JP2007292985A - Image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a sharp image without image deletion under high temperature and high humidity conditions even when no drum heater is used in a copy machine or a printer mounting an a-Si drum, and particularly, to prevent image deletion as well as to obtain cleaning property and durability of a cleaning member, and to maintain long-term high picture quality. <P>SOLUTION: A method for forming a digital image including a cleaning means 106 and using an a-Si photoreceptor 101 is characterized in that: in at least the cleaning step, the surface of a photoreceptor is rubbed and polished with an abrasive comprising a perovskite crystal having an average particle size of 50 to 500 nm; a normal developing system is used; and destaticizing light is distributed prior to the cleaning step CLN. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to electrophotography in which dot-like latent image exposure is performed on a photosensitive member to form a latent image, and more particularly to an image forming method using a photosensitive member having a cleaning process and having a long life. .

  In recent years, digital electrophotographic apparatuses such as laser printers have attracted attention because of their good image quality and high-speed printout.

  In particular, an electrophotographic apparatus using an amorphous silicon photoreceptor (hereinafter referred to as an a-Si photoreceptor) is preferable from the viewpoints of high sensitivity, high stability, and high durability, a long maintenance interval, and a reduction in running cost. .

  18 and 19 are schematic views showing an image forming process of the digital electrophotographic apparatus. In the vicinity of the photosensitive member 1801, a main charging unit 1802, a latent image exposure 1803, a developing unit 1804, and a transfer unit are provided in the vicinity of the photosensitive member. 1808, a cleaning unit 1806, a charge eliminating unit 1807, a transport unit 1809, and the like are provided. The photoreceptor 1801 is a temperature control means (drum heater) (not shown) for suppressing image blur in a high humidity environment, particularly when a highly durable photoreceptor excellent in wear resistance such as an a-Si photoreceptor is used. Called).

  The photosensitive member 1801 is rotationally driven in the X direction, charged by the main charging unit 1802, and irradiated with a latent image exposure 1803 to form an electrostatic latent image. The latent image is developed by supplying toner from the developing means 1804. Thereafter, the image is transferred to a transfer material P such as paper by a transfer means 1808, fixed by a fixing means (not shown), and discharged outside the apparatus. On the other hand, the surface of the photoconductor 1801 after the transfer process is cleaned by a cleaning blade as the cleaning unit 1806, and after being further neutralized by the neutralizing unit 1807, it is again used for the next image forming process. The cleaned transfer residual developer and the like are collected in a waste toner container 1805. Alternatively, it may be collected in another waste toner container (not shown) via a conveying means (not shown). A rubbing member 1810 or waste toner feed blade 1811 may be provided on the upstream side of the cleaning unit 1806.

  On the other hand, with regard to the electrophotographic apparatus itself, as market needs have been reduced in size, increased in productivity, and saved in energy, even in an electrophotographic apparatus using a highly durable photoreceptor, the diameter of the photoreceptor is reduced or the speed is increased. In addition, it is desired to remove heating means such as an environmental heater (referred to as “drum heater-less”).

  In a digital electrophotographic apparatus using a highly durable photoreceptor typified by an a-Si photoreceptor, a method of scraping the charged product together with the surface layer like a conventional organic photoreceptor (OPC) cannot be used. In particular, when there is no drum heater, there is a case where an image defect such as so-called image flow occurs in which an image is blurred in a high humidity environment.

  Further, in reducing the diameter of the a-Si photosensitive member or increasing the speed of the electrophotographic apparatus using the a-Si photosensitive member, the time from the neutralization step to the main charging step is shortened between processes, Since an excessive current is required, the image flow deteriorates as the discharge product increases. Further, particularly in the downsizing, it is necessary to downsize or remove a rubbing member such as a magnetic brush roller provided in the past, in particular, the magnetic brush, and the image flow caused by the reduction in the rubbing polishing force by the magnetic brush is required. Deterioration may occur.

  As a method for solving these problems, an a-Si photoreceptor using a toner surface-treated with two kinds of titanium oxide fine particles defining the average particle size and specific resistance of primary particles and a cleaning roller made of polyurethane foam is used. A method of polishing the surface has been proposed (Patent Document 1). However, since this method uses a sponge roller, when the localized output pattern such as a ruled line is repeated, the polishing force may be biased due to the difference in the image ratio.

  As a response to the localized output, a neutralization light source is provided upstream of the cleaning means comprising a magnetic brush member and a cleaning blade to weaken the electrostatic force of the transfer residual toner, and waste toner from the magnetic brush to the photoreceptor surface A method for making the resupply uniform has been proposed (Patent Document 2). However, this method is not sufficient as a countermeasure against image flow.

  Further, as a method taking into account the rubbing of the surface of the photosensitive member and the charging stability, an auxiliary charging unit provided with a charge eliminating unit upstream of the cleaning unit and further serving as a rubbing unit between the cleaning unit and the charge eliminating unit As a method of using an injection charge for the auxiliary charge (Patent Document 3), a developer containing an abrasive having an average particle diameter and an electric resistance value, and an auxiliary charge comprising an elastic roller. Methods (Patent Documents 4 and 5) using members have been proposed. However, since the method of Patent Document 3 uses injection charging as auxiliary charging, an auxiliary device such as a high-voltage power supply is necessary, and the cost is unavoidable. On the other hand, in the configurations of Patent Documents 4 and 5, as in Patent Document 1, uneven polishing force may occur.

Japanese Patent Laid-Open No. 2005-17524 JP-A-10-49017 JP 2003-91142 A JP 2001-42734 A JP 2001-05256 A

  An object of the present invention is to provide an image forming method that solves the above-described problems. Specifically, an image forming method capable of maintaining a cleaning property capable of satisfactorily removing a charged product from a photoconductor for a long period of time, preventing image defects such as image flow, and maintaining stable image characteristics at a high level. The issue is to provide.

In order to achieve the above object, the image forming method of the present invention comprises:
(1) Using an a-Si photoreceptor, the latent image forming step is a back exposure (hereinafter referred to as BAE; BAE; Back Area Exposure) method, and a perovskite having an average particle diameter D of 30 to 500 nm in the cleaning step. It has a step of rubbing the surface of the photoreceptor through abrasive particles made of inorganic fine particles having a type crystal, and further has a charge eliminating step between the transfer step and the cleaning step.
(2) The 10-point average roughness Rz of the photoreceptor surface is 0.5 to 2 times the average particle diameter D of the abrasive.
(3) The maximum roughness Rmax on the surface of the photoreceptor is not more than 3 times the average particle diameter D of the abrasive.
(4) The developer is a magnetic one-component developer.
(5) A toner having an average particle diameter and an average circularity within a specified range is used.
(6) The time from the cleaning process to the charging process during image formation is 100 msec or less.
(7) Special feature is that the main charging process is a proximity charging system.
(8) It has an abrasive particle recovery step.
(9) Specially applying a bias having a predetermined polarity in the abrasive particle recovery step.

  According to the present invention, even when an a-Si photoconductor having excellent wear resistance is used, the charged product adhering to the surface of the photoconductor drum can be scraped off satisfactorily, and image flow can be prevented.

  In addition, it is possible to equalize the polishing force and load on the cleaning blade when repeatedly used (so-called printing durability) with the output of localized images, images with extremely low density, etc., and prevent image flow. In addition, good cleaning properties can be maintained, and wear of the cleaning blade and the photoreceptor can be suppressed.

  By defining the correlation between the surface shape of the photoreceptor and the particle size of the abrasive, it is possible to improve the fluidity, particularly in the longitudinal direction, mainly in the cleaning process when the charged product is polished and removed with high efficiency.

  By adopting a magnetic one-component development system which is a non-contact development system, it is possible to suppress the recovery of abrasives in the development process and the accompanying deterioration in development characteristics. In addition, the rubbing effect on the surface of the photoreceptor not only by the abrasive but also by the hard magnetic toner is also superimposed.

  By providing a proximity charging method, an abrasive recovery process, etc., it is possible to extend the life of the system including the photosensitive member, the cleaning unit, and the charging unit, and to reduce the maintenance load.

  Hereinafter, the present invention will be described in detail.

FIG. 1 shows an example of an image forming apparatus according to the present invention. A main charging unit 102, a latent image exposure 103, a developing unit 104, a transfer unit 108, a cleaning unit 106, a conveying unit 109, and the like are provided around the photoconductor 101 that is rotationally driven in the X direction. The latent image exposure employs BAE (details will be described later), and the charge eliminating means 107 is disposed between the transfer means 108 and the cleaning means 106.

