JP4521200B2 - Cleaning device and image forming apparatus - Google Patents

Description

  The present invention relates to a cleaning device and an image forming apparatus, and more particularly to a cleaning device for efficiently collecting residual toner from an image carrier in an image forming apparatus such as a printer, a copying machine, and a facsimile, and an image including the same. The present invention relates to a forming apparatus.

  Conventionally, in an image forming apparatus such as a printer, a copying machine, or a facsimile, a toner image is formed on a photoreceptor as an image carrier through a charging process, an exposure process, and a development process, and then transferred onto a recording material by a transfer process. The electrophotographic method is widely used. In the electrophotographic image forming apparatus, not all of the toner constituting the toner image on the photoconductor is transferred, and a small amount of toner remains on the surface of the photoconductor as residual toner. Therefore, various cleaning devices for collecting residual toner from the photoreceptor have been proposed.

  For example, as shown in FIG. 9, a cleaning blade 110a for removing residual toner (T) in contact with the photosensitive member 100 is provided, and an attachment angle of the cleaning blade 110a (an inclination angle formed with the photosensitive member). ) Is abutted so as to be 2 to 25 °, and an image forming apparatus that effectively collects spherical toner (T) having a shape factor of 1.0 to 1.3 is disclosed (for example, Patent Documents). 1).

  Further, as shown in FIG. 10, the cleaning blade 167a for contacting the photoreceptor 161 to remove the residual toner and the vibration means 167b for removing the residual toner attached to the cleaning blade 167a are provided. An image forming apparatus is disclosed in which the excitation unit 167b implements an operation mode in which the degree of excitation differs depending on the operation mode of the image forming apparatus (see, for example, Patent Document 2).

  As shown in FIG. 11, the image forming apparatus 200 includes a cleaning device 208 having a cleaning blade 208a, and includes an image forming apparatus including a piezoelectric element 208b for applying a standing wave to the cleaning blade 208a. 200 is disclosed (for example, see Patent Document 3).

Further, as shown in FIG. 12, a cleaning blade 255 having a free end 255a for cleaning the surface 250 of the photoreceptor (photoreceptor) and a fixed end 255b for fixing to the fixing member is provided. A particle removing device 260 including a piezoelectric element 253 provided in connection with a cleaning blade 255 is disclosed (for example, see Patent Document 4).
Japanese Patent Laid-Open No. 2002-49288 (Claims) JP 2003-255793 A (Claims) JP-A-11-174922 (Claims) JP 11-30938 A (Claims)

  However, in the cleaning device described in Patent Document 1, the edge line of the cleaning blade must be a highly accurate curve, and the mounting angle of the cleaning blade must be strictly limited, and the edge line is processed. There has been a problem that it is difficult to effectively collect the spherical toner when the accuracy is lowered or the mounting angle is changed.

The cleaning devices disclosed in Patent Documents 2 to 4 are all provided with a vibration means for removing the residual toner adhering to the cleaning blade, but the spherical toner that rolls in a layered manner on the photoreceptor. There was a problem that no consideration was given to cleaning.
That is, due to the stick-and-slip phenomenon, the non-spherical toner prepared by the pulverization method or the like can be cleaned relatively effectively, but the cleaning property of the spherical toner is insufficient. More specifically, since the spherical toner created by the polymerization method rolls on the photoreceptor, it is stacked in layers without exhibiting the effect of flipping off, and a toner layer is formed in a finely packed state at the edge of the cleaning blade It is easy to be done. For this reason, the force that the cleaning blade receives from the layered toner layer increases, slips through the nip portion, and is transferred in a streak pattern to the subsequent recording material at the time of the next image formation, so that an image defect is likely to occur. It was observed.

Therefore, according to the present invention, it has been found that by generating a traveling wave along the edge of the cleaning blade by the vibration applying member, not only non-spherical toner but also spherical toner can be sufficiently cleaned. The invention has been completed.
That is, an object of the present invention is to provide a cleaning device that can sufficiently and effectively clean even spherical toner, and an image forming apparatus including such a cleaning device.

