JP2000162943A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove jammed transfer material without soiling the user's hands or the surroundings by unfixed toner stuck to the front and the back of the transfer material by forming a space on an intermediate transfer body or in between the intermediate transfer body and a fixing means. SOLUTION: In this image forming device, when the recording paper P is jammed on a carrying part 160, a lever 311 engaged to a supporting frame body of the intermediate transfer belt 14a is pulled down and the space is formed by separating the intermediate transfer belt 14a from the photoreceptor drum 10. Next, a holder lever 321 where a backside transferring device 14g and/or a paper separating AC static eliminator 14h are/is attached is lifted up against a spring 323 to have it engaged to the spring and the backside transferring device 14g and/or the paper separating AC static eliminator 14h are/is evaded from the surface of the intermediate transfer belt 14 to form the space. Thus, after the jammed recording paper P is enabled to move in this space by moving the intermediate transfer belt 14a, the recording paper P can be crushed in that space or in its vicinity and the jammed recording paper P can be pulled out and removed from the intermediate transfer belt 14a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to copying in which a charging means, an image writing means and a developing means are arranged around an image forming body to transfer and fix a toner image formed on the image forming body onto a transfer material. More particularly, the present invention relates to an image forming apparatus capable of forming an image on both sides of a transfer material.

[0002]

2. Description of the Related Art Conventionally, in double-sided image formation, an image on one side formed on an image forming body is transferred and fixed on a transfer material, and this is temporarily stored in a double-sided reversal feeding device and formed again. A method has been adopted in which a transfer material is fed from a two-sided reversing feed device in synchronization with an image formed on a body, and an image on the other surface is transferred and fixed onto the transfer material.

In this double-sided image forming apparatus, as described above,
The transfer of the transfer material, such as feeding to the two-sided reversing feed device or passing through the fixing device twice, is performed, so that the reliability of transfer of the transfer material is low, causing jams and wrinkles of the transfer material. .

On the other hand, JP-B-49-37538 and JP-B-54-28740, and JP-A-1-44457.
Japanese Patent Application Laid-Open Publication No. 4-214576 and the like propose a method in which a toner image is formed on both surfaces of a transfer material using an image forming body and an intermediate transfer body, and then fixed once.

Further, the present inventors have arranged a plurality of sets of toner image forming means including a charging means, an image writing means, a developing means, etc. around a photosensitive drum (image forming body), and provided on the photosensitive drum. After the formed superimposed color toner image is once transferred to the belt-shaped intermediate transfer body by the first transfer means, the superimposed color toner image is formed again on the photoconductor drum, and the toner on the photoconductor drum is formed. The transfer material fed in time with the image and the toner image on the intermediate transfer body is charged by the transfer material charging means and adsorbed on the intermediate transfer body,
On both sides of the transfer material conveyed by the intermediate transfer body,
The toner image on the photosensitive drum is transferred as a front image by a second transfer unit (using the same one as the first transfer unit), and the toner image on the intermediate transfer body is transferred as a back image by a third transfer unit. Fixing device (fixing means)
The curvature of the roller member provided on the side and stretching the intermediate transfer member,
The transfer material is separated from the intermediate transfer body by static elimination by a transfer material separating unit provided as necessary, and the transfer material is transported to a fixing device through a transport unit, and the toner image on the transfer material is fixed by the fixing device. An image forming apparatus and an image forming method for forming a two-sided color image are disclosed in Japanese Patent Application Laid-Open Nos. 9-258492 and 9-258516.

[0006]

However, the toner images on the front and back sides of the image forming body (photosensitive drum) and the belt-like intermediate transfer body (intermediate transfer belt) are transferred onto a transfer material to form a double-sided image. In a double-sided image forming apparatus for forming a sheet, the jam of the transfer material is likely to occur in a conveying unit or a fixing unit,
When a jam occurred, the intermediate transfer belt was separated from the photoconductor drum, and the jammed transfer material was dragged out and pulled out to the front, but the hands became dirty due to unfixed toner adhering to the front and back of the transfer material. And the surroundings become dirty. In particular, when the transfer material is on the intermediate transfer belt, the transfer material is electrostatically attracted to the intermediate transfer belt and is difficult to peel off. When the transfer material runs out, stain the hands with unfixed toner on the front and back when pulling out the transfer material. And the surroundings are very dirty.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and eliminates the need for unfixed toner adhering to the front and back surfaces of the transfer material to clean the hands and the surroundings of the transfer material during jam processing. It is an object of the present invention to provide an image forming apparatus capable of eliminating the problem.

[0008]

The object of the present invention is to form a toner image formed on an image forming member on both sides of a transfer material via an intermediate transfer member, and then form a toner image on both surfaces of the transfer material. In the image forming apparatus that is fixed by the fixing unit, when the transfer material is jammed, a space is formed on the intermediate transfer body or between the intermediate transfer body and the fixing unit to allow the transfer material to move, The image forming apparatus is characterized in that the transfer material is rounded and pulled out.

[0009]

Embodiments of the present invention will be described below. Note that the description in this column does not limit the technical scope of the claims and the meaning of terms. Also, the following assertive description in the embodiment of the present invention indicates the best mode, and does not limit the meaning of the terms of the present invention or the technical scope. In the following description of the embodiment, the surface of the transfer material on the side facing the image forming body in the transfer area is called the front surface, and the other surface of the transfer material, that is, the surface of the transfer material on the side facing the intermediate transfer body is called the back surface. The image transferred to the front surface of the transfer material is called a front image, and the image transferred to the back surface of the transfer material is called a back image.