  There are roughly two types of digital image forming methods depending on the relationship between the image information and the exposure unit. One is an image exposure method (hereinafter referred to as IAE) for exposing an image portion, and the other is a back exposure method (BAE) for exposing a non-image portion (background portion).

  BAE is the same as the analog image forming method, and a so-called regular developing method, and IAE is a reversal developing method in which the photosensitive member and the developer have opposite polarities.

  FIG. 10 shows the state of one line of IAE on the left side, that is, the state of light beam ON only for one line, the state of one line of BAE on the right side, that is, the latent image state of light beam OFF only for one line, and the development bias. The DC component of is shown. The solid line represents the photoreceptor surface potential during the development process, and the broken line represents the photoreceptor surface potential during the cleaning process when the image forming apparatus as shown in FIGS. 18 to 19 is used. The developing bias is Vdi for IAE and Vdb for BAE.

  The developer is developed on the surface of the photoreceptor by electrostatic adhesion, and the electrostatic adhesion is caused by contrasts of ΔVl1 = Vdi−Vi and ΔVh1 = Vb−Vdb, respectively.

  At the time of entering the cleaning process, the surface potential of the photosensitive member is attenuated and is in a state as indicated by a broken line. As for the contrast applied to the electrostatic adhesion force, ΔVl1 increases to ΔVl2 in IAE, and ΔVh1 decreases to ΔVh2 in BAE. In BAE, the adhesive force of the developer is reduced, so that the developer can easily move in the longitudinal direction of the photoreceptor in the cleaning process, and the residual transfer developer, abrasive particles, and the like are uniformly leveled by the cleaning blade. It is also effective that the potential difference between the image area and the non-image area is reduced as the photoreceptor potential is attenuated.

  In the system of the present invention, since it passes through the static elimination process before entering the cleaning process, at the time of the cleaning process, the potential difference between the image area and the non-image area is further reduced at a lower potential, as shown by the dashed line in FIG. It works more effectively with BAE. In particular, the a-Si photosensitive member is more effective because the potential attenuation is larger than that of OPC or the like.

In IAE, the potential of the non-image area (background area) is higher than that of the image area. Therefore, regarding the transfer separation performance, BAE has a wider latitude than IAE, and BAE is advantageous also in this respect.
Inorganic fine particles As the inorganic fine particles, which are abrasives for removing the charged product adhering to the surface of the photoreceptor, inorganic fine particles having perovskite crystals having an average particle diameter D of 30 to 500 nm are preferable.

  Examples of the material having a perovskite crystal structure include strontium titanate and calcium titanate. The abrasive particles preferably have an average particle size of 30 nm to 500 nm. More preferably, it is 100 nm-300 nm. Within this range, sufficient polishing action and further action as a lubricant at the cleaning blade nip portion maintain good cleaning performance while effectively preventing image flow, and the cleaning blade and the photoreceptor. It is possible to suppress wear and obtain a good image for a long time.

  When the particle size is 30 nm or less, the polishing action is reduced and the amount of slipping through the cleaning blade is large, which may hinder irradiation of the photosensitive member such as static elimination light or latent image exposure. In addition, the cohesiveness is increased, the fluidity, that is, the uniform supply to the cleaning blade is lowered, or the secondary particle has a large particle size, and the cleaning blade or the photoconductor may be worn. On the other hand, in the case of a large particle diameter exceeding 500 nm, it is difficult to enter the vicinity of the nip between the cleaning blade and the photosensitive member, particularly a wedge-shaped portion, and a sufficient polishing action may not be obtained. Further, it is difficult to enter the region, and it is difficult to obtain a sufficient lubricating action at the cleaning blade nip portion, and the cleaning blade or the photoreceptor may be worn.

  If the content of aggregates having a particle size of 600 nm or more is 1% by number or less, good results can be obtained. When the particles and aggregates of 600 nm or more are contained in excess of 1% by number, the electrostatic latent image bearing member may be scratched even if the primary particle size is less than 500 nm. In combination with BAE and a-Si, the agglomerates are easily loosened in the cleaning step.

  About the average particle diameter of inorganic fine particles, 100 particle diameters were measured from the photograph image | photographed with the magnification of 50,000 with the electron microscope, and the average was calculated | required. The particle size was determined as (a + b) / 2, where a is the longest side of the primary particles and b is the shortest side. In addition, the perovskite-type crystalline inorganic fine particles used in the present invention can be made more efficient by increasing the content of particles having a ridge or corner, specifically, a rectangular parallelepiped, to 50% by number or more. It is preferable because the charged product can be removed.

  Furthermore, in the present invention, when abrasive particles are added to the developer, the liberation ratio with respect to the toner particles is preferably 20% by volume or less, and more preferably 15% by volume or less. Here, the liberation ratio is a ratio of perovskite-type crystalline inorganic fine particles liberated from the toner particles in volume%, and is known by a particle analyzer (PT1000: manufactured by Yokogawa Electric Corporation) (non-patent document). It was measured in 1).

  The shape of the abrasive particles may be indefinite, but a shape having ridge lines or corners is preferable. For example, a rectangular parallelepiped shape as shown in FIGS. 13 to 14 is preferable.

  The inorganic fine particles of perovskite crystals used in the present invention can be produced by a known sintering and pulverization method.

  The rectangular parallelepiped fine powder is prepared by adding a strontium hydroxide to a titania sol dispersion obtained by adjusting the pH of a hydrous titanium oxide slurry obtained by hydrolyzing a titanyl sulfate aqueous solution. It can be synthesized by heating to temperature. By setting the pH of the hydrous titanium oxide slurry to 0.5 to 1.0, a titania sol having good crystallinity and particle size can be obtained.

  For the purpose of removing ions adsorbed on the titania sol particles, an alkaline substance such as sodium hydroxide is preferably added to the dispersion of the titania sol. At this time, it is preferable that the pH of the slurry is not 7 or higher so that sodium ions and the like are not adsorbed on the surface of the hydrous titanium oxide. The reaction temperature is preferably 60 ° C. to 100 ° C., and in order to obtain a desired particle size distribution, the temperature rising rate is preferably 30 ° C./hour or less, and the reaction time is preferably 3 to 7 hours.

Examples of the method for subjecting the inorganic fine particles produced by the above method to surface treatment with a fatty acid or a metal salt thereof include the following methods. For example, in an Ar gas or N ₂ gas atmosphere, the inorganic fine particle slurry can be placed in a fatty acid sodium aqueous solution to precipitate the fatty acid on the perovskite crystal surface. Also, for example, in an Ar gas or N ₂ gas atmosphere, the inorganic fine particle slurry is placed in a fatty acid sodium aqueous solution, and the desired metal salt aqueous solution is dropped while stirring to precipitate and adsorb the fatty acid metal salt on the perovskite crystal surface. Can be made. For example, if a sodium stearate aqueous solution and aluminum sulfate are used, aluminum stearate can be adsorbed.

Japan Hardcopy 97 Proceedings, pages 65-68 (Publisher: The Electrophotographic Society, Publication Date: July 9, 1997)

・ Photoconductor (a-Si)
In order to reduce the maintenance load of the image forming system, the photoconductor is preferably a long-life photoconductor. The a-Si photoreceptor is a long-life photoreceptor excellent in wear resistance and potential stability accompanying durability.

  FIG. 11 is a schematic configuration diagram for explaining an example of a layer configuration of an a-Si photosensitive member. The photoreceptor 1100 is provided with a photosensitive layer 1102 on a support 1101. The photosensitive layer 1102 includes a photoconductive layer 1103, a surface layer 1104, and charge injection blocking layers 1105 and 1106 provided as necessary. Each layer is a well-known a-Si photosensitive material and plasma CVD. It can be produced by a known manufacturing method.

  The photoreceptor according to the present invention is preferably a photoreceptor whose surface shape is defined.

  As the 10-point average roughness Rz on the surface of the photoreceptor, the average particle diameter D of the inorganic fine particles is 0.5 to 0.5 in order to effectively flow the inorganic fine particles or loosen aggregates such as the inorganic fine particles. It is preferable that it is 2 times (0.5 ≦ Rz / D ≦ 2.0).

