JP2009053590A - Adhesion force distribution determining method, collection roller, cleaning device, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesion force distribution determining method for determing the distribution of adhesion force between a roller member which collects powder from a body to be cleaned and the powder on the roller member. <P>SOLUTION: The adhesion force between a single toner particle which is a single powder particle and the toner collection roller serving as the roller member for collecting toner from a cleaning roller which is a member to be cleaned is measured in a plurality of places of the toner collection roller. The distribution of adhesion force on the toner collection roller is determined from the frequency distribution of the measured adhesion forces. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an adhesion distribution determination method for determining the distribution of adhesion force generated between a powder and a roller member on a roller member that collects the powder from the object to be cleaned, and to collect the powder from the object to be cleaned. The present invention relates to a roller, a cleaning device having the collection roller, and an image forming apparatus.

  Conventionally, as a method for cleaning the toner on the photoconductor, there is a brush cleaning method as described in Patent Document 1. In the brush cleaning method, a cleaning brush is arranged so as to rub against the surface of the photoconductor, and the toner on the photoconductor is scraped off by the cleaning brush. Then, the toner is collected from the cleaning brush by a collecting roller which is a cleaning member disposed in contact with the cleaning brush. Further, the toner collected on the collecting roller is removed from the surface of the collecting roller by a cleaning blade disposed so as to be in contact with the collecting roller. As described above, by removing the toner from the surface of the collecting roller, the collecting roller can be kept clean, and it is possible to suppress a reduction in toner collecting performance from the cleaning brush.

  Further, there is disclosed a toner that can satisfactorily remove toner from the surface of the collecting roller by using a collecting roller whose friction coefficient on the surface of the collecting roller is smaller than a predetermined friction coefficient set in advance (Patent Document 2, etc.). This is because the friction coefficient on the surface of the collecting roller is reduced to prevent the portion of the cleaning blade that is in contact with the surface of the collecting roller from being turned over, and the toner can be satisfactorily removed by suppressing the toner from slipping through the cleaning blade. It is a thing.

  However, when the inventors actually verified the cleaning performance of the collecting roller with respect to the friction coefficient, the toner could not be removed well from the surface of the collecting roller even though the friction coefficient of the surface of the collecting roller was small. Often resulted. For this reason, the method for evaluating the removal performance of the toner from the surface of the collecting roller by the coefficient of friction is still unreliable.

  On the other hand, a method for measuring the adhesion force between a powder and a member has been conventionally proposed. For example, in the method described in Patent Document 3, a PMMA (polymethyl methacrylate) sphere 1 having a composition, particle size, and shape close to those of a toner is proposed. The adhesion force between the member and the member is measured using an atomic force microscope.

JP 2005-265907 A JP 2005-031396 A JP 2003-330264 A

  The adhesion force between one powder and a member measured by the method described in Patent Document 3 is a characteristic value representing the contact state between one powder and the member. Therefore, it is possible to measure the adhesion force between one powder and the member and determine whether or not the powder can be satisfactorily removed from the member based on the measured adhesion force. However, when it is determined whether or not the powder can be satisfactorily removed from the member based on the adhesive force measured in this way, the following problem may occur.

  16 and 17 measure the adhesive force generated between the member surface and one powder at two or more locations on the member surface for two different members, and show the frequency distribution of the measured adhesive force in a graph. It is a representation. In each figure, the horizontal axis represents the adhesion force between the individual powder and the member, and the vertical axis represents the power of the powder for each specific adhesion force.

  In both the member A and the member B in FIG. 16, the frequencies are concentrated in the vicinity of the average value of the adhesive force measured at the plurality of locations, and the graph has a mountain shape. That is, the adhesion force of most toners is close to the average value, and it can be said that the correlation when the adhesion force is substituted with the average value is high. Here, the average values of the member A and the member B (the member A is a value x indicated by a one-dot chain line, the member B is a value y indicated by a one-dot chain line) are different, and the value y is larger than the value x. It can be seen that member B has a stronger adhesive force than member A. In this case, the removability of the toner from the member B is worse than the member A, and it can be easily predicted that the toner is difficult to remove. For example, if the adhesion force z shown in FIG. 16 is the boundary, the toner can be removed from the member below it, and if the value larger than that cannot be removed from the member, all the toner on the member A can be removed. Therefore, it can be said that all the toner on the member B cannot be removed.

  On the other hand, FIG. 17 is a diagram comparing the adhesion force with the member A using the member C instead of the member B. As shown in FIG. 17, the graph showing the frequency distribution of the adhesion force in the member C has a gentle mountain shape as compared with the member A, and the average value of the frequencies takes the same x as the member A. The average value of the adhesion force of the member C is about the same as that of the member A, but there are places where the adhesion force is stronger or weaker than that of the member A depending on the location of the member surface. For example, even if the average value of the adhesion force of toner on the member C is equal to or less than the boundary value z, there is a portion where the toner strongly adheres to the member C with an adhesion force exceeding the boundary value z. For this reason, even though most of the toner can be removed from the member C, a part of the toner that cannot be removed from the member C exists on the member C.

  Therefore, even if it is determined that the toner adhesion characteristic is evaluated by the average value of the adhesion force with respect to the collecting roller using the member having the adhesion tendency like the member C and it is determined that the member has good toner removability, Since there is toner that cannot be removed, the toner cannot be removed satisfactorily from the collecting roller.

  For this reason, it is important to determine in advance whether or not the adhesion strength is the same at any location where the toner on the member adheres, in other words, the distribution of the adhesion force on the member. Become.

  The present invention has been made in view of the above problems, and the object of the present invention is to distribute the adhesion force generated between the powder and the roller member on the roller member that collects the powder from the object to be cleaned. It is an object of the present invention to provide an adhesion force distribution determination method for determination, a recovery roller for recovering powder from a member to be cleaned, a cleaning device having the recovery roller, and an image forming apparatus.

In order to achieve the above-mentioned object, the invention according to claim 1 measures the adhesion force generated between a roller member for collecting powder from a member to be cleaned and the individual powder at a plurality of locations on the roller member. The adhesion force distribution on the roller member is judged from the distribution state of the measured adhesion force frequency distribution.
Further, the invention of claim 2 is characterized in that, in the method for judging adhesion distribution according to claim 1, the distribution state is expressed by dispersion or standard deviation of the measured adhesion. .
Further, the invention of claim 3 is the adhesive force distribution judging method according to claim 1, wherein the distribution state is expressed by a cumulative frequency or a cumulative relative frequency of the measured adhesive force at a predetermined adhesive force. It is characterized by.
According to a fourth aspect of the present invention, in the method for determining an adhesive force distribution according to the second aspect, the average value of the measured adhesive force is also used for determining the distribution of the adhesive force on the roller member. is there.
Further, the invention of claim 5 is characterized in that, in the adhesive force distribution judging method of claim 4, X / Y> 4 is satisfied when the average value is A and the standard deviation or the square root of the dispersion is B. It is what.
Further, the invention of claim 6 is the adhesive force distribution judging method according to claim 3, wherein the predetermined adhesive force is an adhesive force 1.4 times the average value of the measured adhesive forces, and the cumulative relative frequency. Alternatively, the ratio of the cumulative frequency to the total frequency of the measured adhesive force is 95 [%] or more.
Further, the invention of claim 7 is the method of determining the adhesion force distribution according to claim 1, 2, 3, 4, 5 or 6, wherein the adhesion force is the powder 1 attached to the tip of a deep needle in an atomic force microscope. The adhesion force between the individual and the collection roller is measured.
The invention of claim 8 is the adhesive force distribution judgment method of claim 1, 2, 3, 4, 5, 6 or 7, wherein the powder is toner.
According to a ninth aspect of the present invention, there is provided the adhesive force distribution judging method according to the eighth aspect, wherein the toner has a particle size of 1 [μm] or more and 20 [μm] or less.
Further, the invention of claim 10 is a collecting roller for collecting powder from a member to be cleaned, and measures the adhesive force generated between the roller surface and the individual powder at a plurality of locations on the roller surface. When the average value of the measured adhesion force is X and the standard deviation of the measured adhesion force or the square root of the variance is Y, X / Y> 4 is satisfied.
Further, the invention of claim 11 is a collection roller for collecting powder from a member to be cleaned, and measures the adhesive force generated between the roller surface and the individual powder at a plurality of locations on the roller surface. The cumulative relative frequency of the measured adhesive force at the adhesive force 1.4 times the average value of the measured adhesive force or the ratio of the cumulative frequency to the total frequency of the measured adhesive force is 95% or more. It is characterized by.
According to a twelfth aspect of the present invention, in a cleaning device for cleaning a member to be cleaned, the recovery roller according to the tenth or eleventh aspect is provided.
According to a thirteenth aspect of the present invention, an image forming apparatus including a member to be cleaned and a cleaning unit that cleans the member to be cleaned includes the cleaning device according to the twelfth aspect.

In the present invention, the adhesion force is measured at a plurality of locations on the roller member where one individual powder contacts the roller member, and the above-mentioned roller member is measured from the distribution state of the frequency distribution of the adhesion force measured at the plurality of locations. The distribution of the adhesive force at is determined. For example, if the degree of variation of the frequency distribution is small, it is determined that the adhesion force on the roller member is distributed with the same strength at any location on the roller member. On the other hand, if the degree of variation in the frequency distribution is large, it is determined that the adhesion force on the roller member is distributed with greatly different strengths at different locations on the roller member.
Since the distribution of the adhesion force on the roller member can be determined in this way, for example, the following prediction is possible. By determining that the adhesive force is distributed at the same strength at any location on the roller member, the adhesive force is distributed at a strength that can remove the powder from the roller member. Then, it can be predicted that the powder can be removed from any location on the roller member. In addition, it is judged that the adhesion force is distributed greatly differently for each location on the roller member, so that the adhesion force is too strong on the roller member to remove powder from the roller member. It is possible to predict that there may be a part that cannot be performed.

  As described above, according to the present invention, there is an excellent effect that the distribution of the adhesion force generated between the powder and the roller member on the roller member that collects the powder from the object to be cleaned can be determined.

[Embodiment 1]
Hereinafter, as an image forming apparatus to which the present invention is applied, an embodiment of an electrophotographic printer (hereinafter simply referred to as a printer) will be described.
First, a basic configuration of the printer according to the present embodiment will be described. FIG. 2 is a schematic configuration diagram illustrating the printer according to the present embodiment. The printer shown in the figure includes four image forming process units 1Y, 1C, 1M, and 1K for yellow, cyan, magenta, and black (hereinafter referred to as Y, C, M, and K). These use Y, C, M, and K toners of different colors as image forming substances for forming an image, but the other configurations are the same. Taking Y image forming process unit 1Y for generating a Y toner image as an example, this is configured as shown in FIG. A cleaning device 100Y, a charge removing device 3Y, a charging roller 4Y, an optical writing device 5Y, a developing device 6Y, and the like are provided around the photosensitive member 2Y that is driven to rotate clockwise in the drawing by a driving device (not shown). Yes.

  A charging bias is applied from a charging bias power source (not shown) to the charging roller 4Y disposed so as to be in contact with the photoreceptor 2Y or opposed to the photoreceptor 2Y with a predetermined gap. The charging roller 4Y causes the surface of the photoconductor 2Y to be uniformly charged by generating a discharge with respect to the photoconductor 2Y while rotating counterclockwise in the drawing. Instead of the charging roller 4Y, a charging brush may be contacted. Further, as a charging means for uniformly charging the photoconductor 2Y, a device that uniformly charges the photoconductor 2Y by a charger method, such as a scorotron charger, may be used.

