JP2013142785A - Image forming apparatus and method for cleaning the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the occurrence of image deletion by efficiently removing toner adhered to a photoreceptor surface, paper powder and the like without damaging the photoreceptor surface.SOLUTION: An image forming apparatus 100 comprises: a cleaning part 8 having a brush roller 82 which abuts on a photoreceptor 1 to recover toner adhering to the photoreceptor 1 and a blade 85 which abuts on the photoreceptor 1 on the downstream side in the rotating direction of the brush roller 82 to polish and clean the surface of the photoreceptor 1 with a polishing material contained in the adhered toner; an acquisition part for acquiring a characteristic value of a predetermined factor causing an image failure; and a control part 90 for controlling to increase the amount of the adhered toner reaching the blade 85 by reducing the recovery amount of the adhered toner with the brush roller 82 as the characteristic value of the predetermined factor acquired by the acquisition part changes to cause an image failure.

Description

  The present invention relates to an image forming apparatus and a cleaning method for an image forming apparatus.

  Conventionally, an electrostatic latent image formed on a photoreceptor is developed with toner to form a toner image, the formed toner image is transferred to a sheet of paper, and the transferred toner image is heated and fixed on the sheet of paper. There is known an electrophotographic image forming apparatus for forming an image.

  In such an image forming apparatus, there is provided an image forming apparatus provided with a cleaning unit that collects or removes toner (hereinafter referred to as attached toner), paper dust, and the like attached on a photoreceptor after a toner image is transferred onto a recording sheet. Is provided. As such a cleaning unit, a brush roller that collects adhering toner by rotating while abutting on the surface of the photoconductor, abuts on the photoconductor downstream of the brush roller in the photoconductor rotation direction, and polishes the surface of the photoconductor And a blade or the like for cleaning (see, for example, Patent Document 1).

  In addition, a technique is also provided in which a pre-cleaning charger is provided in the cleaning portion so as to be opposed to the surface of the photoconductor on the upstream side of the photoconductor rotation direction with respect to the brush roller and the blade. In this case, since the pre-cleaning charger imparts a charge having a polarity opposite to that of the adhered toner to the adhered toner on the photosensitive member, the charge amount of the adhered toner is reduced, and the brush roller can more easily collect the adhered toner. Become.

Japanese Patent Laying-Open No. 2005-3769

  However, in the conventional image forming apparatus as described above, depending on the degree of use of the photoconductor and the brush roller, the use environment of the image forming apparatus and the setting conditions, the adhering toner, paper dust and discharge from the photoconductor. In some cases, the product or the like cannot be sufficiently removed. If paper dust or discharge products remain on the surface of the photoconductor, they adsorb moisture and cause image defects such as so-called image flow, in which the image flows blurry or rubbed. In order to cope with such image defects, the conventional image forming apparatus employs a method in which the rotation speed ratio of the brush roller to the photosensitive member is increased and the surface of the photosensitive member is strongly polished to remove adhering toner and paper dust. However, the brush roller may damage the surface of the photoreceptor. Further, such a method cannot sufficiently remove paper dust and the like adhering to the photoreceptor.

  Therefore, the present invention provides an image forming apparatus and an image forming apparatus cleaning method that can efficiently remove toner and paper dust attached to the surface of the photoconductor without damaging the surface of the photoconductor and suppress the occurrence of image flow. The purpose is to provide.

In order to solve the above problems, according to one aspect of the present invention,
A brush roller that contacts the photosensitive member and collects the attached toner that adheres to the photosensitive member, and a polishing member that contacts the photosensitive member at a downstream side of the brush roller in the rotation direction of the photosensitive member and is contained in the attached toner In an image forming apparatus comprising a cleaning unit having a blade for polishing and cleaning the surface of the photoreceptor with an agent,
An acquisition unit that acquires characteristic values of predetermined factors that cause image defects;
As the characteristic value of the predetermined factor acquired by the acquisition unit changes so as to cause an image defect, the amount of collected toner collected by the brush roller is reduced, whereby the adhered toner reaching the blade An image forming apparatus comprising: a control unit that controls the amount of the image to increase.

  Preferably, the predetermined factor is at least one of humidity, recording sheet conveyance speed, recording sheet coverage, usage history of the photosensitive member, and usage history of the brush roller.

  Preferably, the control unit reduces the speed ratio of the brush roller to the photoconductor as the characteristic value of the predetermined factor acquired by the acquisition unit changes so as to cause an image defect. The collection amount of the adhered toner by the brush roller is reduced.

Preferably, the apparatus further includes a pre-cleaning charger that opposes the photoconductor on the upstream side in the rotation direction of the photoconductor relative to the brush roller and imparts an electric charge to the attached toner.
The control unit changes the output value of the pre-cleaning charger as the characteristic value of the predetermined factor acquired by the acquisition unit changes so as to cause an image defect, whereby the adhesion by the brush roller is performed. Reduce the amount of toner collected.

