JP2001305934A - Transfer device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent developer adhering to a transfer member from adhering to the back surface of recording material by cleaning the opposed surface of the transfer member to an image carrier at a proper time. SOLUTION: In an image forming device 1, electrification, optical scanning, developing, transfer and cleaning units 3 to 7 are arranged in this order around a photoreceptor drum 2 so that an electrophotographic processing part P is constituted, and a fixing unit 10 is arranged above the processing part P. A transfer unit 10 for transferring a developer image formed on the drum 2 to the recording material is arranged to be opposed to the surface of the drum 2, and is a provided with a transfer belt 62 to which transfer bias is applied, a cleaning unit 13 for cleaning the surface of the belt 62 opposed to the drum 2, and a control part 31 functioning as a predicting means for predicting the adhesive amount of the developer adhering to the opposed surface of the belt 62 and also as a control means for controlling the unit 13 to act in timing based on the predicted adhesive amount of the developer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer device mounted on an image forming apparatus and transferring a developer image formed on an image carrier provided in the image forming apparatus onto a recording material, and more particularly to a transfer device provided with the transfer device. The present invention relates to a transfer device having a function of cleaning a transfer member.

[0002]

2. Description of the Related Art In an image forming apparatus, in order to electrostatically transfer a developer image formed on an image carrier onto a recording material, a corona discharge having a polarity opposite to the polarity of the developer has conventionally been used. In recent years, transfer devices such as a transfer roller and a transfer belt are arranged in close proximity to or in contact with an image carrier, and a transfer device that applies a transfer bias to the transfer member has been developed. It has become mainstream. This transfer device is a device in which ozone generated by corona discharge is taken into consideration, and is suitably mounted on an image forming apparatus as a device in consideration of environmental issues.

[0003]

In the above-described transfer apparatus using a transfer member such as a transfer roller or a transfer belt, since the transfer member is close to or in contact with the image carrier, an electrostatic charge is applied on the image carrier. The developer adhering to the transfer member may adhere to the transfer member. When the transfer is performed using the transfer member to which the developer is attached, the developer attached to the transfer member is transferred to the back surface of the recording material, and the back surface of the recording material is stained. Means for cleaning the developer adhered to the transfer belt is disclosed in
Although it is disclosed in JP-A-83766 and JP-A-3-230186, it is desired to efficiently clean the developer at a more appropriate time.

An object of the present invention is to clean the surface of a transfer member facing an image carrier at an appropriate time,
An object of the present invention is to provide a transfer device capable of preventing a developer adhered to a transfer member from adhering to a back surface of a recording material.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a transfer device mounted on an image forming apparatus, which transfers a developer image formed on an image carrier provided in the image forming apparatus onto a recording material. A transfer member disposed opposite to the image carrier and to which a transfer bias is applied; cleaning means for cleaning a surface of the transfer member opposed to the image carrier; and a facing surface of the transfer member. Estimating means for estimating the amount of the developer adhering to the surface, and controlling means for cleaning the opposing surface of the transfer member by operating the cleaning means based on the amount of the adhering developer predicted by the estimating means And a transfer device.

According to the present invention, the surface of the transfer member such as the transfer roller or the transfer belt facing the image carrier is cleaned by the cleaning means, and the cleaning operation of the cleaning means is controlled by the control means. Specifically, the control unit controls the cleaning operation of the cleaning unit based on the amount of the developer adhering to the opposing surface of the transfer member predicted by the prediction unit. Therefore, the developer adhering to the transfer member can be efficiently removed at an appropriate time, thereby preventing the back surface of the recording material from being stained.

Further, the present invention is characterized in that the predicting means predicts the amount of the developer adhering to the opposed surface of the transfer member by controlling the amount of the developer supplied.

According to the present invention, the predicting means predicts the amount of the developer adhering to the opposing surface of the transfer member by controlling the amount of developer supplied, and the control means predicts the amount of the developer adhering to the transfer member. The cleaning operation of the cleaning unit is controlled based on the amount of developer adhered to the opposing surface of the transfer member. Therefore, the developer adhering to the transfer member can be efficiently removed at an appropriate time based on the supply amount of the developer, thereby preventing the back surface of the recording material from being stained.

Further, the present invention is characterized in that the predicting means predicts the amount of developer adhering to the opposed surface of the transfer member by managing the number of times of image formation.