An image forming process and each mechanism of an embodiment of the image forming apparatus according to the present invention will be described with reference to FIGS. FIG. 1 is a sectional configuration view of a color image forming apparatus showing an embodiment of the image forming apparatus according to the present invention, FIG. 2 is a side sectional view of the image forming body of FIG. 1, and FIG. FIG. 3A is a diagram illustrating a toner image forming state in the image forming apparatus according to the present invention, and FIG. 3A is a diagram illustrating a toner image forming state when a back surface image formed on an image forming body is transferred onto an intermediate transfer body. FIG. 3B is a diagram illustrating a toner image forming state when a front surface image is formed on an image forming body in synchronization with a back side image on the intermediate transfer body.
FIG. 4C is a diagram illustrating double-sided image formation on a transfer material.

In FIG. 1, reference numeral 10 denotes a photosensitive drum as an image forming body; 11, a scorotron charger as charging means for each color; 12, an exposure optical system as image writing means for each color; The developing device 14a is an intermediate transfer belt which is an intermediate transfer member, and 14c is a first and a second transfer belt.
14g, a backside transfer unit as a third transfer unit, 14m, a neutralizer as a neutralization unit, and 150g.
Is a paper charger which is a transfer material charging means, 14h is a paper separation AC static eliminator which is a transfer material separating means, 160 is a conveying section having a separation claw 210 which is a claw member and a spur 162 which is a spur member, and 17 is a fixing member. It is a fixing device as a means.

The photosensitive drum 10, which is an image forming body, has a transparent conductive layer, a, on the outer periphery of a cylindrical base formed of a transparent member such as optical glass or transparent acrylic resin.
-A photosensitive layer such as an Si layer or an organic photosensitive layer (OPC) is formed, and is rotated clockwise as indicated by an arrow in FIG. 1 with the conductive layer grounded.

The photosensitive drum 10, as shown in FIG.
Flange members 10A and 1A at both ends for engaging and fixing it
The gear G integrated with the flange member 10B is supported by the bearings B1 and B2 fitted into the drum body 0B and supported rotatably by the drum shaft 30 erected and fixed to the apparatus main body. When driven by meshing with the drive gear, it is rotated at a constant speed in a predetermined direction.

A scorotron charger 11, which is a charging unit for each color, an exposure optical system 12, which is an image writing unit for each color, and a developing unit 13, which is a developing unit for each color, form a set of yellow (Y) ), Magenta (M), cyan (C), and black (K) are provided for the image forming process, and four sets are provided.
With respect to the 0 rotation direction, they are arranged in the order of Y, M, C, and K.

The scorotron charger 11, which is a charging means for each color, has a control grid maintained at a predetermined potential and a discharge electrode 11a composed of, for example, a sawtooth electrode, and faces the photosensitive layer of the photosensitive drum 10. And installed
The charging operation (in the present embodiment, negative charging) is performed by corona discharge having the same polarity as that of the toner.
A uniform potential is given to 0. As the discharge electrode 11a, a wire electrode or a needle electrode may be used.

Exposure optical system 1 as image writing means for each color
2 indicates that the exposure position on the photosensitive drum 10 is the photosensitive drum 1 with respect to the scorotron charger 11 for each color described above.
It is arranged inside the photoconductor drum 10 so as to be located on the downstream side in the rotation direction of 0. As shown in FIG. 2, each exposure optical system 12 includes a plurality of LEDs (light emitting diodes) as light emitting elements of image exposure light (image writing light) arranged in the main scanning direction in parallel with the drum axis 30. Linear exposure elements 12a arranged in an array, and a light converging light transmitter (trade name: Selfoc lens array) 12b as an imaging element
And a lens holder 12c, and is attached to the holding member 20. The holding member 20 has a transfer simultaneous exposure device 12d in addition to the exposure optical system 12 for each color.
The uniform exposure device 12e is attached to the photosensitive drum 10, and the uniform exposure device 12e is housed inside the light-transmitting substrate of the photosensitive drum 10. The exposure optical system 12 for each color writes an image on the photosensitive layer of the photosensitive drum 10 from the back surface in accordance with the image data of each color read by a separate image reading device and stored in the memory, and the image is statically placed on the photosensitive drum 10. An electrostatic latent image is formed. Exposure element 12
As a, besides LED, FL (phosphor emission), EL
(Electroluminescence), PL (plasma discharge)
It is also possible to use a plurality of light emitting elements such as those arranged in an array. The light emission wavelength of the light emitting element of the image exposure light (image writing light) is usually in the range of 780 to 900 nm, which is highly transparent to the Y, M, and C toners.
In this embodiment, since the image is written from the back side, the wavelength may be shorter than 400 to 780 nm, which does not sufficiently transmit the color toner. Further, since 80% or more of the image exposure light is absorbed by the photosensitive layer of the photosensitive drum 10, the influence of the reflection and absorption by the color toner on the surface of the photosensitive drum 10 can be neglected. Generally, the development order of the color toner is the toner image or the developing device 1.
The order of Y, M, C, and K is preferable from the relationship of color mixture to 3.
In FIG. 2, WA is a light emitting element (LE) for image exposure light.
D).

A developing device 13 as a developing means for each color keeps a predetermined gap with respect to the peripheral surface of the photosensitive drum 10 and rotates in the forward direction with respect to the rotating direction of the photosensitive drum 10, for example, 0.5 to 1 mm in thickness. And a developing casing 131 formed of a cylindrical nonmagnetic stainless steel or aluminum material having an outer diameter of 15 to 25 mm, and a developing casing 138. Inside the developing casing 138, yellow (Y) and magenta ( M), cyan (C) and black (K) one-component or two-component developers. Each developing unit 13
Is maintained in a non-contact state with the photosensitive drum 10 with a predetermined gap, for example, 100 to 500 μm, by an abutting roller (not shown), and applies a developing bias in which a DC voltage and an AC voltage are superimposed on the developing sleeve 131. By doing
Non-contact reversal development is performed to form a toner image on the photosensitive drum 10.