  If the Rz / D is too large, the inorganic fine particles cannot effectively flow. On the other hand, if the particle size is too small, the inorganic fine particles are hardly rolled.

  For the same reason, the maximum roughness Rmax on the surface of the photoreceptor is preferably 3 times or less than the average particle diameter D of the abrasive.

  The surface shape of the a-Si photosensitive member can be controlled by forming a photosensitive layer after adjusting the surface shape of the support by, for example, cutting the support or processing with a rotating ball mill or the like. .

  Specifically, the surface shape of the support can be controlled by adjusting the type, angle or cutting pitch of the cutting tool when cutting the support such as an aluminum cylinder. In addition, an a-Si photoreceptor generally manufactured by CVD has a surface shape corresponding to the surface shape of the support as shown in FIG.

  Further, the surface roughness of the photosensitive layer can be adjusted by adjusting film forming conditions such as the flow rate of the source gas, plasma discharge power, and substrate temperature during the formation of the a-Si photosensitive layer. For example, when manufacturing by plasma CVD, increasing the source gas flow rate and increasing the discharge power / source gas flow rate ratio tend to increase Rz and Rmax.

  Furthermore, it is possible to control the surface shape by polishing the surface of the produced photoreceptor using a polishing tape or the like.

  These methods for controlling the surface shape may be controlled independently or in combination.

  The surface shape in the present invention refers to the surface shapes Rz and Rmax in the direction corresponding to the longitudinal direction of the cleaning blade, and is defined by JISB0601: 1982, and is a surface roughness measuring device corresponding to JISB0601: 1982. Can be measured.

・ Developers Well-known developers can be used as developers, but in high-speed and long-lived systems, it is preferable that the developing means is also maintenance-free, and the jumping development method which is a non-contact magnetic one-component development method is used. It has been put to practical use in an image forming apparatus for an a-Si photosensitive member.

  Jumping development is also non-contact development, so even if the above-mentioned abrasive slips out of the cleaning process or the like, it is difficult to recover to the developing means, and the abrasive is concentrated in the developing means. It is possible to prevent fluctuations in image characteristics caused by it. Further, since the toner is a magnetic toner, additional actions such as addition of a polishing action by the magnetic substance and use of the magnetic substance as a rubbing recovery member can be expected.

  The magnetic one-component developer is a developer composed of magnetic toner particles and an external additive. The particle diameter of the magnetic toner particles is preferably smaller from high image quality and high definition. On the other hand, if it is too small, toner cleaning may be difficult. In general, as the toner particle size becomes smaller, the contribution ratio of the electrostatic adhesion force to the adhesion force becomes smaller, and it is preferable that it is not too small from the viewpoint of the effect of the BAE in the present invention. The toner particles preferably have a weight average particle diameter X (μm) of 4 μm to 12 μm.

  Further, the average circularity of toner particles having an equivalent circle diameter of 3 μm or more and 400 μm or less measured by a flow type particle image measuring apparatus is 0.930 or more and less than 0.970 (preferably 0.935 or more and less than 0.970). Is preferred. The higher the average circularity a, the better the releasability, that is, the adhesive force can be reduced and the cleaning performance is advantageous, and the transfer efficiency is also improved. On the other hand, when the circularity is too high, such as a spherical shape, the fluidity at the cleaning blade portion is lowered, and the above-mentioned abrasive or the like is lowered evenly in the longitudinal direction of the cleaning blade. As a result, the action of the abrasive particles and a decrease in cleaning properties may be caused.

  The circularity is an index of the degree of unevenness of the toner particles, and indicates 1.00 when the toner is a perfect sphere, and the circularity becomes smaller as the surface shape becomes more complicated.

The average circularity is used as a simple method for quantitatively expressing the particle shape. In the present invention, the flow type particle image analyzer FPIA-2100 manufactured by Sysmex Corporation is used and the environment is 23 ° C. and 60% RH. Measured below, particles within a circle equivalent diameter of 0.60 μm to 400 μm were measured, and the circularity a ′ of the measured particles was determined by the following formula (1). Further, the circle equivalent diameter was 3 μm or more and 400 μm or less. The value obtained by dividing the sum of the circularity a ′ by the total number of particles is defined as the average circularity a.
Circularity a ′ = L0 / L (1)
[In the formula, L0 represents the perimeter of a circle having the same projection area as the particle image, and L represents the particle projection image when image processing is performed with an image processing resolution of 512 × 512 (pixels of 0.3 μm × 0.3 μm). The perimeter of is shown. ]

  As a specific measuring method, 10 ml of ion-exchanged water from which impure solids have been removed in advance is prepared in a container, and a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant therein, followed by further measurement. Add 0.02 g of sample and disperse uniformly. As a means for dispersion, an ultrasonic disperser “Tetora 150 type” (manufactured by Nikka Ki Bios Co., Ltd.) is used, and dispersion treatment is performed for 2 minutes to obtain a dispersion for measurement. In that case, it cools suitably so that the temperature of this dispersion may not be 40 degreeC or more. In order to suppress variation in circularity, the installation environment of the apparatus is controlled at 23 ° C. ± 0.5 ° C. so that the temperature inside the flow type particle image analyzer FPIA-2100 is 26 to 27 ° C. Preferably, autofocus is performed using 2 μm latex particles every 2 hours.

  To measure the circularity of the toner particles, the flow type particle image measuring device is used, and the concentration of the dispersion is readjusted so that the toner particle concentration at the time of measurement is 3000 to 10,000 particles / μl. Measure more than one. After the measurement, data having an equivalent circle diameter of less than 3 μm is cut using this data, and the average circularity of the toner particles is obtained.

  In the circularity distribution based on the number of circularity a ′, it is preferable that 90% by number or more of particles having a circularity a ′ of 0.900 or more are present. The effect of controlling the average circularity works effectively, and the above cleaning property and uniformity in the longitudinal direction of the cleaning blade can be suitably maintained.

  For the production of the magnetic toner particles of the present invention, a known method such as a known pulverization method or polymerization method can be used. As the production means, a known device can be used for any of a mixer, a kneader, a pulverizer, a classifier, and a sieving device. The degree of circularity can also be controlled by using a known mechanical type or surface modification means by heat, or by adjusting the polymerization conditions. Also, well-known materials can be used as additives such as binder resin, magnetic material, and wax used for toner particles, and additives added externally to toner particles.

-Charging method As the charging method, a well-known charging method such as a corona charging method, a contact charging method, or a so-called proximity charging method located between them can be used.

  Further, the bias to be applied may be a DC bias alone, or an AC bias may be superimposed on the DC bias (referred to as AC / DC).

  In general, the contact charging method and the proximity charging method generate less products such as ozone and NOx than the corona charging method. The contact and proximity charging method is excellent in charging performance in a small size, and is effective in downsizing the image forming apparatus.

  In the proximity charging method, the surface of the charging member is hardly contaminated with a bias almost equal to that of contact charging and is not in contact with the photosensitive member, and further, an air flow is generated between the photosensitive member and the charging unit, thereby generating charge. Objects are difficult to accumulate in the charged area.

  In the proximity charging method, the gap between the photosensitive member and the charging unit is 500 μm or less, preferably 20 to 300 μm, more preferably 100 μm or less at the closest part, and the distance from the photosensitive member is large (several mm). Are distinct.

  If this gap is too large, the charging tends to become unstable, and if it is too small, the surface of the charging member may be contaminated when there are abrasive particles remaining on the photoreceptor. There is sex.

  The shape of the charging means may be, for example, a method in which the electrode is fixed in the state of being close to the photoreceptor as shown in FIGS. 3 and 4-1 to 4-2, or a roller or a belt shape as shown in FIG. It may be a movable object. A member such as a spacer can be provided at the end of the charging means so that a gap with the photoreceptor can be maintained. Although a well-known thing can be used for the material of the proximity charging member, it is generally set to a higher hardness than the contact charging means. Any hardness that can maintain the voids is acceptable.

  In particular, in the case of the movable type, the surface area can be substantially increased, the life of the member can be extended, and the airflow can be more suitably formed by operating in synchronization with the surface movement of the photoreceptor.

-Sliding and collecting mechanism A mechanism for rubbing the surface of the photoreceptor and / or collecting the abrasive through the abrasive may be provided.