According to the present invention, the predicting means predicts the amount of the developer adhering to the opposing surface of the transfer member by controlling the number of image formations, and the control means controls the transfer predicted by such a predicting means. The cleaning operation of the cleaning means is controlled based on the amount of the developer adhering to the opposing surface of the member. Therefore, the developer adhering to the transfer member can be efficiently removed at an appropriate time based on the number of times of image formation, thereby preventing the back surface of the recording material from being stained.

Further, the present invention is characterized in that the predicting means predicts an amount of developer adhering to the opposite surface of the transfer member by managing an abnormal state of an image forming operation during image forming. And

According to the present invention, the predicting means predicts the amount of the developer adhering to the opposing surface of the transfer member by managing the abnormal condition of the image forming operation during the image forming, and the control means controls the abnormal state. The cleaning operation of the cleaning unit is controlled based on the amount of developer adhering to the opposing surface of the transfer member predicted by the prediction unit. Therefore, the developer adhering to the transfer member can be efficiently removed at an appropriate time based on the abnormal state of the image forming operation during the image formation, thereby preventing the back surface of the recording material from being stained.

Further, the present invention is characterized in that the control means includes a correction means for correcting the amount of the applied developer predicted by the prediction means in accordance with the operating environment of the transfer device.

According to the present invention, the amount of developer adhesion predicted by the prediction means is corrected by the correction means provided in the control means in accordance with the operating environment of the transfer device, and the control means predicts and corrects the transfer member. The cleaning operation of the cleaning means is controlled based on the amount of developer adhering to the opposing surface of the cleaning means. Therefore, the developer attached to the transfer member can be efficiently removed at a more appropriate time.

Further, the invention is characterized in that the correction means corrects the adhesion amount of the developer which is predicted according to the installation environment of the transfer device.

According to the present invention, the correction means corrects the amount of the developer adhered predicted by the prediction means according to the surrounding environment where the transfer device is installed. The control unit controls the cleaning operation of the cleaning unit based on the predicted and corrected amount of the developer adhering to the opposing surface of the transfer member. Therefore, the developer attached to the transfer member can be efficiently removed at a more appropriate time.

Further, the invention is characterized in that the correction means corrects the estimated amount of the developer attached in accordance with a transfer bias to a transfer member.

According to the present invention, the correction means corrects the amount of the developer adhering predicted by the prediction means in accordance with the transfer bias to the transfer member. The control unit controls the cleaning operation of the cleaning unit based on the predicted and corrected amount of the developer adhering to the opposing surface of the transfer member. Therefore, the developer attached to the transfer member can be efficiently removed at a more appropriate time.

Further, the invention is characterized in that the correction means corrects the adhesion amount of the developer predicted according to the characteristics of the developer transferred by the transfer device.

According to the present invention, the correcting means corrects the amount of the developer adhered predicted by the predicting means according to the characteristics of the developer transferred by the transfer device. The control unit controls the cleaning operation of the cleaning unit based on the predicted and corrected amount of the developer adhering to the opposing surface of the transfer member. Therefore, the developer attached to the transfer member can be efficiently removed at a more appropriate time.

Further, the present invention is characterized in that the predicting means includes a detecting means for detecting an amount of developer adhering to the opposed surface of the transfer member.

According to the present invention, the amount of developer adhering to the opposing surface of the transfer member is detected by the detecting means provided in the estimating means, and the estimating means calculates the amount of adhering to the opposing surface from the detected amount of adhering. Predict. The control unit controls the cleaning operation of the cleaning unit based on the amount of the developer adhering to the opposing surface of the transfer member predicted by the prediction unit. Therefore, the developer adhering to the transfer member can be efficiently removed at an appropriate time based on the amount of adhering to the opposite surface predicted from the detected amount of adhering, thereby preventing the back surface of the recording material from being stained. be able to.

Further, the present invention is characterized in that the detecting means is a sensor, and the sensor is provided at a position separated from a source affecting the sensor.

According to the present invention, by realizing the detecting means with the above-described sensor, an appropriate amount based on the amount of adhesion of the developer adhering to the opposed surface predicted from the amount of adhesion of the developer adhering to the transfer member is detected. It can be efficiently removed at an appropriate time.