  As the charging roller 4Y, a roller formed of a hard conductive material is opposed to the photoconductor 2Y through a minute gap, and may have a configuration described below. desirable. That is, the dimension in the axial direction is set to be slightly longer than the maximum image width that can be output by the printer (about 290 [mm] for an A4 landscape paper machine). It has a gap roller portion as a large diameter and insulating spacer. In such a configuration, the gap roller portions at both ends are brought into contact with the non-image forming regions existing at both end portions in the axial direction of the photosensitive member 2Y, so that 5 to 100 [μm between the central portion of the photosensitive member 2Y and the photosensitive member 2Y. ] (More desirably 20 to 65 [μm]) can be easily formed. In this embodiment, it is set to 55 [μm].

  The surface of the photoreceptor 2Y that is uniformly charged by the charging roller 4Y is exposed and scanned by the scanning light emitted from the optical writing device 5Y to carry a Y electrostatic latent image. The optical writing device 5Y emits laser light or LED light modulated based on image information sent from an external personal computer or the like.

  The developing device 6Y as a developing means develops the electrostatic latent image to obtain a Y toner image by attaching Y toner to the electrostatic latent image carried on the surface of the photoreceptor 2Y by a known technique. This Y toner image is primarily transferred to an intermediate transfer belt described later.

  The cleaning device 100Y removes the transfer residual toner adhering to the surface of the photoreceptor 2Y after the primary transfer process. In the cleaning device of this embodiment, a cleaning brush is disposed so as to contact and rub against the surface of the photosensitive member downstream of the cleaning blade in the rotational direction of the photosensitive member, and a toner recovery roller is disposed in contact with the cleaning brush. A configuration in which the toner is removed from the toner collecting roller by a rubber blade is applied. The surface of the photoreceptor 2Y that has been subjected to the cleaning process by the cleaning device 100Y is neutralized by a neutralizing unit 3Y such as a neutralizing lamp (not shown), and is prepared for the next image formation.

  In FIG. 2 described above, C, M, and K toner images are similarly formed on the photoreceptors 2C, M, and K in the image forming process units 1C, M, and K for other colors, and intermediate transfer is performed. Intermediate transfer is performed on the belt 21.

  Below the image forming process units 1Y, 1C, 1M, and 1K, a transfer unit 20 that is endlessly moved in the counterclockwise direction in the drawing while an intermediate transfer belt 21 as an image carrier is stretched is disposed. . In addition to the intermediate transfer belt 21, the transfer unit 20 as transfer means includes a driving roller 22, a driven roller 23, four primary transfer rollers 24Y, 24C, 24M, 24K, a secondary transfer roller 25, a belt cleaning device (not shown), and the like. ing.

  The intermediate transfer belt 21 is endlessly moved counterclockwise in the figure by the rotational driving of the driving roller 22 while being stretched by the driving roller 22 and the driven roller 23 arranged inside the loop.

  The four primary transfer rollers 24Y, 24C, 24C, 24M, 24K, 24K, and 24K sandwich the intermediate transfer belt 21 that is moved endlessly in this manner between the photoreceptors 2Y, 2C, 2M, and 2K. A primary transfer nip is formed. Then, a transfer bias having a polarity opposite to that of the toner (for example, plus) is applied to the back surface (loop inner peripheral surface) of the intermediate transfer belt 21. The intermediate transfer belt 21 serving as a transfer body sequentially passes through the primary transfer nips for Y, C, M, and K along with the endless movement thereof, and the photoreceptor 2Y, C, M, Y, C, M, and K toner images on K are superimposed and primarily transferred. As a result, a four-color superimposed toner image (hereinafter referred to as a four-color toner image) is formed on the intermediate transfer belt 21.

  A secondary transfer roller 25 to which a secondary transfer bias output from a power source (not shown) is applied is disposed outside the loop of the intermediate transfer belt 21, and this is between the drive roller 22 inside the belt loop. A secondary transfer nip is formed by sandwiching the intermediate transfer belt 21.

  A sheet feeding cassette (not shown) is disposed below the transfer unit 20. In this paper feed cassette, a plurality of recording papers P as transfer members are accommodated in a state of a stack of recording papers, and the uppermost recording paper P is sent to a paper feeding path (not shown) at a predetermined timing. . A registration roller pair 31 is disposed at the end of the paper feed path. The registration roller pair 31 temporarily stops the rotation of both rollers as soon as the recording paper P is sandwiched between the rollers rotating while abutting each other. Then, the recording paper P is sent out toward the secondary transfer nip at a timing at which the recording paper P can be synchronized with the four-color toner image on the intermediate transfer belt 21.

  The four-color toner image formed on the intermediate transfer belt 21 has a secondary transfer electric field formed between the secondary transfer roller 25 to which a secondary transfer bias is applied and the grounded driving roller 22 and a nip pressure. As a result, the secondary transfer is performed on the recording paper P in the secondary transfer nip. Then, combined with the white color of the recording paper P, a full color toner image is obtained.

  The transfer residual toner that has not been transferred to the recording paper P adheres to the intermediate transfer belt 21 after passing through the secondary transfer nip. This is removed by a belt cleaning device (not shown) in which the intermediate transfer belt 21 is sandwiched between the driven roller 23.

  A fixing device (not shown) is disposed above the secondary transfer nip. As is well known in electrophotographic image forming apparatuses, this fixing device fixes a toner image on a recording sheet by pressurization or heating.

  The Y, M, C, and K toners on the photoreceptors 2Y, C, M, and K are applied with a primary transfer bias having a polarity opposite to that of the Y, C, M, and K primary transfer nips. Therefore, there is a case where reverse polarity charge injection is received. For this reason, normal polarity toner particles and reversely charged toner particles are mixed in the transfer residual toner on the photoreceptors 2Y, 2C, 2M, and 2K.

  In the printer having the above basic configuration, the four image forming process units 1Y, 1C, 1M, and 1K transfer toner images onto the endlessly moving surfaces of the photoreceptors 2Y, 2C, 2M, and 2K that are image carriers. It functions as a toner image forming means to be formed. The combination of the four image forming process units 1Y, 1C, 1M, and 1K and the transfer unit 20 serves as a toner image forming unit that forms a toner image on the endlessly moving surface of the intermediate transfer belt 21 that is an image carrier. It is functioning.

  Next, the influence of the degree of toner adhesion when the toner on the toner collecting roller provided in the cleaning device is removed with a rubber blade will be described.

  Conventionally, evaluation methods for evaluating only the frictional force and the coefficient of friction, which are the average value of the adhesive force, have been widely used for the adhesion characteristics of toner to a member such as a toner collecting roller. Here, the frictional force is a force necessary to shift the toner from the member. For example, a change in the driving torque of the member that occurs when a large amount of toner on the rotationally driven member is simultaneously killed by the blade. A conventional method is known in which an average load calculated from the above is regarded as a frictional force.

  However, when the applicant of the present invention actually verified the removal phenomenon with respect to the friction coefficient, the toner removal from the toner collecting roller may not be performed well even though the friction coefficient is small as shown in FIG. It was.

  Here, FIG. 4 shows the relationship between the friction coefficient and the cleaning performance of the toner collecting roller using the members 1 to 4 on the roller surface. The member 1 is a PVDF tube + UV coat, the member 2 is a ceramic hard type C1, the member 3 is stainless steel, and the member 4 is a PVDF tube.

  The friction coefficient of the toner collecting roller on the horizontal axis in the figure is measured by a generally known Euler belt method. Paper is wound around the toner collecting roller, and a weight is attached to one end to wind the paper at a constant speed. The load at which the paper starts to start is read and calculated using a conversion formula. Also, the vertical axis in the figure is the remaining ID that represents how much toner remains on the toner collecting roller after the cleaning by the cleaning blade, and the larger the remaining ID is, the more toner is in the toner collecting roller. Indicates that it remains.

  As can be seen from FIG. 4, in the members 1 and 2, the member 2 having a larger coefficient of friction than the member 1 has a larger residual ID. For this reason, conventionally, the cleaning performance has been evaluated by the magnitude of the friction coefficient. However, when attention is paid to the member 3 and the member 4, the friction coefficient of both of them is the same value as the friction coefficient of the member 1, but the remaining ID of the member 3 and the member 4 is more than the remaining ID of the member 2. It is clear that That is, although the member 3 and the member 4 have a smaller frictional force than the member 2, the toner removal from the toner collecting roller is not performed well. That is, it can be seen that there is no correlation between the friction coefficient and the cleaning property.

Considering this, in general, when measuring the coefficient of friction, the average of the locations of members having a much wider area than the location of the location of the member in contact with one toner, such as the Euler belt method described above, is used. The coefficient of friction in the normalized surface state is measured. However, the surface state in the above-mentioned contact area, for example, a range of several μm ² is not necessarily the same as the surface state in the above-mentioned large area member, for example, a range of several mm ² . For example, even if the surface state is uneven in the entire part of the member having a large area, the surface is wavy in the entire part in contact. Therefore, strictly speaking, the measured coefficient of friction is different from the coefficient of friction at the contact point for one toner. Therefore, even if the coefficient of friction at the location of the member having a large area is small, it is not the coefficient of friction at the location where the toner is actually in contact, and as a result, appropriate cleaning conditions cannot be set. It is considered that toner removal failure may occur. Therefore, it is considered difficult to accurately determine the cleaning property of the toner collecting roller based on the friction coefficient. For that reason, it was not possible to place another trust as a method for explaining the adhesion phenomenon.

  Further, in the above-described surface state, when it is difficult to improve the toner removal failure from the member simply by specifying the surface roughness of the member surface as described in Japanese Patent Application Laid-Open No. 9-15979 or the like for the reasons described above. It is thought that can occur.

  Therefore, the inventors of the present application have considered that it is important to evaluate the adhesion property of one toner to the toner collecting roller to accurately determine the cleaning property of the toner collecting roller. Therefore, the adhesion force of one toner to the toner collecting roller was measured, and it was verified whether or not the cleaning property of the toner collecting roller could be accurately judged from the measured adhesion force.

  Here, it will be explained that it is important to acquire the characteristic value distribution of the adhesive force in the toner collecting roller surface by measuring the adhesive force with one toner. Many of the conventionally known methods for measuring the adhesion force of powders such as toners measure the adhesion force between powder and members as a group. Since it has a distribution, it is impossible to evaluate the distribution of characteristic values on the surface of the member while maintaining repeatability. For example, “M. Takeuchi, A. Onose, M. Anzai, R. Kojima and K. Kawai: Proc. IS & T 7th Int. Congress Adv. Non-Imprint Printing Technology 1, 2081, ol. In the method for measuring the adhesion force using the centrifugal force used in the above, a sample substrate to which powder is adhered is prepared, and the centrifugal force at which the powder separates from the sample substrate is evaluated. However, this method cannot evaluate the distribution of the characteristic values on the member surface for the reasons described above. For this reason, in this embodiment, the adhesion force is always measured with the same particle (one toner), and the in-plane distribution of the adhesion force on the member surface is repeatedly evaluated while maintaining accuracy.

  FIG. 1 shows the adhesion force of one toner to the toner collecting roller in the members 1 to 4 shown in FIG. 4 at a plurality of locations on the surface of the toner collecting roller, specifically, a 2 [μm] square area as shown in FIG. And measured at 7 × 7 = 49 points.

