JP6834373B2 - Image forming device - Google Patents

Description

The present invention relates to an image forming apparatus.

In an image forming apparatus that employs an electrophotographic method, a laser beam is applied to the peripheral surface of a photoconductor drum based on image information read from a document image or image information transmitted from an external device such as a computer to perform electrostatic latent. The image formation process is performed by a series of processes in which an image is formed, toner is supplied from a developing device to an electrostatic latent image to form a toner image, and then the toner image is transferred to paper via an intermediate transfer belt. ing.

By the way, in recent years, in an image forming apparatus, the apparatus configuration has become complicated with the progress of color printing and high-speed processing, and in order to cope with the high-speed processing, the toner stirring member in the developing apparatus has to rotate at high speed. Has been done. As a result, the internal pressure of the developing device tends to be higher than the atmospheric pressure. When the pressure inside the developing device becomes positive, the toner in the developing device may be scattered from the developing device when it is supplied to the photoconductor drum. As a result, there is a problem that the inside of the image forming apparatus is contaminated with toner.

In order to solve this problem, for example, in Patent Document 1, at the time of non-image formation, the air intake port is opened and the exhaust fan is operated with the air inflow path closed to duct a fast air flow. Described is an image forming apparatus that executes a forced discharge mode in which the toner accumulated in the duct and the collecting duct is forcibly discharged by generating the air in the collecting duct.

Japanese Unexamined Patent Publication No. 2013-125148

However, the image forming apparatus described in Patent Document 1 has the following problems. That is, when the forced discharge mode is executed during non-image formation, the air outflow path communicating with the developing roller is closed by the shutter. Therefore, if the toner scattered from the developing roller is deposited on the duct of the air inflow path, There is a problem that the accumulated toner cannot be cleaned. Further, when cleaning the forced discharge mode, the flow velocity of the exhaust air is set to be high, so that the filter provided in the dust collector may penetrate through the toner.

Therefore, in order to solve the above problems, the present invention is to provide an image forming apparatus capable of reliably collecting scattered objects that form an image according to image information such as image coverage.

The image forming apparatus according to the present invention is provided with an image forming unit for forming an image on paper, a suction mechanism having a suction path for sucking scattered objects from the image forming part, and the suction path. A shutter member that opens and closes and a control unit that controls the opening and closing operation of the shutter member based on the image information of the job are provided, and the control unit opens and closes the shutter member based on the image information. A cleaning mode for cleaning the inside of the suction path is executed .

According to the present invention, since the opening of the suction path is controlled by the shutter member based on the image information during or after the job is executed, the flow velocity in the suction path can be optimized and scattered in the suction path. The scattered matter can be effectively recovered.

It is a figure which shows the structural example of the image forming apparatus which concerns on one Embodiment of this invention. It is a figure which shows the structural example of the suction mechanism. It is a figure which shows the structural example of the image forming apparatus. It is a flowchart which shows the operation example of the image forming apparatus in the case of sucking the scattered toner.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The dimensional ratios in the drawings have been expanded for convenience of explanation and may differ from the actual ratios.

[Configuration example of image forming apparatus 100]
FIG. 1 shows an example of the configuration of the image forming apparatus 100 according to the present invention. As shown in FIG. 1, the image forming apparatus 100 is called a tandem type image forming apparatus, and includes an automatic document conveying unit 80 and an apparatus main body 102. The automatic document transfer unit 80 is attached to the upper part of the apparatus main body 102, and feeds the paper set on the transfer table to the image reading unit 82 of the apparatus main body 102 by a transfer roller or the like.

The apparatus main body 102 includes an operation display unit 84, an image reading unit 82, an image forming unit 10, a suction mechanism 70, an intermediate transfer belt 8, a paper feeding unit 20, a resist roller 32, a fixing unit 44, and the like. It has an automatic paper reversing transfer unit 90 (Auto Duplex Unit: hereinafter referred to as ADU).

