JP2009103739A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device which reduces the biased cleaning performance of a cleaning means, which cleans up a remained transfer developer, and also reduces the biased wear of an image carrier which is due to the friction between the image carrier and a cleaning member to form a quality which is satisfactory for image, in a recording medium and can prolong the service life of the image carrier. <P>SOLUTION: The image forming device is provided with an image carrier on which a developer image is formed; an image transfer material which transfers the developer image from the image carrier to a recording medium; a cleaning means which makes the remaining transfer developer contact the image carrier, to clean it up, after the transfer developer is transferred from the image carrier to the recording medium; a plurality of frictional force measuring means which measure the frictional force between the cleaning means and the image carrier; and a control means which controls to form a prescribed developer image on the image carrier and cleans with the cleaning means, without transferring the formed image to the recording medium. The image forming device determines the developer image, which is formed on the image carrier by means of the control means, according to the measured frictional force measured by the plurality of frictional force measuring means. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image forming apparatus.

  Conventionally, in an electrophotographic apparatus in which an electrostatic latent image formed on a photosensitive drum by exposure with a laser beam is developed with toner and transferred to a transfer sheet, the image is transferred to the transfer sheet. A cleaning member that removes untransferred toner adhering to the photosensitive drum from the photosensitive drum while contacting the surface of the photosensitive drum, a vibration detection unit that detects vibration of the cleaning member, and the vibration detection Compares the amplitude of the detected vibration from the means with a predetermined amplitude, which is a preset amplitude immediately before the occurrence of abnormal noise, and outputs the vibration suppression control signal when the detected vibration amplitude exceeds the predetermined amplitude Vibration suppression for exposing a specific pattern for vibration suppression of the cleaning member to the photosensitive drum based on an amplitude suppression control signal from the comparison unit and the amplitude comparison unit Electrophotographic apparatus is characterized by providing a control means is known (see Patent Document 1).

Japanese Patent No. 3126609

  An object of the present invention is to form an electrostatic latent image, develop the electrostatic latent image with a developer, and contact the image carrier on which the developer image is formed. Reduce the bias of the cleaning performance of the cleaning means for cleaning the residual transfer developer after the developer image is transferred to the medium, reduce the uneven wear of the image carrier due to the friction between the image carrier and the cleaning member, An object of the present invention is to provide an image forming apparatus capable of improving the image quality of an image formed on a recording medium and extending the life of an image carrier.

  According to a first aspect of the present invention, there is provided an image carrier on which an electrostatic latent image is formed and the electrostatic latent image is developed with a developer to form a developer image, and the image carrier to the recording medium. An image transfer body for transferring a developer image; and a cleaning means for cleaning the residual transfer developer after the developer image has been transferred from the image holding body to the recording medium by contacting the image holding body; A plurality of frictional force measuring means for measuring the frictional force between the cleaning means and the image holding body, and the cleaning means without forming a predetermined developer image on the image holding body and transferring it to the recording medium. Control means for controlling the developer image, and determining the developer image to be formed on the image holding body by the control means according to the measured friction force measured by the plurality of friction force measurement means. The image forming apparatus.

  According to a second aspect of the present invention, there is provided a first storage unit that stores an initial friction force that is each initial friction force measured by the plurality of friction force measurement units, and each of the measurement units measured by the plurality of friction force measurement units. A first calculation unit that calculates a difference between the measured friction force and each initial friction force for each of the friction force measurement units, and a difference between the friction forces calculated by the first calculation unit is the plurality of friction force measurement units. A first comparison unit that compares the image holding body with the control unit when a comparison value between the plurality of frictional force measurement units compared by the first comparison unit is equal to or greater than a predetermined value. The image forming apparatus according to claim 1, wherein the developer image to be formed is determined.