  In addition, this adhesion force measurement can be performed using, for example, an atomic force microscope. The outline of an atomic force microscope and an adhesion force measuring method using the same will be described below. However, the method for measuring the adhesive force between a single powder such as toner and a member such as a toner collecting roller is only required to be able to measure the adhesive force at a plurality of positions on the member, and is a method using an atomic force microscope. Is not limited. It is also possible to apply the method described in JP 2001-183289 A.

  There are many known documents (for example, Appl. Phys. Lett. 56, 1758 (1990)) regarding the principle of operation of an atomic force microscope (AFM). Using a cantilever having a needle having a material surface such as silicon nitride or silicon dioxide (probe tip, hereinafter also referred to as a tip) at the tip, the tip is brought close to the measurement sample surface, and between the sample surface and the probe tip The working force (surface force) is measured as cantilever warpage or deflection using the reflection of the photodiode, and is linked to feedback control as a signal, and the distance between the tip and the sample surface is controlled by a piezo element. Is the operation principle of a typical non-contact type AFM.

  When measuring adhesion using an atomic force microscope, the cantilever must be decorated. Specifically, the target powder is attached to the cantilever tip with an adhesive such as an epoxy resin. The attaching operation can be performed by using a dedicated device as described in JP-A-2002-62253 or by AFM.

There are mainly two methods for measuring the adhesion force with an atomic force microscope.
One is a method called a force curve method or a force distance curve method. As a specific measuring action, the tip of the cantilever and the sample surface are continuously separated, contacted and separated. In this method, the adhesion force between the cantilever and the sample surface is measured from the deflection amount of the cantilever at the moment of separation between the tip of the cantilever and the sample surface (for example, JP-A-2002-62253).

  The other is a method called a pulse force mode method, which is an application of the force curve method (for example, Appl. Phys. Lett. 18, page 2632 (1997)). Conceptually, the force curve method is a measurement performed at one point, while the pulse force mode method is a measurement in which the force curve method is continuously performed in a two-dimensional region. Specifically, the tip of the cantilever tip is obtained by vibrating the sample stage in the vertical direction at about 100 [Hz] to 1000 [Hz] while scanning the surface of the sample at about 0.1 [Hz] to 10 [Hz]. The sample surface is contacted and separated continuously.

  It is preferable to evaluate the measurement region condition of the sample by setting the region from 500 [nm] to 10000 [nm]. If the area is too small at the time of evaluating the adhesive force distribution, the influence of the local bias of the adhesive force becomes large, and a standard deviation suitable for determining from the adhesive force distribution cannot be obtained, so that proper determination cannot be made. Although it depends on the evaluation target, specifically, it is preferable to set the region to 500 [nm] or more.

  In addition, when an atomic force microscope is used as the adhesive force measuring device, a too large region setting cannot be set. Depending on the model, for example, the maximum setting region in the pulse force mode method is several thousand [nm] to 10,000 [nm]. In addition, in the atomic force microscope, the moving speed of the sample stage (or moving speed of the cantilever) is a maximum of several thousand [nm / s]. Therefore, if the area is set too large, the measurement time becomes too long, which is not preferable.

  Furthermore, the number of data constituting the adhesive force distribution is preferably 5 × 5 = 25 points or more. If the number of data is too small, there is a high possibility that the data tends to be biased.

Table 1 shows the average and dispersion of the adhesion force measured in this way for each member.

  It can be seen from Table 1 and FIG. 4 that the member 1 having a smaller average adhesion than the member 2 has a remaining ID smaller than the member 2. However, it can be seen that the remaining IDs of the member 3 and the member 4 having an average adhesion force smaller than that of the member 2 are larger than those of the member 2. That is, like the relationship between the friction coefficient and the cleaning property, there is no correlation between the average adhesion force and the remaining ID, that is, the average adhesion force and the cleaning property.

  Therefore, the inventors of the present invention have studied by paying attention to variations in adhesion force (distribution state of frequency distribution). That is, attention was paid to whether or not the strength of the adhesive force is the same at any location on the toner collecting roller. In addition, although it performed using dispersion | distribution as shown in Table 1 as dispersion | fluctuation of adhesive force (distribution state of frequency distribution) here, you may carry out also using a standard deviation.

  It can be seen from Table 1 and FIG. 4 that the dispersion is small in the members 1 and 2 with the small remaining ID, and the dispersion is large in the members 3 and 4 with the large remaining ID. That is, when the adhesion force values measured at the plurality of locations are gathered in the vicinity of the average of the adhesion forces, the adhesion strength is similar at any location on the toner recovery roller. For this reason, the cleaning by the cleaning blade for the toner collection roller is stably performed at any location on the toner collection roller, so that the cleaning property is improved, and as a result, the remaining ID is considered to be small. In the case where the adhesion force is far from the average, the adhesion force varies greatly depending on the location on the toner collecting roller. For this reason, it is considered that the cleaning by the toner recovery roller cleaning blade is not stably performed at a part of the toner recovery roller and the cleaning performance is lowered, and as a result, the remaining ID is increased. From this, it is possible to accurately determine the cleaning performance of the toner collecting roller from the dispersion (standard deviation) of the adhesion force measured at the plurality of locations, that is, the degree of variation in adhesion force (distribution state of the frequency distribution).

  The member to which the present invention can be applied is not limited to the toner collecting roller as long as it has a substantially uniform surface state, and any member may be used. For example, the image carrier and the charging unit shown in FIG. A member mounted on an image forming apparatus including at least one of a developing unit and a transfer unit can be applied. In particular, the development of a member that is difficult for toner to adhere by using the present invention in an image carrier, a developing unit, an intermediate transfer member, a cleaning unit, and a charging unit where toner adhesion is not desired, is carried out. Can be done automatically. Details of each member used in the image forming apparatus according to this embodiment will be described below.

<Electrophotographic photoreceptor>
An image carrier will be described as one member mounted on the image forming apparatus used in the present invention.
An electrophotographic photosensitive member can be used as the image carrier used in the present invention. Since the electrophotographic photosensitive member transfers a toner image to a recording paper or an intermediate transfer member, it is not preferable that the electrophotographic photosensitive member has a large adhesive force to the toner. Therefore, the present invention can be preferably used.

  As the electrophotographic photoreceptor, other layers than the above may be formed as long as at least an intermediate layer and a photosensitive layer are provided on the conductive support. For example, a function separation type electrophotographic photosensitive member in which the photosensitive layer shown in FIG. 6 includes a charge generation layer (CGL) and a charge transport layer (CTL) will be described.

Examples of the conductive support include those having a volume resistance of 10 ¹⁰ [Ω · cm] or less, for example, metals such as aluminum, nickel, chromium, nichrome, copper, gold, silver, and platinum, tin oxide, and indium oxide. Metal oxide such as film or cylindrical plastic or paper coated by vapor deposition or sputtering, or a plate of aluminum, aluminum alloy, nickel, stainless steel, etc., and extrusion, drawing, etc. After forming the tube, it is possible to use a tube that has been surface-treated by cutting, superfinishing, polishing, or the like. Endless nickel belts and endless stainless steel belts can also be used as the conductive support.

  In addition to the above, a conductive support dispersed in a suitable binder resin on the conductive support can be used as the conductive support of the present invention. Examples of the conductive powder include carbon black, acetylene black, metal powder such as aluminum, nickel, iron, nichrome, copper, zinc and silver, or metal oxide powder such as conductive tin oxide and ITO. It is done. The binder resin used at the same time is polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer. , Polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinylcarbazole, acrylic resin, silicone resin, epoxy resin, Examples thereof include thermoplastic, thermosetting resins, and photocurable resins such as melamine resin, urethane resin, phenol resin, and alkyd resin. Such a conductive layer can be provided by dispersing and applying these conductive powder and binder resin in a suitable solvent such as tetrahydrofuran, methyl ethyl ketone, or toluene.

  Furthermore, it is electrically conductive by a heat-shrinkable tube in which the conductive powder is contained in a material such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chlorinated rubber, Teflon (registered trademark) on a suitable cylindrical substrate. Those provided with a conductive layer can also be used favorably as the conductive support of the present invention.

Next, the intermediate layer will be described.
The intermediate layer is provided for the purpose of improving adhesiveness, preventing moire, improving the coatability of the upper layer, and reducing the residual potential.

  The intermediate layer generally comprises a resin as a main component, but these resins are resins having a high solubility resistance to general organic solvents in consideration of applying a photosensitive layer thereon using a solvent. It is desirable to be. Examples of such resins include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, polyurethane, melamine resin, alkyd-melamine resin, and epoxy resin. Examples thereof include curable resins that form a three-dimensional network structure. In particular, an alkyd-melamine resin is preferable because it can satisfy many of the functions required as an intermediate layer. Further, fine powders such as metal oxides exemplified by titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide and the like, or metal sulfides and metal nitrides may be added as inorganic pigments. In particular, titanium oxide is white with little absorption in visible light and near infrared light, and is preferable for increasing the sensitivity of the electrophotographic photosensitive member. These intermediate layers can be formed by a common coating method using an appropriate solvent. In order to improve the charging performance of the electrophotographic photosensitive member, at least ethylene glycol monoisopropyl is included in the intermediate layer coating solution. Ether is preferably contained in an amount of 0.1 [wt%] or more and 3 [wt%] or less.

  Further, as the intermediate layer, a metal oxide layer formed by using, for example, a sol-gel method using a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like is also useful.

In addition, an organic material such as Al ₂ O ₃ provided by anodization, polyparaxylylene (parylene), or inorganic materials such as SnO ₂ , TiO ₂ , ITO, and CeO _{2 is} prepared by a vacuum thin film manufacturing method. It may be provided.

  The thickness of the intermediate layer is about 0.1 [μm] to 10 [μm], preferably 1 [μm] to 5 [μm].

Next, the charge generation layer will be described.
For the charge generation layer, known charge generation materials can be used, for example, metal phthalocyanines such as titanyl phthalocyanine and chlorogallium phthalocyanine, metal-free phthalocyanines, azulenium salt pigments, squaric acid methine pigments, and symmetrical carbazole skeletons. Type or asymmetric azo pigments, symmetric or asymmetric azo pigments having a triphenylamine skeleton, symmetric or asymmetric azo pigments having a diphenylamine skeleton, symmetric or asymmetric azo pigments having a dibenzothiophene skeleton, Symmetric or asymmetric azo pigments having a fluorenone skeleton, symmetric or asymmetric azo pigments having an oxadiazole skeleton, symmetric or asymmetric azo pigments having a bis-stilbene skeleton, distyryl oxadia Symmetric or asymmetrical azo pigments having a dye skeleton, symmetric or asymmetrical azo pigments having a distyrylcarbazole skeleton, perylene pigments, anthraquinone or polycyclic quinone pigments, quinoneimine pigments, diphenylmethane and triphenyl Examples thereof include methane pigments, benzoquinone and naphthoquinone pigments, cyanine and azomethine pigments, indigoid pigments, and bisbenzimidazole pigments. Examples of the phthalocyanine pigment used in the present invention include metal-free phthalocyanine or metal phthalocyanine. Synthesis methods described in Moser and Thomas' “phthalocyanine compound” (Rheinhold, 1963), and other suitable methods Use the one obtained by

  Examples of metal phthalocyanines include those having a central metal such as copper, silver, beryllium, magnesium, calcium, zinc, indium, sodium, lithium, titanium, tin, lead, vanadium, chromium, manganese, iron, and cobalt. . Further, a metal halide having a valence of 3 or more may be present in the central nucleus of phthalocyanine instead of the metal atom. Although various crystal forms of phthalocyanine are known, known forms such as crystal forms such as α-type, β-type, Y-type, ε-type, τ-type, and X-type, and amorphous forms can be used.