The intermediate transfer belt 14a, which is an intermediate transfer member, has a volume resistivity of 10 ⁸ Ω · cm to 10 ¹⁶ Ω · cm, preferably 10 ⁹ Ω · cm.
It is an endless belt of 〜１０10 ¹² Ωcm, for example, modified polyimide, thermosetting polyimide, ethylene tetrafluoroethylene copolymer, polyvinylidene fluoride, a thickness of 0.1 to 0.1 to which a conductive material is dispersed in engineering plastic such as nylon alloy This is a seamless belt having a two-layer structure in which a 1.0-mm semiconductive film substrate is coated with a fluorine coating having a thickness of 5 to 50 μm, preferably as a toner filming preventing layer. In addition, as the base of the intermediate transfer belt 14a, a semiconductive rubber belt having a thickness of 0.5 to 2.0 mm in which a conductive material is dispersed in silicon rubber or urethane rubber or the like can be used. The intermediate transfer belt 14a includes a driving roller 1 that is a roller member.
4d, an earth roller 14j, a driven roller 14e, and a tension roller 14i, and are rotated in a counterclockwise direction indicated by an arrow in FIG. The driven roller 14e, the ground roller 14j, and the driving roller 14d are fixedly rotated, and the tension roller 14i is movably supported and rotated by an elastic force such as a spring (not shown). The drive roller 14d is rotated by a drive from a drive motor (not shown), and drives and rotates the intermediate transfer belt 14a. The rotation of the intermediate transfer belt 14a causes the earth roller 14j and the driven roller 1 to rotate.
4e and the tension roller 14i are driven to rotate. Belt slack of the rotating intermediate transfer belt 14a is tensioned by the tension roller 14i. The recording paper P, which is a transfer material, is supplied to a position where the intermediate transfer belt 14a is stretched around the driven roller 14e, and is conveyed by the intermediate transfer belt 14a. The recording paper P is separated from the intermediate transfer belt 14a at a curvature portion KT at an end of the intermediate transfer belt 14a stretched around the drive roller 14d on the fixing device 17 side.

The transfer device 14c as the first or second transfer means is a corona discharge device provided to face the photosensitive drum 10 with the intermediate transfer belt 14a interposed therebetween, and the intermediate transfer belt 14a and the photosensitive drum 10 Transfer area 14 between
b is formed. A DC voltage having a polarity opposite to that of the toner (positive polarity in this embodiment) is applied to the transfer device 14c, and the toner image on the photosensitive drum 10 is transferred to the intermediate transfer belt 1.
4a or onto the surface of the recording paper P as a transfer material.

The back transfer device 14g, which is a third transfer means, is preferably constituted by a corona discharger, and is driven by the transfer device 14c downstream of the transfer device 14c and upstream of the drive roller 14d in the rotation direction of the intermediate transfer belt 14a. Roller 14d
And a DC voltage having a polarity opposite to that of the toner (positive polarity in the present embodiment) is applied to the intermediate transfer belt 14a. Is transferred to the back surface of the recording paper P.

The static eliminator 14m, which is a static eliminator, is constituted by a corona discharger.
In the movement direction, an AC voltage, which is provided in parallel with the transfer device 14c on the downstream side of the transfer device 14c as the first and second transfer means and in which a DC voltage of the same polarity or opposite polarity to the toner is superimposed, The charge of the intermediate transfer belt 14a which is applied and charged by the voltage application of the transfer device 14c is removed.

The paper charger 150, which is a transfer material charging means, is preferably constituted by a corona discharger, is provided opposite to a driven roller 14e, which is grounded with the intermediate transfer belt 14a interposed, and has the same polarity as the toner (this embodiment). (In the embodiment, negative polarity) is applied, and the recording paper P is charged and attracted to the intermediate transfer belt 14a. In addition to the corona discharger, a paper charging brush or a paper charging roller that can abut and release the intermediate transfer belt 14a can be used as the paper charger 150.

Paper separation AC neutralizer 1 as transfer material separating means
Reference numeral 4h denotes a driving roller 14 which is preferably constituted by a corona discharger, and which is grounded to the end of the intermediate transfer belt 14a on the side of the fixing device 17 as required.
d, and an AC voltage obtained by superimposing a DC voltage of the same polarity or opposite polarity to the toner is applied as necessary.
The recording paper P conveyed by the intermediate transfer belt 14a is discharged and separated from the intermediate transfer belt 14a.

The transport section 160 includes a separation claw 210 as a claw member.
And a spur member 162 serving as a spur member. The spur member 162 is provided between the fixing device 17 and the curvature portion KT at the end of the intermediate transfer belt 14a on the fixing device 17 side. The transport unit 160 includes the fixing device 1
7, the intermediate transfer belt 14a is deformed, the toner image carried on the intermediate transfer belt 14a tends to be fused, and the transfer is difficult.
4a is prevented from sticking to the toner.

The separation claw 210, which is a claw member, approaches the curvature portion KT of the intermediate transfer belt 14a, and
Is fixed to the support shaft 221 at a predetermined interval, preferably 0.1 to 2.0 mm, and when the recording paper P is separated from the intermediate transfer belt 14a, the intermediate transfer belt 1
The leading end of the recording paper P, which is bent and conveyed in the direction 4a, is brought into contact with the recording paper P to assist the separation of the recording paper P.

The spur 162, which is a spur member, has a plurality of projections 162a on its peripheral surface, and is provided rotatably about a rotation support shaft 165. The spur 162 guides the back side of the recording sheet P to convey the recording sheet P, prevents the back side toner image of the recording sheet P having the toner image on both sides from being disturbed, and transfers the recording sheet P to the fixing device 17. The recording paper P is stably conveyed to the fixing device 17 while keeping the entering direction constant.

The separation claw 210 and the spur 162 are arranged on the opposite side of the photosensitive drum 10 with respect to the transfer material conveying surface of the intermediate transfer belt 14a or its extension surface PL1. It is also possible to provide spurs 162 as spur members on both sides of the transfer material conveying surface or the extension surface PL1.