[0025]

FIG. 1 is a view showing an image forming apparatus 1 according to an embodiment on which a transfer device according to the present invention is mounted. An electrophotographic processing unit P centered on the photosensitive drum 2 is disposed inside the image forming apparatus 1 and substantially at the left side in the center of the sheet of FIG. More specifically, a charging unit 3 for uniformly charging the surface of the photosensitive drum 2 and an optical scanning unit 4 for scanning an optical image on the photosensitive drum 2 having a uniformly charged surface to write an electrostatic latent image. A developing unit 5 for reproducing the electrostatic latent image written by the optical scanning unit 4 with a developer containing toner, and a transfer for transferring an image stored and reproduced on the photosensitive drum 2 to a sheet-like recording material. A cleaning unit 7 that removes the developer remaining on the unit 6 and the photosensitive drum 2 and enables a new image to be recorded on the photosensitive drum 2 is provided around the photosensitive drum 2 in this order. Be placed. The transfer device according to the present invention corresponds to the transfer unit 6.

Below the electrophotographic process section P inside the image forming apparatus 1, a recording material supply section 8 for storing and supplying the recording material is arranged so as not to protrude from the apparatus 1. From the recording material supply unit 8, the stored recording materials are separated and supplied one by one. The recording material is sequentially fed at a predetermined timing between the photosensitive drum 2 and the transfer unit 6 of the electrophotographic process unit P, and the image reproduced and recorded on the photosensitive drum 2 is transferred. When the recording material is supplied to the recording material storage tray 9 provided in the recording material supply unit 8 or when the recording material stored in the tray 9 is replaced, the recording material storage tray 9 is pulled out toward the near side in FIG. .

A fixing unit 10 is disposed above the electrophotographic process section P inside the image forming apparatus 1. The fixing unit 10 sequentially receives the recording material onto which the image has been transferred, and heats and fixes the toner image transferred onto the recording material.
The recording material on which the toner image has been fixed is discharged to a discharge unit 11 provided on the upper surface of the image forming apparatus 1 in FIG. 1, and is received by the discharge unit 11. In this manner, the recording material is conveyed along the recording material conveyance path X indicated by a dashed line in FIG.

Optical scanning unit 4 inside image forming apparatus 1
The upper and lower space portions 12 include a process control unit (PCU) board for controlling the electrophotographic process section P, an interface board for receiving image data from the outside, and a predetermined image for the image data received from the interface board. An image control unit (ICU) substrate for performing processing and scanning and recording as an image by an optical scanning unit, and a PC
Various substrates such as a U, an interface, and an ICU, and a power supply unit for supplying power to the units 3 to 7 and 10 are arranged.

By externally connecting an image processing apparatus such as a personal computer to the image forming apparatus 1, the image forming apparatus 1 can be operated as a printer for recording and outputting image data from an externally connected device. Further, in the present embodiment, the image forming apparatus 1 including the single recording material supply unit 8 is described. However, the image forming apparatus 1 may include a plurality of recording material supply units 8.

FIG. 2 is a diagram showing a state in which the left side surface portion 21 of the image forming apparatus 1 in FIG. 1 is opened laterally along the recording material conveying path X indicated by a dashed line. . The side portion 21 includes the transfer unit 6, and the transfer unit 6 includes the cleaning unit 13. The cleaning unit 13 includes the transfer unit 6
The surface of the transfer belt 62 described later is cleaned.
The open state of the side surface 21, that is, the state in which the recording material transport path X extending over the recording material supply unit 8, the transfer unit 6, the fixing unit 10, and the discharge unit 11 is open, the recording material of the image forming apparatus 1 in the state of FIG. It is formed when a so-called jam occurs, which is a conveyance error of the recording material in the conveyance path X, so that the recording material stagnant in the recording material conveyance path can be easily removed.

