JP7326921B2 - image forming device - Google Patents

Description

The present invention relates to an image forming apparatus that forms an image on paper.

In an image forming apparatus, a charged photoreceptor is exposed based on image data to form an electrostatic latent image, and a developing unit is used to adhere toner to the photoreceptor, thereby transforming the electrostatic latent image into a toner image. Develop as Then, the toner image is transferred to a transfer belt, and the toner image transferred to the transfer belt is transferred to a recording medium such as paper (hereinafter referred to as paper). A fixing roller heats and presses the paper onto which the toner image has been transferred, thereby fixing the toner image to the paper.

Such an image forming apparatus is provided with a cleaning device that uses a blade to remove toner remaining on the surface of an image carrier such as a photosensitive member or an intermediate transfer belt. 2. Description of the Related Art For example, Japanese Unexamined Patent Application Publication No. 2002-100000 discloses a technique related to a conventional cleaning device.

Japanese Patent Application Laid-Open No. 2002-101002 discloses a cleaning blade that presses against an image carrier, a toner guide member that contacts the image carrier upstream of the pressure contact position of the cleaning blade when viewed in the rotation direction of the image carrier, and a toner guide member that contacts the toner guide member. A technique having a contacting toner discharge restricting member is described.

JP-A-2005-275219

However, in the technology described in Patent Document 1, the temperature of the regulation member rises due to the frictional force generated between the toner guide member representing the toner supply roller and the toner discharge regulation member representing the regulation member. As a result, the technique described in Patent Document 1 has a problem that the temperature of the regulating member rises and the toner around the regulating member adheres.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus capable of reducing the temperature rise of a regulating member in view of the conventional problems described above.

In order to solve the above problems and achieve the object of the present invention, an image forming apparatus of the present invention comprises an image carrier on which a toner image is formed, a cleaning section for removing toner remaining on the image carrier, and a cleaning section. and a control unit for controlling the The cleaning unit includes a cleaning blade that contacts the image carrier, a toner supply roller that is rotatably supported upstream of the cleaning blade and contacts the image carrier, and a regulating member that contacts the toner supply roller. are doing. Then, when a predetermined condition is reached, the control section outputs a frictional force reduction signal for reducing the frictional force between the regulating member and the toner supply roller to control the cleaning section.

According to the image forming apparatus configured as described above, it is possible to reduce the temperature rise of the regulating member.

1 is a schematic configuration diagram of an image forming apparatus according to a first exemplary embodiment of the present invention; FIG. 1 is a schematic configuration diagram showing a cleaning section in an image forming apparatus according to a first exemplary embodiment of the invention; FIG. 2 is a plan view showing a schematic configuration of a cleaning unit in the image forming apparatus according to the first exemplary embodiment of the invention; FIG. 2 is an enlarged configuration diagram showing a regulating member and a toner supply roller of a cleaning section in the image forming apparatus according to the first exemplary embodiment of the present invention; FIG. FIGS. 5A and 5B show an example of the adjustment mechanism and FIG. 5B, respectively, showing an adjustment mechanism in the image forming apparatus according to the first embodiment of the present invention. 1 is a block diagram showing a control system of an image forming apparatus according to a first exemplary embodiment of the invention; FIG. FIG. 7A is a side view and FIG. 7B is a plan view showing an operation example of the cleaning unit in the image forming apparatus according to the first embodiment of the present invention. 4 is a flow chart showing an example of the operation of the cleaning section of the image forming apparatus according to the first exemplary embodiment of the present invention; 9 is a flow chart showing another example of the operation of the cleaning section of the image forming apparatus according to the first exemplary embodiment of the present invention; FIG. 7 is a schematic configuration diagram showing an adjustment mechanism of a cleaning unit of an image forming apparatus according to a second embodiment of the invention;

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments for implementing an image forming apparatus according to the present invention will be described below with reference to FIGS. 1 to 10. FIG. In addition, the same code|symbol is attached|subjected to the member which is common in each figure. Moreover, the present invention is not limited to the following forms.