A fixing device 17 serving as a fixing unit includes a first fixing roller 17a having a heater therein and a second fixing roller 1a.
7b, and a nip portion T between the first fixing roller 17a and the second fixing roller 17b, which are formed by two (a pair of) roller-shaped fixing members and are pressed against each other by a pressing mechanism (not shown). By fixing the recording paper P and applying heat and pressure, the toner image on the recording paper P is fixed.

Next, the image forming process will be described.

The photosensitive drum 10 is rotated clockwise as indicated by an arrow in FIG. 1 by starting a photosensitive member driving motor (not shown) at the start of image recording, and at the same time, is exposed to light by the charging action of a yellow (Y) scorotron charger 11. Body drum 1
Application of a potential to 0 starts.

After the photosensitive drum 10 is applied with a potential, the Y exposure optical system 12 starts image writing with a first color signal, that is, an electrical signal corresponding to the Y image data. An electrostatic latent image corresponding to the Y image of the original image is formed on the front surface.

The latent image is reversal-developed in a non-contact state by the Y developing unit 13, and a yellow (Y) toner image is formed on the photosensitive drum 10.

Next, a potential is applied to the photosensitive drum 10 from above the Y toner image by the charging action of the magenta (M) scorotron charger 11, and the second color signal, that is, the M color signal, is applied by the M exposure optical system 12. Image writing is performed by an electric signal corresponding to the image data, and the magenta (M) toner image is superimposed on the yellow (Y) toner image by non-contact reversal development by the M developing unit 13. It is formed.

By the same process, the cyan (C) toner image corresponding to the third color signal is further superimposed by the cyan (C) scorotron charger 11, the exposure optical system 12 of C, and the developing device 13 of C. The black (K) toner image corresponding to the fourth color signal is sequentially superimposed thereon by a black (K) scorotron charger 11, a K exposure optical system 12, and a K developing device 13. A superposed color toner image of four colors of yellow (Y), magenta (M), cyan (C) and black (K) is formed on the peripheral surface within one rotation of the photosensitive drum 10. (Toner image forming means).

These Y, M, C and K exposure optical systems 12
Image writing on the photosensitive layer of the photosensitive drum 10 is performed from the inside of the drum through the above-described translucent substrate. Therefore, the writing of the images corresponding to the second, third and fourth color signals is performed without any influence from the previously formed toner image, and is equivalent to the image corresponding to the first color signal. Can be formed.

The superimposed color toner image, which is the back image formed on the photosensitive drum 10 as the image forming body by the above image forming process, is transferred to the transfer area 14b.
By the transfer device 14c as a first transfer unit, the transfer is performed collectively (first transfer) on the intermediate transfer belt 14a as the intermediate transfer body (FIG. 3A). At this time, uniform exposure may be performed by the simultaneous transfer exposure device 12d provided inside the photoconductor drum 10 so that good transfer is performed. The charge on the intermediate transfer belt 14a charged by the transfer device 14c is removed by the charge remover 14m.

After the toner remaining on the peripheral surface of the photosensitive drum 10 after the transfer is subjected to static elimination by the photosensitive drum AC static eliminator 16, the toner is transferred to a cleaning device 19 which is an image forming body cleaning means. The toner is cleaned by a cleaning blade 19a made of a rubber material in contact with the toner, and collected by a screw 19b in a toner discharge container (not shown). Further, the peripheral surface of the photosensitive drum 10
For example, a uniform exposure device 12 before charging using a light emitting diode
The history of the photosensitive drum 10 in the previous image formation is eliminated by the exposure by e.

After the superimposed color toner image serving as the back side image is formed on the intermediate transfer belt 14a as described above, the front side image is continuously formed on the photosensitive drum 10 in the same manner as the above-described color image forming process. Is formed (FIG. 3B). On this occasion,
The image data is changed so that the front surface image formed on the photoconductor drum 10 becomes a mirror image with respect to the rear surface image formed on the photoconductor drum 10.

With the formation of a surface image on the photosensitive drum 10, recording paper P as a transfer material is sent out from a paper feed cassette 15 as a transfer material storage means by a feed roller 15a, and is used as a transfer material feeding means. Timing roller 1
5b, and the timing roller 15b drives the front surface image color toner image formed on the photosensitive drum 10 to synchronize with the back surface image color toner image carried on the intermediate transfer belt 14a. Transfer area 14
b. At this time, the fed recording paper P is charged to the same polarity as that of the toner by a paper charger 150 which is a transfer material charging means provided on the front side of the recording paper P, and is attracted to the intermediate transfer belt 14a to transfer the recording paper P 14b. By charging the paper with the same polarity as that of the toner, the toner is prevented from being attracted to the toner image on the intermediate transfer belt 14a and the toner image on the photosensitive drum 10, thereby preventing the toner image from being disturbed.

In the transfer area 14b, a second voltage to which a voltage having a polarity opposite to that of the toner (positive in this embodiment) is applied.
The surface image on the photosensitive drum 10 is collectively transferred (second transfer) to the surface of the recording paper P by the transfer device 14c as the transfer means. At this time, the back surface image on the intermediate transfer belt 14a is not transferred to the recording paper P but exists on the intermediate transfer belt 14a. Transfer device 1 as second transfer means
At the time of the second transfer by 4c, uniform transfer is performed by a simultaneous transfer exposure unit 12d using a light emitting diode, for example, provided inside the photosensitive drum 10 in opposition to the transfer area 14b so that good transfer is performed. Exposure may be performed. The charge on the intermediate transfer belt 14a charged by the transfer device 14c is removed by the charge remover 14m.

The recording paper P on which the color toner image has been transferred to the front surface is conveyed to a back transfer device 14g as a third transfer means to which a voltage having a polarity opposite to that of the toner (positive polarity in this embodiment) is applied. Then, the back surface image on the peripheral surface of the intermediate transfer belt 14a is collectively transferred (third transfer) to the back surface of the recording paper P by the back transfer device 14g (FIG. 3).
(C)).

