JPH08328395A - Image forming device - Google Patents

Abstract

PURPOSE: To provide an image forming device capable of preventing the deterioration of attracting means and the transporting means, performing excellent transferring, and restraining the cleaning defect from occurring. CONSTITUTION: This device is provided with a transporting belt 20 for transporting a transfer material 10, plural transfer devices 21Y, 21M, 21C and 21BK disposed opposing respective photoreceptor drum 2Y, 2M, 2C and 2BK, for transferring images formed on the photoreceptor drum 2Y, 2M, 2C and 2BK to the transfer material 10, the attracting roller 29 for attracting the transfer material 10 on the transfer belt 20, and attaching detaching means for attaching/detaching plural photoreceptor drums 2Y, 2M, 2C and 2BK to the transporting belt 20 corresponding to a monochrome or multicolor image forming mode, while attaching/detaching the attracting roller 29 with respect to the transfer belt 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus and is provided with a plurality of image forming mechanisms for forming images of different colors on a plurality of image carriers, for example, to obtain a multicolor image, for example, color copying. The present invention relates to an image forming apparatus such as a machine.

[0002]

2. Description of the Related Art In recent years, in response to the color orientation of offices,
Color printers and color copiers have appeared. One of the systems of these image forming apparatuses is a 4-tandem photosensitive drum tandem system.

In this system, four photoconductor drums are arranged in parallel, and a toner image is formed on each photoconductor drum by using yellow, magenta, cyan, and black toners, and the toner image is formed by a registration roller. This is a system in which color images are obtained by sequentially transferring to one transfer material that is aligned and conveyed by a transfer and conveyance belt.

In this case, the transfer material is taken into the apparatus from a paper feed cassette or a manual feed tray built in the main body of the apparatus by the rotation of the paper feed roller, and is sent to the transfer belt after the front end is aligned by a pair of registration rollers. And is electrostatically adsorbed by the adsorption roller.

After that, the transfer material is conveyed by the conveyor belt via the photosensitive drums of the respective colors and is sent to the fixing device to be permanently fixed. The conveyor belt after the transfer material is peeled off is cleaned by a cleaner.

On the other hand, at the time of printing a monochrome image, the transfer / conveying belt is brought into contact with only the black photoconductor drum and separated from the other photoconductor drums to obtain a monochrome image.

By the way, when a color image is printed, the transfer position of the first color is close to the registration roller pair, and the transfer material is attracted to the transfer / conveying belt at the time of transfer. Good printed images can be obtained without color misregistration until the transfer of colors.

On the other hand, when printing a monochrome image, since the distance from the registration roller pair to the black image transfer position is long, conveyance failure occurs on a small object such as a postcard or thick paper, so that the suction roller is required.

Further, in the above-mentioned cleaner, in particular, in the blade cleaner, the change in the bite amount with respect to the conveyor belt, for example, when the bite amount is large, the edge of the blade hits the belly without hitting, and when the bite amount is small,
Due to the elasticity of the blade, the transfer belt may hit the edge or may not hit the edge, resulting in poor cleaning.Therefore, it is necessary to provide a blade cleaner where there is no displacement due to the contact / separation operation of the conveyor belt with respect to the photosensitive drum. .

[0010]

However, in the prior art, since the suction roller is always in contact with the conveyor belt, the suction roller and the conveyor belt are prone to deterioration, and when color image printing is performed, particularly, high temperature In a high-humidity state, the transfer material absorbs moisture, and both transfer and adsorption charges are applied, resulting in defective transfer.

Since the distance from the registration roller to the black image transfer position is long during monochrome image printing, both transfer and adsorption charges are not applied unlike in the case of color images.

Further, when the conveyor belt is moved toward and away from the photosensitive drum, the position relative to the conveyor belt is largely displaced, so that the amount of bite of the cleaner, particularly the blade cleaner, changes with respect to the conveyor belt. When the blade is large, the edge of the blade hits without hitting the edge, and when the biting amount is small, the elasticity of the blade hits the transfer belt with the edge or does not hit the edge, resulting in poor cleaning. I went up.

Therefore, the present invention prevents deterioration of the suction means and the conveying means and enables good transfer,
Moreover, it is an object of the present invention to provide an image forming apparatus in which cleaning failure does not occur.