FIG. 3 is a diagram showing a state in which the transfer unit 6 has been removed from the side surface 21 of the image forming apparatus 1 in FIG. In the image forming apparatus 1, the exchange unit U is configured by the transfer unit 6 including the cleaning unit 13 integrally. The transfer unit 6 includes a pair of rollers 6
1. The cleaning unit 13 includes a transfer belt 62 which is a transfer member stretched around the roller 61 and the cleaning unit 13. The cleaning unit 13 includes a cleaning blade 14 in contact with the surface of the transfer belt 62 and a storage unit 15 for collecting and storing the developer removed from the surface of the transfer belt 62 by the cleaning blade 14. The cleaning blade 14 comes into contact with the surface of the transfer belt 62 at a pressure at which the developer attached to the surface of the transfer belt 62 is recovered to a certain extent. Although the cleaning efficiency can be improved by increasing the pressure contact force of the cleaning blade 14, damage to the surface of the transfer belt 62 due to the edge of the cleaning blade 14 causes a problem such as transfer failure, so that an appropriate level can be achieved. It is preferable to set

FIG. 4 is a block diagram showing various sensor groups S1 to S6, a control unit 31, and an operation panel 32 arranged inside the image forming apparatus 1. The sensors S1 to S3 are
They are arranged along the recording material conveyance path X, respectively. Sensor S
Reference numeral 1 denotes a sensor for confirming the recording material sent from the recording material supply unit 8 and performing registration for supplying the recording material to the electrophotographic process unit P at a proper timing. The sensor S2 is a sensor for confirming whether or not the recording material on which the toner image has been transferred in the electrophotographic process unit P is heated and fixed in the fixing unit 10 and then reliably transported from the fixing unit 10. The sensor S3 detects that the recording material P is reliably discharged from the image forming apparatus 1 to the discharge section 1 on the upper surface of the apparatus.
This is a sensor for confirming whether or not the light has been emitted toward 1.

The sensor S4 is a sensor that detects environmental conditions such as temperature, humidity, and atmospheric pressure around the electrophotographic process unit P, that is, environmental conditions in which the image forming apparatus 1 is installed.

The sensor S5 is a sensor for checking the characteristics of the developer supplied to the image forming apparatus 1 and supplied to the developing unit 5. The image forming apparatus 1 is housed in the developer cartridge 51 by detecting the signal source 53 provided in the developer cartridge 51 containing the developer supplied to the developing unit 5 by the sensor S5. Check the properties of the developer. The developer cartridge 51 includes a supply roller 52 for supplying the stored developer to the developing unit 5. The developer cartridge 51 is always fixed and stable in accordance with the consumption of the developer stored in the developing unit 5. Appropriate supply is performed so as to obtain development conditions.

The sensor S6 is a sensor for estimating the amount of the developer adhering to the surface of the transfer belt 62.
For example, it is a non-contact optical sensor, and is arranged so as to face the transfer belt 62. The sensor S6 is provided in the vicinity of the electrophotographic process unit P at a position away from a source that affects the sensor S6 and is not affected. For example, it is arranged at a position distant from the fixing unit 10 that generates heat, at a position distant from the transfer unit 6 where scattering of toner, paper dust, or the like is considered. As a result, malfunction of the sensor S6 can be prevented.

The control unit 31 receives outputs from the sensors S1 to S6 via the PCU board, the interface board, and the ICU board disposed in the upper and lower space section 12, and receives an input from the operation panel 32. Information is given. The control unit 31 controls the operation of each of the units 3 to 7 and 10 based on the output and input information of each of the sensors S1 to S6. For example, the control unit 31 controls the application of a transfer bias to the transfer roller 61 of the transfer unit 6, whereby the main operation of the transfer unit 6 is to transfer the toner image formed on the photosensitive drum 2 onto the recording material. Is controlled. Further, it controls the overall operation of the image forming apparatus 1 such as a recording material transport mechanism.

In the image forming apparatus 1 configured as described above, according to the present invention, the control unit 31
The cleaning of the transfer belt 62 is performed by estimating the amount of the developer that may adhere to the transfer belt 62. That is, the amount of the developer that will adhere to the transfer belt 62 is predicted, and when the predicted amount reaches a predetermined level, the cleaning process of the transfer belt 62 is performed at a predetermined timing. Thereby, during the step of transferring the toner image formed on the photosensitive drum 2 onto the recording material,
The developer adhering to the transfer belt 62 is prevented from adhering to the back surface of the recording material, thereby preventing the back surface of the recording material from being stained.

Next, the first to third methods for determining the cleaning time by estimating the amount of the developer that will adhere to the transfer belt 62 will be described.