  According to a third aspect of the present invention, the difference between the second calculation unit that calculates the variation amount of each measured friction force measured by the plurality of friction force measurement units and the variation amount calculated by the second calculation unit is calculated. A second comparison unit that compares the plurality of friction force measurement means, and a comparison value between the plurality of friction force measurement means compared by the second comparison unit is equal to or greater than a predetermined value. The image forming apparatus according to claim 1, wherein the developer image formed on the image holding member is determined by a control unit.

  According to a fourth aspect of the present invention, there is provided a second storage unit that stores a natural frequency of the cleaning unit and a natural vibration state corresponding to the natural frequency, and each measurement measured by the plurality of frictional force detection units. A third calculation unit that calculates the frequency of the frictional force fluctuation; and a third comparison unit that compares the frequency calculated by the third calculation unit and the natural frequency. The development formed on the image carrier by the control means when the compared frequency is the natural frequency and the natural vibration mode corresponding to the natural frequency is a predetermined natural mode. The image forming apparatus according to claim 1, wherein an agent image is determined.

  According to a fifth aspect of the present invention, the control means is configured such that an area of the image carrier having a large measured frictional force among the measured frictional forces measured by the plurality of frictional force measuring means is the other image holding. 5. The image forming apparatus according to claim 1, wherein the developer image is formed so as to be developed with a large amount of developer on a body region.

  According to a sixth aspect of the present invention, the control unit forms a predetermined developer image on the image carrier and transfers the developer image to the recording medium or transfer body. At the time of the transfer, the control unit and the image carrier 6. The image transfer body or a peripheral speed with the transfer body is changed, and the residual transfer developer after the transfer is controlled to be cleaned by the cleaning means. The image forming apparatus described.

  The invention described in claim 7 is characterized in that the plurality of frictional force measuring units measure the measured frictional force based on a measurement value measured by a measuring unit that measures the displacement of the cleaning unit. The image forming apparatus according to claim 1.

  According to the first aspect of the present invention, the unevenness of the cleaning performance of the cleaning means is reduced as compared with the case where the present configuration is not provided, and uneven wear of the image holding member due to friction between the image holding member and the cleaning member is reduced. This can reduce the image quality of the image formed on the recording medium and extend the life of the image carrier.

  According to the invention described in claim 2, similarly, the bias of the cleaning performance of the cleaning means is reduced as compared with the case where the present configuration is not provided, and the image holding member is caused by friction between the image holding member and the cleaning member. Uneven wear can be reduced, the quality of the image formed on the recording medium can be improved, and the life of the image carrier can be extended.

  According to the invention described in claim 3, similarly, the bias of the cleaning performance of the cleaning means is reduced as compared with the case where the present configuration is not provided, and the image holding member is caused by friction between the image holding member and the cleaning member. Uneven wear can be reduced, the quality of the image formed on the recording medium can be improved, and the life of the image carrier can be extended.

  According to the invention described in claim 4, similarly, the bias of the cleaning performance of the cleaning means is reduced as compared with the case where the present configuration is not provided, and the image holding member is caused by friction between the image holding member and the cleaning member. Uneven wear can be reduced, the quality of the image formed on the recording medium can be improved, and the life of the image carrier can be extended.

  According to the fifth aspect of the present invention, similarly, the bias of the cleaning performance of the cleaning unit is reduced as compared with the case where the present configuration is not provided, and the image holding member is caused by friction between the image holding member and the cleaning member. Uneven wear can be reduced, the quality of the image formed on the recording medium can be improved, and the life of the image carrier can be extended.

  According to the invention described in claim 6, similarly, the bias of the cleaning performance of the cleaning means is reduced as compared with the case where the present configuration is not provided, and the image holding member is caused by friction between the image holding member and the cleaning member. Uneven wear can be reduced, the quality of the image formed on the recording medium can be improved, and the life of the image carrier can be extended.

  According to the seventh aspect of the invention, similarly, the bias of the cleaning performance of the cleaning unit is reduced as compared with the case where the present configuration is not provided, and the image holding member is caused by friction between the image holding member and the cleaning member. Uneven wear can be reduced, the quality of the image formed on the recording medium can be improved, and the life of the image carrier can be extended.