  As the rubbing / recovering mechanism, a well-known member such as a fur brush, an elastic member, a magnetic brush, or the like can be used. By providing a rubbing / collecting step separately from the cleaning blade, the photosensitive member slide in the cleaning blade is provided. The load of rubbing and polishing can be reduced, which is effective in suppressing the wear of the cleaning blade.

  Known forms can also be used.

  The elastic member preferably has an Asker C hardness of 5 to 40 °. With a hard elastic member exceeding 40 °, the photoreceptor may be worn out. In addition, with an elastic member having a low hardness of less than 5 °, the contact pressure of the elastic member is lowered, the sliding effect is reduced, the elastic member is damaged, the outer diameter is changed, etc. There was no case.

  Although the fur brush depends on the material, good results were obtained when it was a fur brush of 0.56 to 3.33 tex (5D to 30D). When it was less than 0.56 tex, the fur was worn or deformed, and the rubbing effect was insufficient. Further, when it exceeds 0.33 tex, the photoconductor may be worn.

  It is preferable that these members are driven with a relative speed difference with respect to the surface of the photosensitive member because the rubbing / recovering action is improved. Further, especially after being left for a long period of time, the charged product may accumulate due to the standing. Before the image formation after the standing, the driving speed of the rubbing / recovery mechanism is driven at a speed different from that at the time of normal image formation, such as improving the rubbing property by increasing the relative speed difference. It is also preferable.

  As a driving condition for the rubbing member, the relative speed [%] with respect to the surface speed of the photosensitive member is generally -100 to + 200%, although it depends on the physical properties of the material of the member, the surface speed of the photosensitive member, the penetration pressure, and the like. It is a range. Except for -10 to + 10% and +90 to + 110% of the approximate rotation, it is more preferable.

  As for the relative speed [%], + is the forward direction with respect to the photoconductor, − is the counter direction, for example, + 100% is the state where the photoconductor is rotated, 0% is the stop state, and −100% is the photoconductor surface. It refers to the state of rotating in the counter direction at the same speed as the speed.

  The difference in relative speed is preferably large, but if it is too large, the member may be worn out. In addition, scattering of inorganic fine particles may occur due to centrifugal force or the like when a rubbing / collecting member is installed outside the cleaning means.

  On the other hand, when the rubbing / recovering mechanism is a blade, it is preferable from the viewpoint of simplifying the mechanism. As the rubbing / recovering member, the same material as the cleaning blade can be used. In particular, for the rubbing / recovering property, the contact nip width with the photosensitive member is increased or the contact pressure is increased. Is preferred. Since the blade is not mainly intended for toner cleaning, by selecting an installation condition such as setting an obtuse angle with respect to the photosensitive member, both friction / polishing properties and a long life of the member are achieved. be able to.

  In order to recover the abrasive in these rubbing / recovery members, it is also preferable to apply a bias having a polarity opposite to that of the abrasive.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings, but the present invention is not limited to the present experimental example.

{Examples of inorganic fine particle production}
In the following production example, abrasive particles made of strontium titanate were produced.

<Production Example 1 of Perovskite Crystalline Inorganic Fine Particle>
The hydrous titanium oxide obtained by hydrolysis by adding ammonia water to the aqueous titanium tetrachloride solution was washed with pure water, and 0.3% sulfuric acid was added to the hydrous titanium oxide slurry as SO _{3 with} respect to the hydrous titanium oxide. Added. Next, hydrochloric acid was added to the hydrous titanium oxide slurry to adjust the pH to 0.6 to obtain a titania sol dispersion. NaOH was added to the titania sol dispersion, the pH of the dispersion was adjusted to 5.0, and washing was repeated until the electrical conductivity of the supernatant liquid reached 50 μS / cm.

0.97-fold molar amount of Sr (OH) ₂ .8H ₂ O was added to the hydrous titanium oxide, and the mixture was placed in a SUS reaction vessel and purged with nitrogen gas. Furthermore, distilled water was added so as to be 0.6 mol / liter in terms of SrTiO ₃ . The slurry was heated to 60 ° C. at a rate of 10 ° C./hour in a nitrogen atmosphere, and reacted for 7 hours after reaching 60 ° C. After the reaction, the reaction solution was cooled to room temperature, and the supernatant was removed. Then, the washing was repeated with pure water, and then filtered with Nutsche. The obtained cake was dried to obtain strontium titanate fine particles not passing through the sintering step. The strontium titanate fine particles were designated as inorganic fine particles A. Table 1 shows the physical properties of the inorganic fine particles A.

<Production Example 2 of Perovskite Crystalline Inorganic Fine Particle>
Hydrous titanium oxide obtained by hydrolysis by adding aqueous ammonia to titanium tetrachloride aqueous solution is washed with pure water, and 0.25% sulfuric acid is added to the hydrous titanium oxide slurry as SO3 with respect to hydrous titanium oxide. did. Next, hydrochloric acid was added to the hydrous titanium oxide slurry to adjust the pH to 0.65 to obtain a titania sol dispersion. NaOH was added to the titania sol dispersion, the pH of the dispersion was adjusted to 4.7, and washing was repeated until the electrical conductivity of the supernatant reached 50 μS / cm.

A 0.95-fold molar amount of Sr (OH) ₂ .8H ₂ O was added to the hydrous titanium oxide, and the mixture was placed in a SUS reaction vessel and purged with nitrogen gas. Further, distilled water was added so as to be 0.6 mol / liter in terms of SrTiO ₃ .

  The slurry was heated to 65 ° C. at a rate of 10 ° C./hour in a nitrogen atmosphere, and reacted for 8 hours after reaching 65 ° C. After the reaction, the mixture was cooled to room temperature, the supernatant was removed, and washing was repeated with pure water.

  Further, in a nitrogen atmosphere, the slurry is placed in an aqueous solution in which 2% by mass of sodium stearate is dissolved with respect to the solid content of the slurry, and while stirring, an aqueous magnesium sulfate solution is dropped, and magnesium stearate is deposited on the perovskite crystal surface. Was precipitated.

  The slurry was washed repeatedly with pure water and then filtered with Nutsche, and the resulting cake was dried to obtain strontium titanate fine particles whose surface was treated with magnesium stearate. The surface-treated strontium titanate fine particles that have not passed through the sintering step are referred to as inorganic fine particles B. Table 1 shows the physical properties of the inorganic fine particles B.

<Production Example 3 of Perovskite Crystalline Inorganic Fine Particles>
The inorganic fine particle C which consists of a strontium titanate fine particle was adjusted with respect to the said manufacture example 2 by adjusting the quantity and pH of the sulfuric acid to add, slurry temperature rising temperature, and reaction time. Table 1 shows the physical properties of the inorganic fine particles C.

<Production Example 4 of Perovskite Crystalline Inorganic Fine Particles>
The hydrous titanium oxide slurry obtained by hydrolyzing the aqueous titanyl sulfate solution was washed with an alkaline aqueous solution. Next, hydrochloric acid was added to the hydrous titanium oxide slurry to adjust the pH to 0.7 to obtain a titania sol dispersion. NaOH was added to the titania sol dispersion, the pH of the dispersion was adjusted to 5.0, and washing was repeated until the electrical conductivity of the supernatant reached 70 μS / cm.

0.98-fold molar amount of Sr (OH) ₂ .8H ₂ O was added to the hydrous titanium oxide, and the mixture was placed in a SUS reaction vessel and purged with nitrogen gas. Further, distilled water was added so as to be 0.5 mol / liter in terms of SrTiO ₃ . The slurry was heated to 80 ° C. at a rate of 7 ° C./hour in a nitrogen atmosphere, and reacted for 6 hours after reaching 80 ° C. After the reaction, the reaction solution was cooled to room temperature, and the supernatant was removed. Then, the washing was repeated with pure water, and then filtered with Nutsche. The obtained cake was dried to obtain strontium titanate fine particles not passing through the sintering step. The strontium titanate fine particles were designated as inorganic fine particles D. Table 1 shows the physical properties of the inorganic fine particles D.

  Moreover, the photograph image | photographed with the magnification of 50,000 times with the electron microscope of the inorganic fine particle D is shown in FIG. In FIG. 13, rectangular parallelepiped strontium titanate fine particles having an average primary particle diameter D of 100 nm can be seen.