The operation display unit 84 has a touch panel in which a display unit and an input unit are combined, and a plurality of operation keys including a start key and a decision key provided on a peripheral portion of the touch panel. The operation display unit 84 displays a menu screen or the like on the screen, and receives information such as image formation conditions and fixing conditions input by touch operations on the menu screen or operation of operation keys.

The image reading unit 82 scans and exposes the original placed on the platen or the original conveyed by the automatic original conveying unit 80 by the optical system of the scanning exposure apparatus, and the scanned original image is captured by a CCD (Charge Coupled Device). ) An image information signal is generated by photoelectric conversion by an image sensor. The image information signal is output to the image forming unit 10 after analog processing, analog / digital (hereinafter referred to as A / D) conversion processing, shooting correction, image compression processing, and the like are performed by an image processing unit (not shown).

The image forming unit 10 forms an image by an electrophotographic method, and includes an image forming unit 10Y for forming a yellow (Y) color image, an image forming unit 10M for forming a magenta (M) color image, and the like. It has an image forming unit 10C for forming a cyan (C) color image and an image forming unit 10K for forming a black (K) color image. In this example, a common function name, for example, Y, M, C, and K indicating a color to be formed is added after the reference numeral 10.

The image forming unit 10Y includes a photoconductor drum 1Y, a charging unit 2Y arranged around the photoconductor drum 1Y, an exposure unit (optical writing unit) 3Y, a developing device 5Y, and a cleaning unit 6Y. The image forming unit 10M includes a photoconductor drum 1M, a charging unit 2M, an exposure unit 3M, a developing device 5M, and a cleaning unit 6M arranged around the photoconductor drum 1M. The image forming unit 10C includes a photoconductor drum 1C, a charging unit 2C, an exposure unit 3C, a developing device 5C, and a cleaning unit 6C arranged around the photoconductor drum 1C. The image forming unit 10K includes a photoconductor drum 1K, a charging unit 2K, an exposure unit 3K, a developing device 5K, and a cleaning unit 6K arranged around the photoconductor drum 1K.

Photoreceptor drums (image carriers) 1Y, 1M, 1C, 1K, charged parts 2Y, 2M, 2C, 2K, exposed parts 3Y, 3M, 3C, 3K, developed in the image forming units 10Y, 10M, 10C, 10K, respectively. The devices 5Y, 5M, 5C, 5K and the cleaning units 6Y, 6M, 6C, 6K have common contents. Hereinafter, unless a distinction is necessary, Y, M, C, and K are not added.

The charging unit 2 charges the surface of the photoconductor drum 1 substantially uniformly. The exposure unit 3 is composed of, for example, an LPH (LED Print Head) having an LED array and an imaging lens, or a polygon mirror type laser exposure scanning device, and laser light is applied on the photoconductor drum 1 based on an image information signal. Scan to form an electrostatic latent image. The developing device 5 develops the electrostatic latent image formed on the photoconductor drum 1 with toner. As a result, a toner image which is a visible image is formed on the photoconductor drum 1.

A suction mechanism 70 for sucking and collecting the toner scattered from the developing device 5 is provided in the peripheral portion of the developing device 5. The details of the suction mechanism 70 will be described later.

The intermediate transfer belt 8 is stretched by a plurality of rollers and is rotatably supported. Along with the rotation of the intermediate transfer belt 8, the primary transfer roller 7 and the photoconductor drum 1 rotate, and a predetermined voltage is applied between the primary transfer roller 7 and the photoconductor drum 1 to obtain a photoconductor. The toner image formed on the drum 1 is transferred onto the intermediate transfer belt 8 (primary transfer).

The paper feed unit 20 has a plurality of paper feed trays 20A and 20B in which paper P such as A3 and A4 is stored. The paper P conveyed from the paper feed trays 20A and 20B by the transfer rollers 22, 24, 26, 28 and the like is conveyed to the resist roller 32. The number of paper feed trays is not limited to two. Further, a single or a plurality of large-capacity paper feeding devices capable of accommodating a large-capacity paper P may be connected as needed.