  Among these, titanyl phthalocyanine (hereinafter referred to as TiOPc) having titanium as a central metal is particularly desirable because of its particularly high sensitivity and excellent characteristics.

Next, the charge transport layer will be described.
As described above, the charge transport layer can be formed by dissolving or dispersing the charge transport material and the binder resin in an appropriate solvent, and applying and drying the solution on the charge generation layer. Moreover, a plasticizer, a leveling agent, antioxidant, etc. can also be added as needed.

  Charge transport materials include hole transport materials and electron transport materials. Examples of the charge transport material include chloranil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4 , 5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7-tri Examples thereof include electron-accepting substances such as nitrodibenzothiophene-5,5-dioxide and benzoquinone derivatives.

  Examples of the hole transport material include poly-N-vinylcarbazole and derivatives thereof, poly-γ-carbazolylethyl glutamate and derivatives thereof, pyrene-formaldehyde condensates and derivatives thereof, polyvinylpyrene, polyvinylphenanthrene, polysilane, oxazole derivatives, Oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, triarylamine derivatives, stilbene derivatives, α-phenylstilbene derivatives, benzidine derivatives, diarylmethane derivatives, triarylmethane derivatives, 9-styrylanthracene derivatives, pyrazolines Derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives, butadiene derivatives, pyrene derivatives, etc., bisstilbene derivatives, enamine derivatives, etc. Other known materials may be mentioned. These charge transport materials may be used alone or in combination of two or more.

  As the binder resin, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, Polyvinylidene chloride, polyarate, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol Examples thereof include thermoplastic or thermosetting resins such as resins and alkyd resins.

  The amount of the charge transport material is 20 to 300 parts by weight, preferably 40 to 150 parts by weight, with respect to 100 parts by weight of the binder resin. Further, as described above, the thickness of the charge transport layer needs to be 30 [μm] or more from the viewpoint of durability. Further, when the thickness of the charge transport layer is extremely increased, there is a problem that the resolution is lowered. Therefore, the thickness is preferably set to 30 [μm] to 50 [μm]. As the solvent used here, it is desirable to use a non-halogen solvent for the purpose of reducing environmental burdens, specifically, cyclic ethers such as tetrahydrofuran, dioxolane and dioxane, and aromatics such as toluene and xylene. Hydrocarbons and their derivatives are used favorably.

  In the photoreceptor of the present invention, a protective layer may be provided on the outermost layer for the purpose of protecting the photosensitive layer and maintaining a low surface friction coefficient. As the binder resin used for the protective layer, ABS resin, ACS resin, olefin-vinyl monomer copolymer, chlorinated polyether, aryl resin, phenol resin, polyacetal, polyamide, polyamideimide, polyacrylate, polyallylsulfone, Polybutylene, polybutylene terephthalate, polycarbonate, polyethersulfone, polyethylene, polyethylene terephthalate, polyimide, acrylic resin, polymethylbenten, polypropylene, polyphenylene oxide, polysulfone, polystyrene, polyarylate, AS resin, butadiene-styrene copolymer, polyurethane, Examples thereof include resins such as polyvinyl chloride, polyvinylidene chloride and epoxy resin.

  Further, a filler material may be added to the protective layer of the photoreceptor for the purpose of improving the wear resistance. As the filler, there are an organic filler and an inorganic filler. From the viewpoint of the hardness of the filler, the use of the inorganic filler is advantageous for improving the wear resistance. Such inorganic filler materials include metal powders such as copper, tin, aluminum, and indium, silica, tin oxide, zinc oxide, titanium oxide, alumina, zirconium oxide, indium oxide, antimony oxide, bismuth oxide, and calcium oxide. Metal oxides such as tin oxide doped with antimony and indium oxide doped with tin, metal fluorides such as tin fluoride, calcium fluoride and aluminum fluoride, inorganic such as potassium titanate and boron nitride Materials.

These fillers can be surface-treated with at least one surface treatment agent, and it is preferable to do so from the viewpoint of the dispersibility of the filler. Lowering the dispersibility of the filler not only increases the residual potential, but also lowers the transparency of the coating, causes defects in the coating, and lowers the wear resistance. It can develop into a big problem. As the surface treatment agent, all conventionally used surface treatment agents can be used, but a surface treatment agent capable of maintaining the insulating properties of the filler is preferable. For example, a titanate coupling agent, an aluminum coupling agent, a zircoaluminate coupling agent, a higher fatty acid, etc., or a mixing treatment of these with a silane coupling agent, Al ₂ O ₃ , TiO ₂ , ZrO ₂ , Silicone, aluminum stearate, or the like, or a mixture thereof is more preferable from the viewpoint of filler dispersibility and image blur. The treatment with the silane coupling agent is strongly influenced by image blur, but the influence may be suppressed by performing a mixing treatment of the surface treatment agent and the silane coupling agent. The surface treatment amount varies depending on the average primary particle size of the filler used, but 3 [wt%] to 30 [wt%] is suitable, and 5 [wt%] to 20 [wt%] is more preferable. If the surface treatment amount is less than this, the filler dispersion effect cannot be obtained, and if it is too much, the residual potential is significantly increased.

  As the solvent to be used, all solvents used in the charge transport layer 23 such as tetrahydrofuran, dioxane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, methyl ethyl ketone, acetone and the like can be used.

  In addition, the addition of the charge transport materials mentioned in the charge transport layer to the protective layer is effective and useful for reducing the residual potential and improving the image quality.

  As a method for forming the protective layer, conventional methods such as dip coating, spray coating, beat coating, nozzle coating, spinner coating, ring coating, etc. can be used. preferable.

  Although the thickness of the protective layer can be set freely, it is recognized that when the protective layer thickness is significantly increased, the image quality tends to be slightly deteriorated. About 0.1 to 10 [μm] is appropriate.

<Description of toner>
As the toner, toner in which an additive is contained in particles is used. As this additive, conventionally known additives can be used. Specifically, oxides such as Si, Ti, Al, Mg, Ca, Sr, Ba, In, Ga, Ni, Mn, W, Fe, Co, Zn, Cr, Mo, Cu, Ag, V, and Zr And composite oxides. In particular, silica, titania, alumina and the like, which are oxides of Si, Ti, and Al, are suitable. The addition amount of the additive is preferably 0.5 to 1.8 parts by weight, particularly preferably 0.7 to 1.5 parts by weight with respect to 100 parts by weight of the base particles.

  Further, as the toner, it is desirable to use a toner that has been subjected to a surface treatment using a treatment agent. As the treating agent used for the surface treatment, an organic silane compound or the like is preferable. For example, alkylchlorosilanes such as methyltrichlorosilane, octyltrichlorosilane, and dimethyldichlorosilane, and alkylmethoxysilanes such as dimethyldimethoxysilane and octyltrimethoxysilane. Further, hexamethyldisilazane, silicone oil, etc. may be used. Examples of the surface treatment method include a method of dipping an additive in a solution containing an organosilane compound and drying, a method of spraying a solution containing an organosilane compound on the additive and drying.

  Further, it is desirable to use a toner having a volume average particle size in the range of 3 [μm] to 7 [μm].

<About toner shape>
Equation 1 shows a formula for calculating the shape factor SF1 of the toner. As shown in FIG. 7, the shape factor SF1 is a numerical value indicating the ratio of the roundness in the shape of the spherical substance, and the square of the maximum length MXLNG of the elliptical figure formed by projecting the spherical substance on a two-dimensional plane. Divided by the graphic area AREA and multiplied by 100π / 4.
That is, it is defined by Equation 1.

  In the present invention, a spherical toner having a shape factor SF1 of 100 to 150 is preferable.

<Description of career>
As the magnetic carrier C, conventionally known ones such as iron powder, ferrite powder, magnetite powder, magnetic resin carrier having a particle diameter of about 20 [μm] to 200 [μm] can be used. In this printer, a core made of metal or resin contains a magnetic material such as ferrite and the surface layer is coated with a silicone resin or the like and has an average particle size of 55 [μm]. As the coating material for the surface layer, amino resins such as urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, epoxy resin and the like can be used. Further, polyvinyl resin, polyvinylidene resin, acrylic resin, polymethyl methacrylate resin, polyacrylonitrile resin, polyvinyl acetate resin, polyvinyl alcohol resin, polyvinyl butyral resin, polystyrene resin, and the like may be used. Further, polystyrene resins such as styrene acrylic copolymer resins, halogenated olefin resins such as polyvinyl chloride, polyester resins such as polyethylene terephthalate resin and polybutylene terephthalate resin, and the like may be used. Further, polycarbonate resins, polyethylene resins, polyvinyl fluoride resins, polyvinylidene fluoride resins, polytrifluoroethylene resins, polyhexafluoropropylene resins, copolymers of vinylidene fluoride and acrylic monomers, and the like may be used. Further, a copolymer of vinylidene fluoride and vinyl fluoride, a fluoroterpolymer such as a terpolymer of tetrafluoroethylene, vinylidene fluoride, and a non-fluorinated monomer, or a silicone resin may be used. In addition, you may contain electrically conductive powder etc. in coating resin as needed. As such conductive powder, metal powder, carbon black, titanium oxide, tin oxide, zinc oxide, or the like can be used. These conductive powders preferably have an average particle diameter of 1 [μm] or less. This is because if the average particle diameter is larger than 1 [μm], it is difficult to control the electric resistance.

<Toner collection roller>
As one of the cleaning methods used for the cleaning unit, there is a brush cleaning method that reduces the surface film scraping of the image carrier (mainly the photoreceptor) and has a reliable cleaning property even when cleaning these small particle size toner / spherical toner. In this configuration, a cleaning brush is disposed so as to contact and rub against the surface of the photosensitive member, a collection roller is disposed in contact with the cleaning brush, and toner is removed from the collection roller by means such as a rubber blade. Since a voltage is applied to the collection roller or both the collection roller and the brush and cleaning is performed by electrostatic force, it is advantageous when using spherical toner.

  Since the collecting roller to which the toner hardly adheres is advantageous at the time of toner removal, the collecting roller is a member to which the present invention can be preferably applied.

The roller is made of a material having a volume resistance of 10 ¹⁰ [Ω · cm] or less, such as a metal such as aluminum, nickel, chromium, nichrome, copper, gold, silver, platinum, or the surface of a conductive shaft. The structure has a resistance layer. As the material of the resistance layer, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, Polyvinylidene chloride, polyarate, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol Examples thereof include thermoplastic or thermosetting resins such as resins and alkyd resins.

<Charging part>
One type of charging member is a charging roller using a roller system. The image bearing member is uniformly charged by the charging roller. If dirt is attached to the charging roller at this time, the image bearing member is unevenly charged, which causes disturbance of the image output from the image forming apparatus. Since most of the dirt adhering to the charging roller is toner, it is preferable that the toner is difficult to adhere to the charging roller. Therefore, the present invention can be preferably used.