  Preferably, the control unit sets the polarity of the output value of the pre-cleaning charger so that an image forming area where a toner image to be transferred onto a recording sheet is formed on the photoconductor and a toner image which is not transferred onto the recording sheet. It is different depending on the formed inter-image region.

According to another aspect of the invention,
A brush roller that contacts the photosensitive member and collects the attached toner that adheres to the photosensitive member, and a polishing member that contacts the photosensitive member at a downstream side of the brush roller in the rotation direction of the photosensitive member and is contained in the attached toner In a cleaning method of an image forming apparatus comprising a cleaning unit having a blade for polishing and cleaning the surface of the photoreceptor with an agent,
An acquisition step of acquiring a characteristic value of a predetermined factor causing an image defect;
As the characteristic value of the predetermined factor acquired in the acquisition step changes so as to cause an image defect, the amount of collected toner collected by the brush roller is reduced, thereby the adhesion reaching the blade And a method for controlling the amount of toner adhered to increase the amount of toner.

  According to the present invention, it is possible to efficiently remove toner, paper dust, and the like adhering to the surface of the photoconductor without damaging the surface of the photoconductor, thereby suppressing the occurrence of image flow.

1 is a schematic view showing an image forming apparatus according to the present invention. FIG. 2 is a schematic diagram illustrating a cleaning unit and its peripheral structure of the image forming apparatus in FIG. 1. It is a block diagram which shows control systems, such as a cleaning part. It is the schematic which shows the modification of an image forming apparatus. 6 is a graph showing the degree of occurrence of image flow when the humidity in the image forming apparatus is changed in Embodiment 1. 6 is a graph showing the degree of occurrence of image flow when the humidity in the image forming apparatus is changed in Comparative Example 1. 10 is a graph showing the degree of occurrence of image flow when the recording paper conveyance speed is changed in Example 2. 9 is a graph showing the degree of occurrence of image flow when the recording paper conveyance speed is changed in Comparative Example 2. In Example 3, it is a graph which shows the grade of generation | occurrence | production of an image flow when the coverage of the image formed is changed. In Comparative Example 3, it is a graph showing the degree of occurrence of image flow when the coverage of the image to be formed is changed. In Example 4, it is a graph which shows the grade of generation | occurrence | production of an image flow when the travel time of a photoconductor is changed. In Comparative Example 4, it is a graph showing the degree of occurrence of image flow when the running time of the photoconductor is changed. In Example 5, it is a graph which shows the grade of generation | occurrence | production of an image flow when the travel time of a brush roller is changed. In comparative example 5, it is a graph which shows the grade of generation | occurrence | production of image flow when the travel time of a brush roller is changed. 10 is a graph showing the degree of occurrence of image flow when the humidity in the image forming apparatus is increased in Example 6.

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated using drawing. However, although various technically preferable limitations for implementing the present invention are given to the embodiments described below, the scope of the invention is not limited to the following embodiments and illustrated examples.

FIG. 1 is a schematic configuration diagram of an image forming apparatus 100 according to the present invention.
The image forming apparatus 100 is an image forming apparatus including an image reading device 71 and an automatic document feeder 72, and forms an image on the recording sheet S conveyed by the sheet conveying system 7 by the image forming unit 10 and the fixing unit 9. .

  The document d placed on the document table of the automatic document feeder 72 is scanned and exposed by the optical system of the scanning exposure device of the image reading device 71 and read into the image sensor CCD. The analog signal photoelectrically converted by the image sensor CCD is subjected to analog processing, A / D conversion, shading correction, image compression processing, and the like in the image processing unit 20 and then input to the exposure device 3 of the image forming unit 10. The

  The paper transport system 7 includes a plurality of trays 16, a plurality of paper feeding units 11, a transport roller 12, a transport belt 13, and the like. The tray 16 accommodates recording paper S of a determined size, and operates the paper supply unit 11 of the tray 16 determined according to an instruction from the control unit 90 to supply the recording paper S. The transport roller 12 transports the recording paper S sent out from the tray 16 by the paper feeding unit 11 or the recording paper S carried in from the manual paper feeding unit 15 to the image forming unit 10.

  The image forming unit 10 includes a charger 2, an exposure unit 3, a developing unit 4, a transfer unit 5, a charge removal unit 6, and a cleaning unit 8 in this order around the photoconductor 1 along the rotation direction of the photoconductor 1. Arranged and configured.