1. First embodiment example 1-1. Configuration of Image Forming Apparatus First, the overall configuration of an image forming apparatus according to a first embodiment of the present invention (hereinafter referred to as "this example") will be described. FIG. 1 is a schematic configuration diagram of an image forming apparatus 1 of this example.

The image forming apparatus 1 of this example forms an image on paper by an electrophotographic method, and superimposes four color toners of yellow (Y), magenta (M), cyan (C), and black (Bk). This is a tandem type color image forming apparatus.

As shown in FIG. 1, the image forming apparatus 1 includes a document conveying portion 10, a paper storage portion 20, an image reading portion 30, an image forming portion 40, an intermediate transfer belt 50, a secondary transfer portion 70, A fixing unit 80 is provided.

The document conveying section 10 has a document feeding table 11 on which a document is set and a plurality of rollers 12 . Documents G set on the document feeding table 11 of the document conveying section 10 are conveyed one by one to the reading position of the image reading section 30 by a plurality of rollers 12 . The image reading section 30 reads the image of the document G conveyed by the document conveying section 10 or the document placed on the document platen 13 and generates an image signal.

The paper storage unit 20 is arranged in the lower part of the apparatus main body, and a plurality of paper storage units 20 are provided according to the size of the paper S. As shown in FIG. The paper S is fed by the paper feed unit 21 and sent to the transport unit 23, and transported by the transport unit 23 to the secondary transfer unit 70, which is the transfer position. In other words, the transport unit 23 functions to transport the paper S fed from the paper feed unit 21 to the secondary transfer unit 70 and forms a transport path for transporting the paper S. As shown in FIG. A manual feed section 22 is provided in the vicinity of the paper storage section 20 . From the manual feed unit 22, paper of a size not stored in the paper storage unit 20, tag paper having a tag, and special paper such as an OHP sheet are sent to the transfer position.

An image forming section 40 and an intermediate transfer belt 50 are arranged between the image reading section 30 and the paper storage section 20 . The image forming section 40 has four image forming units 40Y, 40M, 40C, and 40K for forming toner images of yellow (Y), magenta (M), cyan (C), and black (Bk). .

The first image forming unit 40Y forms a yellow toner image, and the second image forming unit 40M forms a magenta toner image. The third image forming unit 40C forms a cyan toner image, and the fourth image forming unit 40K forms a black toner image. Since these four image forming units 40Y, 40M, 40C, and 40K have the same configuration, the first image forming unit 40Y will be described here.

The first image forming unit 40Y includes a drum-shaped photosensitive member 41 as an image bearing member, a charging section 42 arranged around the photosensitive member 41, an exposure section 43, a developing section 44, and a cleaning section 45. have. The photosensitive member 41 is rotated counterclockwise by a driving motor (not shown). The charging unit 42 charges the photoreceptor 41 to uniformly charge the surface of the photoreceptor 41 . The exposure unit 43 performs exposure scanning on the surface of the photoreceptor 41 based on image data read from the document G to form an electrostatic latent image on the photoreceptor 41 .

The developing unit 44 causes yellow toner to adhere to the electrostatic latent image formed on the photoreceptor 41, which is an image carrier. As a result, a yellow toner image is formed on the surface of the photoreceptor 41 . The developing section 44 of the second image forming unit 40M adheres magenta toner to the photoreceptor 41, and the developing section 44 of the third image forming unit 40C adheres cyan toner to the photoreceptor 41. FIG. Then, the developing section 44 of the fourth image forming unit 40K causes the photosensitive member 41 to adhere black toner.

The toner adhering to the photoreceptor 41 is transferred to an intermediate transfer belt 50, which is an example of an image carrier. The cleaning unit 45 removes toner remaining on the surface of the photoreceptor 41 after the transfer onto the intermediate transfer belt 50 .