The charging member has an ion conductive rubber layer formed on a stainless steel core. The resistance of the rubber layer is about 10 ⁴ [Ω] to 10 ⁸ [Ω] in terms of resistance value. The rubber hardness of the roller is 40 [°] or more, preferably 70 [°] or more, according to JIS-A. Moreover, what has electroconductivity other than rubber | gum may be sufficient and an elastomer, resin, etc. are mention | raise | lifted. These also desirably have a hardness corresponding to the rubber hardness. When the resin is used, since the material does not have elasticity, it is easy to maintain the gap accurately, that is, there is an advantage that a difference in gap is not easily generated between the photosensitive member and the photosensitive member in the axial direction. A surface layer having a resistance value of about 10 ¹⁰ [Ω] is formed on the surface layer. This is to prevent a phenomenon in which current flows in a concentrated manner when there is a low resistance part such as a pinhole on the photoconductor. This surface layer prevents the current from concentrating on the pinhole. It is out. The resistance value of the surface layer may be 10 ¹⁰ [Ω] or more.

<Development part>
A developing unit that develops an electrostatic latent image formed on a photoreceptor generally has a developing roller as a member that supplies toner to the photoreceptor. Since the developing roller has a function of delivering the toner to the image carrier, it is not preferable that the developing roller has a large adhesion force to the toner. Therefore, the present invention can be preferably used.

<Developing roller for single component development>
The developing roller includes a roller portion whose outer peripheral portion is formed of an elastic material having a low coefficient of friction such as rubber in order to charge one-component toner by friction, and a metal shaft portion that penetrates the center of the roller portion. .

  Examples of the material used for the elastic material include elastic members such as elastic material rubber and elastomer. Specifically, butyl rubber, fluorine-based rubber, acrylic rubber, EPDM, NBR, acrylonitrile-butadiene-styrene rubber, natural rubber, Isoprene rubber, styrene-butadiene rubber, butadiene rubber, urethane rubber, syndiotactic 1,2-polybutadiene, epichlorohydrin rubber, polysulfide rubber, polynorbornene rubber, thermoplastic elastomer (for example, polystyrene, polyolefin, poly One type or two or more types selected from the group consisting of vinyl chloride, polyurethane, polyamide, polyurea, polyester, and fluororesin) can be used. However, it is not limited to the said material.

<Developing roller for two-component development>
As in the case of one component, a roller having an outer peripheral portion made of an elastic material having a low coefficient of friction, such as rubber, and a metal shaft passing through the center of the roller portion, or a roller having a surface made of metal For example, metals such as aluminum, nickel, chromium, nichrome, copper, gold, silver, and platinum are also used. The surface of the developing roller may be appropriately coated with a coating material in order to stabilize the quality over time. The surface layer coating material may have a polarity opposite to that of the toner, or may have the same polarity when the toner is not provided with a function of tribocharging the toner to a desired polarity. Examples of the former surface layer coating material include materials containing a resin, such as silicon, acrylic, and polyurethane, and rubber. Examples of the latter surface layer coating material include a material containing fluorine. A so-called Teflon (registered trademark) material containing fluorine has a low surface energy and excellent releasability, and therefore toner filming with time is extremely difficult to occur. Also, as general resin materials that can be used for the surface layer coating material, polytetrafluoroethylene (PTFE), tetrafluoroethylene perfluoroalkyl vinyl ether (PFA), tetrafluoroethylene / hexafluoropropylene polymer (FEP) , Polychlorotrifluoroethylene (PCTFE), tetrafluoroethylene / ethylene copolymer (ETFE), chlorotrifluoroethylene / ethylene copolymer (ECTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), etc. Can be mentioned. In order to obtain conductivity, a conductive material such as carbon black is often contained in this. In order to coat the developing roller more uniformly, other resins may be mixed together.

<Intermediate transfer member>
Since the intermediate transfer member transfers the toner image onto the recording paper, it is not preferable that the intermediate transfer member has a large adhesion to the toner. Therefore, the present invention can be preferably used.

  FIG. 8 is a longitudinal sectional view of an example of an intermediate transfer member used in an image forming apparatus to which the present invention can be applied. The intermediate transfer member used in the image forming apparatus is composed of at least a base layer, an elastic layer, and a surface coat layer. The intermediate transfer member is provided with an elastic layer having low hardness so that it can be deformed with respect to the toner layer and the paper having poor smoothness at the transfer nip portion. Since the surface of the intermediate transfer body can be deformed following local unevenness, it is possible to obtain good adhesion without excessively increasing the transfer pressure with respect to the toner layer, there is no loss of character transfer, It is possible to obtain a transfer image having excellent uniformity and having no transfer unevenness in a solid portion or the like even on paper having poor smoothness. Examples of the material used for the elastic layer include elastic members such as elastic material rubber and elastomer. Specifically, butyl rubber, fluorine rubber, acrylic rubber, EPDM, NBR, acrylonitrile-butadiene-styrene rubber, natural rubber, Isoprene rubber, styrene-butadiene rubber, butadiene rubber, urethane rubber, syndiotactic 1,2-polybutadiene, epichlorohydrin rubber, polysulfide rubber, polynorbornene rubber, thermoplastic elastomer (for example, polystyrene, polyolefin, poly One type or two or more types selected from the group consisting of vinyl chloride, polyurethane, polyamide, polyurea, polyester, and fluororesin) can be used. However, it is not limited to the said material.

  The thickness of the elastic layer is preferably in the range of 0.07 [mm] to 0.3 [mm], although it depends on the hardness and the layer structure. If it is as thick as 0.3 [mm] or more, it will be bent by the pressing force of the cleaning blade, or the cleaning blade will be pushed into the intermediate transfer member, preventing smooth movement of the intermediate transfer member. On the other hand, if it is as thin as 0.07 [mm] or less, the pressure on the toner on the intermediate transfer body 10 at the secondary transfer nip portion becomes high, and transfer loss is likely to occur, and the toner transfer rate decreases. .

  The hardness of the elastic layer is preferably 10 ≦ HS ≦ 65 (JIS-A). Although the optimum hardness differs depending on the layer thickness of the intermediate transfer member, if the hardness is lower than 10 [°] JIS-A, transfer deficiency tends to occur. On the other hand, when the hardness is higher than 65 [°] JIS-A, it is difficult to stretch the roller, and since it is stretched by long-term stretching, there is no durability and early replacement is necessary.

  In addition, the base layer of the intermediate transfer member is made of a resin with little elongation. Specifically, materials used for the base layer include polycarbonate, fluorine resin (ETFE, PVDF, etc.), polystyrene, chloropolystyrene, poly-α-methylstyrene, styrene-butadiene copolymer, styrene-vinyl chloride copolymer. Styrene-vinyl acetate copolymer, styrene-maleic acid copolymer, styrene-acrylic acid ester copolymer (styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer) Polymer, styrene-octyl acrylate copolymer and styrene-phenyl acrylate copolymer), styrene-methacrylic acid ester copolymer (styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, Styrene-phenyl methacrylate copolymer, etc.), steel -Α-chloromethyl acrylate copolymer, styrene resin such as styrene-acrylonitrile-acrylate ester copolymer (monopolymer or copolymer containing styrene or styrene substitution product), methyl methacrylate resin, methacryl Acid butyl resin, ethyl acrylate resin, butyl acrylate resin, modified acrylic resin (silicone modified acrylic resin, vinyl chloride resin modified acrylic resin, acrylic / urethane resin, etc.), vinyl chloride resin, styrene-vinyl acetate copolymer, chloride Pinyl-vinyl acetate copolymer, rosin-modified maleic resin, phenol resin, epoxy resin, polyester resin, polyester polyurethane resin, polyethylene, polypropylene, polybutadiene, polyvinylidene chloride, ionomer resin, polyurethane resin, silicone Fat, ketone resins, ethylene - can be used ethyl acrylate copolymer, xylene resin and polyvinyl butyral resin, polyamide resin, one kind or two kinds or more selected from the group consisting of modified polyphenylene oxide resin. However, it is not limited to the said material.

  In addition, a method of forming a core layer made of a material that prevents elongation, such as canvas, from a rubber material having a large elongation in the base layer, and forming the elastic layer 12 thereon can be used. As a material for preventing elongation used for the core layer at this time, for example, natural fibers such as cotton and silk, polyester fibers, nylon fibers, acrylic fibers, polyolefin fibers, polyvinyl alcohol fibers, polyvinyl chloride fibers, One kind selected from the group consisting of synthetic fibers such as polyvinylidene chloride fiber, polyurethane fiber, polyacetal fiber, polyfluoroethylene fiber and phenol fiber, inorganic fibers such as carbon fiber and glass fiber, and metal fibers such as iron fiber and copper fiber Alternatively, two or more types can be used and those in the form of yarn or woven fabric can be used. Of course, the material is not limited to the above. The above-described yarn may be twisted in any manner, such as one or a plurality of filaments twisted, one-twisted yarn, various twisted yarns, double yarn, or the like. Further, for example, fibers of a material selected from the above material group may be blended. Of course, the yarn can be used after being subjected to an appropriate conductive treatment. On the other hand, the woven fabric can be any woven fabric such as knitted weave, and of course, a woven fabric that has been woven can also be used and can be subjected to a conductive treatment.

  Further, the coating layer on the surface of the intermediate transfer body is for coating the surface of the elastic layer with, for example, a fluororesin, and is composed of a layer having good smoothness. The material used for the coating layer is not particularly limited, but generally, a material that reduces secondary toner transfer to the surface of the intermediate transfer member to improve secondary transferability is used. For example, one or more types of polyurethane, polyester, epoxy resin, etc., or materials that reduce surface energy and increase lubricity, such as fluorine fats, fluorine compounds, fluorocarbons, titanium oxide, silicon carbide, etc. Can be used by dispersing one type or two or more types or changing the particle size as required. Further, it is also possible to use a material such as a fluorine-based rubber material in which a heat treatment is performed to form a fluorine layer on the surface and the surface energy is reduced.

  If necessary, the base layer 11, the elastic layer 12 or the coat layer 13 is, for example, carbon black, graphite, metal powder such as aluminum or nickel, tin oxide, titanium oxide, antimony oxide, Conductive metal oxides such as indium oxide, potassium titanate, antimony oxide-tin oxide composite oxide (ATO), and indium oxide-tin oxide composite oxide (ITO) can be used. Here, the conductive metal oxide may be coated with insulating fine particles such as barium sulfate, magnesium silicate, and calcium carbonate. However, it is not limited to the said material.

Next, a modified printer in which a partial configuration of the printer according to the embodiment is changed to another configuration will be described.
[Modification]
FIG. 9 is a schematic configuration diagram showing a printer according to a modification, which is a so-called revolver type full color printer. In this figure, this printer has only one photoconductor as an image carrier. Around the photosensitive member 2, a cleaning device 100, a charge eliminating unit 3, a charging roller 4, an optical writing device 5, and four developing devices 6Y, 6C, 6M, and 6K are disposed.

  The four developing devices 6Y, 6C, 6M, and 6K are individually reciprocated by a moving mechanism (not shown). Specifically, the developing sleeve can be reciprocated between a developing position where the developing sleeve is brought into contact with or close to the photosensitive member 2 and a retracted position which is further away from the photosensitive member 2. Only the one at the development position develops the electrostatic latent image on the photoreceptor 2.

  The configurations of the charge eliminating unit 3, the charging roller 4, and the optical writing device 5 are the same as those of the image forming process unit 1Y according to the above-described embodiment.