[0014]

In order to solve the above-mentioned problems, the present invention provides a device according to claim 1 in which a plurality of image bearing members arranged in parallel and a plurality of image bearing members are provided on the plurality of image bearing members. A plurality of image forming means for respectively forming images, a conveying means constituted of a conveyor belt for traveling the plurality of image carriers to convey the transfer material, and a plurality of conveying means provided for the respective image carriers. A plurality of transfer means for transferring the image formed on the image carrier to the transfer material, a suction means for sucking the transfer material on the transport means, and a plurality of single colors for the plurality of image carriers and the transport means. Alternatively, it is provided with contacting / separating means for contacting / separating according to the multicolor image forming mode and for contacting / separating the suction means with respect to the conveying means.

According to a second aspect of the present invention, a plurality of image carriers arranged in parallel, a plurality of image forming means for forming images on the plurality of image carriers, respectively, and a plurality of the image carriers. Conveying means including a conveyor belt that conveys the transfer material, which is opposed to the body, and the image forming member, which is provided to face each of the image carriers and transfers the image formed on the image carrier to the transfer material. A plurality of transfer means, a suction means for sucking the transfer material to the transport means, and a transport means for moving the contact means to and from the plurality of image carriers according to a single-color or multicolor image forming mode. At the same time, it comprises a contacting / separating means for contacting / separating the suction means with respect to the conveying means.

According to a third aspect of the present invention, a plurality of image bearing members arranged in parallel, a plurality of image forming means for respectively forming images on the plurality of image bearing members, and the plurality of image bearing members. Conveying means including a conveyor belt that conveys the transfer material, which is opposed to the body, and the image forming member, which is provided to face each of the image carriers and transfers the image formed on the image carrier to the transfer material. A plurality of transfer means, a suction means for sucking the transfer material onto the conveying means, a plurality of image carriers and a plurality of image forming means, and a single color or multicolor image forming mode for the conveying means. And contacting / separating means for contacting / separating the suction means with respect to the conveying means.

According to a fourth aspect of the present invention, a plurality of image carriers arranged in parallel, a plurality of image forming means for forming images on the plurality of image carriers, respectively, and a plurality of the image carriers. Conveying means including a conveyor belt that conveys the transfer material, which is opposed to the body, and the image forming member, which is provided to face each of the image carriers and transfers the image formed on the image carrier to the transfer material. A plurality of transfer means, a contacting / separating means for contacting / separating the transporting means and the plurality of image carriers with each other in accordance with a single-color or multicolor image forming mode, and abutting force on the transporting means. Cleaning means for cleaning the conveying means without changing the contacting / separating operation of the means.

According to a fifth aspect of the present invention, a plurality of image carriers arranged in parallel, a plurality of image forming means for respectively forming images on the plurality of image carriers, and a plurality of the image carriers. Conveying means including a conveyor belt that conveys the transfer material, which is opposed to the body, and the image forming member, which is provided to face each of the image carriers and transfers the image formed on the image carrier to the transfer material. A plurality of transfer means, a contacting / separating means for contacting / separating the conveying means and the plurality of image carriers with each other in accordance with a single-color or multicolor image forming mode, and an end portion of the conveying means for contacting the corresponding contact position. By the contacting and separating operation of the conveying means,
It is a position that does not change the distance between the end portion and the carrying means, and is provided with a cleaning means for cleaning the carrying means at this position.

According to a sixth aspect of the present invention, a plurality of image carriers arranged in parallel, a plurality of image forming means for respectively forming images on the plurality of image carriers, and a plurality of the image carriers. Conveying means including a conveyor belt that conveys the transfer material, which is opposed to the body, and the image forming member, which is provided to face each of the image carriers and transfers the image formed on the image carrier to the transfer material. A plurality of transfer means, a contacting / separating means for contacting / separating the conveying means with respect to the plurality of image carriers according to a single-color or multicolor image forming mode, and a cleaning means for contacting the conveying means. And a supporting means for supporting the cleaning means and moving the cleaning means integrally with the conveying means at the time of the contacting / separating operation of the conveying means.

[0020]

According to the first aspect of the present invention, in the monochromatic image forming mode, the conveying means and the plurality of image carriers are separated from each other except one of them, and the adsorbing means is brought into contact with the conveying means. By bringing the conveying means into contact with the plurality of image carriers and separating the suction means from the conveying means, deterioration of the suction means and the conveying means can be prevented, and transfer failure can be prevented.

According to a second aspect of the present invention, in the monochromatic image forming mode, the conveying means is separated from a plurality of image carriers except one of them, and the suction means is brought into contact with the conveying means to form a multicolor image formation. In the mode, the transporting means is brought into contact with the plurality of image carriers and the suction means is separated from the transporting means, whereby the suction means and the transporting means are prevented from being deteriorated and the transfer failure is prevented.