The intermediate transfer belt 50 is formed in an endless shape and is wound around a plurality of pulleys 54 . The intermediate transfer belt 50 is rotated clockwise in a direction opposite to the rotating direction of the photoreceptor 41 by a drive motor (not shown). A primary transfer portion 51 is provided at a position facing the photoreceptor 41 of each of the image forming units 40Y, 40M, 40C, and 40K on the intermediate transfer belt 50 . The primary transfer section 51 applies a polarity opposite to that of the toner to the intermediate transfer belt 50 to transfer the toner image formed on the photoreceptor 41 to the intermediate transfer belt 50 .

As the intermediate transfer belt 50 rotates, toner images formed by the four image forming units 40Y, 40M, 40C, and 40K are sequentially transferred onto the surface of the intermediate transfer belt 50 . As a result, yellow, magenta, cyan, and black toner images are superimposed on the intermediate transfer belt 50 to form a color image.

In the vicinity of the intermediate transfer belt 50 and downstream of the conveying section 23, a secondary transfer section 70 including a secondary transfer roller is arranged. The secondary transfer section 70 transfers the color image formed on the intermediate transfer belt 50 onto the sheet S sent by the conveying section 23 .

Further, the intermediate transfer belt 50 is provided with a cleaning section 52, which is an example of the cleaning device of this embodiment. The cleaning unit 52 removes toner remaining on the surface of the intermediate transfer belt 50 after transferring onto the paper S. FIG. A detailed configuration of the cleaning unit 52 will be described later.

Further, a fixing section 80 is provided on the paper S discharge side of the secondary transfer section 70 . The fixing section 80 pressurizes and heats the toner image transferred onto the sheet S to fix it. The fixing section 80 has a pair of rollers. In the fixing section 80, the toner image is fixed on the sheet S by sandwiching the sheet S having the unfixed toner image between a pair of rollers and applying pressure and heat.

A switching gate 24 is arranged downstream of the fixing section 80 . The switching gate 24 switches the conveying path of the sheet S that has passed through the fixing section 80 . That is, the switching gate 24 causes the sheet S to advance straight when performing face-up discharge in single-sided image formation. As a result, the sheet S is discharged by the pair of discharge rollers 25 . Further, the switching gate 24 guides the sheet S downward in the case of performing face-down ejection, in which the image forming surface faces downward in single-sided image formation, and in the case of double-sided image formation.

In the case of face-down ejection, after the sheet S is guided downward by the switching gate 24, the sheet reversing and conveying section 26 reverses the sheet S and conveys it upward. As a result, the sheet S is discharged by the pair of discharge rollers 25 . In the case of double-sided image formation, after the sheet S is guided downward by the switching gate 24, it is turned upside down by the sheet reversing/conveying section 26, and the sheet is fed again to the transfer position by the refeeding path 27. FIG.

Further, a post-processing device that folds the paper S or performs stapling or the like on the paper S may be arranged downstream of the pair of paper discharge rollers 25 .

1-2. Configuration Example of Cleaning Unit Next, the configuration of the cleaning unit 52 will be described with reference to FIGS. 2 to 5. FIG.
2 is a side view showing the configuration of the cleaning section 52, and FIG. 3 is a plan view showing the configuration of the cleaning section 52. As shown in FIG. FIG. 4 is an explanatory diagram showing the cleaning portion 52 in an enlarged manner.

As shown in FIGS. 2 and 3, the cleaning unit 52 includes a housing 101, a cleaning blade 102, a toner supply roller 103, a regulation member 104, a backup roller 56, and an adjustment mechanism 110 (FIGS. 5A and 5B). ) and .