First, the first method will be described. The control unit 31 estimates the amount of the developer that will adhere to the transfer belt 62 based on the supply amount of the developer stored in the developer cartridge 51. Then, the time when the predicted amount reaches a predetermined level is defined as the cleaning time of the surface of the transfer belt 62. Specifically, as shown in FIG. 4, an appropriate amount of the developer contained in the developer cartridge 51 is supplied into the developing unit 5 by the rotation of the supply roller 52. Therefore, by controlling the rotation amount of the supply roller 52, it is possible to predict the amount of the developer that may adhere to the transfer belt 62. When the predicted amount reaches a predetermined level, the surface of the transfer belt 62 becomes contaminated with the consumption of the developer.

Next, the second method will be described. The control unit 31 estimates the amount of the developer that may adhere to the transfer belt 62 based on the number of times of image formation. And
The transfer belt 6 determines when the predicted amount reaches a predetermined level.
It is time to clean the surface of No. 2. Image forming apparatus 1
Is usually provided with an internal counter for ascertaining the operation status of the apparatus, periodic inspection, and the like. By using the internal counter, the number of image formations,
Can determine the amount of image formed. The amount of developer that will adhere to the transfer belt 62 is predicted based on the grasped number of image formations. When the predicted amount reaches a predetermined level, the surface of the transfer belt 62 is formed along with image formation. Since it becomes dirty, this time is set as the cleaning time of the transfer belt 62.

Here, the size of the recording material includes all sizes that can be passed through the image forming apparatus 1 and various shapes. The amount of the developer adhered to the surface of the transfer belt 62 varies depending on conditions such as the size of the recording material and the conveyance direction. It is possible to find a more appropriate cleaning time of the transfer belt 62 by managing the conditions including the above condition.

Further, the third method will be described. The control unit 31 estimates the amount of the developer that will adhere to the transfer belt 62 based on an abnormal state of the image forming operation during the image forming. Then, the time when the predicted amount reaches a predetermined level is defined as the cleaning time of the surface of the transfer belt 62. The abnormal condition of the image forming operation during the image forming is a condition (the number of times) that the image forming operation is interrupted (stopped) in the middle of forming the image on the photosensitive drum 2 and, for example, should be formed. This is the number of times the image forming operation is stopped due to paper conveyance abnormality such as the recording material size being smaller than the image size.

The image forming apparatus 1 usually includes a photosensitive drum 2
Transfer the toner image formed on the recording material onto the recording material,
The toner image formed on the photosensitive drum 2 is not transferred to the recording material due to an abnormal supply of the recording material, that is, the recording material is not supplied between the photosensitive drum 2 and the transfer belt 62, and The transfer belt 62 may come into direct contact with the toner image electrostatically formed on the drum 2, and the surface of the transfer belt 62 may become dirty. Also, the photosensitive drum 2
When the size of the recording material is smaller than the size of the toner image formed on the photosensitive drum 2 and the transfer belt 62,
In a region where no recording material exists between the transfer belt 62 and the transfer belt 62, the toner image electrostatically formed on the photosensitive drum 2 and the transfer belt 62 come into direct contact with each other, and the surface of the transfer belt 62 may become dirty. By managing such an abnormal situation, the amount of the developer that will adhere to the transfer belt 62 is predicted, and when the predicted amount reaches a predetermined level, the amount of the developer together with the abnormal situation is determined. Since the surface of the transfer belt 62 becomes dirty, this time is set as the cleaning time of the transfer belt 62.

Subsequently, in order to optimize the execution time of the cleaning process predicted as described above, the supply amount of the developer, the number of times of image formation, and management information indicating the abnormal state of the image forming operation are stored in the operation of the apparatus. Correction will be described based on the environment, the installation environment of the apparatus, and the correction conditions that are the characteristics of the developer.

First, how to correct the management information based on the operating environment of the apparatus to determine the cleaning time will be described. The operating environment of the apparatus is, for example, the transfer output and the characteristics of the developer. The transfer environment conditions in the electrophotographic process change according to such an operation environment. Therefore, the amount of toner adhering to the transfer belt 62 also changes.
Therefore, the time for cleaning also changes. Therefore, the cleaning timing of the transfer belt 62 can be optimized by correcting the cleaning timing according to the operating environment of the apparatus.

Next, how to correct the management information based on the installation environment of the apparatus and determine the cleaning time will be described. The installation environment of the device is, for example, temperature or humidity. The transfer efficiency in the electrophotographic process changes according to such an installation environment. Therefore, the amount of toner adhering to the transfer belt 62 also changes. Therefore, the time for cleaning also changes. Therefore,
By correcting the cleaning timing according to the installation environment of the apparatus, the cleaning timing of the transfer belt 62 can be optimized.

