable with respect to the image forming apparatus main body by rotation or linear movement, and when the secondary image carrier is opened, the secondary transfer unit operates on the image forming apparatus main body side. An image forming apparatus characterized by remaining in the image forming apparatus. The image forming apparatus according to claim 2,
The secondary image carrier is provided so as to be openable and closable with respect to the image forming apparatus main body by rotation or linear movement, and when the secondary image carrier is opened, the recording medium separating means is connected to the image forming apparatus main body side. An image forming apparatus characterized by remaining in the image forming apparatus. The image forming apparatus according to claim 1,
An image characterized in that the secondary transfer means is unitized integrally with the primary image carrier or other image forming-related members, and the unit is provided so as to be able to be pulled out from the image forming apparatus main body. Forming equipment. The image forming apparatus according to claim 1,
An image characterized in that the recording medium separating means is unitized integrally with the primary image carrier or other image forming members, and the unit is provided so as to be able to be pulled out from the image forming apparatus main body. Forming equipment.

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