A photoconductor 1 as an image carrier is an image carrier having a photoconductive layer formed on the surface thereof, and is configured to be rotatable in a direction of an arrow in FIG. 1 by a driving device (not shown). A thermohygrometer 17 that detects the temperature and humidity in the image forming apparatus 100 is provided in the vicinity of the photoreceptor 1.
The charger 2 uniformly charges the surface of the photoreceptor 1 and charges the surface of the photoreceptor 1 uniformly. The exposure device 3 includes a beam emission source such as a laser diode, and the charged surface of the photosensitive member 1 is irradiated with beam light so that the charge on the irradiated portion disappears. An electrostatic latent image is formed. The developing unit 4 supplies toner contained therein to the photoconductor 1 to form a toner image on the surface of the photoconductor 1. The toner contained in the developing unit 4 contains an abrasive as an additive. Such an abrasive is contained in the toner in an amount of 0.05 to 1.5% by weight, and a titanate compound having an average primary particle size of 0.1 to 1.0 μm, particularly a metal titanate salt compound. Some calcium titanate, magnesium titanate, strontium titanate, barium titanate, aluminum titanate, zirconium titanate, sodium titanate and the like are used. The transfer unit 5 and the charge eliminating unit 6 face the photoconductor 1 through the recording paper S, transfer the toner image formed on the photoconductor 1 to the recording paper S, and the photoconductor after transferring the toner image. Perform static elimination on 1. The cleaning unit 8 cleans the surface of the photoreceptor 1 and removes toner remaining on the surface of the photoreceptor 1.
The recording sheet S to which the toner image is transferred is conveyed to the fixing unit 9 by the conveying belt 13.

  The fixing unit 9 applies heat and pressure to the recording paper S to which the toner image has been transferred by a fixing roller and a pressure roller to perform heat fixing processing, thereby fixing the image on the recording paper S. The recording sheet S on which the image is fixed is transported to the paper discharge unit 14 by the transport roller, and is discharged from the paper discharge unit 14 to the outside of the apparatus.

  Further, the image forming apparatus 100 includes a sheet reversing unit 24, and the recording sheet S that has been heat-fixed is conveyed to the sheet reversing unit 24 before the paper discharge unit 14, and is discharged with the front and back reversed. Alternatively, the recording sheet S with the front and back reversed can be conveyed again to the image forming unit 10 to form an image on both sides of the recording sheet S.

  An operation display unit 21 is provided in the upper part of the image forming apparatus 100, and the user can set the size and number of sheets of recording paper S when performing image formation from the operation display unit 21.

  The control unit 90 controls each unit of the image forming apparatus 100. The control unit 90 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), and a ROM (Read Only Memory) (not shown), and performs various operations according to various processing programs for the image forming apparatus 100.

Here, the cleaning unit 8 according to the present invention will be described below with reference to FIG.
The cleaning unit 8 is a PCC (pre-cleaning charger) 81 provided facing the photoconductor 1, and a brush roller 82 provided in contact with the photoconductor 1 on the downstream side in the rotation direction of the photoconductor 1 with respect to the PCC 81. , A collection roller 83 provided in contact with the brush roller 82, a scraper 84 provided with the tip in contact with the collection roller 83, and a tip at the downstream side in the rotation direction of the photoconductor 1 with respect to the brush roller 82. 1, a blade 85 provided in contact with the housing 1, a housing 86 that accommodates each member other than the PCC 81, a screw 87 provided at the bottom of the housing 86 and vertically below the collection roller 83 and the scraper 84, Etc.

The PCC 81 is a corotron type charger, and a predetermined constant current power source (not shown) is connected to the electrode thereof, and the application timing and the amount of current are controlled by the control unit 90. The PCC 81 imparts a charge having a polarity opposite to that of the attached toner to the attached toner on the photoconductor 1, thereby reducing the charge amount of the attached toner and facilitating the toner collection by the brush roller 82. That is, when the toner adhering on the photoreceptor 1 is negatively charged, the PCC 81 gives a positive charge to the toner adhering, and the toner adhering on the photoreceptor 1 is positively charged. The PCC 81 gives a negative charge to the adhered toner.
Note that the control unit 90 determines the polarity of the current applied to the PCC 81 on the image forming area where the toner image to be transferred to the recording paper S is formed on the photoconductor 1 and on the recording paper S on the photoconductor 1. It is different depending on the inter-image area where a toner image that is not transferred is formed. The toner image formed in the inter-image area and not transferred onto the recording paper S tries to continuously consume a certain amount of toner for the purpose of preventing deterioration of the toner stored in the developing unit 4. In this case, it is a belt-like toner image formed on the photoreceptor 1. Since the toner image is removed by the cleaning unit 8 without being transferred onto the recording paper S, no charge is applied by the transfer unit 5 and the polarity of the charge is different from that of the toner image in the image forming region. Therefore, in such a case, the control unit 90 makes the polarities of the current applied to the PCC 81 different between the image forming area and the inter-image area.