The cleaning blade 102 is made of an elastic rubber member. The cleaning blade 102 is formed in a substantially flat plate shape. Further, the cleaning blade 102 is fixed to the housing 101 by a fixing member (not shown), and its tip portion is in contact with the surface of the intermediate transfer belt 50 . As the intermediate transfer belt 50 rotates, the toner remaining on the surface of the intermediate transfer belt 50 is scraped off by the cleaning blade 102 toward the toner supply roller 103 described later.

Also, when the amount of toner adhering to the intermediate transfer belt 50 is small, the frictional force between the cleaning blade 102 and the intermediate transfer belt 50 increases, and the cleaning blade 102 may be damaged. Therefore, in the cleaning unit 52 of this example, the toner supply roller 103 is arranged upstream of the cleaning blade 102 in the rotation direction of the intermediate transfer belt 50 .

As shown in FIG. 3, the shaft portion 103a of the toner supply roller 103 is provided with a bearing portion 103b. The toner supply roller 103 is rotatably supported by the housing 101 via a bearing portion 103b. In addition, the toner supply roller 103 is rotated counterclockwise in a direction opposite to the rotation direction of the intermediate transfer belt 50 by a drive unit (not shown). Then, the toner supply roller 103 supplies the toner adhering to the surface to the intermediate transfer belt 50 . As a result, since a predetermined amount of toner is supplied to the cleaning blade 102 side, an increase in the frictional force between the cleaning blade 102 and the intermediate transfer belt 50 can be prevented, and damage to the cleaning blade 102 can be prevented. can.

A regulating member 104 that regulates the amount of toner supplied from the toner supply roller 103 to the intermediate transfer belt 50 is arranged on the opposite side of the toner supply roller 103 from the intermediate transfer belt 50 . The regulating member 104 is formed in a substantially flat plate shape. The restricting member 104 is fixed to a fixing member 106 provided on the housing 101 .

As shown in FIG. 4, one surface 104a of the regulating member 104 facing the toner supply roller 103 is in contact with the outer peripheral surface of the toner supply roller 103 with a predetermined force. Hereinafter, the force with which the regulation member 104 contacts the toner supply roller 103 is referred to as contact force. As a result, the toner supply roller 103 is pressed toward the intermediate transfer belt 50 . A portion of the toner scraped off by the cleaning blade 102 is present in a region Q1 surrounded by the outer peripheral surface of the toner supply roller 103, the portion of the regulation member 104 that contacts the toner supply roller 103, and the tip of the regulation member 104. part accumulates. The toner that has passed through the contact portion between the regulation member 104 and the toner supply roller 103 adheres to the surface of the toner supply roller 103 .

The backup roller 56 is arranged at a position facing the toner supply roller 103 with the intermediate transfer belt 50 interposed therebetween. The backup roller 56 is in contact with the other surface of the intermediate transfer belt 50 opposite to the surface on which the toner is transferred. Also, the backup roller 56 is supported by an adjustment mechanism 110 (see FIGS. 5A and 5B) so as to be movable toward and away from the other surface of the intermediate transfer belt 50 .

FIG. 5A is an explanatory diagram showing an example of an adjustment mechanism.
The adjustment mechanism 110 has a cam member 111 installed on the rotating shaft 56 a of the backup roller 56 and an adjustment driving section (not shown) that rotates the cam member 111 . As the cam member 111 rotates, the position of the rotating shaft 56a of the backup roller 56 is displaced. As a result, the backup roller 56 moves toward or away from the other surface of the intermediate transfer belt 50 . The tension of the intermediate transfer belt 50 is adjusted by changing the position of the backup roller 56 .

FIG. 5B is an explanatory diagram showing another example of the adjusting mechanism.
An adjusting mechanism 110A according to another example has a rotary shaft 56a of the backup roller 56, a cam member 111A that contacts the backup roller 56, and an adjustment driving section (not shown) that rotates the cam member 111A. In the adjustment mechanism 110A according to another example, as in the adjustment mechanism 110 described above, the rotation of the cam member 111 causes the backup roller 56 to move toward or away from the other surface of the intermediate transfer belt 50. . Thereby, the tension of the intermediate transfer belt 50 is adjusted.