<Production Example 5 of Perovskite Crystalline Inorganic Fine Particles>
The hydrous titanium oxide slurry obtained by hydrolyzing the aqueous titanyl sulfate solution was washed with an alkaline aqueous solution. Next, hydrochloric acid was added to the hydrous titanium oxide slurry to adjust the pH to 0.8 to obtain a titania sol dispersion. NaOH was added to the titania sol dispersion, the pH of the dispersion was adjusted to 5.0, and washing was repeated until the electrical conductivity of the supernatant reached 70 μS / cm.

A 0.95-fold molar amount of Sr (OH) ₂ .8H ₂ O was added to the hydrous titanium oxide, and the mixture was placed in a SUS reaction vessel and purged with nitrogen gas. Further, distilled water was added so as to be 0.7 mol / liter in terms of SrTiO ₃ . The slurry was heated to 65 ° C. at 8 ° C./hour in a nitrogen atmosphere, and reacted for 5 hours after reaching 65 ° C. After the reaction, the reaction solution was cooled to room temperature, and the supernatant was removed. Then, the washing was repeated with pure water, and then filtered with Nutsche. The obtained cake was dried to obtain strontium titanate fine particles not passing through the sintering step. The strontium titanate fine particles were designated as inorganic fine particles E. Table 1 shows the physical properties of the inorganic fine particles E.

<Production Example 6 of Perovskite Crystalline Inorganic Fine Particles>
Strontium titanate fine particles F were obtained by adjusting the pH, the molar amount of Sr (OH) ₂ · 8H ₂ O to be added to the hydrous titanium oxide, the slurry temperature rise temperature and the reaction time. Table 1 shows the physical properties of the inorganic fine particles F.

<Production Example 7 of Perovskite Crystalline Inorganic Fine Particles>
The hydrous titanium oxide slurry obtained by hydrolyzing the aqueous titanyl sulfate solution was washed with an alkaline aqueous solution. Next, hydrochloric acid was added to the hydrous titanium oxide slurry to adjust the pH to 1.5 to obtain a titania sol dispersion. NaOH was added to the titania sol dispersion, the pH of the dispersion was adjusted to 5.3, and washing was repeated until the electrical conductivity of the supernatant reached 100 μS / cm.

A 1.07-fold molar amount of Sr (OH) ₂ .8H ₂ O was added to the hydrous titanium oxide, placed in a SUS reaction vessel, and purged with nitrogen gas. Further, distilled water was added so as to be 0.3 mol / liter in terms of SrTiO ₃ .

  The slurry was heated to 87 ° C. at 70 ° C./hour in a nitrogen atmosphere, and reacted for 5 hours after reaching 87 ° C. After the reaction, the mixture was cooled to room temperature, the supernatant was removed, and washing was repeated with pure water.

  Furthermore, in a nitrogen atmosphere, the slurry is placed in an aqueous solution in which 1% by mass of sodium stearate is dissolved with respect to the solid content of the slurry, and while stirring, an aqueous zinc sulfate solution is added dropwise to the surface of the perovskite crystal. Was precipitated.

  The slurry was washed repeatedly with pure water and then filtered with Nutsche, and the resulting cake was dried to obtain strontium titanate fine particles whose surface was treated with zinc stearate. The strontium titanate fine particles having an average primary particle size of 320 nm were designated as G. Table 1 shows the physical properties of the inorganic fine particles G.

<Production Example 8 of Perovskite Crystalline Inorganic Fine Particle>
The hydrous titanium oxide obtained by hydrolysis by adding ammonia water to the aqueous titanium tetrachloride solution was washed with pure water until the electrical conductivity of the supernatant reached 90 μS / cm.

A 1.5-fold molar amount of Sr (OH) ₂ .8H ₂ O was added to the hydrous titanium oxide, and the mixture was placed in a SUS reaction vessel and purged with nitrogen gas. Further, distilled water was added so as to be 0.2 mol / liter in terms of SrTiO ₃ .

  The slurry was heated to 80 ° C. at 15 ° C./hour in a nitrogen atmosphere, and reacted for 5 hours after reaching 80 ° C. After the reaction, it was cooled to room temperature, and after removing the supernatant, washing was repeated with pure water.

  Further, in a nitrogen atmosphere, the slurry is placed in an aqueous solution in which 18% by mass of sodium stearate is dissolved with respect to the solid content of the slurry, and while stirring, an aqueous zinc sulfate solution is dropped, and zinc stearate is deposited on the perovskite crystal surface. Was precipitated.

  The slurry was washed repeatedly with pure water and then filtered with Nutsche, and the resulting cake was dried to obtain strontium titanate fine particles whose surface was treated with zinc stearate. The primary particles were strontium titanate fine particles H having an average particle size of 350 nm. Table 1 shows the physical properties of the inorganic fine particles H.

<Production Example 9 of Perovskite Crystalline Inorganic Fine Particle>
For Production Example 8, the electrical conductivity of the supernatant, the amount of Sr (OH) ₂ .8H ₂ O to be added, the temperature rise and the reaction time were adjusted, and strontium titanate having an average primary particle size of 420 nm. Fine powder I was obtained. Table 1 shows the physical properties of the inorganic fine particles I.

<Production Example 10 of Perovskite Crystalline Inorganic Fine Particle>
For Production Example 8, the electrical conductivity of the supernatant, the amount of Sr (OH) ₂ .8H ₂ O to be added, the temperature rise temperature and the reaction time were adjusted, and strontium titanate having an average primary particle size of 500 nm. Fine particle J was designated. Table 1 shows the physical properties of the inorganic fine particles J.

<Production Example 11 of Perovskite Crystalline Inorganic Fine Particle>
Strontium titanate fine particles K having an average primary particle size of 130 nm and an amorphous crystal shape were used. Table 1 shows the physical properties of the inorganic fine particles K.

<Production Example 12 of Perovskite Crystalline Inorganic Fine Particle>
Strontium titanate fine particles L having an average primary particle size of 280 nm and an amorphous crystal shape were used. Table 1 shows the physical properties of the inorganic fine particles L.

<Production Example 13 of Perovskite Crystalline Inorganic Fine Particle>
The inorganic fine powder E was sintered at 1000 ° C. and then crushed to obtain strontium titanate fine particles via a sintering process. Inorganic fine particles M were strontium titanate fine particles having an average primary particle size of 50 nm and an irregular particle shape. Table 1 shows the physical properties of the inorganic fine particles M.

<Comparative Production Example 1 of Perovskite Crystalline Inorganic Fine Particle>
The hydrous titanium oxide slurry obtained by hydrolyzing the aqueous titanyl sulfate solution was washed with an alkaline aqueous solution. Next, hydrochloric acid was added to the hydrous titanium oxide slurry to adjust the pH to 4.0 to obtain a titania sol dispersion. NaOH was added to the titania sol dispersion, the pH of the dispersion was adjusted to 8.0, and washing was repeated until the electrical conductivity of the supernatant reached 100 μS / cm.

1.02 times the molar amount of Sr (OH) ₂ .8H ₂ O was added to the hydrous titanium oxide, and the mixture was placed in a SUS reaction vessel and purged with nitrogen gas. Further, distilled water was added so as to be 0.3 mol / liter in terms of SrTiO ₃ . The slurry was heated to 90 ° C. at 30 ° C./hour in a nitrogen atmosphere, and reacted for 5 hours after reaching 90 ° C. After the reaction, the reaction solution was cooled to room temperature, and the supernatant was removed. Then, the washing was repeated with pure water, and then filtered with Nutsche. The obtained cake was dried to obtain strontium titanate fine particles having an average primary particle size of 25 nm. The strontium titanate fine particles were used as comparative powder A. Table 1 shows the physical properties of the comparative powder A.

<Comparative Production Example 2 of Perovskite Crystalline Inorganic Fine Particles>
Strontium titanate fine particles having an average primary particle size of 620 nm were obtained. The strontium titanate fine particles were used as comparative fine particles B. Table 1 shows the physical properties of the comparative fine particles B.

<Comparative Production Example 3 of Perovskite Crystalline Inorganic Fine Powder>
Strontium titanate fine particles having an average primary particle size of 24 nm and an amorphous crystal shape were obtained. The strontium titanate fine particles were used as comparative fine particles C. The physical properties of the comparative fine particles C are shown in Table 1.

<Comparative Production Example 4 of Perovskite Crystalline Inorganic Fine Particles>
Strontium titanate fine particles having an average primary particle size of 530 nm and an amorphous crystal shape were obtained. The strontium titanate fine particles were used as comparative fine particles D. Table 1 shows the physical properties of the comparative fine particles D.