  The brush roller 82 is disposed so as to face the surface of the photoreceptor 1 and is configured to be rotatable in the direction of the arrow in FIG. 2 by a driving device (not shown). The brush roller 82 is configured by planting a plurality of elastic conductive fibers on the surface of the rotating member. Further, the brush roller 82 is connected to a predetermined power source (not shown), and a current having a polarity opposite to that of the toner adhering to the photoreceptor 1 is applied. Thereby, the toner adhering on the photoreceptor 1 can be electrically captured by the conductive fibers on the brush roller 82.

  The collection roller 83 is disposed so as to face the brush roller 82 and is configured to be rotatable by a driving device (not shown). The collection roller 83 is connected to a predetermined power source (not shown), and a current having a polarity opposite to that of the toner adhering to the photoreceptor 1 is applied. The amount of current applied to the collection roller 83 is a current having a larger absolute value than the amount of current applied to the brush roller 82 so that a current difference occurs with the brush roller 82. Thereby, the toner captured by the brush roller 82 can be collected on the surface of the collection roller 83.

  The scraper 84 is fixed in the housing 86 with its tip end pressed against the surface of the collection roller 83. When the collection roller 83 is driven to rotate, the toner collected on the collection roller 83 and attached on the surface is scraped off by the scraper 84.

  The blade 85 is an elastic member provided with its tip portion in contact with the photoreceptor 1. Since the toner contained in the developing unit 4 of the image forming apparatus 100 contains an abrasive as an additive, the friction coefficient of the blade 85 is increased when the toner containing the abrasive is collected at the tip of the blade 85. The photosensitive member 1 is polished by lowering. The blade 85 polishes the surface of the photoconductor 1 in this manner, thereby scraping off the adhering toner remaining on the photoconductor 1 and removing adhering substances such as paper powder other than the adhering toner. The toner scraped off from the photoreceptor 1 by the blade 85 falls on the brush roller 82 or the screw 87 and is collected.

  The housing 86 accommodates the brush roller 82, the recovery roller 83, the scraper 84, the blade 85, and the like described above, and a screw 87 is provided at the bottom of the housing 86. The casing 86 is formed in such a shape that the inner wall tapers toward the screw 87 provided at the bottom so that the toner falling from each member is conveyed to the screw 87 provided at the bottom of the casing 86. preferable.

  The screw 87 is configured to be rotatable in a predetermined direction by a driving device (not shown), and collects toner that has dropped from above. The screw 87 conveys the collected toner to the developing unit 4 via a toner recycling device (not shown) or stores it in a waste toner box (not shown).

The cleaning unit 8 configured as described above is controlled by the control unit 90 described above.
In addition, the control unit 90 functions as an acquisition unit in the present invention, and acquires a characteristic value of a predetermined factor that causes an image defect such as image flow in an image formed on the recording paper S. Here, the predetermined factors that cause image defects include the conveyance speed of the recording paper S, the coverage of the image formed on the recording paper S, the usage history of the photoreceptor 1, the usage history of the brush roller 82, and the like. Can be mentioned. The usage history refers to the travel time, travel distance, rotation speed, etc. of the photoreceptor 1 or the brush roller 82.

  If the predetermined factor causing the image defect is the conveyance speed of the recording paper S, the control unit 90 reads and acquires a preset conveyance speed of the recording paper S. When the predetermined factor is the coverage of the image formed on the recording paper S, the control unit 90 calculates and acquires the coverage of the image on the recording paper S based on the image data. When the predetermined factor is the usage history of the photosensitive member 1 or the brush roller 82, the control unit 90 counts the traveling time, the traveling distance, the rotational speed, etc. of the photosensitive member 1 or the brush roller 82 in advance. Is read and acquired.

  In addition, as an acquisition part which acquires the predetermined factor which causes an image defect, the control part 90 does not need to have a function of an acquisition part, and the predetermined acquisition part which can acquire the characteristic value of each factor May be provided separately from the control unit 90.

  Further, the predetermined factor causing the above-described image defect may be humidity in the image forming apparatus 100. The humidity is acquired by a thermohygrometer 17 provided in the vicinity of the photoreceptor 1 as an acquisition unit. Note that the image forming apparatus 100 may further include a thermohygrometer that acquires the humidity outside the image forming apparatus 100. In that case, a predetermined defect that causes an image defect in consideration of humidity outside the apparatus. The characteristic value of the factor can be determined.

  When the characteristic value of the predetermined factor causing the image defect described above varies, it becomes difficult to remove paper dust and the like on the photoreceptor 1, and image defects such as image flow are likely to occur. That is, when the humidity in the image forming apparatus 100 is increased, the conveyance speed of the recording paper S is low, the coverage of the image formed on the recording paper S formed immediately before is low, the usage of the photoreceptor 1 Is large, when the usage of the brush roller 82 is small, paper dust or the like on the photoreceptor 1 is not removed, and image defects are likely to occur.