1-3. Configuration of Control System Next, the configuration of the control system of the image forming apparatus 1 will be described with reference to FIG.
FIG. 6 is a block diagram showing the configuration of the control system of the image forming apparatus 1. As shown in FIG.

As shown in FIG. 6 , the image forming apparatus 1 has a control section 200 . The control unit 200 includes, for example, a CPU (Central Processing Unit) 201, a ROM (Read Only Memory) 202 for storing programs executed by the CPU 201, and a RAM (Random Access Memory) 203 used as a work area for the CPU 201. and have Further, the image forming apparatus 1 has a hard disk drive (HDD) 204 as a mass storage device and an operation display section 205 . As the ROM 202, an electrically erasable programmable ROM is normally used.

The control unit 200 is connected to the image reading unit 30, the image processing unit 36, the image forming unit 40, the paper feeding unit 21, the cleaning unit 52, the adjusting mechanism 110, the operation display unit 205, and the HDD 204 via the system bus 207. Controls the entire device.

The HDD 204 stores image data of a document image read by the image reading unit 30, and stores output image data and the like. The operation display unit 205 is a touch panel including a display such as a liquid crystal display (LCD) or an organic ELD (Electro Luminescence Display). The operation display unit 205 displays an instruction menu for the user, information about acquired image data, and the like. Further, the operation display unit 205 has a plurality of keys and serves as an input unit for receiving input of data such as various instructions, characters, numbers, etc. by user's key operation.

The image reading unit 30 optically reads an original image and converts it into an electric signal. For example, when reading a color document, image data having 10-bit RGB luminance information per pixel is generated. Image data generated by the image reading unit 30 and image data transmitted from a PC (personal computer) 220, which is an example of an external device connected to the image forming apparatus 1, are sent to the image processing unit 36, where image processing is performed. be done. The image processing unit 36 performs image processing such as shading correction, image density adjustment, and image compression on the received image data as necessary. Further, the image forming section 40 receives image data that has undergone image processing by the image processing section 36, and forms an image on the sheet S based on the image data.

The cleaning unit 52 controls the rotation of the toner supply roller 103 based on a signal transmitted from the control unit 200 and adjusts the amount of toner supplied to the intermediate transfer belt 50 . The adjustment mechanism 110 also controls the cam member 111 based on a signal transmitted from the control section 200 to control the tension of the intermediate transfer belt 50 .

In this example, an example using a personal computer as an external device has been described, but the present invention is not limited to this, and various other devices such as a facsimile device can be used as the external device.

1-4. Operation Example of Cleaning Unit 52 Next, an operation example of the cleaning unit 52 having the above-described configuration will be described with reference to FIGS. 7 to 9. FIG.
7A and 7B are explanatory diagrams showing an example of the operation of the cleaning section 52, and FIG. 8 is a flowchart showing an example of the operation of the cleaning section 52. FIG.

As shown in FIG. 8, control unit 200 receives a signal from image forming unit 40 and determines whether or not the number of printed sheets has reached a predetermined number (step S11). In the processing of step S<b>11 , when the control unit 200 determines that the number of printed sheets has reached the predetermined number (YES determination in step S<b>11 ), the control unit 200 outputs a frictional force decrease signal to the adjusting mechanism 110 . Then, the adjustment mechanism 110 performs a frictional force reduction operation (step S12).

In the process of step S12, the adjustment mechanism 110 rotates the cam member 111 (see FIGS. 5A and 5B) to move the backup roller 56 away from the intermediate transfer belt 50, as shown in FIG. 7A. As the backup roller 56 moves away from the intermediate transfer belt 50 , the tension of the intermediate transfer belt 50 is weakened, and the stress from the toner supply roller 103 to the intermediate transfer belt 50 is also reduced. Therefore, the contact force of the regulating member 104 against the toner supply roller 103 is also reduced, and the frictional force between the regulating member 104 and the toner supply roller 103 is also reduced.