  Embodiments of the present invention will be described below with reference to the drawings.

[First embodiment]
1 to 6 are diagrams illustrating a first embodiment of an image forming apparatus according to the present invention.

  FIG. 1 is a schematic diagram illustrating an image forming apparatus according to the present embodiment. As shown in FIG. 1, the image forming apparatus 1 forms a toner image (developer image) based on image information in an apparatus main body (not shown) and finally forms the toner image on a sheet (recording medium). An image forming apparatus 10 for transferring the toner image to the image forming apparatus 10, a fixing apparatus 30 for fixing the toner image by passing the sheet 9 on which the toner image is transferred, and a paper feeding apparatus 35 for supplying the sheet 9 to the image forming apparatus 10. Equipped. Reference numeral 4 in the drawing is a first control device that comprehensively controls the operation and the like of each component of the image forming apparatus 1.

  The image forming apparatus 10 can form and transfer a toner image using a known electrophotographic system, for example. Specifically, a cylindrical photosensitive drum 12 (image holding member) that is rotationally driven in the direction of arrow A is provided, and the surface of the photosensitive drum 12 is uniformly charged around the photosensitive drum 12. From a charging device 13 provided with a charging roll, an LED array that irradiates light based on image information (signal) on the surface of the photosensitive drum 12 after charging, and forms an electrostatic latent image having a potential difference, a laser scanning device, and the like An exposure device 14, a developing device 15 for transferring and adhering toner (developer) to the electrostatic latent image to form a toner image, and a transfer roll (transferring the toner image onto the paper 9 supplied from the paper supply device 35. A transfer device 16 provided with an image transfer member 16a and the like; a cleaning blade 51 (cleaning means) that cleans toner (residual transfer developer) remaining on the surface of the photosensitive drum 12 after transfer by contacting the photosensitive drum 12; Have A cleaning device 50 and a plurality of friction force measuring device (frictional force measuring means) for measuring the frictional force between the photosensitive drum 12 and the cleaning blade 51 60, are predominantly located.

  Among these, the photosensitive drum 12 is obtained by forming a photoconductive layer (photosensitive layer) made of an organic photosensitive material on a drum-shaped base material (conductive support). The charging device 13 is installed such that a charging roll formed by forming a semiconductive elastic layer or the like on a conductive roll base material (conductive support) is brought into contact with the surface of the photosensitive drum 12 and rotated. In addition, a predetermined charging voltage is applied to the charging roll from a power supply device (not shown). The exposure device 14 is obtained by subjecting image information input from an external device such as a document reading device or a computer connected or equipped to the image forming apparatus 1 to an image processing apparatus (not shown) during image formation. An image signal is input.

  Further, the developing device 15 is equipped with a developing roll for transporting and supplying the contained toner to a developing position facing the photosensitive drum 12, and a predetermined power is supplied to the developing roll from a power supply device (not shown). The developing voltage is applied. The transfer device 16 is installed so that a transfer roll formed by forming a semiconductive elastic layer on a conductive roll base material is brought into contact with the surface of the photosensitive drum 12 and is driven to rotate. A predetermined transfer voltage is applied to a power source device (not shown).

  The cleaning device 50 includes a cleaning blade 51 whose tip is in contact with the surface of the photosensitive drum 12 after transfer at a predetermined pressure, and a blade support member 52 that supports the cleaning blade 51.

  The frictional force measuring device 60 is detected by a plurality of frictional force detecting members 61 provided on the cleaning blade 51 of the cleaning device 50 and detecting a frictional force between the photosensitive drum 12 and the cleaning blade 51, and a plurality of frictional force detecting members 61. It comprises a plurality of friction force measuring units 62 provided corresponding to each friction force detecting member 61 that measures the friction force between the photosensitive drum 12 and the cleaning blade 51 based on the detected value.