According to a third aspect of the present invention, in the single-color image forming mode, a plurality of image carriers except one of them are separated from the conveying means, and the suction means is brought into contact with the conveying means to form a multicolor image. In the mode, the plurality of image carriers are brought into contact with the transporting means and the suction means is separated from the transporting means to prevent deterioration of the suction means and the transporting means and prevent transfer failure.

According to a fourth aspect of the present invention, the cleaning means is brought into contact with the conveying means, and the conveying means is cleaned without changing the contact force by the contacting / separating operation of the conveying means. Even if it can be cleaned well.

According to a fifth aspect of the present invention, the end portion of the cleaning means is brought into contact with the conveying means, and the contact position is changed by the contacting / separating operation of the conveying means to change the distance between the end portion and the conveying means. It is a position where the transfer means is not allowed to be cleaned, and by cleaning the transfer means at this position, it is possible to perform good cleaning even if the transfer means moves in and out.

According to a sixth aspect of the present invention, the carrying means is provided with a supporting means for supporting the cleaning means abutting against the carrying means and moving the carrying means integrally with the carrying means at the time of the contacting / separating operation of the carrying means. Even if the contacting / separating operation is performed, the cleaning means is made to follow the cleaning operation so that the cleaning can be performed well.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in the drawings. FIG. 1 schematically shows the overall structure of a color copying machine as an image forming apparatus, and FIG. 2 is an enlarged view showing the inside thereof.

In the figure, reference numeral 1 denotes a main body of the apparatus, and in the main body 1 of the apparatus, photosensitive drums 2Y, 2M, 2C as image bearing members,
Recording devices 3Y, 3M, 3C, and 3BK for recording images of four colors of yellow (Y), magenta (M), cyan (C), and black (BK) are arranged so as to be parallel to 2BK. Since each of the recording devices 3Y, 3M, 3C, and 3BK has the same configuration, only the yellow recording device 3Y arranged in the preceding stage will be described, and other recording devices 3M, 3C, and 3BK have the same parts. Are denoted by the same reference numerals and subscripts indicating colors, and description thereof will be omitted.

The recording device 3Y includes a photosensitive drum 2Y.
And an image forming unit 4Y which is provided corresponding to the same and repeatedly forms a yellow image on the photoconductor drum 2Y.
Have. The image forming unit 4Y includes a charging device 5Y, an exposure device 6Y, a developing device 7Y, a cleaning device 8Y, a charge eliminating device 9Y, and the like.

Further, each of the recording devices 3Y, 3M, 3C,
A transfer / transport belt 20 as a transfer material transport unit is stretched below the position where 3BK is disposed, and the transfer material 10 such as a sheet is transported to the photosensitive drums 2Y, 2M, 2C, and 2BK. It is supposed to do.

Further, the photosensitive drums 2Y, 2M, 2
Transfer devices 21Y, 21M, and 21 as transfer means sandwiching the transfer / conveying belt 20 at positions facing C and 2BK.
C and 21BK are provided, and the photosensitive drum 2 is provided.
The toner images of the respective colors formed on Y, 2M, 2C, and 2BK are transferred onto the transfer material 10 conveyed by the conveyor belt 20. The transfer material 10 is supplied onto the conveyor belt 20 by the paper feeding system 22 at a timely timing.

As shown in FIG. 1, the paper feed system 22 includes a pickup roller 23 that takes out the transfer material 10 from the paper feed cassette 19, a feed roller pair 24 that conveys the transfer material 10 taken out by the pickup roller 23, and a pair of feed rollers 24. ,
The transfer roller pair 24 includes a registration roller pair 25 that aligns the leading edge of the transfer material 10 conveyed by the feed roller pair 24 and feeds the transfer material 10 at a timing.

The transfer speed of the transfer material 10 by the registration roller pair 25 and the transfer / conveying belt 20 is set to be equal to the peripheral speed of the photosensitive drums 2Y, 2M, 2C and 2BK.

Further, a fixing device 26, a pair of paper discharge rollers 27, and a paper discharge tray 28 are sequentially arranged in the transfer material transfer direction by the transfer transfer belt 20 (in the left direction in the drawing), and the fixing device 26, the paper discharge tray 28, and the transfer device 20 are arranged in this order. The recording devices 3Y, 3M, and 3 are provided on the inner bottom.
A control unit 50 that controls the operations of the C, 3BK, the paper feeding system 22, and other devices is provided.