Since the frictional force between the regulating member 104 and the toner supply roller 103 is thus reduced, the heat generated by the friction is also reduced, and the temperature rise at the contact portion between the regulating member 104 and the toner supply roller 103 can be reduced. can. As a result, it is possible to prevent the toner accumulated in the area Q1 shown in FIG. 4 from sticking.

Note that the frictional force reduction operation in step S12 is performed while no toner image is formed on the intermediate transfer belt 50, for example, the time between image forming processes in the image forming apparatus 1, or Performed during stabilization operation. Furthermore, the amount of movement of the backup roller 56 is set within a range that satisfies the cleaning function of the cleaning section 52 .

Further, the control unit 200 controls the adjustment mechanism 110 after a predetermined period of time has elapsed, moves the backup roller 56 toward the intermediate transfer belt 50, and returns the backup roller 56 to the initial position. As a result, the tension of the intermediate transfer belt 50 is restored. The above-described operation is performed each time the number of printed sheets reaches a predetermined number.

FIG. 9 is a flow chart showing another example of the operation of the cleaning section 52. As shown in FIG.
As shown in FIG. 9 , the control unit 200 acquires environmental temperature information from a temperature sensor installed in the image forming apparatus 1 . Then, the control unit 200 determines whether or not the environmental temperature has reached a predetermined temperature signal (step S21). In the processing of step S<b>21 , when control unit 200 determines that the temperature has reached the predetermined temperature (YES determination in step S<b>21 ), control unit 200 outputs a frictional force decrease signal to adjustment mechanism 110 . Then, the adjustment mechanism 110 performs a frictional force reduction operation (step S22). Note that the frictional force reducing operation in the adjustment mechanism 110 is the same as the operation described above, so the description thereof will be omitted.

As a result, the frictional force between the regulating member 104 and the toner supply roller 103 is reduced, so the heat generated by the friction is also reduced, and the temperature rise at the contact portion between the regulating member 104 and the toner supply roller 103 can be reduced. .

In the example shown in FIG. 9, the frictional force reduction operation is performed based on the environmental temperature of the image forming apparatus 1, but the present invention is not limited to this. For example, as in the operation example shown in FIG. 8, when the frictional force is reduced for each predetermined number of sheets, the predetermined number of sheets in the process of step S11 is set smaller under the condition that the environmental temperature is higher than the predetermined temperature. As a result, under high temperature conditions, the interval between the frictional force reduction operations can be set short.

Also, a temperature sensor that measures the temperature of the regulation member 104 may be provided. Then, when the temperature measured by the temperature sensor reaches a predetermined temperature, the control section 200 may output a control signal to the cleaning section 52 and the adjusting mechanism 110 so as to perform the friction force reducing operation.

2. Second Embodiment Next, an image forming apparatus according to a second embodiment will be described with reference to FIG.
FIG. 10 is a side view of the cleaning unit according to the second embodiment. Parts common to the cleaning unit 52 according to the first embodiment are denoted by the same reference numerals, and overlapping descriptions are omitted.

As shown in FIG. 10, the cleaning section 52B according to the second embodiment includes a housing 101, a cleaning blade 102, a toner supply roller 103, a regulation member 104B, and a backup roller 56. there is In the cleaning section 52B according to the second embodiment, instead of changing the position of the backup roller 56, the position of the regulating member 104B changes. The regulation member 104B is movably supported by the housing 101 by a support member 106B.

The regulating member 104B moves away from the toner supply roller 103 in response to a control signal from the controller 200 (see FIG. 6). As a result, the contact force of the regulating member 104B with the toner supply roller 103 is reduced, and the frictional force between the regulating member 104B and the toner supply roller 103 is reduced.