The resist roller 32 corrects the bending of the paper P by forming a loop by abutting the tip of the paper P with the loop rollers 30. The paper P whose bending of the paper P has been corrected is conveyed to the secondary transfer roller 34 at a predetermined timing. In the secondary transfer roller 34, the Y-color, M-color, C-color, and K-color toner images transferred on the intermediate transfer belt 8 are collectively transferred to the surface of the paper P (secondary transfer). The secondary transferred paper P is transported to the fixing portion 44 on the downstream side in the paper transport direction D1.

The fixing portion 44 has a pressure roller and a heating roller. The fixing section 44 presses and heat-treats the paper P on which the toner image is transferred by the secondary transfer roller 34 to fix the toner image on the surface of the paper P to the paper P.

On the downstream side of the paper transport direction D1 of the fixing portion 44, a transport path switching portion 48 for switching the transport path of the paper P to the paper discharge path side or the ADU90 side is provided. The transport path switching unit 48 controls the transfer path switching based on the selected print mode (single-sided printing mode, double-sided printing mode, etc.).

The paper P for which single-sided printing has been completed in the single-sided printing mode or the paper P for which double-sided printing has been completed in the double-sided printing mode is ejected onto the output tray by the output roller 46.

Further, when an image is formed on the back surface side of the paper P in the double-sided printing mode, the paper P on which the image is formed on the front surface side is conveyed to the ADU 90 via a conveying roller 92 or the like. In the switchback path of the ADU 90, the paper P is conveyed to the U-turn path section with the rear end of the paper P at the head by the reverse rotation control of the ADU roller 94, and is turned upside down by the transfer rollers 96, 98 and the like provided in the U-turn path section. In this state, the paper is re-fed to the secondary transfer roller 34.

[Structure example of suction mechanism 70]
FIG. 2 shows an example of the configuration of the suction mechanism 70 that collects the toner scattered from the developing rollers 50Y, 50M, 50C, and 50K. As shown in FIG. 2, the suction mechanism 70 includes a suction path 60, shutter members 68Y, 68M, 68C, 68K, and a toner dust collector 78.

The suction path 60 has a main body side duct 64 and a developing device side duct 62Y, 62M, 62C, 62K provided corresponding to the developing devices 5Y, 5M, 5C, 5K of each color. Here, the main body side duct 64 has a configuration pre-assembled to the device main body 102, and the developing device side ducts 62Y, 62M, 62C, 62K (developing devices 5Y, 5M, 5C, 5K) are attached to the device main body 102. It has a removable structure.

The main body side duct 64 has a duct main body 64A and branch ducts 64Y, 64M, 64C, 64K. The duct body 64A extends along the arrangement direction of the developing devices 5Y, 5M, 5C, and 5K. The branch ducts 64Y, 64M, 64C, 64K branch from the duct main body 64A corresponding to each of the developing devices 5Y, 5M, 5C, and 5K, and have a predetermined length in a direction orthogonal to the arrangement direction of the developing devices 5Y and the like. It's been extended.

The developing device side duct 62Y extends between the vicinity of the outer peripheral surface of the developing roller 50Y and the branch duct 64Y. The opening formed at one end of the developing device-side duct 62Y faces the outer peripheral surface side of the developing roller 50Y, so that the toner scattered by the developing roller 50Y or the like can be efficiently sucked. The other end of the developing device side duct 62Y is connected to the branch duct 64Y via the connecting portion 66Y.

The developing device side duct 62M extends between the vicinity of the outer peripheral surface of the developing roller 50M and the branch duct 64M. The opening formed at one end of the developing device-side duct 62M faces the outer peripheral surface side of the developing roller 50M, so that the toner scattered by the developing roller 50M or the like can be efficiently sucked. The other end of the developing device side duct 62M is connected to the branch duct 64M via the connecting portion 66M.