When color image formation is designated from the operation input unit (not shown), the recording devices 3Y, 3M, 3C for yellow (Y), magenta (M), cyan (C), and black (BK) are selected. 3BK operates at a predetermined timing to form a toner image of each color on each of the photoconductor drums 2Y, 2M, 2C and 2BK.

That is, taking the recording device 3Y as an example, the photosensitive drum 2Y rotates in the clockwise direction (direction of arrow A) in the figure, and the surface thereof is uniformly charged by the charging device 5Y. Then, an exposure operation is performed by the exposure device 6Y on the uniformly charged photosensitive drum 2Y, and a latent image corresponding to a yellow image is formed. By facing the developing device 7Y, the latent image is supplied with toner to be developed and a yellow toner image is formed on the photosensitive drum 2Y.

The recording devices 3M, 3C, 3BK for other colors
In the same way, a toner image is similarly formed. On the other hand, in synchronization with this toner image forming operation, the transfer material 10 is taken out from the paper feed cassette 19, the leading end of the transfer material 10 is aligned by the registration roller pair 25, and then the transfer material 10 is fed onto the transfer / transport belt 20.

The transfer material 10 fed onto the transfer / transport belt 20 is transported along with the traveling of the transfer / transport belt 20 while being electrostatically attracted to the transfer / transport belt 20 by a suction roller 29 as suction means. First, the yellow toner image transfer position, that is, the photosensitive drum 2Y and the transfer device 21Y are fed to a position where they oppose each other with the transfer / transport belt 20 interposed therebetween.

At this yellow toner image transfer position, the transfer material 10 comes into contact with the yellow toner image on the photoconductor drum 2Y, and the transfer device 21Y functions to transfer the yellow toner image on the transfer device 21Y. 1
0 is transcribed.

The transfer device 21Y is composed of a transfer roller having semi-conductivity, and has an electric field having a polarity opposite to the potential of the yellow toner image electrostatically attached to the photosensitive drum 2Y from the back side of the conveyor belt 20. To supply. This electric field acts on the yellow toner image on the photoconductor drum 2Y through the transport belt 20 and the transfer material 10, and as a result,
The yellow toner image is transferred from the photosensitive drum 2Y to the transfer material 10.

The transfer material 10 on which the yellow toner image has been transferred in this manner is then sequentially conveyed to the toner image transfer position of each of the magenta recording device 3M, the cyan recording device 3C, and the black recording device 3BK, and the magenta toner is transferred. The image, the cyan toner image, and the black toner image are sequentially transferred to form a color image.

The transfer material 10 on which the color toner image has been formed is then peeled off from the transfer / transport belt 20 and fixed by the fixing device 26.
And the color toner image with the color superposed is permanently fixed, and then the paper is ejected from the paper ejection tray 2 via the paper ejection roller pair 27.
It is carried out to 8.

On the other hand, the transfer conveyance belt 20 from which the transfer material has been peeled off is driven to rotate as it is, the residual toner and the paper dust are cleaned by the belt cleaning device 31, and then the surface potential is made constant by the charge eliminating roller 30.

Further, the photoconductor drums 2Y, 2M, 2C and 2BK after the toner image is transferred are rotationally driven as they are, the residual toner and the paper dust are cleaned by the cleaning devices 8Y, 8M, 8C and 8BK. The surface potential is made constant by the static elimination lamps of the static eliminators 9Y, 9M, 9C and 9BK. Then, if necessary, a series of processes from the charging devices 5Y, 5M, 5C and 5BK will be started again.

By the way, in the present embodiment, as shown in FIGS. 2 and 3, the transfer / conveying belt 20 has all the photosensitive drums 2 with the center of the photosensitive drum 2BK as a fulcrum.
The photoconductor drum 2BK is abutted from the abutment positions with Y, 2M, 2C, and 2BK, and is movably supported and fixed to a frame (not shown) at a position separated from the photoconductor drums 2Y, 2M, and 2C. The transfer / conveying belt 20 is configured to move between the contact position and the separation position by a separation mechanism 33 as a first contact / separation unit.

The separating mechanism 33 is formed by combining a solenoid and a crank mechanism, and includes a solenoid 32 fixed to a body frame (not shown) and a crank 36 having an intermediate portion rotatably supported on the body frame by a pivot 37.
A compression spring 38, which is provided between the driven roller 12 and the main body frame and biases the driven roller 12 to the contact position, engages a frame (not shown) rotatably supported from below. ing. One end of the crank 36 is
The solenoid 32 is connected to the movable portion 34, and the other end thereof rotatably engages the shaft of the driven roller 12 from above. Further, a separating mechanism having the same structure is provided at the other end of the driven roller 12 as well.