The control unit 90 acquires a characteristic value of a predetermined factor that causes an image defect, and reduces the amount of toner collected by the brush roller 82 as the value changes to a tendency to cause the image defect. Examples of a method for reducing the amount of toner collected by the brush roller 82 include reducing the speed ratio of the brush roller 82 to the photoreceptor 1 or changing the output value of the PCC 81. By doing either of these, the amount of toner collected by the brush roller 82 can be reduced. However, by doing both of these, the amount of toner collected by the brush roller 82 can be further reduced. It is.
Note that the control unit 90 may acquire one of the predetermined factors that cause the image defect described above and control the collected amount of adhered toner by the brush roller 82. A plurality of them may be acquired to control the amount of collected toner collected by the brush roller 82.

  The controller 90 reduces the amount of toner deposited by the brush roller 82 as the value of a predetermined factor that causes image failure changes to a tendency to cause image failure. The remaining amount increases. As a result, the amount of adhering toner that reaches the contact portion between the blade 85 and the photoreceptor 1 is increased, and the amount of the abrasive contained in the adhering toner is also increased, so that the polishing force by the blade 85 is improved. This makes it possible to efficiently remove paper dust and the like adhering to the photoconductor 1 by the blade 85 even under image forming conditions and environments where it is difficult to remove paper dust and the like from the photoconductor 1. .

  As described above, according to the present embodiment, the characteristic value of the predetermined factor that causes the image defect is acquired, and the characteristic value of the predetermined factor changes so as to cause the image defect. By reducing the collection amount, the amount of attached toner to be brought into contact with the blade 85 is adjusted. Therefore, the amount of attached toner that reaches the blade 85 can be increased as image defects are likely to occur. As a result, the amount of abrasive supplied to the tip of the blade 85 can be increased, and the polishing force by the blade 85 can be increased only when image defects are likely to occur. Therefore, regardless of the conditions for image formation, the toner adhering to the photoreceptor 1, paper dust, and the like can be efficiently removed, and the occurrence of image defects can be suppressed. Further, since the polishing force by the blade 85 is increased only under conditions where image defects are likely to occur, the amount of use of the blade 85 is not increased excessively, and deterioration of the blade 85 can be suppressed.

  Further, the predetermined factor that causes the image defect is at least one of humidity, recording paper conveyance speed, coverage of the image formed on the recording paper, usage history of the photoreceptor 1, and usage history of the brush roller 82. Therefore, the characteristic value of the predetermined factor can be measured easily and accurately, and the occurrence of image defects can be efficiently suppressed.

  Further, the amount of toner collected by the brush roller 82 is reduced by reducing the speed ratio of the brush roller 82 to the photosensitive member 1 as the characteristic value of the predetermined factor obtained changes so as to cause image defects. Therefore, it is possible to easily control the toner collection amount.

  Further, as the characteristic value of the acquired predetermined factor changes so as to cause an image defect, the toner collection amount by the brush roller 82 is decreased by changing the output value of the PCC 81. Control can be easily performed.

  Further, the polarity of the charge applied by the PCC 81 is different between the image forming area where the toner image transferred to the recording paper S on the photoreceptor 1 is formed and the inter-image area where the toner image is not formed on the recording paper S. Therefore, the amount of toner collected by the brush roller 82 can be controlled even when control is performed to form a toner image in the inter-image region in order to prevent toner deterioration.

  In the above-described embodiment, the amount of adhered toner collected by the brush roller 82 is adjusted by reducing the speed ratio of the brush roller 82 or changing the output value of the PCC 81. However, the present invention is not limited thereto. For example, the amount of adhered toner collected by the brush roller 82 may be adjusted by adjusting the amount of current applied to the brush roller 82.

<Modification>
Here, a modified example of the image forming apparatus 100A will be described with reference to FIG. FIG. 4 is a schematic configuration diagram illustrating an image forming apparatus 100A according to a modification.
Since configurations other than those described below are substantially the same as those of the image forming apparatus 100 of the above-described embodiment, the same configurations are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

  The image forming apparatus 100A according to the modification is a color image forming apparatus including image forming units 10Y, 10M, 10C, and 10K for each color of yellow Y, magenta M, cyan C, and black K as shown in FIG.

  The image forming apparatus 100A includes a transfer belt 60, and around the transfer belt 60, four sets of image forming units 10Y including yellow Y, magenta M, cyan C, and black K color toner image forming units are provided. 10M, 10C, and 10K are provided. In each of the image forming units 10Y, 10M, 10C, and 10K, Y, M, C, and K toner images are formed and transferred onto the transfer belt 60 in an overlapping manner. The transferred toner image is collectively transferred onto the recording paper S. The configurations of these image forming units 10Y, 10M, 10C, and 10K are substantially the same as those of the image forming unit 10 of the present embodiment described above.