The developing device side duct 62C extends between the vicinity of the outer peripheral surface of the developing roller 50C and the branch duct 64C. The opening formed at one end of the developing device-side duct 62C faces the outer peripheral surface side of the developing roller 50C, so that the toner scattered by the developing roller 50C or the like can be efficiently sucked. The other end of the developing device side duct 62C is connected to the branch duct 64C via the connecting portion 66C.

The developing device side duct 62K extends between the vicinity of the outer peripheral surface of the developing roller 50K and the branch duct 64K. The opening formed at one end of the developing device-side duct 62K faces the outer peripheral surface side of the developing roller 50K, so that the toner scattered by the developing roller 50K or the like can be efficiently sucked. The other end of the developing device side duct 62K is connected to the branch duct 64K via the connecting portion 66K.

As described above, in the present embodiment, the developing device side ducts 62Y, 62M, 62C, 62K and the branch ducts 64Y, 64M, 64C, 64K are integrated into one duct main body 64A.

The shutter member 68Y is a member for opening and closing the opening of the suction path 60, and is installed on the branch duct 64Y side in the vicinity of the connecting portion 66Y. In the present embodiment, the shutter member 68Y optimizes the flow velocity of the wind in the suction path 60 by adjusting the opening amount of the suction path 60, and is deposited in the developing device side duct 62Y by the optimized wind. Reduce the amount of toner to a certain amount or less.

The shutter member 68M is a member for opening and closing the opening of the suction path 60, and is installed on the branch duct 64M side and in the vicinity of the connecting portion 66M. In the present embodiment, the shutter member 68M optimizes the flow velocity of the wind in the suction path 60 by adjusting the opening amount of the suction path 60, and is deposited on the developing device side duct 62M by the optimized wind. Reduce the amount of toner to a certain amount or less.

The shutter member 68C is a member for opening and closing the opening of the suction path 60, and is installed on the branch duct 64C side and in the vicinity of the connecting portion 66C. In the present embodiment, the shutter member 68C optimizes the flow velocity of the wind in the suction path 60 by adjusting the opening amount of the suction path 60, and is deposited in the developing device side duct 62C by the optimized wind. Reduce the amount of toner to a certain amount or less.

The shutter member 68K is a member for opening and closing the opening of the suction path 60, and is installed on the branch duct 64K side and in the vicinity of the connecting portion 66K. In the present embodiment, the shutter member 68K optimizes the flow velocity of the wind in the suction path 60 by adjusting the opening amount of the suction path 60, and is deposited in the developing device side duct 62K by the optimized wind. Reduce the amount of toner to a certain amount or less.

The toner dust collector 78 is connected to the downstream end of the duct main body 64A in the suction direction D2. The toner dust collector 78 centrifuges the toner from a fan that generates an air flow (wind) in the direction from the inlet of each developer side duct 62Y, 62M, 62C, 62K to the outlet of the main body side duct 64, and the toner. It has a cyclone portion that collects the particles by dropping them by gravity, and a dust collection filter that collects discharge products such as toner and ozone that are not separated by the cyclone portion.

[Example of block configuration of image forming apparatus 100]
FIG. 3 is a block diagram showing an example of the functional configuration of the image forming apparatus 100. As shown in FIG. 3, the image forming apparatus 100 includes a control unit 76 for controlling the operation of the entire apparatus. The control unit 76 has a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). By executing the software (program) read from the ROM, the CPU realizes an image forming process including toner recovery control corresponding to image coverage.

A drive motor 72Y for Y color, a drive motor 72M for M color, a drive motor 72C for C color, a drive motor 72K for K color, and a fan drive motor 74 are connected to the control unit 76, respectively.

The drive motor 72Y is composed of, for example, a stepping motor, a DC brushless motor, or the like, and is driven based on a drive signal supplied from the control unit 76 to open and close the Y-color shutter member 68Y.

The drive motor 72M is composed of, for example, a stepping motor, a DC brushless motor, or the like, and is driven based on a drive signal supplied from the control unit 76 to open and close the shutter member 68M for M color.