When the solenoid 32 is turned on, the movable portion 34 projects and the crank 36 rotates clockwise about the pivot 37, and is moved to the separated position against the biasing force of the compression spring 38 (FIG. 6). (A)}. Also, the solenoid is off
Then, it is returned to the contact position by the compression spring 38 (FIG. 6).
(B)}.

FIG. 6A shows a monochrome image print state,
(B) shows a color image print state. At this time, the suction roller 29 is also provided with a separating mechanism having a similar configuration. That is,
A separation mechanism 63 as a second contact / separation unit is provided as shown in FIG. 7 in which the suction roller 29 contacts the transfer / conveyance belt 20 in the monochrome printing state, and the suction roller 29 separates in the color printing state.

The separating mechanism 63 is constructed by combining a solenoid and a crank mechanism, and the solenoid 62 fixed to the main body frame, the crank 66 whose middle portion is rotatably supported by the main body frame by the pivot 67, and the suction roller 29. A tension spring 68 is installed between the shaft and the body frame and biases the suction roller 29 to the separated position. The one end of the crank 66 is connected to the solenoid 6
The second end is connected to the second movable portion 64, and the other end engages the shaft of the suction roller 12 from above. Further, a separating mechanism having the same structure is provided at the other end of the suction roller 29.

When the solenoid 62 is turned on, the movable portion 64 projects and the crank 66 rotates clockwise around the pivot 67, and is moved to the contact position by the urging force of the tension spring 68 {FIG. 8 (A). )}.

When the solenoid 62 is turned off, the tension spring 68 returns the solenoid 62 to the separated position (see FIG. 8).
(B)}. FIG. 8A is a monochrome image printing state, FIG.
(B) shows a color image print state.

FIG. 4 shows the transfer belt 20 and the suction roller 29.
5 is a block diagram for explaining the contacting / separating mechanism of FIG.
9 shows a flowchart illustrating an example. By using such a contact / separation mechanism of the suction roller 29, the transfer position of the first color is close to the registration roller 25 at the time of printing a color image, and the transfer material is attracted to the transfer / conveying belt 20 at the time of transfer. Even without 29, a good printed image with no color shift can be obtained from the transfer of the first color to the transfer of the fourth color.

However, when printing a monochrome image, the distance from the registration roller 25 to the black image transfer position is long, so that a small object such as a postcard or thick paper may cause conveyance failure, so that the suction roller 29 is required.

Further, when a color image is printed while pressing the attraction roller 29 with force, the transfer material absorbs moisture particularly in a high temperature and high humidity state, and transfer failure occurs due to the charges of both transfer and attraction being applied.

Since the distance from the registration roller 25 to the black image transfer position is long during monochrome image printing, both transfer and adsorption charges are not applied unlike in the case of a color image.

Therefore, by using the contacting / separating mechanism 63 of the suction roller 29 according to the present invention, the suction roller 29 may be pressed as necessary, so that the deterioration of the suction roller 29 can be prevented, and further, the suction roller 29 can be prevented. Deterioration of the transfer / transport belt 20 due to wear of the rollers 29, the photosensitive drum 2Y,
It also leads to reduction of deterioration of 2M, 2C and 2BK.

In the present invention, FIG. 3 of the separating method of the transfer / conveying belt 20 and FIG. 7 of the contact / separation mechanism 63 of the suction roller 29.
11 can be used to more easily separate the transfer belt 20 in the monochrome mode and bring the suction roller 29 into contact therewith.

The separating mechanism 73 is constructed by combining a solenoid and a crank mechanism. The solenoid 72 fixed to the main body frame, the crank 76 whose middle portion is rotatably supported by the main body frame by the pivot 77, and the suction roller 29. A tension spring 78 that is installed between the shaft and the main body frame and urges the suction roller 29 to a position separated from the transfer / conveyance belt 20, and a compression that urges the driven roller 12 to a contact position with the photosensitive drum. A frame (not shown) that includes a spring 79 and is rotatably supported is engaged from below.

One end of the crank 76 is connected to the movable portion 74 of the solenoid 72, and the other end is connected to the suction roller 2
The shaft 9 is engaged from above. A separating mechanism having the same structure is also provided at the other end of the suction roller 29.

When the solenoid 72 is turned on, the movable part 7
4 protrudes, the crank 76 rotates clockwise around the pivot 77, is moved to the contact position with the transfer belt 20 against the urging force of the tension spring 78, and the driven roller 12
Is pressed down to move to a position away from the color photoconductor (FIG. 12 (A)).