The recording paper P on which the color toner images are formed on both sides is formed by the curvature of the curvature portion KT of the intermediate transfer belt 14a and the paper as transfer material separating means provided at the end of the intermediate transfer belt 14a as necessary. The spur 162 provided on the transport unit 160 is separated from the intermediate transfer belt 14a by the static elimination action of the separation AC neutralizer 14h and the separation claw 210 provided on the transport unit 160 at a predetermined interval from the intermediate transfer belt 14a. Fixing device 17 as fixing means through
The toner image on the recording paper P is fixed by applying heat and pressure at a nip portion T between the first fixing roller 17a and the second fixing roller 17b. The recording paper P on which double-sided image recording has been performed is sent upside down and sent.
The sheet is discharged to a tray outside the apparatus by a discharge roller 18.

The toner remaining on the peripheral surface of the intermediate transfer belt 14a after the transfer is provided opposite to the driven roller 14e with the intermediate transfer belt 14a interposed therebetween, and is applied to the intermediate transfer belt 14a with the support shaft 142 as a rotation fulcrum. The intermediate transfer member is cleaned by an intermediate transfer member cleaning device 140 which is an intermediate transfer member cleaning unit having an intermediate transfer member cleaning blade 141 capable of contacting and releasing contact.

The toner remaining on the peripheral surface of the photoconductive drum 10 after the transfer is subjected to static elimination by the photoconductive drum AC static eliminator 16 and then cleaned by the cleaning device 19, so that the uniform exposure device before charging is removed. By 12e, the history of the photosensitive drum 10 in the previous image formation is eliminated, and the next image formation cycle is started.

Since the superposed color toner images are collectively transferred by using the above-described method, the color image of the color image on the intermediate transfer belt 14a is hardly displaced, the toner is scattered or rubbed, and the image deterioration is small. Double-sided color image formation is performed.

A method of forming a space for removing jammed paper and a method of removing the jammed paper will be described with reference to FIGS. FIG. 4 is a diagram illustrating a first example of a method of forming a space for removing jammed paper, FIG. 5 is a diagram illustrating a method for removing a transfer material, and FIG. 6 is a diagram illustrating a method for removing jammed paper. It is a figure which shows the 2nd example of the way of space formation, FIG. 7: is a figure which shows the 3rd example of the way of space formation for jam paper removal, and FIG. 8 is FIG. FIG. 9 is a diagram illustrating a fourth example of a method of forming a space, and FIG. 9 is a diagram illustrating a fifth example of a method of forming a space for removing jammed paper.
FIG. 8 is a diagram showing a sixth example of a method of forming a space for removing jammed paper.

According to FIG. 4 or FIG. 5, the transport unit 16 does not reach the intermediate transfer belt 14a or the fixing device 17 without reaching the fixing device 17.
As shown in FIG. 4, when the recording paper P is jammed on the recording paper P, the lever 311 connected to the support frame of the intermediate transfer belt 14a (not shown) is pivoted about the fixed shaft J2 as necessary. The intermediate transfer belt 14a is lowered from the position shown by the dotted line in FIG. 4 to the position shown by the solid line locked by the stopper 312.
Is rotated from the position shown by the dotted line in FIG. 4 to the position shown by the solid line with the center axis J1 of the drive roller 14d as a support shaft, and the intermediate transfer belt 14a is separated from the photosensitive drum 10 so that the intermediate transfer belt 14a A space is formed between the body drum 10. This facilitates movement of the intermediate transfer belt 14a. Next, a backside transfer unit 14g as a third transfer unit and / or a paper separation AC as a transfer material separation unit
The holder lever 321 to which the static eliminator 14h is attached is moved from a position locked by a stopper 322 indicated by a dotted line in FIG. 4 around a fixed axis J3 by a link mechanism (not shown) to a position indicated by a solid line against the spring 323. The back transfer device 14g and / or the paper separation AC static eliminator 14h are retracted from the surface of the intermediate transfer belt 14a by being lifted and locked by a locking member (not shown), and the back transfer device 14g and / or the paper separation AC are removed.
A space is formed between the neutralizer 14h and the intermediate transfer belt 14a. Thus, after the recording paper P jammed by moving the intermediate transfer belt 14a can be moved in the space, the recording paper P is rolled into the space or in the vicinity thereof, and the jammed recording paper P is pulled out to perform the intermediate transfer. Remove from belt 14a. The intermediate transfer member cleaning blade 141 for cleaning the intermediate transfer belt 14a is desirably released to facilitate movement. As shown in FIG. 5, the recording paper P is rolled up by using a pinching member 301 having a large friction coefficient, for example, a rubber material 301 a attached to the leading end, and holding the recording paper P jammed by the pinching member 301 by hand. After that, the jammed recording paper P is rolled by turning the pinching member 301 and pulled out by the pinching member 301 to be removed.

As described above, during the jam processing, the hands are not stained with the unfixed toner adhering to the front and back surfaces of the transfer material.
Further, the jammed transfer material can be removed without polluting the surroundings. In particular, when the transfer material is on the intermediate transfer belt, it can be easily moved with the intermediate transfer belt when the transfer material is electrostatically attracted to the intermediate transfer belt and pulled out, and the amount of adhesion on the front and back of the transfer material The jammed transfer material can be removed without soiling the hands and the surroundings with the unfixed toner.