The drive motor 72C is composed of, for example, a stepping motor, a DC brushless motor, or the like, and is driven based on a drive signal supplied from the control unit 76 to open and close the shutter member 68C for C color.

The drive motor 72K is composed of, for example, a stepping motor, a DC brushless motor, or the like, and is driven based on a drive signal supplied from the control unit 76 to open and close the shutter member 68K for K color.

The fan drive motor 74 is composed of, for example, a stepping motor, a DC brushless motor, or the like, and is driven based on a drive signal supplied from the control unit 76 to rotationally drive the fan constituting the toner dust collector 78.

[Operation example of image forming apparatus 100]
FIG. 4 is a flowchart showing an example of the operation of the image forming apparatus 100 at the time of job execution and after the job is completed. The CPU of the control unit 76 realizes the process shown in the flowchart of FIG. 4 by executing the software read from the ROM.

As shown in FIG. 4, in step S100, when the control unit 76 receives a job transmitted from a personal computer or the like, the control unit 76 acquires image information included in the received job. In this embodiment, image data coverage (printing rate) is used as image information. The coverage of the image data can be obtained from the exposure information or the like in the image data of the job to be executed. When step S100 is completed, the process proceeds to step S110.

In step S110, the control unit 76 determines whether or not the coverage of the acquired image data is low coverage. In the present embodiment, the low coverage value is set to, for example, 5% or less (first coverage). The low coverage value is not limited to 5% or less. When the control unit 76 determines that the coverage of the acquired image data is low coverage, the control unit 76 proceeds to step S120.

In step S120, the control unit 76 starts the printing process of forming an image on the paper P by controlling the image forming unit 10 and the like based on the job. After starting step S120, the process proceeds to step S160.

On the other hand, in step S110, when the control unit 76 determines that the coverage of the acquired image data is not low coverage, that is, high coverage, the process proceeds to step S130. In the present embodiment, the high coverage value is set to, for example, more than 5% (second coverage).

In step S130, the control unit 76 starts the printing process of forming an image on the paper P by controlling the image forming unit 10 and the like based on the job. After starting step S130, the process proceeds to step S140.

In step S140, the control unit 76 determines whether or not the number of printed sheets has reached, for example, 1000 or more since the start of the job. This is because when the coverage changes from low coverage to high coverage or when high coverage continues during job execution, a large amount of toner is scattered from the developing rollers 50Y, 50M, 50C, and 50K in proportion to the number of prints. Because there is a tendency to do. When the control unit 76 determines that the number of printed sheets is 1000 or more, the control unit 76 proceeds to step S150.

In step S150, the control unit 76 narrows the opening of the suction path 60 by closing any of the shutter members 68Y, 68M, 68C, and 68K corresponding to a specific color. For example, when the coverage of the Y color image data is high, the drive motor 72Y for the Y color is controlled to close the shutter member 68Y to a position where the opening of the suction path 60 becomes 1/3. On the other hand, the drive motor 72M for M color is controlled to fully open the shutter member 68M, the drive motor 72C for C color is controlled to fully open the shutter member 68C, and the drive motor 72K for K color is controlled to shutter. The member 68K is fully opened. As a result, the flow velocity in the duct 62Y on the developing device side can be made faster than the others, and the scattered toner in the duct 62Y on the developing device side can be sucked more effectively.

After a certain period of time has elapsed, the shutter members 68M, 68C, 68K are controlled to open and close so that the opening of the suction path 60 is narrowed in order from the upstream side to the downstream side in the rotation direction of the intermediate transfer belt 8. , The toner scattered in the ducts 62M, 62C, 62K on the developing device side may be cleaned. Further, the opening / closing control of the shutter member 68Y or the like described above may be performed from the start of printing or the like. When step S150 is completed, the process proceeds to step S160. Further, in step S140, even if the number of printed sheets is less than 1000, the process proceeds to step S160.