When the solenoid is turned off, the transfer belt 20 is brought into contact with the photosensitive member by the tension spring 78 and the compression spring 79, and the suction roller 29 is returned to the position separated from the transfer belt 20 (FIG. 12 (B)). .

In the present invention, the color photosensitive drums 2Y, 2M and 2C are used as a method for separating the color photosensitive drums 2Y, 2M and 2C from the transfer / conveying belt 20 as in the first embodiment. It is also possible to move.

For example, as shown in FIG. 9, the color image forming means and the monochrome image forming means are separate blocks, that is, the monochrome image forming means is fixed to the main body frame 1A, and the color image forming means is different from the main body frame 1A. The sub-frame 1B is fixed to the sub-frame 1B, and the sub-frame 1B is mounted so that the photosensitive drums 2Y, 2M and 2C can move between the contact position with the transfer / conveyance belt 20 and the separated position.

The color image forming means prints at the contact position when printing a color image, and the color image forming means prints at the separated position when printing a monochrome image. Then, the suction roller 2 as shown in FIG. 7 which is the main subject of the present invention.
As shown in FIG. 10, the suction mechanism 29 is moved to the separation position by using the separation mechanism 9 when the color image is printed, and is moved to the contact position when the monochrome image is printed.

By doing so, it is sufficient to press the suction roller 29 as necessary, so that the deterioration of the suction roller 29 can be prevented, and further, the deterioration of the transfer / conveying belt 20 due to the abrasion with the suction roller 29 and the exposure to light. It also reduces the deterioration of the body drum.

The present invention is also good when the transfer / conveying belt 20 is separated from the color photosensitive drums 2Y, 2M, 2C in the monochrome mode by using the cleaner fixed to the apparatus main body 1 as shown in FIG. The purpose is to obtain a good cleaning power.

As described in the above embodiment, the present invention is premised on that the transfer / conveying belt 20 and the black photoconductor 2BK are not separated from each other, and therefore the rotation center A at the time of separation is the center of the black photoconductor 2BK.

Description will be made with reference to FIGS. 14 and 15. First, before and after separation of the transfer / conveying belt 20 by the method of FIG. 3, that is, the states of the color mode and the monochrome mode are shown (the dotted line is the monochrome mode). Here, a blade cleaner will be used for explanation.

In the blade cleaner, with the transfer belt 20 in contact with the photoconductors 2Y, 2M, 2C and 2BK, as shown in FIG. 15, the center of the black photoconductor 2BK is A and the transfer belt 20 is the photoconductor. When the opposite side of the contacting transfer point is B, and the angle θ rotated around A by the transfer belt separating mechanism is θ, the cleaning point C is upstream from the point B and θ / 2 rotations around A on the left side in the figure. It will be the position you did.

If cleaning is performed at this position, the transfer belt 20 is at a position that does not change even if it is separated from the photosensitive member, so that the amount of cleaner bite does not change and a good cleaning force can be obtained.

In particular, in the case of a blade cleaner, when the amount of bite changes, or when the amount of bite is large, the edge of the blade does not hit and it is in the abdominal area, and when the amount of bite is small, the edge of the transfer belt hits the transfer belt due to the elasticity of the blade. Since they do not hit each other and defective cleaning occurs respectively, it is necessary to provide them in places where there is no displacement as much as possible.

Further, as described above, in the cleaner, particularly in the blade cleaner, the quality of cleaning is determined by the biting amount (pressing) of the edge of the blade. Therefore, the transfer belt 20 is set in the image printing mode as shown in FIG.
Even if it rotates like, it is desirable to follow it.

In FIG. 16, the cleaner follows the transfer belt 20 so that cleaning failure does not occur even if the transfer belt 20 is rotated or displaced. That is, the transfer belt cleaner 31 is attached to the driving roller 20a of the transfer / transport belt 20 and the holding member 90 of the driven roller 20b.

Particularly, the driving roller 20a and the driven roller 20
By disposing the cleaner 31 at a position where b can be used as a backup member,
Regardless of the operation of 0, it is possible to always follow with an optimum bite amount and obtain good cleaning.

[0074]

As described above, according to the present invention, in the first aspect, in the monochromatic image forming mode, the conveying means and the plurality of image carriers are separated apart from one of them, and the suction means is provided. When the multi-color image forming mode is brought into contact with the transporting means, the transporting means and the plurality of image carriers are brought into contact with each other, and the suction means is separated from the transporting means. Can be prevented.