Further, how to correct the management information based on the characteristics of the developer to determine the cleaning time will be described. The transfer efficiency in the electrophotographic process changes according to the characteristics of the developer contained in the developer cartridge 51 loaded in the mounting. Therefore, the amount of toner adhering to the transfer belt 62 also changes. Therefore,
The time for cleaning also changes. Therefore, the cleaning timing of the transfer belt 62 can be optimized by correcting the cleaning timing according to the characteristics of the developer stored in the developer cartridge 51 loaded in the mounting. The characteristics of the developer can be confirmed by detecting the signal source 53 provided on the developer cartridge 51 with the sensor S5.

As described above, the amount of the developer that will adhere to the transfer belt 62 is predicted based on the management information, and the management information for predicting the amount of the developer is corrected depending on the condition. The optimal timing for cleaning the surface of the transfer belt 62 that is in contact with or close to the photosensitive drum 2 can be determined.

Next, the step of cleaning the transfer belt 62 will be described. In the transfer unit 6 of the image forming apparatus 1 shown in FIGS. 1 to 4, the cleaning blade 14 is in contact with a surface of a transfer belt 62 stretched between a pair of rollers 61 at a predetermined pressure. At this time, the pressure of the cleaning blade 14 is relatively weak, not enough to completely remove the developer from the surface of the transfer belt 62.
And the transfer belt 62 is under such a pressure as to pass through. This is to minimize damage to the surface of the transfer belt 62, as described above, and the pressure is determined by the relationship between the material of the transfer belt 62 and the cleaning blade 14, and the like. As a result, the state of the surface of the transfer belt 62 is maintained in an appropriate state, and transfer efficiency and transfer quality are ensured. If the transfer belt 62 is rotated at a predetermined time for a predetermined time in such a pressure contact state, a predetermined amount or more of the developer does not adhere to the transfer belt 62,
Staining due to the adhesion of the developer on the back surface of the recording material is less likely to occur.

In this embodiment, the transfer belt 62 has been described as an example of a transfer member. However, an example in which a transfer roller is used as a transfer member in contact with or in proximity to the photosensitive drum 2 also falls within the scope of the present invention.

The unit 13 including the cleaning blade 14 has been described as an example of the cleaning unit 13 of the transfer belt 62. As shown in FIG.
The collection of the developer adhered to the transfer belt 62 by bringing the developer into contact with the transfer belt 62 also belongs to the scope of the present invention. FIG.
As shown in FIG. 5, the transfer belt 62 is brought into contact with the photosensitive drum 2 and a bias roller is brought into contact with the back surface of the transfer belt 62, that is, one of the pair of rollers 61 is used as a bias roller, A configuration in which a bias having a reverse polarity different from the normal transfer polarity is applied to the bias roller also belongs to the scope of the present invention.

[0052]

As described above, according to the present invention, the cleaning operation of the transfer member is controlled on the basis of the estimated amount of the developer adhering to the opposing surface of the transfer member. The developer adhering to the recording material can be efficiently removed at an appropriate time, thereby preventing the back surface of the recording material from being stained.

Further, according to the present invention, the amount of the developer adhering to the opposing surface of the transfer member is predicted by controlling the supply amount of the developer. It can be efficiently removed at an appropriate time based on the supply amount of the agent.

Further, according to the present invention, the amount of the developer adhering to the opposing surface of the transfer member is predicted by controlling the number of image formations. Can be efficiently removed at an appropriate time based on the

According to the present invention, the amount of the developer adhering to the opposing surface of the transfer member is predicted by managing an abnormal state of the image forming operation during image formation. The attached developer can be efficiently removed at an appropriate time based on an abnormal situation of the image forming operation during the image forming.

Further, according to the present invention, since the estimated amount of the adhered developer is corrected according to the operating environment of the transfer device, the developer adhered to the transfer member is efficiently removed at a more appropriate time. be able to.

Further, according to the present invention, since the estimated amount of the deposited developer is corrected according to the installation environment of the transfer device, the developer attached to the transfer member is efficiently removed at a more appropriate time. be able to.