  The transfer belt 60 is an endless belt and is stretched by a driving roller 61 and a plurality of tension rollers 62. The transfer belt 60 is configured to be rotatable in the direction of the arrow in FIG. The secondary transfer roller 63 faces the tension roller 62 via the transfer belt 60 and transfers the toner image transferred on the transfer belt 60 onto the recording paper S supplied by the paper transport system 7. The recording sheet S on which the toner image is transferred is conveyed to the fixing unit 9a.

  A cleaning unit 8a is provided in the vicinity of the transfer belt 60 configured as described above. In the cleaning unit 8a of the image forming apparatus 100A according to the modification, the PCC 81a is disposed to face the transfer belt 60, and the brush roller 82a and the blade 85a are provided in contact with the surface of the transfer belt 60. Other than that, the cleaning unit 8a is configured in the same manner as the cleaning unit 8 of the present embodiment described above.

  Accordingly, even in a color image forming apparatus including the transfer belt 60, it is possible to efficiently remove paper dust and the like on the transfer belt 60 by the cleaning unit 8a, and to suppress the occurrence of image defects.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these.
In the embodiment described below, an image forming apparatus of bizhub PRO1200 (manufactured by Konica Minolta Business Technologies) equipped with a cleaning unit having the same configuration as the cleaning unit 8 described above is used. As the photoreceptor 1 of the image forming apparatus 100, a photoreceptor having a curable surface layer made of an inorganic filler and a monomer was used. Further, the brush roller 82 of the image forming apparatus 100 is made of a material corresponding to B-TCF (manufactured by Teijin Ltd.) of low resistance (10 ¹ to 10 ⁵ Ω · cm), shape: loop, fine diameter: 10d. Density: 45 kf / inch, length: 362 mm, shaft diameter: φ12 mm, outer diameter: φ19.3 mm, hair length: 3.65 mm. The blade 85 of the image forming apparatus 100 is made of material: urethane rubber, hardness: 65 ° (JIS A), rebound resilience: 51%, length: 363.5 mm, thickness: 2 mm, free length: 9 mm. Was used. As the developer accommodated in the developing unit 4, a two-component developer composed of a 6 μm toner, a 60 μm carrier and the like prepared by a polymerization method is used, and the developer contains calcium titanate as an abrasive. Yes.

A predetermined number of sheets of recording paper (in this embodiment, European paper PROFI A4 is used in this embodiment) are passed continuously through the image forming apparatus 100, and the apparatus is left for 5 minutes. % Halftone images were formed and their image quality was evaluated. The number of recording sheets to be passed is 0, 1000, 2000, 3000, and no image is formed on the recording sheets to be passed (coverage 0%).
Note that the image quality was evaluated visually, and the degree of occurrence of image flow was represented by “1” to “5”. “5” indicates that no image flow occurs, and indicates that the occurrence of image flow becomes more prominent as it approaches “1”.

  In the first embodiment, the interior of the image forming apparatus when continuously passing recording paper is in a high temperature and high humidity environment (HH environment), in a normal temperature and normal humidity environment (NN environment), and in a low temperature and low humidity environment. The above evaluation was performed for each of the cases below (HH environment).

Further, in the first embodiment, the control unit 90 sets the output value of the PCC 81 and the speed ratio of the brush roller 82 to the photoreceptor 1 as follows as the humidity in the image forming apparatus 100 acquired by the thermohygrometer 17 increases. As shown in Table 1, the change control is performed.
As Comparative Example 1, the same evaluation as in Example 1 was performed without changing the output value of PCC 81 and the speed ratio of brush roller 82 to photoreceptor 1.
The result of Example 1 is shown in FIG. 5, and the result of Comparative Example 1 is shown in FIG.

  From FIG. 6, it can be seen that image flow tends to occur when the number of sheets passed exceeds 1000 in the HH environment. 5 and 6, according to the present embodiment, the output value of the PCC 81 and the speed ratio of the brush roller 82 are adjusted as the humidity increases, so that image flow is not generated even in an HH environment. It was confirmed that image formation can be performed.

  In Example 2, the humidity in the image forming apparatus 100 was not changed, and the conveyance speed of the recording paper was changed as follows. Otherwise, the evaluation was performed in the same manner as in Example 1.

  In Example 2, the above evaluation was performed for each of the cases where the conveyance speed of the recording paper when continuously passing the recording paper is 570 mm / sec, 460 mm / sec, and 330 mm / sec. .

In the second embodiment, the control unit 90 changes the output value of the PCC 81 and the speed ratio of the brush roller 82 to the photosensitive member 1 as shown in Table 2 below as the conveyance speed of the acquired recording sheet decreases. It was assumed that control was performed. When the recording paper conveyance speed is 460 mm / sec, as shown in Table 2, only the output value of the PCC 81 may be changed, or only the speed ratio of the brush roller 82 to the photoreceptor 1 is reduced. Also good.
As Comparative Example 2, the same evaluation as in Example 2 was performed without changing the output value of PCC 81 and the speed ratio of brush roller 82 to photoreceptor 1.
The result of Example 2 is shown in FIG. 7, and the result of Comparative Example 2 is shown in FIG.