Further, according to FIG. 6, the recording paper P on the transport section 160 includes a nip portion T between the first fixing roller 17a and the second fixing roller 17b, which are constituted by a pair of fixing members of the fixing device 17. When the paper jam occurs, the pressing mechanism (not shown) is released, and the pressing of the first fixing roller 17a and / or the second fixing roller 17b is released (in the present embodiment, the second fixing roller 17b is connected to the first fixing roller 17b). 17a)
After a space is formed between the pair of fixing members so that the jammed recording paper P can move in the space, the sandwiching member 301 (not shown in FIG. 6) is used as described above with reference to FIG. Then, after the recording sheet P jammed by the pinching member 301 by hand, the recording sheet P jammed by turning the pinching member 301 is turned.
Into the space or the vicinity thereof,
Withdraw and remove by A holder on which the backside transfer unit 14g and / or the paper separation AC static eliminator 14h are further attached so that the jammed recording paper P can be further easily removed, or when the jammed recording paper P also hangs on the intermediate transfer belt 14a. The lever 321 is lifted from the position shown by the dotted line in FIG. 6 to the position shown by the solid line in the same manner as described above with reference to FIG. 4, and the back transfer device 14g and / or the paper separation AC neutralizer 14h are moved from the surface of the intermediate transfer belt 14a. The space is formed between the intermediate transfer belt 14a and the back surface transfer device 14g and / or the paper separation AC static eliminator 14h by retreating, so that the jammed recording paper P can be moved in the space and then sandwiched. The recording paper P jammed by the member 301 (not shown in FIG. 6) is rolled into the space or its vicinity, pulled out, and removed.

As described above, at the time of the jam processing, the hands are not stained with the unfixed toner adhering to the front and back surfaces of the transfer material.
Further, the jammed transfer material can be removed without polluting the surroundings.

According to FIG. 7 or FIG. 8, when the recording sheet P jams on the intermediate transfer belt 14a or on the transport unit 160 without reaching the fixing device 17, as described above with reference to FIG. The space between the intermediate transfer belt 14a and the photosensitive drum 10 is formed by separating the intermediate transfer belt 14a from the photosensitive drum 10 from a position shown by a dotted line to a position shown by a solid line in FIG. . This facilitates movement with the intermediate transfer belt 14a. Further, a holder lever 331 holding the transport unit 160 provided with a spur 162 as a spur member and a separation claw 210 as a claw member
From the position shown by the dotted line to the position shown by the solid line in FIG.
d, and is retracted from between the intermediate transfer belt 14a and the fixing device 17 so that the intermediate transfer belt 1
A space is formed between 4a and the fixing device 17. This allows the jammed recording paper P to move in the space together with the intermediate transfer belt 14a. Then, as described above with reference to FIG. 5, the holding member 301 (not shown in FIG. 7) is used. After the jammed recording paper P is sandwiched by 301, the jammed recording paper P is rolled by turning the sandwiching member 301 into the space or in the vicinity thereof and pulled out by the sandwiching member 301 to be removed. Further, to make it easier to remove the jammed recording paper P,
As shown in FIG. 8, a holder lever 321 to which the back surface transfer device 14g and / or the paper separation AC static eliminator 14h are attached.
4 is lifted from the position shown by the dotted line in FIG. 8 to the position shown by the solid line in the same manner as described above with reference to FIG.
4a, a space is formed between the back transfer device 14g and / or the paper separation AC neutralizer 14h and the intermediate transfer belt 14a, so that the jammed recording paper P can move in the space. Thereafter, the recording paper P jammed by the sandwiching member 301 (not shown in FIG. 8) is rolled into the space or its vicinity, pulled out, and removed.

As described above, at the time of jam processing, the hands are not stained with unfixed toner adhering to the front and back surfaces of the transfer material.
Further, the jammed transfer material can be removed without polluting the surroundings. In particular, when the transfer material is on the intermediate transfer belt, the hand is stained with unfixed toner that adheres to the front and back surfaces of the transfer material when the transfer material is electrostatically attracted to the intermediate transfer belt and is pulled out. This makes it possible to remove the jammed transfer material without causing any contamination and surroundings.

According to FIG. 9, the recording paper P is transported on the transport section 160 including a nip portion T between the first fixing roller 17a and the second fixing roller 17b, which are constituted by a pair of fixing members of the fixing device 17. When the paper jam occurs, the pressing mechanism (not shown) is released, and the pressing of the first fixing roller 17a and / or the second fixing roller 17b is released (in the present embodiment, the second fixing roller 17b is connected to the first fixing roller 17b). 17a)
A space is formed between the pair of fixing members, and a holder lever 331 that holds the transport unit 160 provided with a spur 162 as a spur member and a separation claw 210 as a claw member, as described above with reference to FIG. From the position shown by the dashed line in FIG. 9 to the position shown by the solid line, it rotates below the drive roller 14 d (back side) with the center axis J1 of the drive roller 14 d as a support shaft, and moves between the intermediate transfer belt 14 a and the fixing device 17. To form a space between the intermediate transfer belt 14a and the fixing device 17. As a result, after the jammed recording paper P is made movable in the space, the recording paper P jammed by the hand using the sandwiching member 301 (not shown in FIG. 9) as described above with reference to FIG. After the paper P is sandwiched, the jammed recording paper P is rolled into the space or in the vicinity thereof by rotating the sandwiching member 301, pulled out by the sandwiching member 301, and removed.

As described above, during the jam processing, the hands are not stained with the unfixed toner adhering to the front and back surfaces of the transfer material.
Further, the jammed transfer material can be removed without polluting the surroundings.