  First, an electrostatic latent image for Y is formed on the surface of the photoreceptor 2, and this is developed into a Y toner image by the developing device 6Y for Y. Then, primary transfer is performed on the intermediate transfer belt 21. Thereafter, while the intermediate transfer belt 21 moves endlessly by three rounds, C, M, and K toner images are sequentially formed on the surface of the photosensitive member 2 and are primarily transferred onto the Y toner image on the intermediate transfer belt 21 in sequence. The As a result, a four-color toner image is formed on the intermediate transfer belt 21.

  The secondary transfer roller 25 disposed below the intermediate transfer belt 21 is brought into contact with and separated from the belt by a contact / separation mechanism (not shown). In the step where the intermediate transfer belt 21 moves endlessly over a plurality of turns and the Y, C, M, and K toner images are sequentially superimposed on the belt surface, the secondary transfer roller 25 is separated from the belt surface. Yes. Thereafter, when a four-color toner image is formed on the surface of the belt by overlay transfer, the secondary transfer roller 25 comes into contact with the belt to form a secondary transfer nip. At the secondary transfer nip, the four-color toner images on the belt surface are collectively transferred onto the recording paper P.

  The cleaning device 100Y removes the transfer residual toner adhering to the surface of the photoreceptor 2Y after the primary transfer process. In the cleaning device of this embodiment, a cleaning brush is disposed so as to contact and rub against the surface of the photosensitive member downstream of the cleaning blade in the rotational direction of the photosensitive member, and a toner recovery roller is disposed in contact with the cleaning brush. A configuration in which the toner is removed from the toner collecting roller by a rubber blade is applied.

  It goes without saying that the same effect as described above can be obtained by using the present invention in such an image forming apparatus.

[Embodiment 2]
Hereinafter, an embodiment in which the present invention is applied to an electrophotographic copying machine (hereinafter simply referred to as a copying machine 100) as an image forming apparatus will be described.
FIG. 10 is a schematic configuration diagram showing a main part of the copier according to the present embodiment. The copying machine 100 performs single-color copying, and forms a monochrome image based on image data read by an image reading unit (not shown).

First, the configuration of the entire copying machine 100 will be described.
As shown in FIG. 10, the copying machine 100 includes a drum-shaped photosensitive member 101 as an image carrier. A charging roller 3 as a charging unit and a developing device 106 as a developing unit that is a toner image forming unit that converts a latent image into a toner image are disposed around the photoreceptor 1. In addition, a transfer roller 115 as a transfer unit that transfers a toner image formed by the developing device 106 onto a transfer sheet as a recording medium, and a cleaning device 120 that is a cleaning device that cleans toner remaining on the surface of the photoreceptor 101 after transfer. A neutralizing lamp 102 for neutralizing the surface of the photoreceptor 101 is disposed. Further, a light shielding plate 140 that shields the light from the static elimination lamp is provided between the static elimination lamp 102 and the charging roller 103.

The charging roller 103 is disposed on the surface of the photoconductor 101 in a non-contact manner at a predetermined distance, and charges the surface of the photoconductor 101 to a predetermined polarity and a predetermined potential. In the copying machine 100, the surface of the photoreceptor 101 is uniformly charged to a negative polarity.
The surface of the photoconductor 101 uniformly charged by the charging roller 103 is irradiated with laser light 104 from an exposure device (not shown) based on image data to form an electrostatic latent image.

The developing device 106 includes a developing roller 108 as a developer carrying member including a magnet as a magnetic field generating unit. A developing bias is applied to the developing roller 108 from a power source (not shown). In the casing 107 of the developing device 106, a supply screw 109 and an agitation screw 110 are provided that agitate the two-component developer composed of toner and carrier contained in the casing 107 while conveying them in opposite directions. A doctor 105 for regulating the developer carried on the developing roller 108 is also provided. The toner used in this embodiment is pulverized (indeterminate) toner.
The toner in the developer stirred and conveyed by the two screws of the supply screw 109 and the stirring screw 110 is charged to a negative polarity. The developer is pumped up to the developing roller 108 by the action of a magnet contained in the developing roller 108. The developer thus pumped up is regulated by the doctor 105, and in a developing region facing the photoconductor 101, the developer is brought up by a magnetic force of a magnet to form a magnetic brush.
Further, a transfer bias is applied to the transfer roller 115 from a power source (not shown).

Next, an image forming operation in the copying machine 100 will be described.
In the copying machine 100, when a copy start button of an operation unit (not shown) is pressed, reading of an original is started by an image reading unit (not shown). A predetermined voltage or current is sequentially applied to the charging roller 103, the developing roller 108, the transfer roller 115, and a cleaning brush 123, which will be described in detail later, at predetermined timing. In synchronism with this, the photosensitive member 101 is rotationally driven in the direction of arrow A in the figure by a photosensitive member driving motor (not shown) as driving means. Simultaneously with the rotation of the photosensitive member 101, the developing roller 108, the transfer roller 115, the supply screw 109, the stirring screw 110, and a toner discharge screw 119, a cleaning brush 123, and a toner collection roller 124, which will be described in detail later, are also rotated in a predetermined direction. Is done.

  When the photoconductor 101 rotates in the direction of arrow A in the figure, first, the surface of the photoconductor is charged to a potential of, for example, −700 [V] by the charging roller 103 of the charging device. Then, a laser beam 4 corresponding to an image signal is irradiated onto the photosensitive member 1 from an exposure device (not shown), and the potential on the photosensitive member 1 at a portion irradiated with the laser beam 104 is lowered to, for example, −120 [V], An electrostatic latent image is formed.

  The photoreceptor 1 on which the electrostatic latent image is formed is rubbed against the surface of the photoreceptor 101 with a developer magnetic brush formed on the developing roller 108 at a portion facing the developing device 106. At this time, the negatively charged toner on the developing roller 108 is moved to the electrostatic latent image side by a developing bias of, for example, −450 [V] applied to the developing roller 108, and is formed into a toner image (development). As described above, in this embodiment, the electrostatic latent image formed on the photosensitive member 1 is reversely developed by the developing device 106 with the negatively charged toner. In this embodiment, an example using a non-contact charging roller system of N / P (negative positive: toner adheres to a place where the potential is low) has been described, but the present invention is not limited to this.

  The toner image formed on the photosensitive member 101 is guided by guide plates 113 and 114 from a paper feeding unit (not shown) through a facing portion between the lower registration roller 111 and the upper registration roller 112, and the photosensitive member 101 and the transfer roller 115. Are transferred to a transfer sheet fed to a transfer area formed between the two. At this time, the transfer sheet is supplied in synchronism with the leading edge of the image at a portion where the lower registration roller 111 and the upper registration roller 112 face each other. Further, at the time of transfer to transfer paper, a transfer bias whose constant current is controlled to +10 [μA], for example, is applied to the transfer roller 115. The transfer paper onto which the toner image has been transferred is separated from the photoreceptor 101 by a separation claw 116 as a separation unit, guided by a conveyance guide plate 141, and conveyed to a fixing device as a fixing unit (not shown). By passing through the fixing device, the toner image is fixed on the transfer paper by the action of heat and pressure, and the transfer paper is discharged out of the apparatus. On the other hand, the residual toner after the transfer is removed from the surface of the photoreceptor 101 after the transfer by the cleaning device 120, and the charge is removed by the charge removal lamp 102.

Next, the cleaning device 20 for removing toner on the surface of the photoreceptor 101 will be described.
As shown in FIG. 10, the cleaning device 120 includes a cleaning brush 123 to which a plus voltage is applied from a brush power source 130. Further, a conductive material to which a negative voltage is applied from the blade power source 129 is disposed at a position facing the surface of the photoconductor 101 upstream of the surface of the photoconductor 101 with respect to the position where the cleaning brush 123 removes the toner on the photoconductor 101. A cleaning blade 122 is provided.
The cleaning brush 123 is a brush roller that is driven to rotate about the brush rotation shaft 123a, and the brush power supply 130 is configured to apply a voltage to the brush rotation shaft 123a.

  Here, the charge amount of the toner that adheres to the surface of the photosensitive member 101 as the transfer residual toner and reaches the portion facing the cleaning device 120 will be described. FIG. 11 is a graph showing the charge potential distribution immediately before the transfer of the toner carried on the photoreceptor 1 and the charge potential distribution of the untransferred toner remaining on the photoreceptor 101 after the transfer. As shown in FIG. 11, most of the toner on the surface of the photoconductor 101 immediately before transfer is charged with a negative polarity. At the time of transfer, most of the toner charged to a positive polarity before transfer is directly attached to the photoreceptor 101. Further, even if the toner is charged with a negative polarity before transfer, the charged polarity may be reversed to the positive polarity by receiving a positive polarity charge injection applied to the transfer roller 115. Therefore, the untransferred toner on the surface of the photoconductor 101 after the transfer has a distribution in which positive polarity toner and negative polarity toner are mixed as shown in FIG.

The transfer residual toner that adheres to the surface of the photoconductor 101 that has passed through the portion facing the transfer roller 115 reaches the position facing the cleaning blade 122 due to the surface movement of the photoconductor 101.
FIG. 12 is an explanatory diagram of the cleaning blade 122 when the surface of the photoconductor 101 is moved. Most of the untransferred toner that reaches the position facing the cleaning blade 122 is mechanically scraped off by the cleaning blade 122. However, as shown in FIG. 12, the cleaning blade 122 causes a so-called stick slip when the surface of the photosensitive member 101 is cleaned, and a part of the transfer residual toner passes through the portion facing the cleaning blade 122.

  A negative polarity voltage having the same polarity as the charging polarity of the toner is applied to the cleaning blade 122, and when the transfer residual toner passes through the opposite portion between the cleaning blade 122 and the photosensitive member 101, the toner is injected with electric charge. Is done. That is, when the toner passes through the opposing portion between the cleaning blade 122 and the photosensitive member 101, the cleaning blade 122 charges the toner to the normal charging polarity (negative polarity).

The toner charged to the regular charging polarity by the cleaning blade 122 is transferred to a position where the cleaning brush 123 removes the toner on the photoconductor 101 by the surface movement of the photoconductor 101. As shown in FIG. 11, a voltage having a polarity (positive polarity) opposite to the charging polarity of the toner is applied to the cleaning brush 123, and the toner that has passed through the contact portion between the cleaning blade 122 and the photoreceptor 1 is removed. Adsorbs electrostatically.
The toner that has moved onto the cleaning brush 123 moves to the toner collection roller 124 to which a positive polarity voltage higher than that of the cleaning brush 123 is applied by the collection power supply 128 by a potential gradient. The toner that has moved onto the toner collecting roller 124 is scraped off by the toner collecting roller cleaning blade 127, and is discharged out of the cleaning device 120 by the toner discharge screw 119 or returned to the inside of the developing device 106.

Next, details of the case where the charging polarity of the toner passing through the conductive cleaning blade 122 to which a voltage of the same polarity (negative polarity) as that of the toner is applied will be described.
The electrical resistance of the cleaning blade 122 is 10 ⁶ to 10 ⁸ [Ω · cm], and the linear pressure of the contact portion with the photosensitive member 101 is 20 to 40 [g / cm] so as to contact in the counter direction. ing. When no voltage is applied to the cleaning blade 122, the toner that passes through the cleaning blade 122 is frictionally charged by the pressure at the contact portion between the photosensitive member 1 and the cleaning blade 122. The charge potential distribution of the toner is shifted to the normal charge polarity (minus polarity) side of the toner. FIG. 13 is a graph showing the charge potential distribution after the transfer of the toner carried on the photoconductor 101 and the charge potential distribution of the untransferred toner that has passed through the portion facing the cleaning blade 122. As shown in FIG. 13, by passing through the portion facing the cleaning blade 122, it is slightly charged with a negative polarity and shifts to the normal charging polarity side of the toner. It becomes a mixed distribution. Since the charge amount distribution of the transfer residual toner is broad as shown in FIG. 13, all of the transfer residual toner is not charged to the normal charge polarity. Therefore, means other than frictional charging are required in order to set the charging polarity of all the transfer residual toners to the normal polarity.