  The fixing device 30 includes a heating roll 32 that is heated to a predetermined temperature and is driven to rotate in the direction of the arrow, and a pressurization that is driven to rotate along the axial direction of the heating roll 32. A pressure member 33 such as a roll is provided. Fixing is performed by heating and pressurizing the toner image and the like by introducing and passing the sheet 9 on which the toner image is transferred to the pressure contact portion between the heating roll 32 and the pressure member 33.

  The paper feeding device 35 is a paper feeding cassette 36 in which a plurality of paper sheets 9 to be supplied to the image forming device 10 are stacked and stored, and a feeding mechanism that sends out the paper 9 stored in the paper feeding cassette 36 one by one. 37 is mainly provided. A plurality of paper feed cassettes 36 are provided as necessary. Further, the paper feeding device 35 is a pair of paper transporting rollers 38a, 38b, 38c,... For transporting the paper 9 from the paper feeding cassette 36 to the transfer section (between the photosensitive drum 12 and the transfer device 16) of the image forming device 10. And a paper conveyance path composed of guide members and the like. The sheet conveyance path is also provided between the image forming device 10 and the fixing device 30 and between the fixing device 30 and the paper discharge unit (tray or the like) 39. For example, on the paper discharge side of the fixing device 30, a discharge roll pair 38 d for discharging and transporting the fixed paper 9 to the paper discharge unit 39 is installed.

  Reference numeral 11 in the figure denotes a process cartridge that is detachable from the image forming apparatus 1. The process cartridge 11 in this embodiment includes process devices such as a photosensitive drum 12, a charging device 13, a developing device 15, and a cleaning device 50.

  Reference numeral 70 in the figure denotes an arithmetic unit (third arithmetic unit) that calculates the frequency of each frictional force (measured frictional force) variation measured by a plurality of frictional force measuring devices 60.

  Reference numeral 72 in the drawing denotes a storage unit (second storage unit) that stores a natural frequency of the cleaning blade 51 of the cleaning device 50 and a natural vibration mode (appearance) corresponding to the natural frequency.

  Reference numeral 74 in the figure is a comparison unit (third comparison unit) that compares the frequency calculated by the calculation unit 70 with the natural frequency stored in the storage unit 72.

  Reference numeral 76 in the figure denotes the natural vibration mode stored in the storage unit 72 corresponding to the natural frequency when the frequency compared by the comparison unit 74 is the natural frequency stored in the storage unit 72. Is a predetermined natural vibration mode, a second control for controlling the first control device 4 to clean the cleaning device 50 without forming a predetermined toner image on the photosensitive drum 12 and transferring it to the paper 9. Device (control means).

  FIG. 2 is a perspective view showing an arrangement example of the frictional force detection members in the present embodiment.

  The photosensitive drum 12 is formed in a long cylindrical shape and is driven to rotate in the direction of arrow A.

  The cleaning blade 51 is formed in a long plate shape, and is disposed so that the longitudinal direction thereof is substantially parallel to the axis of the photosensitive drum 12 and the front end thereof contacts the surface of the photosensitive drum 12 at a predetermined angle. The predetermined angle is a tangent to the photosensitive drum 12 at a portion where the tip of the cleaning blade 51 contacts the surface of the cleaning blade 51 on the photosensitive drum 12 side (the back surface of the cleaning blade 51) and the surface of the photosensitive drum 12. Is an acute angle.

  Three frictional force detection members 61 are provided on the surface of the cleaning blade 51. The three frictional force detection members 61 are a first frictional force detection member 61a, a second frictional force detection member 61b, and a third frictional force detection member 61c from the left end. The ratio of the interval W1 between the first frictional force detection member 61a and the second frictional force detection member 61b and the interval W2 between the second frictional force detection member 61b and the third frictional force detection member 61c is, for example, specific to the secondary mode. It is about 1: 3 for detecting the frequency.

  The frictional force detection member 61 may be any member that can detect the frictional force between the photosensitive drum 12 and the cleaning blade 51, and examples thereof include a strain gauge, a load cell, and a vibration pickup.