<Comparative Production Example 5 of Perovskite Crystalline Inorganic Fine Particle>
600 g of strontium carbonate and 350 g of titanium oxide were wet mixed in a ball mill for 8 hours and then filtered and dried. The mixture was molded at a pressure of 10 kg / cm ² and sintered at 1200 ° C. for 7 hours. This was mechanically pulverized to obtain strontium titanate fine particles having an average primary particle diameter of 700 nm through a sintering process. The strontium titanate fine particles were used as comparative fine particles E. Table 1 shows the physical properties of the comparative fine particles E.

{Photoconductor production example}
In the following production example, an a-Si photosensitive member was produced.

The surface of the support 1101 having an outer diameter of 30 mm (described as φ30) was cut using a commercially available cutting lathe. A support body in which the type of the R-shaped tool was shaken and a support body in which the installation angle and penetration amount of the flat tool were controlled were prepared. In addition, a rotating ball mill was used to collide metal spheres having different particle diameters with the cylinders to produce irregularly shaped supports. The spectral sensitivity peak of the a-Si photosensitive member was approximately 660 to 700 nm, and the resistivity of the surface layer was 2 × 10 ¹⁶ Ω · cm.

  The film formation conditions of the photosensitive layer were fixed to the conditions shown in Table 2 below, and film formation was performed by RF-CVD to prepare positively charged a-Si photoconductors P01 to P05. Further, the photoconductor produced by the same method as P01 was buffed to obtain P06 to P07.

  Using the surface roughness measuring device (Surfcoder SE-3400: manufactured by Kosaka Laboratories), the surface shape of the produced photoreceptors P01 to P07 was measured with a measurement length of 8 mm, a speed of 0.05 mm / sec, a cutoff λc of 0.8 mm, and JIS 1982. The mode was measured in the longitudinal direction of the photoreceptor. The results are shown in Table 3.

  Although details are omitted in this example, the surface shape can also be controlled by changing the conditions of plasma CVD. For example, when the gas flow rate is increased and the discharge power / gas flow rate is increased, Rz and Rmax are increased.

  The results obtained by dividing the average primary particle size D (see Table 1) of the inorganic fine particles A to the comparative fine particles E (see Table 1) by the surface shapes Rz and Rmax (see Table 3) of the photoreceptors P01 to P07 are shown in Table 4 below. They are shown in 5 respectively.

{Developer production example}
In the following production example, a developer composed of toner particles and various additives was prepared.

  Well-known polyester binder resin 100 parts by mass, magnetic iron oxide 100 parts by mass, monoazo iron compound 2 parts by mass, salicylic acid Al compound 1 part by mass, Fischer-Tropsch wax (DSC peak top temperature = 104 ° C., Mw / Mn = 1. 8) After premixing 4 parts by mass of the mixture with a Henschel mixer, the mixture was melt kneaded with a biaxial extruder heated to 130 ° C., and the cooled kneaded product was coarsely pulverized with a hammer mill to obtain a coarsely pulverized toner product.

  The obtained coarsely pulverized product is adjusted to -15 ° C at the inlet air temperature, 48 ° C at the outlet air temperature, and -5 ° C to cool the cooling rotor and liner, using a mechanical pulverizer turbo mill. And finely pulverized finely and coarsely at the same time using a multi-division classifier (Nihon Iron Mining Co., Ltd. elbow jet classifier) using the Coanda effect. . Thereafter, toner particles having various circularities were prepared using a mechanical surface reformer.

The toner particles are mixed with 100 parts by mass, 1.5 parts by mass of hydrophobized silica particles obtained by subjecting BET 200 m ² / g dry silica to a hydrophobization treatment, and mixed with a Henschel mixer so that the weight average particle diameter X is 6. Negatively chargeable toners T1 to T11 having an average circularity as shown in Table 6 below at 4 μm were obtained.

{Rubbing / recovery member production example}
In the following production examples, various rubbing / collecting members were produced.

<Manufacture example 1 of a rubbing and collection | recovery member> Elastic roller Elastic roller DR1 which consists of foaming urethane which disperse | distributed carbon on the core metal of (phi) 8 was produced by the well-known method. The elastic roller DR1 has a large number of single bubble cells having an average pore diameter of φ100 μm. Asker-C hardness was 20 degrees, and it was installed so as to penetrate 0.5 mm into the photoreceptor. In addition, a scraper was prepared and installed in the cleaning device so as to enter 0.2 mm into the elastic roller.

<Manufacture example 2 of rubbing / recovering member> Fur brush roller 2 tex (18D) rayon in which carbon is dispersed is 9.3 × 10 ³ f / cm ² (60 kf / inch ² ) on the photoconductor. Brush roller BR1 was prepared so as to penetrate 5 mm. Further, a scraper was prepared in the cleaning device so as to penetrate 0.5 mm into the brush roller, and installed so as to abut on the photoconductor in parallel.

<Manufacture example 3 of a rubbing and collection | recovery member> Magnetic brush The magnet roller which consists of a plastic magnet on the core metal of (phi) 8 was produced by the well-known method. A thickness regulating member was provided on the magnet roller so that the magnetic developer was coated with a thickness of 1.5 mm, thereby producing a magnetic brush MR1. The magnetic brush was placed in contact with the surface of the photoreceptor with an intrusion amount of 0.2 mm.

  The elastic roller DR1, the fur brush roller FR1, and the magnetic brush MR1 have driving means that is driven to rotate at an arbitrary speed with respect to the surface speed of the photosensitive member in synchronization with the rotation of the photosensitive member.

<Manufacture example 4 of a rubbing and collection | recovery member> Blade It consists of the same material as a cleaning blade. A blade material BLD1 having a thickness of 2 mm was prepared. The member has a free length of 5 mm, a contact angle of 140 ° (40 ° in the forward direction), and a contact pressure of 800 g in total, so that it can be installed downstream of the cleaning blade.

  The rubbing / polishing portion was grounded to prevent charge-up. If necessary, a bias applying means may be added instead of grounding as in the embodiments described later.

[Example 1]
As an evaluation apparatus, a Canon copier iR400 as shown in FIG. 19 was modified to obtain an evaluation machine as shown in FIG. Specifically, an LED having a peak wavelength of 680 nm was used as the charge eliminating means 107, and was disposed between the transfer process and the cleaning process as shown in FIG.

  The surface speed of the photoconductor is set to 50 ppm (ppm; Print Per minute) at 240 mm / sec, and the polarity and bias can be adjusted by modifying the high-voltage power supply for regular development of the positively charged a-Si photoconductor and the negatively charged developer. I made it.

  Further, the latent image exposure means was modified, a laser having a center wavelength of 660 nm was used, and a BAE of 256 dpi with a spot diameter of 40 μm was set to PWM of 256 gradations.

  Further, the transfer residual toner, paper dust, and the like collected by the cleaning unit are collected in a waste toner box (not shown) by a conveyance unit such as a waste toner conveyance unit 107c. Furthermore, modifications such as adjustment of exposure amount and charging conditions and installation of an electrometer were made so that potential evaluation could be performed. The electrometer used was 344 made by TRek 杜 and probe 555P-1 made by the same company, and was installed at the developing means position with a dedicated jig to measure the potential.

  Further, the waste toner feeding blade of the iR400 cartridge was removed, inorganic fine particles were set in the cartridge, and a fur brush was installed as a member 110 for supplying the inorganic fine particles. In FIG. 1, the hatched portion is the inorganic fine particle installation region. The supply member 110 was driven to rotate at a speed of + 130% (in the same direction as the surface of the photoconductor and 130% of the surface speed of the photoconductor).

  A to M were used as the inorganic fine particles, and T10 (average circularity a = 0.918) was used as the developer.

  The above-described P01 was used as the evaluation photoreceptor.

  Using this evaluation apparatus, ruled lines (500 μm lines at equal intervals in the sheet passing direction were arranged at 10 mm intervals in an environment of 30 ° C./80% humidity (H / H) as shown in FIG. ) Was continuously fed at 20 k sheets / day, and various image formations for evaluation were performed, and the main switch was turned off and left at night. The next morning, after the evaluation image was formed, the 20 k sheet / day printing durability test was continued in the same manner, and the printing durability test up to 300 k was performed.

  Next, in a (L / L) environment at a temperature of 10 ° C./humidity of 15%, similarly, 100 k sheets, a total of 400 k sheets, was passed.