Further, as shown in FIG. 12, the cleaning blade 122 generates a so-called stick slip in which the contact state changes in the rotation direction of the photosensitive member 101. Then, when the cleaning blade 122 is in a state indicated by C in FIG. 12, toner slip occurs.
As shown in FIG. 10, when a negative voltage is applied to the cleaning blade 22, when the toner is sandwiched between the cleaning blade 122 and the photoreceptor 101, the toner is applied to the toner with the voltage applied to the cleaning blade 122. Current flows in. The toner is charged to the polarity on the applied voltage side and passes through the cleaning blade 122. Further, the toner is charged with the same polarity as the applied voltage by the discharge of the minute gap portion at the entrance and exit of the wedge portion formed by the photosensitive member 101 and the cleaning blade 122.
The toner having the same polarity on one side and passed through the cleaning blade 122 is electrostatically removed by the cleaning brush 123 to which a voltage having a polarity opposite to the toner charging polarity (plus polarity) is applied.

Here, a conventionally known blade cleaning method for cleaning the surface of the photoreceptor by bringing the cleaning blade into contact with the surface of the photoreceptor will be described.
An image forming apparatus is required to have a high resolution so that a higher-precision and higher-definition image can be formed. One means for achieving this is to use a toner having a smaller particle size. Further, in order to improve the transfer rate, the shape of toner is changed from an indefinite shape to a shape closer to a sphere. However, with a conventionally known blade cleaning method, cleaning a toner with a small particle diameter or a spherical diameter has a small particle diameter or a spherical shape. Is a difficult situation. Even when the spherical toner is cleaned by the blade cleaning method, if the linear pressure when pressing the cleaning blade against the surface of the photosensitive member is extremely high (specifically, the linear pressure is 100 [gf / cm] or more), the cleaning can be performed. However, the life of the photosensitive drum and the cleaning blade is extremely shortened accordingly. For example, the life of a photoconductor at a normal linear pressure (20 [gf / cm]) (life when the photosensitive layer is scraped by about 1/3) is about 100,000 sheets at Φ30, and the cleaning blade life (scraps and cleaning failure occurs) The service life is about 120,000 sheets. On the other hand, at a high linear pressure (100 [gf / cm]), the life of the photoconductor is about 20,000 sheets, and the life of the cleaning blade is about 20,000 sheets.

  However, since the image quality is improved when a small particle size toner or a spherical toner is used, this embodiment has a good cleaning property even when cleaning the small particle size toner or the spherical toner, and the surface film of the photoreceptor is shaved. The electrostatic brush cleaning method, which is a cleaning method that suppresses mechanical rubbing that can be reduced, is applied. The same effect can be obtained even when a cleanerless system or the like is used as another cleaning system.

[Experiment 1]
In this embodiment, the adhesion force of one toner to the sample surface was measured using the pulse force mode method described in the first embodiment. Specifically, using the pulse force mode method (SII Nanotechnology Co., Ltd. name: Adhesion Mode), the sample surface is scanned in the vertical direction while scanning the surface of the sample at about 0.1 [Hz] to 10 [Hz]. By vibrating the platform at about 100 [Hz] to 1000 [Hz], the individual toner attached to the tip of the cantilever and the sample surface are continuously contacted and separated, and the adhesion force of the individual toner to the sample surface is increased. It was measured. Further, by measuring the adhesive force in this way, an adhesive force image as shown in FIGS. 14A and 14B is obtained, and frequency distribution is made from this adhesive force image by dedicated software (SII). In the case of Nanotechnology Adhesion Mode, an error signal image is used). For example, this process is possible using SPIP manufactured by Image Metrology. The number of data of the frequency distribution is determined by the condition for acquiring the adhesion force image. Under this condition, the distribution is composed of 128 × 128 = 16384 points.

  In the present embodiment, the roller 1 and the roller 2 which are two types of toner collecting rollers in which the surface layer is changed as will be described later are used as measurement targets. The roller 1 has a PVDF layer having a thickness of 0.5 [mm] formed on the surface of φ30 stainless steel as a core metal, and a thin film layer made of acrylic resin is formed on the surface of the PVDF layer. . The roller 2 has a PVDF layer having a thickness of 0.5 [mm] formed on the surface of a stainless steel of φ30 that is a core metal. And each surface layer of the roller 1 and the roller 2 was peeled off from stainless steel, and it cut out to about 10 [mm] square, and measured with the atomic force microscope (AFM).

Next, experimental conditions are shown.
・ Measurement conditions (pulse force mode method):
Atomic force microscope (AFM): scanning probe microscope SPI4000, multifunctional unit SPA400 (manufactured by SII Nanotechnology)
Measurement mode: Adhesion mode Cantilever: Olympus Corporation standard silicon nitride cantilever OMCL-RC800PSA, spring constant: 0.76 [N / m]
・ Measurement area: 1 [μm] corner ・ Number of lines: 128 in the vertical direction and 128 in the horizontal direction
・ Measurement scanning frequency: 1 [Hz]
・ Z frequency (adhesion frequency): 1 [kHz]
・ Maximum load condition: Set with the aim of pressing strength of the cantilever tip and sample surface to 50 [nN] (set by cantilever deflection and adhesion amplitude)
-Toner particle size at the tip of the cantilever: 7.2 [μm]
・ Toner type: Ricoh Co., Ltd. PxP toner prototype

  FIG. 14A and FIG. 14B show images of adhesion force measurement results in the longitudinal direction 128 × lateral direction 128 of the rollers 1 and 2 respectively. Further, FIG. 15 shows an adhesion force distribution obtained from 128 × 128 adhesion force measurement values which are constituent elements of this measurement result.

[Experiment 2]
The roller 1 and the roller 2 were mounted as the toner collection roller 124 of the cleaning device 120 provided in the copying machine 100 shown in FIG.

Next, experimental conditions are shown.
-Toner type: Ricoh PxP toner prototype-Cleaning brush: Brush fiber (conductive polyester with 3 mm bristle), Φ12 [mm]
-Material of toner collecting roller: cored bar (stainless steel), surface layer (acrylic coat with a layer thickness of 10 [μm]), Φ10 [mm]
-Applied voltage: photoreceptor charging potential (-800 [V])
Developing roller (-400 [V])
Conductive blade (-450 [V])
Cleaning brush (+350 [V])
Toner recovery roller (+650 [V])

The conditions for image output operation are shown below.
・ Copy machine: Ricoh's imgio Neo C600
-Number of output sheets: A4 horizontal 100 sheets-Experiment environment: 27 [° C] 55 [%]
Output image: Image area 5 [%] chart

  As a result of outputting the image under the experimental conditions and the image output conditions as described above, the output image after outputting 100 sheets is a normal image in the roller 1, and the roller 2 has a streaky abnormality in the output image due to poor cleaning. The image was a defective image.

[Evaluation Example 1]
The present inventors have found that the adhesive force measurement value is 95% or more below 1.4 times the average value of the adhesive force based on various research results. It has been found that the variation in the direction in which the adhesion force is large is within a certain range, and the strength of the adhesion force is the same at any location on the toner recovery roller. Therefore, in the evaluation example 1, the evaluation was performed while paying attention to this. Note that an adhesion force 1.4 times the average adhesion force of each roller, which will be described later, is an adhesion force large enough to remove toner from the toner collection roller by the toner collection roller cleaning blade 127.

  From the results of Experiment 1, the average adhesion force between the roller 1 and the roller 2 was 52.7 [nN] for the roller 1 and 44.1 [nN] for the roller 2.

  The roller 1 has an adhesive force measurement value of about 99 [%] below 73.8 [nN] which is 1.4 times the average adhesive force value. That is, the measured adhesive force value of the roller 1 is the average adhesive force value. The adhesive force showing a value 1.4 times the value is 95% or more.

  As described above, when the roller 1 is used as the toner collecting roller 124 of the cleaning device 120, an adhesion force measurement value of about 99 [%] exists below 73.8 [nN], which is 1.4 times the average adhesion force. is doing. Therefore, the variation in the direction in which the adhesion force is large with respect to the average value in the frequency distribution of the adhesion force measured as described above is within a certain range, and the strength of the adhesion force is the same at any location on the roller. Therefore, it is considered that stable cleaning was performed at any location on the roller. Therefore, it is considered that even if image output is performed as in the result of Experiment 2 described above, cleaning failure does not occur and streaky abnormal images are not output. In other words, it exhibits an excellent function in cleaning characteristics in which adhesion to toner is greatly involved.

  On the other hand, the roller 2 has an adhesive force measurement value of about 81 [%] below 61.8 [nN] which is 1.4 times the average adhesive force value. There is no more than 95 [%] in the adhesive force showing 1.4 times the average adhesion force.

  As described above, when the roller 2 is used as the toner collecting roller 124 of the cleaning device 120, an adhesion force measurement value of about 95 [%] exists below 73.8 [nN] which is 1.4 times the average adhesion force. Not done. For this reason, since the variation in the direction of large adhesion force with respect to the average value in the frequency distribution of the adhesion force does not fall within a certain range, the strength of the adhesion force varies greatly depending on the location on the roller. It is considered that the cleaning is no longer performed stably at the point. Therefore, it can be considered that streaky abnormal image generation was output in the output image due to defective cleaning as in the result of Experiment 2 described above.

[Evaluation Example 2]
From the various research results, the inventors of the present invention have found that the adhesive force variation is smaller than the adhesive force average value by satisfying the relationship of Equation 2 when the adhesive force average value is X and the standard deviation is Y in the measured adhesive force value. It has been found that the strength of the adhesive force falls within a certain range and the adhesive strength is the same at any location on the toner collecting roller. Therefore, in the evaluation example 2, the cleaning property was evaluated by paying attention to this. The average adhesion force is an adhesion force that can remove toner from the toner collection roller by the toner collection roller cleaning blade.

  From the results of Experiment 1, the average adhesion force between the roller 1 and the roller 2 was 52.7 [nN] for the roller 1 and 44.1 [nN] for the roller 2.

  The standard deviations of the adhesion forces between the roller 1 and the roller 2 were 9.1 [nN] for the roller 1 and 21.8 [nN] for the roller 2.

When the average value of the adhesion force and the standard deviation of the roller 1 and the roller 2 described above are substituted into the formula 2, the formula 1 is given for the roller 1 and the formula 4 is given for the roller 2.

  From Equation 3, the roller 1 satisfies the relationship shown in Equation 2. As a result, as described above, the variation in the adhesion force is within a certain range with respect to the average adhesion force, and the strength of the adhesion force is the same at any location on the roller. It is considered that stable cleaning was also performed in this part. Therefore, it is considered that even if image output is performed as in the result of Experiment 2 described above, cleaning failure does not occur and streaky abnormal images are not output.