Since other configurations are the same as those of the cleaning unit 52 according to the first embodiment, description thereof will be omitted. Even with the cleaning unit 52B having such a configuration, it is possible to obtain the same effects as those of the image forming apparatus 1 according to the above-described first embodiment.

Also, the method of reducing the frictional force is not limited to the examples described above. For example, the frictional force between the regulation member 104 and the toner supply roller 103 may be reduced by reducing the number of rotations of the toner supply roller 103 . According to this method, a mechanism for moving the backup roller 56 and the regulating member 104 is not required, so the number of parts can be reduced, and the method can be applied to existing image forming apparatuses.

In the above, the embodiment of the image forming apparatus has been described, including its effects. However, the image forming apparatus of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the invention described in the claims.

In the above-described embodiment, the four sets of image forming units 40Y, 40M, 40C, and 40K are used to form a color image. A single-color image may be formed using the ink. Further, the image forming apparatus is not limited to a copying machine, and may be a printer, a facsimile machine, or a multifunction machine having a plurality of functions.

Further, in the above-described embodiment, an example in which the cleaning section 52 for removing toner remaining on the intermediate transfer belt 50 is applied as the cleaning section provided with the conveying/discharging unit has been described, but the present invention is not limited to this. do not have. For example, it may be applied to a cleaning section that removes toner remaining on a secondary transfer belt or other image carrier.

In this specification, words such as "parallel" and "perpendicular" are used, but these do not strictly mean only "parallel" and "perpendicular", but include "parallel" and "perpendicular". Furthermore, it may be in a "substantially parallel" or "substantially orthogonal" state within the range where the function can be exhibited.

DESCRIPTION OF SYMBOLS 1... Image forming apparatus 10... Document conveyance part 11... Document feed table 13... Document table 20... Paper storage part 21... Paper feed part 30... Image reading part 40... Image forming part 41... Photoconductor 42 Charging section 43 Exposure section 44 Development section 45, 52 Cleaning section 47 Toner collection section 50 Intermediate transfer belt 51 Primary transfer section 56 Backup roller 70 Secondary transfer unit 80 Fixing unit 101 Housing 102 Cleaning blade 103 Toner supply roller 104, 104B Regulating member 104a One surface 106B Supporting member 110, 110A Adjusting mechanism 111, 111A... cam member, 200... control unit

Claims (5)

an image carrier on which a toner image is formed;
a cleaning unit for removing toner remaining on the image carrier;
a control unit that controls the cleaning unit;
The cleaning unit
a cleaning blade that contacts the image carrier;
a toner supply roller rotatably supported upstream of the cleaning blade and in contact with the image carrier;
a regulating member that contacts the toner supply roller;
The control unit outputs a frictional force reduction signal for reducing the frictional force between the regulation member and the toner supply roller when a predetermined condition is reached, and controls the cleaning unit ,
The cleaning unit reduces the number of rotations of the toner supply roller upon receiving the frictional force reduction signal from the control unit.
Image forming device. The image carrier is an endless belt member,
The cleaning unit includes a backup roller that faces the toner supply roller and the image carrier with the image carrier therebetween and adjusts the tension of the image carrier;
an adjusting mechanism for moving the backup roller toward and away from the image carrier,
2. The image forming apparatus according to claim 1, wherein when the frictional force reduction signal is received from the control section, the cleaning section causes the adjustment mechanism to move the backup roller away from the image carrier. the cleaning unit includes a supporting member that supports the regulating member so as to be able to approach and separate from the toner supply roller;
2. The image forming apparatus according to claim 1, wherein upon receiving the frictional force reduction signal from the control section, the cleaning section causes the support member to move the regulation member away from the toner supply roller. The image forming apparatus according to claim 1, wherein the controller outputs the frictional force reduction signal when the number of images formed reaches a predetermined number. 2. The image forming apparatus according to claim 1, wherein the controller outputs the frictional force reduction signal when the regulating member reaches a predetermined temperature.

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