  In addition, as an image for evaluation, a grid image in which 300 μm lines were crossed at intervals of 5 mm, a halftone image of 1 dot 1 space, 1 dot 2 space, solid black, and a 17 gradation image were formed.

  For the image flow, the evaluation image was visually evaluated in an H / H environment.

  The cleaning performance was evaluated by filming and rubbing due to poor cleaning, vibration noise (chatter) of the cleaning member, and resonance noise.

  The cleaning durability was evaluated by observing the edge portion of the cleaning member with a microscope before and after the durability and evaluating the wear level.

  The photoconductor durability was evaluated by the amount of abrasion on the surface of the photoconductor and scratches. The amount of wear was measured with a reflection spectroscopic interferometer (trade name: MCPD-2000, manufactured by Otsuka Electronics Co., Ltd.), and was calculated as wear rate [nm / rotation] per rotation. Further, the scratches on the surface of the photosensitive member were measured with a surface roughness measuring machine (manufactured by Kosaka Laboratory, Surfcoder SE-3400) at any 12 points on the surface of the photosensitive member, and where the scratches or streaks were visually confirmed. It was measured by using JIS 1982 mode, measuring speed 0.1 mm / sec, measuring length 5 mm, and cut-off λc = 0.8 mm.

  The evaluation criteria are as follows.

・ Image flow (H / H environment)
Judgment was made from the sample image of the morning after printing. The judgment criteria are as follows.
◎: Very good No blurring of lines and dots in the above evaluation image ○: Good The grid image cannot be recognized, and dot blurring or density decrease in some areas of the halftone or gradation image. However, recovery is possible within 50 sheets of A4 paper. ●: Practical use The grid image cannot be recognized as a flow, and dot blurring or density reduction occurs in halftone or gradation images. 50 to 100 sheets until recovery Δ: Practical use The grid image cannot be recognized as a flow, and dot blurring or density reduction occurs in a halftone or gradation image. Over 100 sheets until recovery.
Or, a little flow can be recognized with the grid image, but within 50 images until the flow recovery of the grid image x;

CLN durability After the printing test, the cut surface and the contact surface of the cleaning blade were observed with a microscope, and cleaning defects such as chipping and scuffing of the cleaning blade, toner slipping, chattering and scoring were evaluated. The judgment criteria are as follows.
A: Very good No blade chipping. No more than 3 spots or chippings below the toner particle size. No scraping. No turning, chattering or resonance sound ○: Good 4-5 spots of wrinkles or chippings below the toner particle size. No dripping or chipping exceeding the toner particle size. No scraping. No turning, resonance sound may occur when the photoconductor is stopped, or chatter may occur (frequently)
●: Practical use 6 to 10 spots of wrinkles or chips below the toner particle size. There are wrinkles or chipping larger than the toner particle size, but none more than twice the toner particle size. No scraping. Resonance or chatter may occur (rare)
Δ: Practical use Ten or more wrinkles or chippings less than the toner particle size. There are wrinkles or chips more than twice the particle size of the toner, but there is no abrasion. Both resonance and chatter may occur (rare)
×: Other than the above There may be scraping due to blade wear such as chipping / scratching or mekre. There is chatter and resonance sound or frequency

-Photoconductor durability The film thickness wear of each photoconductor before and after the printing test was measured.

  In the measurement of the thickness of the photoreceptor, the surface layer thickness of the photoreceptor was measured at a total of 36 locations, 6 locations in the circumferential direction and 6 locations in the major axis direction, and the average value was taken as the average surface layer thickness. The amount of wear was calculated as wear rate [nm / 10k rotation (rot)] per 10,000 rotations by dividing by the difference in average surface layer thickness before and after endurance and the number of rotations of the photoreceptor. The image density was measured as an absolute density, and the above image at the time of each image evaluation was measured using a densitometer “RD-918” (manufactured by Macbeth).

The judgment criteria are as follows.
◎: Very good Wear rate is 1.5 [nm / 10 krot] or less and no uneven wear. ○: Good wear rate is 1.5 [nm / 10 krot] or less, but there is uneven wear. No measurement point exceeding 0 [nm / 10 krot]. In addition, the difference in image density between the unevenly worn portion and the vicinity thereof is 0.2 or less x; other than the above. There are measurement points where the wear rate exceeds 1.5 [nm / 10 krot] or exceeds 2.0 [nm / 10 krot]. . Or, the difference in image density between the unevenly worn part and its vicinity exceeds 0.2.

  The evaluation results are shown in Tables 7-9.

[Examples 2 to 7]
As for the photoconductor for evaluation, P02 to P07 were evaluated in the same manner as in Example 1. The results are shown in Tables 7-9.

  In particular, the flow and CLN durability results are shown in FIG. 16 as a correlation with the average primary particle size D of the inorganic fine particles. From Tables 7 to 9 and FIG. 16, good results were obtained when the average particle diameter D was 30 to 500 nm. Even better results were obtained when the particle size D was 100-300 nm.

  FIG. 17 shows the correlation between the flow evaluation result of ● or more, that is, the inorganic fine particles having an average particle diameter D of 30 to 500 nm and the ratio (Rz / D) to Rz of the photoreceptors P01 to P07. Show. FIG. 17 shows that even better results are obtained when Rz / D is 0.5 to 2.0.

  In a low-speed machine having a time from the cleaning process to the charging center of greater than 100 mm / sec (approximately less than 20 ppm), the life level required in the market is several k to several tens of k. A long-life photosensitive member such as the present invention and a rubbing member can provide good technical results, but are not practical from the viewpoint of cost effectiveness because of increased costs.

[Comparative Examples 1-7]
Evaluations similar to those in Examples 1 to 7 were performed except that Comparative Fine Particles A to E were used as the inorganic fine particles. Tables 7 to 9 show the printing durability evaluation results of Comparative Examples 1 to 7. In particular, the flow and CLN durability were different from those of the examples.

[Example 8] Scorotron As shown in Fig. 2, a scorotron charger was used as the charging means 102, and a suction power source to which a voltage of up to 800V was applied was used for the grid of the scorotron. In this state, the high-voltage power supply was changed so that the dark portion potential could be adjusted by adjusting the current to the wire. The transfer means 108 is also a corotron corona charging system. The other evaluations were the same as in Examples 1 to 7 and Comparative Examples 1 to 5.

  As a result, similar to Examples 1 to 7, good results were obtained when the average temporary particle size of the inorganic fine particles was 30 to 500 nm, and even better results were obtained at 100 to 300 nm.

[Example 9] External addition of abrasive agent As a developer to be used, 1.5 parts by mass of inorganic fine particles used in Example 1 were added externally to 100 parts by mass of toner particles used in Example 1. The product was used as a developer. Along with this, the inorganic fine particle reservoir (shaded portion in FIG. 1) and the inorganic fine particle supply member 106 provided in Example 1 were removed to obtain the original waste toner feed blade (1811 in FIG. 19). Except this, it evaluated similarly to Examples 1-7.

  As a result, similar to Examples 1 to 7, good results were obtained when the average temporary particle size of the inorganic fine particles was 30 to 500 nm, and even better results were obtained at 100 to 300 nm. The inorganic fine particles may be supplied by using a supply member as in Examples 1 to 8, or by adding to the developer as in this example.

[Example 10] Shape of inorganic fine particles: cuboid Among the developers used in Example 9, those having externally added inorganic fine particles J and M having an average primary particle diameter D of 500 nm were used. Further, P01 was used as the photosensitive member, the photosensitive member surface speed was set to 65 ppm at 270 mm / sec, and 500 μm lines were arranged at 20 mm intervals as images formed in the printing durability test. The image ratio was 2.5%. The speed of each means such as paper feeding and paper discharging means, the bias condition applied to the charging means, the exposure means, etc. were adjusted in association with the photoreceptor surface speed.

  Under these conditions, the printing durability test and the evaluation were performed in the same manner as in Example 9. The results are shown in Table 10.

  From Table 10, it can be seen that the rectangular solid-shaped inorganic fine particles J have a greater latitude for flow and CLN durability than the amorphous inorganic fine particles M.

[Example 11] Circularity a = 0.930-0.970
P01 was used as the photoreceptor. In addition, a developer obtained by externally adding fine particles G having an average primary particle diameter D of 320 nm to T1 to T11 as in Example 9 was used.