  From Expression 4, the roller 2 does not satisfy the relationship shown in Expression 2. As a result, the dispersion of the adhesive force does not fall within a certain range with respect to the average value of the adhesive force, so the strength of the adhesive force varies greatly depending on the location on the roller, and the cleaning is stable at some locations on the roller. It is thought that it was not done. Therefore, it can be considered that streaky abnormal image generation was output in the output image due to defective cleaning as in the result of Experiment 2 described above.

  From these facts, it can be seen that by evaluating the degree of toner adhesion to the roller member using the standard deviation in addition to the average value of the adhesion force, it is possible to determine the degree of adhesion of the member in accordance with a more natural phenomenon. . That is, many of the abnormal phenomena related to the degree of adhesion of the powder in the image forming apparatus, the air blowing apparatus, the powder conveying apparatus, etc. do not occur at all positions on the member surface. The abnormal phenomenon occurs in a region where the adhesion force is extremely large or small. Therefore, the abnormal phenomenon cannot be detected with high sensitivity only by the characteristic value at a certain point or the average value in the region. In other words, instead of evaluating with a single characteristic value on the surface of the member to be measured, measure the in-plane distribution of adhesion force on the surface of a certain range of the member to be measured, and evaluate with the average value and standard deviation of the distribution This is because it is more in line with the natural phenomenon of adhesion.

As described above, according to each embodiment, the adhesion force generated between a toner collecting roller that is a roller member that collects toner from a cleaning roller that is a member to be cleaned and a single toner that is a single powder is measured by the toner collecting roller. Measurement is made at a plurality of locations, and the distribution of the adhesion force on the toner collecting roller is judged from the distribution state of the measured adhesion force frequency distribution. For example, if the degree of variation of the frequency distribution is small, it is determined that the adhesion force on the toner collection roller is distributed with the same strength at any location on the toner collection roller. On the other hand, if the degree of variation in the frequency distribution is large, it is determined that the adhesion force on the toner collection roller is distributed with a significantly different strength at each location on the toner collection roller. Since the distribution of the adhesion force on the toner collecting roller can be determined in this way, for example, the following prediction is possible. By determining that the adhesion force is distributed with the same strength at any location on the toner collection roller, the adhesion force is distributed with a strength capable of removing the toner from the toner collection roller. Then, it can be predicted that the toner can be removed from any location on the toner collecting roller. Further, it is judged that the adhesion force is greatly different for each location on the toner collection roller, and the adhesion force is too strong on the toner collection roller to remove the toner from the toner collection roller. It is possible to predict that there may be a part that cannot be performed. Therefore, it can be predicted whether the toner can be satisfactorily removed from the toner collection roller.
Further, according to each embodiment, the distribution state is represented by the dispersion or standard deviation of the measured adhesion force. Thereby, the dispersion | variation degree with respect to the average value of the measured said adhesive force can be grasped | ascertained easily from the frequency distribution of the measured said adhesive force. Therefore, as described above, when the average value is an adhesive force capable of removing the toner from the toner collecting roller, the above determination can be easily performed.
According to the second embodiment, the distribution state is represented by a cumulative frequency or a cumulative relative frequency of the measured adhesion force at a predetermined adhesion force. Thereby, it is possible to easily grasp how many degrees of the measured adhesion force are gathered below the predetermined adhesion force. Therefore, for example, it is possible to grasp whether the measured adhesion force exists within the range of the adhesion force with which the toner can be removed from the toner collection roller, so that the determination can be easily performed.
Further, according to each embodiment, the average value of the measured adhesion force is also used to determine the distribution of the adhesion force on the toner collection roller, so that the distribution of the adhesion force on the toner collection roller as described above. However, it is possible to easily determine whether the toner is distributed with such a strength that the toner can be removed from the toner collection roller.
Further, according to the second embodiment, when the average value is X and the standard deviation or the square root of the dispersion is Y, satisfying X / Y> 4, the variation in the measured adhesive force is the average value. In contrast, it is possible to discriminate excellent members that fall within a certain range. Further, according to the second embodiment, the predetermined adhesive force is an adhesive force that is 1.4 times the average value of the measured adhesive force, and the cumulative relative frequency at the predetermined adhesive force or the measured adhesive force. Since the ratio of the cumulative frequency to the total frequency of 95% or more is 95% or more, the variation in the direction in which the adhesive force is large with respect to the average value in the measured adhesive force frequency distribution falls within a certain range. It is possible to discriminate such excellent members.
Further, according to each embodiment, the adhesion force is obtained by measuring the adhesion force between the individual toner attached to the deep needle tip and the toner collecting roller in the atomic force microscope. As a result, the adhesion force between one toner and the toner collecting roller can be accurately and efficiently measured.
In addition, according to each embodiment, since the powder is toner, it is possible to determine a toner collecting roller that does not easily adhere to the toner or a toner that does not easily adhere to a specific toner collecting roller.
Further, according to each embodiment, when the particle diameter of the toner is 1 [μm] or more and 20 [μm] or less, the toner adheres to a toner collecting roller or a specific toner collecting roller to which the toner hardly adheres. Difficult toner can be discriminated with high accuracy.
Further, according to the second embodiment, in the toner collecting roller that is a collecting roller that collects powdered toner from the cleaning roller that is the member to be cleaned, the adhesion force generated between the roller surface and the individual toner is applied to the roller. By measuring at a plurality of locations on the surface, the average value of the measured adhesion force is X, and the standard deviation of the measured adhesion force or the square root of the dispersion is Y, satisfying X / Y> 4 For example, as described above, a roller member that can satisfactorily clean the toner recovery roller can be used for the toner recovery roller.
Further, according to the second embodiment, in the toner collecting roller that is a collecting roller that collects powdered toner from the cleaning roller that is the member to be cleaned, the adhesion force generated between the roller surface and the individual toner is applied to the roller. Cumulative relative frequency of the above measured adhesive force at an adhesive force 1.4 times the average value of the measured adhesive force or a ratio of the cumulative frequency to the total frequency of the above measured adhesive force For example, as described above, a roller member that can satisfactorily clean the toner collection roller can be used as the toner collection roller.
In addition, according to each embodiment, since the cleaning device includes the above-described toner collection roller, it is possible to provide a cleaning device with good cleaning properties over time.
In addition, according to each embodiment, by providing the image forming apparatus with the above-described cleaning device having the toner collection roller, it is possible to provide an image forming apparatus including a cleaning device with good cleaning properties over time.

(A) The graph which showed the measurement result of the adhesive force of the member 1. (B) The graph which showed the measurement result of the adhesive force of the member 2. FIG. (C) The graph which showed the measurement result of the adhesive force of the member 3. (D) The graph which showed the measurement result of the adhesive force of the member 4. 1 is a schematic configuration diagram illustrating a printer according to a first embodiment. FIG. 3 is an enlarged configuration diagram illustrating an image forming process unit for Y in the printer. 6 is a graph showing the relationship between the friction coefficient of the toner recovery roller and the cleaning performance. The figure which showed the adhesive force measurement area. The figure which showed the photosensitive layer of the photoreceptor. The figure which represented the shape of the toner typically in order to demonstrate shape factor SF-1. The longitudinal cross-sectional view of an intermediate transfer body. FIG. 9 is a schematic configuration diagram of a printer according to a modification. FIG. 3 is a schematic configuration diagram of a copier according to a second embodiment. 6 is a graph showing a charge potential distribution immediately before transfer of toner carried on a photoconductor and a charge potential distribution of transfer residual toner remaining on the photoconductor after transfer. Explanatory drawing of the cleaning blade at the time of photoreceptor surface movement. 6 is a graph showing a charge potential distribution after transfer of toner carried on a photoreceptor and a charge potential distribution of residual toner that has passed through a portion facing a cleaning blade. (A) Adhesive force image with a scale of nanometer order. (B) Adhesive force image with a scale of micrometer order. 3 is a graph showing the adhesion force distribution of the roller 1 and the roller 2. The conceptual diagram showing distribution of the adhesive force produced between powder and the surface of the members A and B. FIG. The conceptual diagram showing distribution of the adhesive force produced between the powder and the surface of the members A and C.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming process part 2 Photoconductor 4 Charging roller 5 Optical writing device 6 Developing device 50 Cleaning device 52 Cleaning blade 53 Cleaning brush 54 Toner recovery roller 57 Toner recovery roller cleaning blade 100 Copier 101 Photoconductor 102 Static elimination lamp 103 Charging Roller 106 Developing device 108 Developing roller 115 Transfer roller 119 Toner discharge screw 120 Cleaning device 122 Cleaning blade 123 Cleaning brush 123a Brush rotating shaft 124 Toner recovery roller 127 Toner recovery roller cleaning blade 128 Recovery power source 129 Blade power source 130 Brush power source 131 Brush fiber 132 Conductive Material 133 Insulating Material

Claims (13)

  The adhesion force generated between the roller member for collecting powder from the member to be cleaned and the individual powder is measured at a plurality of locations on the roller member, and the roller is determined from the distribution state of the frequency distribution of the measured adhesion force. A method for determining an adhesion force distribution, comprising: determining the distribution of the adhesion force on a member. In the adhesive force distribution judging method according to claim 1,
The distribution state is represented by the dispersion or standard deviation of the measured adhesion force. In the adhesive force distribution judging method according to claim 1,
The distribution state is represented by a cumulative frequency or a cumulative relative frequency of the measured adhesion force at a predetermined adhesion force. In the adhesive force distribution determination method according to claim 2,
An adhesion force distribution determination method, wherein the average value of the measured adhesion force is also used to determine the adhesion force distribution on the roller member. In the adhesive force distribution judging method according to claim 4,
A method for determining an adhesive force distribution, wherein X / Y> 4 is satisfied, where A is the average value and A is the standard deviation or B is the square root of the variance. In the adhesive force distribution determination method according to claim 3,
The predetermined adhesive force is an adhesive force 1.4 times the average value of the measured adhesive force,
A method for determining an adhesive force distribution, wherein a ratio of the cumulative frequency to the cumulative relative frequency or the total frequency of the measured adhesive force is 95% or more. In the adhesive force distribution judgment method according to claim 1, 2, 3, 4, 5 or 6,
The adhesion force distribution determination method according to claim 1, wherein the adhesion force is obtained by measuring an adhesion force between the individual powder attached to the tip of a deep needle in an atomic force microscope and the recovery roller. In the adhesive force distribution judging method according to claim 1, 2, 3, 4, 5, 6 or 7,
A method for determining an adhesion force distribution, wherein the powder is toner. In the adhesion force distribution judgment method according to claim 8,
A method of determining an adhesion force distribution, wherein the toner has a particle size of 1 [μm] or more and 20 [μm] or less. In the collection roller that collects powder from the member to be cleaned,
The adhesion force generated between the roller surface and one individual powder is measured at a plurality of locations on the roller surface, the average value of the measured adhesion force is X, and the standard deviation of the measured adhesion force Alternatively, a collection roller satisfying X / Y> 4, where Y is the square root of dispersion. In the collection roller that collects powder from the member to be cleaned,
The adhesion force generated between the roller surface and the individual powder is measured at a plurality of locations on the roller surface, and the measured adhesion is 1.4 times the average value of the measured adhesion force. A collecting roller, wherein the cumulative relative frequency of the adhesion force or the ratio of the cumulative frequency to the total frequency of the measured adhesion force is 95% or more. In a cleaning device for cleaning a member to be cleaned,
A cleaning device comprising the collection roller according to claim 10. A member to be cleaned;
In an image forming apparatus provided with a cleaning means for cleaning the member to be cleaned,
An image forming apparatus comprising the cleaning device according to claim 12.