From FIG. 8, it can be seen that when the conveyance speed of the recording paper is 330 mm / sec, image flow occurs immediately after the continuous paper feeding is started. 7 and 8, according to the present embodiment, the output value of the PCC 81 and the speed ratio of the brush roller 82 are adjusted as the recording paper conveyance speed decreases, so that the recording paper conveyance speed is low. It was also confirmed that image formation can be performed without causing image flow.
It has been confirmed that the occurrence of image flow can be suppressed even when only the output value of the PCC 81 or only the speed ratio of the brush roller 82 is adjusted when the conveyance speed of the recording paper is 460 mm / sec.

  In the third embodiment, the humidity in the image forming apparatus 100 is not changed, and image formation is performed with the coverage shown below on recording paper that is continuously passed. Otherwise, the evaluation was performed in the same manner as in Example 1.

  In the third embodiment, an image with a coverage of 25% is formed when an image is formed with a coverage of 0% (when no image is formed), an image with a coverage of 5% is formed on a recording sheet that is continuously passed. The above evaluation was performed for each case.

Further, in the third embodiment, the control unit 90 calculates the coverage of the image from the image data of the image formed on the recording sheet immediately before, and the output value of the PCC 81 and the brush according to the calculated coverage value. Control to change the speed ratio of the roller 82 to the photoreceptor 1 as shown in Table 3 below was performed.
As Comparative Example 3, the same evaluation as in Example 3 was performed without changing the output value of PCC 81 and the speed ratio of brush roller 82 to photoreceptor 1.
The result of Example 3 is shown in FIG. 9, and the result of Comparative Example 3 is shown in FIG.

  FIG. 10 shows that when the coverage is 0% (when image formation is not performed), image flow occurs when the number of sheets passing exceeds 1000. 9 and 10, according to the present embodiment, when the coverage is low, the output value of the PCC 81 and the speed ratio of the brush roller 82 are adjusted. Therefore, even when image formation with low coverage is performed, image flow is performed. It has been confirmed that image formation can be performed without generating the above.

  In Example 4, the humidity in the image forming apparatus 100 was not changed, and the running time of the photoreceptor 1 in the image forming apparatus 100 was changed as follows. Otherwise, the evaluation was performed in the same manner as in Example 1.

  In Example 4, the above evaluation was performed for each of the cases where the running time of the photosensitive member 1 immediately before starting the continuous passage of recording paper is 0h, 30h, 60h, and 100h. It was.

In the fourth embodiment, the control unit 90 acquires the travel time of the photosensitive member 1 stored in advance, and the output value of the PCC 81 and the brush roller 82 increase as the acquired travel time of the photosensitive member 1 increases. Control to change the speed ratio with respect to the photoreceptor 1 as shown in Table 4 below was performed. When the running time of the photosensitive member 1 is 30 to 60 h, as shown in Table 4, only the output value of the PCC 81 may be changed, or only the speed ratio of the brush roller 82 to the photosensitive member 1 is reduced. May be.
As Comparative Example 4, the same evaluation as in Example 4 was performed without changing the output value of the PCC 81 and the speed ratio of the brush roller 82 to the photoreceptor 1.
The result of Example 4 is shown in FIG. 11, and the result of Comparative Example 4 is shown in FIG.

From FIG. 12, when the running time of the photosensitive member 1 is 60 h, an image flow occurs when the number of passing sheets exceeds 1000, and when the running time is 100 h, continuous sheet feeding is started. It can be seen that image flow occurs immediately. Further, according to the present embodiment, the output value of the PCC 81 and the speed ratio of the brush roller 82 are adjusted as the traveling time of the photosensitive member 1 increases, so that the image flow can be obtained even when the traveling time of the photosensitive member 1 is large. It was confirmed that image formation can be performed without causing it to occur.
In addition, when the running time of the photosensitive member 1 is 30 to 60 h, it was confirmed that the occurrence of image flow can be suppressed even when only the output value of the PCC 81 is adjusted or only the speed ratio of the brush roller 82 is adjusted. .

  In Example 5, the humidity in the image forming apparatus 100 was not changed, and the running time of the brush roller 82 in the image forming apparatus 100 was changed as follows. Otherwise, the evaluation was performed in the same manner as in Example 1.

  In Example 5, the above evaluation was performed for each of the cases where the running time of the brush roller 82 immediately before starting continuous feeding of recording paper is 0h, 30h, 60h, and 100h. It was.

In the fifth embodiment, the control unit 90 acquires the travel time of the brush roller 82 stored in advance, and the output value of the PCC 81 and the sensitivity of the brush roller 82 according to the acquired travel time of the brush roller 82. Control to change the speed ratio with respect to the body 1 as shown in Table 5 below was performed.
As Comparative Example 5, the same evaluation as in Example 5 was performed without changing the output value of the PCC 81 and the speed ratio of the brush roller 82 to the photoreceptor 1.
The result of Example 5 is shown in FIG. 13, and the result of Comparative Example 5 is shown in FIG.