  The frictional force detection member 61 may be a measuring device (measuring unit) that measures the displacement of the cleaning blade 51 of the cleaning device 50, and includes a laser displacement meter. In the case where a measuring device is applied as the frictional force detecting member 61, the frictional force measuring unit 62 determines the frictional force (measured frictional force) between the photosensitive drum 12 and the cleaning blade 51 based on the measured value measured by the measuring device. Measure.

  FIG. 3 is a graph showing a relationship between the arrangement position (detection position) of the frictional force detection member with respect to the cleaning blade and the frictional force measured by the frictional force measuring device in the present embodiment.

  The graph showing the relationship between the lowest detection position and the frictional force is when the photosensitive drum 12 is stationary.

  The graph showing the relationship between the middle detection position and the frictional force is when the image forming apparatus 10 forms a toner image based on the image information and finally transfers the toner image onto the paper 9 when normal. .

  The graph showing the relationship between the uppermost detection position and the frictional force is when the image forming apparatus 10 forms a toner image based on image information and finally transfers the toner image to the paper 9 when abnormal. .

  At the time of abnormal operation, the frictional force fluctuation (vibration) occurs in the middle of the detection position direction as compared with the normal operation.

  As a factor that causes the frictional force fluctuation (vibration), for example, the discharge product generated by the discharge between the charging device 13 and the photosensitive drum 12 is deliquescent, and the friction between the photosensitive drum 12 and the cleaning blade 51 occurs. For example, the force increases and stick slip occurs between the photosensitive drum 12 and the cleaning blade 51.

  When frictional force fluctuation (vibration) occurs, toner and external additives are unevenly distributed between the photosensitive drum 12 and the cleaning blade 51, and the wear amount is unevenly generated on the surface of the photosensitive drum 12.

  FIG. 4 is a graph showing the relationship between the frictional force fluctuation frequency and the frictional force (amplitude) between the photosensitive drum and the cleaning blade in this embodiment.

  The fluctuation of the frictional force between the photosensitive drum 12 and the cleaning blade 51 increases when the cleaning blade 51 vibrates at a natural frequency (frequency).

  The frequency at the time of abnormal operation in FIG. 3 may be the natural frequency of the cleaning blade 51.

  FIG. 5 is a graph showing an example of the natural vibration mode of the cleaning blade derived from the relationship between the arrangement position (detection position) of the frictional force detection member with respect to the cleaning blade and the frictional force measured by the frictional force measuring device in the present embodiment. It is.

  In the natural vibration mode of the cleaning blade 51, the frequency of the frictional force detected by the first frictional force detection member 61a, the second frictional force detection member 61b, and the third frictional force detection member 61c is the natural vibration of the cleaning blade 51. The amplitude of the friction force detected by the first friction force detection member 61a and the third friction force detection member 61c is small, and the amplitude of the friction force detected by the second friction force detection member 61b is large. .

  FIG. 6 is a perspective view illustrating an example of an electrostatic latent image formed on the photosensitive drum by the second control device according to the present embodiment controlling the first control device.

  The electrostatic latent image formed on the photosensitive drum 12 by the second control device 76 controlling the first control device 4 has a large measured friction force among the measured friction forces measured by the plurality of friction force measuring devices 60. The area of the photoconductive drum 12 is formed so as to form a toner image that is developed with more toner than the area of the other photoconductive drum 12.

[Second Embodiment]
Next, a second embodiment of the image forming apparatus according to the present invention will be described. In the present embodiment, the same components as those shown in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  FIG. 7 is a schematic view showing an image forming apparatus in the present embodiment. The image forming apparatus 200 is obtained by changing the configuration of the calculation unit 70, the storage unit 72, the comparison unit 74, and the second control device 76 of the image forming apparatus 1.

  Reference numeral 202 denotes a storage unit (first storage unit) that stores initial frictional forces that are initial frictional forces measured by the plurality of frictional force measuring devices 60.

  Reference numeral 204 denotes a calculation unit (first calculation unit) that calculates a difference between each measured friction force measured by the plurality of friction force measurement devices 60 and each initial friction force for each friction force measurement device 60.