  Using these photoreceptors, inorganic fine particles, and developers, printing durability and evaluation were performed in the same manner as in Example 9. J results are shown in Table 11.

  From Table 11, good results were obtained when the toner average circularity a was 0.930 to 0.970, particularly 0.935 or more. By controlling the circularity of the toner, it is considered that the uniformity in the vicinity of the contact portion of the cleaning means and the cleaning performance itself are maintained well.

[Example 12] Proximity charging CCC
As the charging means 102, a metal electrode having substantially the same curvature as that of the surface of the photoconductor 101 was prepared, and a resin layer with adjusted resistance was provided on the side facing the photoconductor.

  As shown in FIG. 3, as the charging means 102, a spacer is provided at the end outside the image area at the length of the electrode provided with the electrode close to the photosensitive member 101, and the gap distance between the closest part to the photosensitive member 101 is 50 μm. did. The air gap was installed as shown in FIG. The bias conditions applied to the charging means were adjusted, and the same evaluation as in Example 1 was performed. The results are shown in Table 12.

  From Table 12, a better result than Example 1 was obtained. Further, in the printing durability test under the N / L environment, in Example 1, the charging member 102 may be soiled due to adhesion of inorganic fine particles that have passed through the cleaning means 106 or fine particles such as external additives. However, in this non-contact example, contamination of the charging means was very small.

  Also, as a result of setting the charging unit 102 with a wide setting on the downstream side as shown in FIG. 4B and performing the same printing durability evaluation, the same good results were obtained.

Example 13 Proximity Charging Proximity Roller As shown in FIG. 5, a charging means 102 was set by providing a spacer at the end of the charging roller used in Example 1 and setting the gap distance of the closest part to 50 μm. Table 12 shows the results of a printing durability evaluation test similar to that of Example 12. From Table 12, good results were obtained as in Example 12.

  Also, the hardness of the charging roller is changed to an Asker C hardness of 90 degrees, and the charging means 102 is provided with a driving means (not shown) so that the surface speed is synchronized with the driving of the photoconductor 101. Was driven to rotate at a constant speed. Table 06 shows the results of a printing durability evaluation test similar to that of Example 12. From Table 06, good results were obtained as in Example 12.

  Using these charging members, the same evaluation as in Example 1 was performed. Better results than in Example 1 were obtained. In particular, when the roller-shaped charging unit 102 was driven to rotate, very good results were obtained.

  It is considered that the proximity charging method or the drive-type proximity charging generates an air flow in the vicinity of the surface of the photoconductor 101, and the airflow or the like works well.

[Embodiment 14] Rubbing / Recovering Step Rotation drive type charging means uses the proximity charging means used in Example 13, and a rubbing / collecting member 111 is installed as a rubbing / recovering member as shown in FIG. Created a device. An elastic roller DR1 was used as the rubbing recovery member 111, and it rotated in the forward direction with a relative speed of -50% with respect to the surface speed S of the photoreceptor. Further, an evaluation apparatus using the fur brush roller BR1 and driving at −60% and an evaluation apparatus using the magnetic brush MR1 and driving at −60% were similarly prepared. Further, an evaluation apparatus provided with an elastic blade BLD1 as shown in FIG. 7 was prepared.

  These were evaluated for printing durability in the same manner as in Example 9 using P0 for the photoreceptor and externally added inorganic fine particles to T10 for the developer.

  The results are shown in Table 13.

  From Table 13, both the flow and CLN durability are improved by the rubbing recovery member.

  Further, the same printing durability evaluation as described above was performed by using the charging means 102 as a contact charging system similar to that in Example 1. When the charging unit 102 is observed after the printing durability test, the one having the rubbing / collecting member has almost no inorganic fine particles or external additives attached to the charging unit 102 as compared with the one without the rubbing / recovering member. The fluctuation of the charging current was also suppressed. The rubbing / recovery unit 111 may be driven at a predetermined speed at all times, or from the viewpoint of the durability of the member, the speed difference may be reduced during image formation, for example, before the image formation. The speed difference may be increased at the time of rotation or after rotation.

  Also, as shown in FIGS. 8 to 9, it is preferable to provide a plurality of these rubbing / collecting means 111 to increase the efficiency of rubbing / collecting. In addition, applying a bias for recovery or a bias having the same polarity as the charging means can also reduce the bias of the charging means 102 and, in turn, reduce the amount of charge generating material, resulting in flow, CLN durability, and contamination of the charging means. It is preferable for this.

Embodiment of image forming apparatus according to the present invention Another example of the embodiment of the image forming apparatus according to the present invention Another example of the embodiment of the image forming apparatus according to the present invention Approximate enlarged view of the proximity charging system installation section Approximate enlarged view of the proximity charging system installation section Another example of the embodiment of the image forming apparatus according to the present invention Another example of the embodiment of the image forming apparatus according to the present invention Another example of the embodiment of the image forming apparatus according to the present invention Another example of the embodiment of the image forming apparatus according to the present invention Another example of the embodiment of the image forming apparatus according to the present invention Model diagram comparing latent images of BAE and IAE Model diagram showing an example of layer structure of a-Si photoconductor Schematic model showing the relationship between the support shape and surface shape of the a-Si photosensitive member SEM photograph of an example of suitable inorganic fine particles according to the present invention Conceptual figure of rectangular parallelepiped shape Schematic of images formed in printing durability test of Examples and Comparative Examples Graph showing average primary particle diameter D of inorganic fine particles and evaluation results Graph showing Rz / D and evaluation results Example of conventional image forming apparatus Example of conventional image forming apparatus

Explanation of symbols

101, 1801, 1100; photoreceptors 102, 1802; charging means 103, 1803; latent image forming exposure 104, 1804; developing means 105, 1805; waste toner containers 106, 1806; cleaning means 107, 1807; Transfer means 109, 1809; transport means 110; inorganic fine particle supply means 111 (111-i, 111-ii); rubbing / recovery means 1101; support 1102; photosensitive layer 1103; photoconductive layer 1104; surface layer 1105; 1106; charge injection blocking layer 1810; rubbing member 1811; waste toner feed blade X; photosensitive member traveling direction P; transfer material Vdi, Vdb; developing bias DC potentials ΔVl1, ΔVl1;

Claims (10)

A charging step for charging the photosensitive member; a latent image forming step for forming a latent image on the charged photosensitive member; a developing step for developing the latent image with a developer; and the developed developer image as a transfer material. In an image forming method having a transfer step of transferring, and a cleaning step of an elastic blade for cleaning the photoreceptor,
The photoconductor is a photoconductor having a photoconductive layer formed on a conductive support and made of a non-single crystal material containing a hydrogen atom and / or a halogen atom with a silicon atom as a base, and exhibiting photoconductivity.
The latent image forming step is a back exposure method,
A step of rubbing the surface of the photoreceptor through abrasive particles made of inorganic fine particles having perovskite crystals having an average particle diameter D of 30 to 500 nm in the cleaning step;
Further, the image forming method, further comprising a charge eliminating step between the transfer step and the cleaning step.   The image forming method according to claim 1, wherein the inorganic fine particles have an average particle diameter D of 100 to 300 nm.   3. The image forming method according to claim 1, wherein a 10-point average roughness Rz of the surface of the photoreceptor is 0.5 to 2 times the average particle diameter D of the abrasive particles.   4. The image forming method according to claim 1, wherein the developer used in the development step is a magnetic one-component developer composed of magnetic toner particles and an external additive.   The developer has a weight average particle diameter X (μm) of the magnetic toner particles of 4 μm to 12 μm, and a circularity a ′ measured by an equivalent circle diameter of 3 μm or more and 400 μm or less measured by a flow type particle image measurement method. The image forming method according to claim 4, wherein an average value (average circularity a) is 0.930 or more and less than 0.970.   The image forming method according to claim 1, wherein the inorganic fine particles are rectangular parallelepiped inorganic fine particles.   The image forming method according to claim 1, wherein a moving time of the surface of the photoreceptor from the cleaning process to the center of the charging process is 100 msec or less.   8. The image forming method according to claim 1, wherein the charging step is a proximity charging method.   9. The image forming method according to claim 1, wherein the charging step is a rotation method (roller shape, belt shape).   The image forming method according to claim 1, further comprising a step of rubbing the surface of the photoreceptor through the abrasive particles and / or collecting the abrasive particles.

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