According to a second aspect of the present invention, in the monochromatic image forming mode, the conveying means is separated from a plurality of image carriers except one of them, and the suction means is brought into contact with the conveying means to form a multicolor image. In the mode, the transporting means is brought into contact with the plurality of image carriers and the suction means is separated from the transporting means, so that the suction means and the transporting means can be prevented from being deteriorated and the transfer failure can be prevented.

According to a third aspect of the present invention, in the monochromatic image forming mode, a plurality of image carriers except one of them are separated from the conveying means, and the suction means is brought into contact with the conveying means to form a multicolor image. In the mode, since the plurality of image carriers are brought into contact with the transporting means and the suction means is separated from the transporting means, it is possible to prevent deterioration of the suction means and the transporting means and prevent transfer failure.

According to the fourth aspect of the present invention, the cleaning means is brought into contact with the conveying means, and the conveying means is cleaned without changing the contact force by the contacting / separating operation of the conveying means. However, it can be cleaned well.

According to a fifth aspect of the present invention, the end portion of the cleaning means is brought into contact with the conveying means, and the corresponding contact position changes the distance between the end portion and the conveying means by the contacting / separating operation of the conveying means. This is a position where the transfer means is not allowed to be cleaned, and since the transfer means is cleaned at this position, good cleaning can be performed even if the transfer means moves in and out.

According to a sixth aspect of the present invention, since the cleaning means contacting the conveying means is supported, and the supporting means moves integrally with the conveying means at the time of the contacting / separating operation of the conveying means, the conveying means contacts. Even if the separating operation is performed, the cleaning means can follow the cleaning operation and the cleaning can be performed well.

[Brief description of drawings]

FIG. 1 is a sectional view showing the overall configuration of an image forming apparatus that is an embodiment of the present invention.

FIG. 2 is an enlarged view showing a transfer / conveying belt portion of the image forming apparatus of FIG.

FIG. 3 is a perspective view showing a contact / separation mechanism of the transfer / transport belt of FIG.

4 is a block diagram showing a drive control system of the transfer / conveyance belt contact / separation mechanism of FIG.

5 is a flowchart showing the operation of the transfer / conveyance belt contact / separation mechanism of FIG.

6A and 6B show the contact / separation operation of the transfer / transport belt of FIG. 2, FIG. 6A showing the transfer / transport belt separated from the photosensitive drum, and FIG. FIG. 3 is a diagram showing a state of being in contact with a photosensitive drum.

FIG. 7 is a diagram showing a contact / separation mechanism of a suction roller that comes into contact with the transfer / transport belt of FIG.

8A and 8B are diagrams showing a suction roller operated by the contact / separation mechanism of FIG. 7, FIG. 8A showing a state where the suction roller is in contact with the conveyor belt, and FIG. The figure which shows the state which the roller separated.

FIG. 9 is a front view showing a contacting / separating mechanism of a photosensitive drum which is another embodiment of the present invention.

FIG. 10 shows a state in which the suction roller comes in contact with and separates from the conveyor belt with which the photosensitive drum is brought into contact with and separated from by the contacting / separating mechanism of FIG. 9. FIG. 10A shows a state in which the suction roller comes into contact with the conveyor belt. FIG. 10B is a diagram showing a state in which the suction roller is separated from the conveyor belt.

FIG. 11 is a perspective view showing a mechanism for simultaneously contacting and separating a transfer / conveying belt and a suction roller according to another embodiment of the present invention.

12A and 12B show a conveyance belt and a suction roller which are brought into contact with and separated from each other by the contacting / separating mechanism of FIG. 11, and FIG. 12A is a diagram showing a state where the suction roller is in contact with the conveyance belt.
FIG. 6B is a diagram showing a state in which the suction roller is separated from the conveyor belt.

FIG. 13 is a diagram showing a state in which a transfer belt according to an embodiment of the present invention is cleaned.

FIG. 14 is a diagram showing a state in which the transfer belt of FIG. 13 is rotated to come into contact with and separate from the photosensitive drum.

FIG. 15 is a diagram illustrating a cleaner mounting position according to contact and separation of the transfer belt of FIG.

FIG. 16 is a diagram showing a mounting state of a cleaner of a transfer belt which is another embodiment of the present invention.