According to FIG. 10, recording is performed across the nip portion T between the first fixing roller 17a and the second fixing roller 17b, which are constituted by a pair of fixing members of the fixing device 17, and the intermediate transfer belt 14a. When the paper P is jammed, the pressing mechanism (not shown) is released and the first fixing roller 17a and / or
Alternatively, the pressure contact of the second fixing roller 17b is released (in this embodiment, the second fixing roller 17b is
7a), a space is formed between the pair of fixing members, and the transport unit 160 is provided with a spur 162 as a spur member and a separation claw 210 as a claw member as described above with reference to FIG. The holder lever 331 to be moved is shown in FIG.
From the position indicated by the dotted line to the position indicated by the solid line at 0, the rotation is performed below the drive roller 14d (back side) with the center axis J1 of the drive roller 14d as a support shaft, and the position between the intermediate transfer belt 14a and the fixing device 17 is changed. By retracting, a space is formed between the intermediate transfer belt 14a and the fixing device 17, and a holder lever to which the back transfer unit 14g and / or the paper separation AC static eliminator 14h are attached as described above with reference to FIG. 321 is lifted from the position shown by the dotted line to the position shown by the solid line in FIG.
4h is withdrawn from the surface of the intermediate transfer belt 14a to form a space between the back transfer device 14g and / or the paper separation AC static eliminator 14h and the intermediate transfer belt 14a, and as described above with reference to FIG. The intermediate transfer belt 14a
Is separated from the photosensitive drum 10 from a position shown by a dotted line to a position shown by a solid line in FIG. 10 to form a space between the intermediate transfer belt 14a and the photosensitive drum 10. This facilitates the movement of the intermediate transfer belt 14a, so that the jammed recording paper P can move in the space, and then use the sandwiching member 301 (not shown in FIG. 10) as described above with reference to FIG. And the recording paper P jammed by the pinching member 301 by hand
, The recording paper P that has been jammed by rotating the pinching member 301 is rolled into the space or in the vicinity thereof, and the pinching member 30 is rotated.
Withdraw by 1 and remove.

As described above, during the jam processing, the hands are not stained with the unfixed toner adhering to the front and back surfaces of the transfer material.
Further, the jammed transfer material can be removed without polluting the surroundings. In particular, when the transfer material is on the intermediate transfer belt, the hand is stained with unfixed toner that adheres to the front and back surfaces of the transfer material when the transfer material is electrostatically attracted to the intermediate transfer belt and is pulled out. This makes it possible to remove the jammed transfer material without causing any contamination and surroundings.

Another embodiment of the image forming apparatus according to the present invention will be described with reference to FIG. FIG. 11 is a schematic explanatory view of a color image forming apparatus showing another embodiment of the image forming apparatus according to the present invention.

In the image forming apparatus of this embodiment, as shown in FIG. 11, a photosensitive drum 10b as a first image forming body for forming a toner image to be a back image (back toner image) and a front image are formed. A photosensitive drum 10a, which is a second image forming member for forming a toner image (front toner image), is separately provided, and a back toner image formed on the photosensitive drum 10b is
Polarity opposite to toner (positive polarity in this embodiment)
Transfer device 1 which is a first transfer unit to which a voltage of
14b, an intermediate transfer belt 114a as an intermediate transfer member
After the transfer (first transfer), the recording paper P, which is a transfer material, is supplied onto the intermediate transfer belt 114a between the photosensitive drum 10b and the photosensitive drum 10a.
The recording paper P is charged by the paper charger 150 provided opposite the ground roller 14k, which is grounded across the recording paper P.
Is adsorbed on the intermediate transfer belt 114a and conveyed, and the surface toner image formed on the photosensitive drum 10a is transferred by a second transfer unit to which a voltage having a polarity opposite to that of the toner (positive polarity in this embodiment) is applied. After transfer (second transfer) to the front surface of the recording paper P by a certain secondary transfer device 114c, the reverse toner image (positive polarity in the present embodiment) is applied to the back toner image on the intermediate transfer belt 114a. The third transfer unit 114g, which is a third transfer unit, transfers the image to the back surface of the recording paper P (third transfer) by forming a front and back toner image on the recording paper P, and forms a color toner image on both surfaces. Is formed on the recording paper P with the curvature portion K of the intermediate transfer belt 114a.
The curvature of T, the neutralization effect of the paper separation AC neutralizer 14h as a transfer material separating means provided as needed at the end of the intermediate transfer belt 114a, and the conveyance unit 160 with a predetermined interval from the intermediate transfer belt 114a. Separation claw 2 provided on
10, the toner image is separated from the intermediate transfer belt 114a, and is conveyed to a fixing device 17 as a fixing unit through a spur 162 provided in a conveying unit 160, and is fixed to a first fixing roller 17a.
At the nip portion T between the recording paper P and the second fixing roller 17b.
The upper toner image is fixed to obtain a double-sided image.

The photosensitive drums 10a and 10b and the intermediate transfer belt 114a in the image forming apparatus of this embodiment have the same function and structure as those of the photosensitive drum 10 and the intermediate transfer belt 14a described in the image forming apparatus. Can be The intermediate transfer belt 114a is stretched in contact with a driving roller 14d, a ground roller 14j, a facing ground roller 14k, a driven roller 14e, and a tension roller 14i, which are roller members. Each of the charge eliminators 114m and 114n, which is a charge eliminator, is preferably constituted by a corona discharger, and is disposed after the primary transfer device 114b and the secondary transfer device 114c in the moving direction of the intermediate transfer belt 114a. An AC voltage, which is provided in parallel with the transfer device 114b and the secondary transfer device 114c and is superimposed with a DC voltage of the same polarity or opposite polarity to the toner, is applied, and is charged by the application of the voltages of the primary transfer device 114b and the secondary transfer device 114c. The charge of the intermediate transfer belt 114a is removed.

A toner image forming means (first toner image forming means) for forming a toner image serving as a back image on the photosensitive drum 10b serving as a first image forming body, and a toner image serving as a front image as a second image The toner image forming means (second toner image forming means) formed on the photosensitive drum 10a as a forming body includes:
Four sets of developing units 13 (developing means) of yellow (Y), magenta (M), cyan (C) and black (K) and a scorotron charger 11 (charging) similar to those used in the above-described image forming apparatus. Means), and an exposure optical system 12 (image writing means) is used for each of the photosensitive drums 10b and 10a to form a toner image of a back side image and a toner image of a front side image, respectively.