Further, according to the present invention, the estimated amount of the applied developer is corrected in accordance with the transfer bias to the transfer member, so that the developer attached to the transfer member is efficiently removed at a more appropriate time. can do.

Further, according to the present invention, the predicted amount of the applied developer is corrected according to the characteristics of the developer.
The developer attached to the transfer member can be efficiently removed at a more appropriate time.

According to the present invention, the amount of the developer adhering to the opposing surface of the transfer member is detected, and the amount of the adhering agent to the opposing surface is predicted based on the detected amount of adhering. The attached developer can be efficiently removed at an appropriate time based on the amount of the attached developer predicted from the detected amount of the attached material, thereby preventing the back surface of the recording material from being stained.

Further, according to the present invention, the amount of the developer adhering to the opposing surface of the transfer member can be detected by the sensor, whereby the amount of the developer adhering to the transfer member can be detected on the opposing surface predicted from the detected adhering amount. It can be efficiently removed at an appropriate time based on the amount of the adhered substance.

[Brief description of the drawings]

FIG. 1 is a diagram showing an image forming apparatus 1 according to an embodiment of the present invention.

FIG. 2 shows a side surface portion 21 of the image forming apparatus 1 as a recording material conveying path X
It is a figure which shows the state opened along.

FIG. 3 is a diagram illustrating a state in which a transfer unit 6 is removed from a side surface portion 21 of the image forming apparatus 1.

FIG. 4 is a block diagram showing various sensor groups S1 to S6, a control unit 31, and an operation panel 32 arranged inside the image forming apparatus 1.

FIG. 5 is a diagram illustrating a cleaning unit of a transfer belt of an image forming apparatus according to another embodiment of the present invention.

FIG. 6 is a diagram illustrating a cleaning unit of a transfer belt 62 of an image forming apparatus according to still another embodiment of the invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Photoreceptor drum 6 Transfer unit 13 Cleaning unit 14 Cleaning blade 15 Housing part 31 Control part 61 A pair of rollers 62 Transfer belt 71 Cleaning bias roller S1-S6 Sensor

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 2H027 DA09 DA11 DA14 DA27 DA45 DA47 DC03 DC05 DC11 DC14 DC19 DC20 DE02 DE07 DE10 EA03 EC10 ED10 ED17 ED24 ED30 EE02 HB01 HB05 HB13 HB16 HB19 2H032 AA05 BA03 BA18 CA30 CA02

Claims (10)

[Claims] 1. A transfer device mounted on an image forming apparatus, wherein the transfer device transfers a developer image formed on an image carrier included in the image forming device onto a recording material. A transfer member to which a transfer bias is applied facing the transfer member; cleaning means for cleaning a surface of the transfer member facing the image carrier; and an amount of the developer adhering to the surface of the transfer member. And a control unit for cleaning the facing surface of the transfer member by operating the cleaning unit based on the amount of developer adhesion predicted by the prediction unit. Transfer device. 2. The transfer device according to claim 1, wherein the predicting unit predicts an amount of the developer adhering to the opposite surface of the transfer member by managing a supply amount of the developer. . 3. The transfer apparatus according to claim 1, wherein the prediction unit predicts an amount of the developer adhered to the opposite surface of the transfer member by managing the number of times of image formation. 4. The image forming apparatus according to claim 1, wherein the predicting unit predicts an amount of the developer adhering to the opposite surface of the transfer member by managing an abnormal state of the image forming operation during the image forming. Item 2. The transfer device according to Item 1. 5. The transfer device according to claim 1, wherein the control unit includes a correction unit that corrects a developer adhesion amount predicted by the prediction unit in accordance with an operating environment of the transfer device. 6. The transfer device according to claim 5, wherein the correction unit corrects the estimated amount of the developer attached according to an installation environment of the transfer device. 7. The transfer apparatus according to claim 5, wherein the correction unit corrects the estimated amount of the developer attached in accordance with a transfer bias to a transfer member. 8. The transfer device according to claim 5, wherein the correction unit corrects the adhesion amount of the developer predicted according to the characteristics of the developer transferred by the transfer device. 9. The transfer apparatus according to claim 1, wherein the prediction unit includes a detection unit that detects an amount of the developer attached to the facing surface of the transfer member. 10. The transfer apparatus according to claim 9, wherein the detection means is a sensor, and the sensor is provided at a position separated from a source affecting the sensor.