[Explanation of symbols]

1 ... Image forming apparatus main body 2Y, 2M, 2C, 2BK ... Photosensitive drum (image bearing member) 3Y, 3M, 3C, 3BK ... Recording device 4Y, 4M, 4C, 4BK ... Image forming means 5Y, 5M, 5C, 5BK ... Charging device 6Y, 6M, 6C, 6BK ... Exposure device 7Y, 7M, 7C, 7BK ... Developing device 8Y, 8M, 8C, 8BK ... Cleaning device 9Y, 9M, 9C, 9BK ... Static elimination device 10 ... Transfer material 11 ... Transfer material 11 Transport belt driving roller 12 ... Transfer transport belt driven roller 19 ... Paper feed cassette 20 ... Transfer transport belt (transport means) 21Y, 21M, 21C, 21BK ... Transfer device (transfer means) 22 ... Paper feed system 23 ... Pickup roller 24 ... Feed roller pair 25 ... Registration roller pair 27 ... Paper ejection roller pair 28 ... Paper ejection tray 29 ... Adsorption roller (adsorption means) 30 ... Static elimination roller 1 ... belt cleaning device (cleaning means) 50 ... control unit section

Claims (6)

[Claims] 1. A plurality of image carriers arranged in parallel, a plurality of image forming means for respectively forming images on the plurality of image carriers, and a plurality of image carriers that face the plurality of image carriers. And a plurality of transfer means that are provided to face each of the image carriers and that transfer an image formed on the image carrier to the transfer material. An adsorbing means for adsorbing the transfer material to the conveying means, a plurality of image carriers and the conveying means are brought into contact with and separated from each other according to a single-color or multi-color image forming mode, and the adsorbing means with respect to the conveying means. An image forming apparatus comprising: a contacting / separating unit that contacts and separates. 2. A plurality of image carriers arranged in parallel, a plurality of image forming means for respectively forming images on the plurality of image carriers, and a plurality of image carriers that face the plurality of image carriers. And a plurality of transfer means that are provided to face each of the image carriers and that transfer an image formed on the image carrier to the transfer material. An adsorbing means for adsorbing the transfer material to the conveying means; and a moving means for bringing the plurality of image carriers into and out of contact with each other in accordance with a single-color or multicolor image forming mode, and the adsorbing means. An image forming apparatus comprising: a contacting / separating unit configured to contact / separate the sheet with a conveying unit. 3. A plurality of image carriers arranged in parallel, a plurality of image forming means for forming images on the plurality of image carriers, respectively, and a plurality of image carriers that face the plurality of image carriers. And a plurality of transfer means that are provided to face each of the image carriers and that transfer an image formed on the image carrier to the transfer material. An adsorbing means for adsorbing a transfer material to the conveying means, and a plurality of image carriers and a plurality of image forming means are moved so that the conveying means is brought into contact with or separated from the conveying means according to a single-color or multicolor image forming mode. An image forming apparatus, further comprising: a contacting / separating means for contacting / separating the suction means with respect to the conveying means. 4. A plurality of image carriers arranged in parallel, a plurality of image forming means for respectively forming images on the plurality of image carriers, and a plurality of image carriers that face the plurality of image carriers. And a plurality of transfer means that are provided to face each of the image carriers and that transfer an image formed on the image carrier to the transfer material. A contacting / separating means for contacting / separating the conveying means and the plurality of image carriers with each other in accordance with a monochromatic or multicolor image forming mode; An image forming apparatus comprising: a cleaning unit that cleans the conveying unit without changing the temperature. 5. A plurality of image carriers arranged in parallel, a plurality of image forming means for forming images on the plurality of image carriers, respectively, and a plurality of image carriers that face the plurality of image carriers. And a plurality of transfer means that are provided to face each of the image carriers and that transfer an image formed on the image carrier to the transfer material. A contacting / separating means for contacting / separating the conveying means and the plurality of image carriers with each other in accordance with a monochromatic or multicolor image forming mode; An image forming apparatus comprising: a position that does not change a gap between the end portion and the conveying unit by a separating operation, and a cleaning unit that cleans the conveying unit at this position. 6. A plurality of image carriers arranged in parallel, a plurality of image forming means for forming images on the plurality of image carriers, respectively, and a plurality of image carriers that face the plurality of image carriers. And a plurality of transfer means that are provided to face each of the image carriers and that transfer an image formed on the image carrier to the transfer material. A contacting / separating means for contacting / separating the conveying means with respect to the plurality of image carriers according to a single-color or multicolor image forming mode; and a cleaning means for contacting the conveying means to clean the conveying means, An image forming apparatus, comprising: a supporting unit that supports the cleaning unit and moves integrally with the conveying unit when the conveying unit comes into contact with and separates from the conveying unit.