In step S160, the control unit 76 determines whether or not the job has been completed. If it is determined that the job has not been completed, the process returns to step S100, and the above-mentioned image formation process is repeatedly executed. On the other hand, when the control unit 76 determines that the job has been completed, the control unit 76 proceeds to step S170.

In step S170, the control unit 76 determines whether or not the fluctuation range of the coverage at the time of job execution exceeds the reference value. When the control unit 76 determines that the fluctuation range of the coverage at the time of job execution exceeds the reference value, the control unit 76 proceeds to step S180. For example, when the job is executed, the image data fluctuates from 5% of low coverage to 20% of high coverage.

On the other hand, when the control unit 76 determines that the fluctuation range of the coverage at the time of executing the job does not exceed the reference value, the control unit 76 proceeds to step S190. In step S190, the control unit 76 determines whether or not high coverage is continuous in the image data when the job is executed.

When the control unit 76 determines that the high coverage is not continuous in the image data, the control unit 76 ends a series of image forming processes. This is because if the coverage fluctuation of the image data is small or the coverage continues to be low, it is unlikely that a large amount of toner scattered from the developing roller 50Y or the like will be deposited on the developing device side duct 62Y or the like, and it is necessary to carry out the cleaning mode. Because there is no.

On the other hand, in step S190, when the control unit 76 determines that the high coverage is continuous in the image data, the control unit 76 proceeds to step S180. For example, when the job is executed, the coverage of 20% is continuous.

In step S180, the control unit 76 implements the cleaning mode because there is a high possibility that the toner scattered from the developing roller 50Y or the like is deposited on the developing device side duct 62Y or the like. In the cleaning mode, the opening of the suction path 60 is narrowed by closing any of the shutter members 68Y, 68M, 68C, and 68K corresponding to a specific color. For example, when the coverage of the Y color image data is high, the drive motor 72Y for the Y color is controlled to close the shutter member 68Y to a position where the opening of the suction path 60 becomes 1/3. Further, the drive motor 72M for M color is controlled to close the shutter member 68M, the drive motor 72C for C color is controlled to close the shutter member 68C, and the drive motor 72K for K color is controlled to close the shutter member 68K. Close. As a result, the flow velocity in the duct 62Y on the developing device side can be made faster than the others, and the scattered toner in the duct 62Y on the developing device side can be sucked more effectively.

After a certain period of time has elapsed, the shutter members 68M, 68C, 68K are controlled to open and close in order so that the opening of the suction path 60 is narrowed in order from the upstream side to the downstream side in the rotation direction of the intermediate transfer belt 8. , Clean the toner scattered in the ducts 62M, 62C, 62K on the developing device side. In the present embodiment, such the above-described processing is repeatedly executed.

As described above, according to the present embodiment, when the job changes from low coverage to high coverage or when high coverage continues, the shutter members 68Y, 68M, 68C, 68K are used during or after the job is executed. Is controlled so that the opening of the suction path 60 is narrowed, so that the flow velocity in the suction path 60 can be increased, and the amount of toner deposited in the developing device side ducts 62Y, 62M, 62C, 62K is kept below a certain amount. be able to. As a result, toner spillage from the developing device side duct 62Y or the like to the developing roller 50Y or the like or the photoconductor drum 1Y or the like can be suppressed, and as a result, image defects can be prevented.

Although the present invention has been described using the embodiments, the technical scope of the present invention is not limited to the scope described in the above-described embodiments. Various changes or improvements can be made to the above-described embodiments without departing from the spirit of the present invention.

For example, in the above-described embodiment, it is determined whether or not to implement the cleaning mode by using the coverage of the image data to be printed as the image information, but the present invention is not limited to this. For example, it may be determined whether or not to implement the cleaning mode by using information such as the number of prints, graphic data, text data, and image data as image information.

Further, the upper plate members constituting the developing device side ducts 62Y, 62M, 62C, 62K can be provided on the developing device 5Y, 5M, 5C, 5K side, or can be provided on the device main body 102 side.