  Reference numeral 206 denotes a comparison unit (first comparison unit) that compares the difference in friction force calculated by the calculation unit 204 among the plurality of friction force measuring devices 60.

  Reference numeral 208 denotes that a predetermined toner image is formed on the photosensitive drum 12 and transferred to the sheet 9 when the comparison value between the plurality of frictional force measuring devices 60 compared by the comparison unit 206 is equal to or larger than a predetermined value. The second control device (control means) controls the first control device 4 so that the cleaning device 50 performs cleaning.

[Third embodiment]
Next, a third embodiment of the image forming apparatus according to the present invention will be described. In the present embodiment, the same components as those shown in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  FIG. 8 is a schematic view showing an image forming apparatus according to the present embodiment. The image forming apparatus 300 is obtained by changing the configuration of the calculation unit 70, the storage unit 72, the comparison unit 74, and the second control device 76 of the image forming apparatus 1.

  Reference numeral 302 denotes a calculation unit (second calculation unit) that calculates the amount of fluctuation of each measured friction force measured by the plurality of friction force measurement devices 60.

  Reference numeral 304 denotes a comparison unit (second comparison unit) that compares the difference in variation calculated by the calculation unit 302 among the plurality of frictional force measuring devices 60.

  Reference numeral 306 indicates that a predetermined toner image is formed on the photosensitive drum 12 and transferred to the sheet 9 when the comparison value between the plurality of frictional force measuring devices 60 compared by the comparison unit 304 is equal to or larger than a predetermined value. The second control device (control means) controls the first control device 4 so that the cleaning device 50 performs cleaning.

[Fourth embodiment]
Next, a fourth embodiment of the image forming apparatus according to the present invention will be described. In the present embodiment, the same components as those shown in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  FIG. 9 is a schematic diagram illustrating an image forming apparatus according to the present embodiment. The image forming apparatus 400 is obtained by changing the configuration of the second control device 76 of the image forming apparatus 1.

  Reference numeral 402 denotes a case where the frequency compared by the comparison unit 74 is a natural frequency stored in the storage unit 72, and the natural vibration mode stored in the storage unit 72 corresponding to the natural frequency is predetermined. In the natural vibration mode, a predetermined toner image is formed on the photosensitive drum 12 and transferred to the paper 9 or the intermediate transfer body, and the peripheral speed between the photosensitive drum 12 and the transfer body is changed during the main transfer. The second control device (control means) controls the first control device 4 so that the toner remaining on the surface of the photosensitive drum 12 after the main transfer is cleaned by the cleaning device 50.

When the toner image formed on the photosensitive drum is transferred by changing the peripheral speed between the photosensitive drum 12 and the transfer body, the components of the external additive contained in the toner are biased. It remains on the photosensitive drum 12. By supplying the component of the external additive to the cleaning unit where the photosensitive drum 12 and the cleaning blade 51 are in contact with each other, discharge products generated in the image forming process by the image forming apparatus 10 are easily removed. Examples of the component of the external additive include CeO ₂ and ZnSt.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation implementation is possible within the range of the summary of this invention.

FIG. 1 is a schematic diagram illustrating an image forming apparatus according to the first embodiment. FIG. 2 is a perspective view showing an arrangement example of the frictional force detection members in the first embodiment. FIG. 3 is a graph showing the relationship between the arrangement position (detection position) of the frictional force detection member relative to the cleaning blade and the frictional force measured by the frictional force measuring device in the first embodiment. FIG. 4 is a graph showing the relationship between the frictional force fluctuation frequency and the frictional force (amplitude) between the photosensitive drum and the cleaning blade in the first embodiment. FIG. 5 shows an example of the natural vibration mode of the cleaning blade derived from the relationship between the arrangement position (detection position) of the frictional force detection member relative to the cleaning blade and the frictional force measured by the frictional force measuring device in the first embodiment. It is a graph. FIG. 6 is a perspective view illustrating an example of an electrostatic latent image formed on the photosensitive drum by the second control device according to the first embodiment controlling the first control device. FIG. 7 is a schematic diagram illustrating an image forming apparatus according to the second embodiment. FIG. 8 is a schematic diagram illustrating an image forming apparatus according to the third embodiment. FIG. 9 is a schematic diagram illustrating an image forming apparatus according to the fourth embodiment.