Also in the image forming apparatus of this embodiment, as described with reference to FIGS. 4 to 10, the recording paper P is jammed on the conveying section 160, the intermediate transfer belt 114a as an intermediate transfer body, the fixing device 17, and the like. In this case, the space between the intermediate transfer belt 114a and the photosensitive drum 10a is formed by separating the intermediate transfer belt 114a from the photosensitive drum 10a as necessary, and the same as the back transfer device 14g in the previous example. 3 as the third transfer means of function and structure
Next transfer unit 114g and / or paper separation AC static eliminator 14h
The tertiary transfer unit 114g and / or the tertiary transfer unit 114g and / or the paper separation AC charge eliminator 14h are retracted from the surface of the intermediate transfer belt 114a by lifting up a holder lever 321 (not shown in FIG. 11) to which is attached. Or paper separation A
Formation of a space between the C neutralizer 14h and the intermediate transfer belt 114a, and release of pressure bonding of the first fixing roller 17a and / or the second fixing roller 17b (the second fixing roller 17a in this embodiment).
A holder lever for holding a space between a pair of fixing members by the fixing roller 17b (separated from the first fixing roller 17a) and a transport unit 160 provided with a spur 162 as a spur member and a separation claw 210 as a claw member The intermediate transfer belt 114 retracted from between the intermediate transfer belt 114a and the fixing device 17 by the rotation of the drive roller 14d downward (back side) of the drive roller 331 (not shown in FIG. 11).
After the space between the fixing device 17 and the fixing device 17 is formed, and the jammed recording paper P can move in the space, the jammed recording paper P is manually pinched using the pinching member 301 (not shown in FIG. 11). After the jammed recording paper P is sandwiched by the member 301, the jammed recording paper P is rolled into the space or in the vicinity thereof by turning the sandwiching member 301, and is pulled out and removed by the sandwiching member 301.

In this way, at the time of jam processing, the hands are not stained with unfixed toner adhering to the front and back surfaces of the transfer material,
Further, the jammed transfer material can be removed without polluting the surroundings. In particular, when the transfer material is on the intermediate transfer belt, when the transfer material is electrostatically attracted to the intermediate transfer belt and the transfer material that is difficult to peel is pulled out, the transfer material is cut or the unfixed amount adheres to the front and back of the transfer material The jammed transfer material can be removed without soiling the hands and surroundings with the toner.

Although the color image forming apparatus has been described as an example of each of the above image forming apparatuses, the present invention is not necessarily limited to this, and the same process as described with reference to FIG. 1 or FIG. The present invention is also applied to a monochrome image forming apparatus.

Further, according to the image forming apparatus of the present invention, in addition to the double-sided image forming for forming an image on both sides of the transfer material as described in each of the above-described image forming apparatuses, the image forming apparatus may be provided on one side of only the front surface or the back surface of the transfer material. It goes without saying that single-sided image formation for forming an image can also be performed.

[0065]

According to the present invention, during jam processing, the jammed transfer material can be removed without uncleaning the hands and the surrounding area with unfixed toner attached to the front and back surfaces of the transfer material. Becomes possible.

[Brief description of the drawings]

FIG. 1 is a cross-sectional configuration diagram of a color image forming apparatus showing an embodiment of an image forming apparatus according to the present invention.

FIG. 2 is a side sectional view of the image forming body of FIG. 1;

FIG. 3 is a diagram illustrating a toner image forming state in the image forming apparatus according to the present invention.

FIG. 4 is a first diagram illustrating a method of forming a space for removing jammed paper.
It is a figure showing the example of.

FIG. 5 is a diagram illustrating a method of removing a transfer material.

FIG. 6 shows a second method of forming a space for removing jammed paper.
It is a figure showing the example of.

FIG. 7 shows a third method of forming a space for removing jammed paper.
It is a figure showing the example of.

FIG. 8 shows a fourth method of forming a space for removing jammed paper.
It is a figure showing the example of.

FIG. 9 shows a fifth method of forming a space for removing jammed paper.
It is a figure showing the example of.

FIG. 10 is a diagram illustrating a sixth example of a method of forming a space for removing jammed paper.

FIG. 11 is a schematic explanatory view of a color image forming apparatus showing another embodiment of the image forming apparatus according to the present invention.

[Explanation of symbols]

 10, 10a, 10b Photoconductor drum 11 Scorotron charger 12 Exposure optical system 13 Developing device 14a, 114a Intermediate transfer belt 14c Transfer device 14g Back surface transfer device 14h Paper separation AC neutralizer 14m, 114m, 114n Static neutralizer 17 Fixing device 17a 1 fixing roller 17b second fixing roller 114b primary transfer unit 114c secondary transfer unit 114g tertiary transfer unit 160 transport unit 162 spur 301 sandwiching member P recording paper

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yotaro Sato 2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica Corporation F-term (reference) 2H028 BA05 BA12 2H071 BA14 BA15 BA35 DA09 DA23 DA24 2H072 EA18 EA19 3F048 AA02 AB01 EA12

Claims (4)

[Claims] An image forming apparatus that forms a toner image on both surfaces of a transfer material via an intermediate transfer member on a toner image formed on the image forming body, and then fixes the toner images on both surfaces of the transfer material by a fixing unit; In the case where the transfer material is jammed, a space is formed on the intermediate transfer member or between the intermediate transfer member and the fixing unit so that the transfer material can be moved, and the transfer material is rolled into the space. An image forming apparatus, which is drawn out. 2. A transfer material separating means for separating the transfer material from the intermediate transfer body and / or a third transfer means for transferring a toner image on the intermediate transfer body to a back surface of the transfer material, The image forming apparatus according to claim 1, wherein a space is formed. 3. The image forming apparatus according to claim 1, wherein a spur member that conveys the transfer material from the intermediate transfer member to the fixing unit is retracted to form the space. 4. The image forming apparatus according to claim 1, wherein a pair of fixing members provided in the fixing unit are separated from each other to form the space.