Further, although the image forming apparatus 100 shown in FIG. 1 forms a color image, the present invention can be applied not only to an image forming apparatus for forming a color image but also to an image forming apparatus for forming a monochrome image. it can.

Further, in the above-described embodiment, low coverage and high coverage are set with a reference of 5%, but the present invention is not limited to this, and any other value can be set.

Further, in the above-described embodiment, an example in which the suction mechanism 70 is applied to the developing device 5 has been described, but the present invention is not limited to this. For example, when applying the suction mechanism 70 of the present invention when sucking ozone (scattered matter) generated in the charged portion 2, or when sucking exhaust heat (scattered matter) from the secondary transfer roller 34 or the fixing portion 44. The suction mechanism 70 of the present invention can be applied to the above.

1Y, 1M, 1C, 1K Photoreceptor drum (image carrier)
5Y, 5M, 5C, 5K Developer 10 Image forming unit 10Y, 10M, 10C, 10K Image forming unit 50Y, 50M, 50C, 50K Developing roller 60 Suction mechanism 62Y, 62M, 62C, 62K Developer side duct (second) duct)
64 Main body side duct (first duct)
68Y, 68M, 68C, 68K Shutter member 70 Suction mechanism 76 Control unit 78 Toner dust collector 100 Image forming device

Claims (13)

An image forming part that forms an image on paper,
A suction mechanism having a suction path for sucking scattered objects from the image forming portion,
A shutter member provided in the suction path and opening and closing the suction path,
A control unit that controls the opening / closing operation of the shutter member based on the image information of the job is provided .
The image forming apparatus is characterized in that the control unit executes a cleaning mode for cleaning the inside of the suction path by opening and closing the shutter member based on the image information. The image forming apparatus according to claim 1, wherein the suction mechanism is connected to the suction path and has a dust collector that collects the scattered matter sucked by the suction path. The suction path is
A first duct arranged on the device main body side and one end of which is connected to the dust collector,
A second duct in which one end is arranged around the image forming portion and the other end is connected to the other end of the first duct.
The image forming apparatus according to claim 1 or 2, wherein the image forming apparatus has. The image forming unit has an image forming unit corresponding to a plurality of colors, and has an image forming unit.
A plurality of the second ducts are provided corresponding to the plurality of image forming units, and each of the plurality of second ducts is connected to the first duct.
The image forming apparatus according to claim 3, wherein a plurality of the shutter members are provided corresponding to the plurality of second ducts. The image forming unit has an image carrier and a developing roller arranged so as to face the image carrier.
The image forming apparatus according to claim 4, wherein the suction mechanism sucks the developer as the scattered matter scattered from the developing roller. The image forming apparatus according to any one of claims 1 to 5, wherein the image information is at least one or more information of a print rate, a number of prints, a graphic, and a text. The image forming apparatus according to any one of claims 3 to 6, wherein the shutter member is provided at a connecting portion between the first duct and the second duct. Wherein,
Prior Symbol cleaning mode, open the shutter member that corresponds to a specific color, the image forming apparatus according to any one of 7 claim 1, characterized in that closing the shutter member corresponding to the non-relevant color. Wherein, when changing from the first coverage in the job to the first second coverage larger than the coverage of claims 1-8, characterized in that executing the cleaning mode after the job is finished The image forming apparatus according to any one item. The image forming apparatus according to claim 9 , wherein the control unit does not execute the cleaning mode after the job is completed when the first coverage is continuous in the job. The image forming apparatus according to claim 9 or 10 , wherein the control unit executes the cleaning mode after the job is completed when the second coverage is continuous in the job. When the control unit changes from the first coverage to the second coverage larger than the first coverage in the job, after printing a predetermined number of sheets, the control unit controls the opening and closing of the shutter member to narrow the suction path. The image forming apparatus according to any one of claims 1 to 8, wherein the image forming apparatus is used. 12. The control unit according to claim 12 , wherein when the second coverage is continuous in the job, after printing a predetermined number of sheets, the control unit controls the opening and closing of the shutter member to narrow the suction path. Image forming device.

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