  From FIG. 14, when the running time of the brush roller 82 is 0 h, image flow occurs immediately after the start of continuous sheet passing, and when the running time is 30 h, the number of passing sheets is 1000 sheets. It can be seen that if it exceeds, image flow occurs. From FIG. 13 and FIG. 14, according to the present embodiment, when the travel time of the brush roller 82 is small, the output value of the PCC 81 and the speed ratio of the brush roller 82 are adjusted. It was confirmed that image formation can be performed without causing image flow even in a small case.

In the sixth embodiment, when high humidity is detected by the thermometer 17, the control unit 90 reduces the speed ratio of the brush roller 82 to the photosensitive member 1 to the limit, that is, stops the rotation of the brush roller 82. In the case where the image forming apparatus 100 is in an HH environment, the same evaluation as in Example 1 was performed.
The result of Example 6 is shown in FIG. 15 together with the result under the HH environment in Comparative Example 1 described above.

  From FIG. 15, it is confirmed that according to the present embodiment, even in an HH environment where image flow is likely to occur, image formation can be performed without causing image flow by stopping the rotation of the brush roller 82. It was done.

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charger 3 Exposure device 4 Developing part 5 Transfer part 6 Static elimination part 7 Paper conveyance system 8, 8a Cleaning part 9 Fixing part 10 Image formation part 11 Paper feed part 12 Conveyance roller 13 Conveyor belt 14 Paper discharge part 15 Manual feed Paper feed unit 16 Tray 17 Temperature / humidity meter (acquisition unit)
20 Image processing unit 21 Operation display unit 24 Paper reversing unit 60 Transfer belt 61 Driving roller 62 Tension roller 63 Secondary transfer roller 71 Image reading device 72 Automatic document feeder 81, 81a PCC (pre-cleaning charger)
82, 82a Brush roller 83 Collection roller 84 Scraper 85, 85a Blade 86 Housing 87 Screw 90 Control unit (acquisition unit)
100 Image forming apparatus d Document S Recording paper

Claims (6)

A brush roller that contacts the photosensitive member and collects the attached toner that adheres to the photosensitive member, and a polishing member that contacts the photosensitive member at a downstream side of the brush roller in the rotation direction of the photosensitive member and is contained in the attached toner In an image forming apparatus comprising a cleaning unit having a blade for polishing and cleaning the surface of the photoreceptor with an agent,
An acquisition unit that acquires characteristic values of predetermined factors that cause image defects;
As the characteristic value of the predetermined factor acquired by the acquisition unit changes so as to cause an image defect, the amount of collected toner collected by the brush roller is reduced, whereby the adhered toner reaching the blade An image forming apparatus comprising: a control unit that performs control so as to increase the amount of the image.   2. The predetermined factor is at least one of humidity, recording sheet conveyance speed, recording sheet coverage, usage history of the photosensitive member, and usage history of the brush roller. Image forming apparatus.   The control unit reduces the speed ratio of the brush roller to the photoconductor as the characteristic value of the predetermined factor acquired by the acquisition unit changes so as to cause an image defect, whereby the brush roller The image forming apparatus according to claim 1, wherein the amount of the adhered toner collected by the toner is reduced. A pre-cleaning charger that opposes the photoconductor on the upstream side in the rotational direction of the photoconductor relative to the brush roller and that imparts a charge to the adhered toner;
The control unit changes the output value of the pre-cleaning charger as the characteristic value of the predetermined factor acquired by the acquisition unit changes so as to cause an image defect, whereby the adhesion by the brush roller is performed. The image forming apparatus according to claim 1, wherein the toner collection amount is reduced.   The control unit is configured to form an image forming area in which a toner image transferred to a recording sheet is formed on the photosensitive member, and a toner image not transferred to the recording sheet. The image forming apparatus according to claim 4, wherein the image forming area is different from the image-to-image area. A brush roller that contacts the photosensitive member and collects the attached toner that adheres to the photosensitive member, and a polishing member that contacts the photosensitive member at a downstream side of the brush roller in the rotation direction of the photosensitive member and is contained in the attached toner In a cleaning method of an image forming apparatus comprising a cleaning unit having a blade for polishing and cleaning the surface of the photoreceptor with an agent,
An acquisition step of acquiring a characteristic value of a predetermined factor causing an image defect;
As the characteristic value of the predetermined factor acquired in the acquisition step changes so as to cause an image defect, the amount of collected toner collected by the brush roller is reduced, thereby the adhesion reaching the blade A method of cleaning an image forming apparatus, comprising: an adhering toner amount control step of increasing a toner amount.

Images