Explanation of symbols

1, 200, 300, 400: image forming apparatus, 9: paper (recording medium), 12: photosensitive drum (image holding member), 16a: transfer roll (image transfer member), 51: cleaning blade (cleaning means), 60: Friction force measuring device (friction force measuring means), 70: Calculation unit (third calculation unit), 72: Storage unit (second storage unit), 74: Comparison unit (third comparison unit), 76, 208, 306, 402: second control device (control means), 202: storage unit (first storage unit), 204: calculation unit (first calculation unit), 206: comparison unit (first comparison unit), 302: calculation unit (Second calculation unit), 304: comparison unit (second comparison unit)

Claims (7)

An image carrier on which an electrostatic latent image is formed and the electrostatic latent image is developed with a developer to form a developer image;
An image transfer member for transferring the developer image from the image carrier to a recording medium;
Cleaning means for cleaning the residual transfer developer after the developer image has been transferred from the image carrier to the recording medium in contact with the image carrier;
A plurality of friction force measuring means for measuring the friction force between the cleaning means and the image carrier;
Control means for controlling the cleaning means to form the predetermined developer image on the image carrier and transfer it to the recording medium without transferring it, and
An image forming apparatus, wherein the developer image to be formed on the image holding member is determined by the control unit according to the measured frictional force measured by the plurality of frictional force measuring units. A first storage unit for storing an initial friction force, which is an initial friction force measured by the plurality of friction force measuring means;
A first calculation unit for calculating a difference between each measured friction force measured by the plurality of friction force measuring means and each initial friction force for each friction force measuring means;
A first comparison unit that compares the friction force difference calculated by the first calculation unit between the plurality of friction force measurement units,
The developer image to be formed on the image carrier is determined by the control unit when a comparison value between the plurality of friction force measurement units compared by the first comparison unit is a predetermined value or more. The image forming apparatus according to claim 1. A second calculator that calculates the amount of fluctuation of each measured friction force measured by the plurality of friction force measuring means;
A second comparison unit that compares the difference in the amount of variation calculated by the second calculation unit among the plurality of friction force measurement units,
The developer image to be formed on the image carrier is determined by the control unit when a comparison value between the plurality of frictional force measurement units compared by the second comparison unit is a predetermined value or more. The image forming apparatus according to claim 1. A second storage unit that stores a natural frequency of the cleaning means and a natural vibration state corresponding to the natural frequency;
A third calculator that calculates the frequency of each measured friction force variation measured by the plurality of friction force detection means;
A third comparison unit that compares the vibration frequency calculated by the third calculation unit and the natural frequency;
When the frequency compared by the third comparison unit is the natural frequency, and the natural vibration mode corresponding to the natural frequency is a predetermined natural vibration mode, the control unit holds the image. The image forming apparatus according to claim 1, wherein the developer image formed on a body is determined.   In the control means, among the measured frictional forces measured by the plurality of frictional force measuring means, the area of the image carrier having the large measured frictional force is more developer than the other areas of the image carrier. 5. The image forming apparatus according to claim 1, wherein the developer image is formed so as to be developed by the image forming method.   The control unit forms a predetermined developer image on the image carrier and transfers the developer image to the recording medium or transfer body, and at the time of transfer, the peripheral speed between the image carrier and the image transfer body or transfer body The image forming apparatus according to claim 1, wherein the residual transfer developer after the transfer is controlled to be cleaned by the cleaning unit.   The plurality of frictional force measuring units measure the measured frictional force based on measurement values measured by a measuring unit that measures the displacement of the cleaning unit. The image forming apparatus described in 1.

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