According to the present invention, the cleaning blade for scraping and removing the toner remaining on the surface of the image carrier and the traveling wave along the edge of the cleaning blade in contact with the cleaning blade are generated and scraped. And a vibration imparting member for collecting the residual toner while moving, wherein the linear pressure of the cleaning blade with respect to the image carrier is set to a value within a range of 10 to 50 g / cm, and vibration is imparted. The driving power of the member is controlled, and the dynamic friction coefficient (μ) defined by the following formula between the image carrier and the cleaning blade is set to a value in the range of 0.2 to 1.5. A cleaning device is provided to solve the above-mentioned problems.
Coefficient of dynamic friction (μ) = (T2−T1) / (F · r)
T2: Rotational torque (kgf · cm) of the image carrier with the cleaning blade in pressure contact
T1: Rotational torque (kgf · cm) of the image carrier in a state where the pressure contact of the cleaning blade is released
F: Load of the cleaning blade (kgf)
r: radius of image carrier (cm)

  In configuring the cleaning device of the present invention, it is preferable that the vibration applying member is brought into contact with the end portion of the cleaning blade.

  In configuring the cleaning device of the present invention, it is preferable that the vibration applying member is brought into contact with the blade surface of the cleaning blade.

  In constituting the cleaning device of the present invention, the vibration applying member is preferably a piezoelectric element.

In configuring the cleaning device of the present invention, a plurality of vibration applying members are provided, and the interval between adjacent vibration applying members is set to λ / 4 (λ: wavelength of a standing wave generated by the vibration applying member), and adjacent vibrations are provided. It is preferable to shift the phase of the standing wave generated in the applying member by π / 2.

  Further, in configuring the cleaning device of the present invention, an extension is provided in the lateral direction of the cleaning blade so that the width of the cleaning blade is longer than the width of the photosensitive member, and vibration is applied to the extension of the cleaning blade. It is preferable to make the member contact.

  In configuring the cleaning device of the present invention, it is preferable to provide a feedback circuit for controlling the value of the dynamic friction coefficient to control the driving power of the vibration applying member.

According to another aspect of the present invention, there is provided an image forming apparatus including a cleaning device, wherein the cleaning device scrapes the image carrier to remove residual toner, and contacts the cleaning blade. And a vibration applying member for generating a traveling wave along the edge of the cleaning blade and collecting the scraped residual toner while moving , and the linear pressure of the cleaning blade against the image carrier is 10 to 50 g / cm. And the driving power of the vibration applying member is controlled, and the dynamic friction coefficient (μ) defined by the following formula between the image carrier and the cleaning blade is 0.2 to 1.5. An image forming apparatus having a value within a range .
Coefficient of dynamic friction (μ) = (T2−T1) / (F · r)
T2: Rotational torque (kgf · cm) of the image carrier with the cleaning blade in pressure contact
T1: Rotational torque (kgf · cm) of the image carrier in a state where the pressure contact of the cleaning blade is released
F: Load of the cleaning blade (kgf)
r: radius of image carrier (cm)

  According to the cleaning apparatus of the present invention, a cleaning blade and a vibration imparting member for vibrating the cleaning blade are provided, and the vibration imparting member is brought into contact with the cleaning blade to generate a predetermined traveling wave and to carry an image. By collecting the residual toner scraped from the body while moving it, not only non-spherical toner but also spherical toner can be cleaned sufficiently and effectively.

  According to the cleaning device of the present invention, the traveling wave can be efficiently generated by bringing the vibration applying member into contact with the end of the cleaning blade.

  Further, according to the cleaning device of the present invention, the spherical member can be sufficiently and effectively cleaned by bringing the vibration applying member into contact with the blade surface of the cleaning blade.

  Further, according to the cleaning device of the present invention, by providing the piezoelectric element as the vibration applying member, the device can be easily reduced in size and the traveling wave can be generated efficiently.

  Further, according to the cleaning device of the present invention, it is possible to generate a high-intensity traveling wave by providing a plurality of vibration applying members and setting the interval between adjacent vibration applying members to a predetermined value. In addition, by providing a plurality of vibration imparting members, it is possible to generate a traveling wave satisfactorily even when a metal or the like that absorbs less vibration energy and easily generates a standing wave due to a reflected wave is used for the cleaning blade. In addition, it is possible to reduce the possibility of the image carrier being damaged by the edge portion of the cleaning blade by generating minute vibration at the contact portion with the image carrier.

  Further, according to the cleaning device of the present invention, the vibration applying member is brought into contact with the extending portion provided in the lateral direction of the cleaning blade, whereby the distance between the traveling wave generation location and the image carrier can be increased. Therefore, damage to the image carrier can be effectively prevented.

Further, according to the cleaning device of the present invention, by setting the dynamic friction coefficient between the image carrier and the cleaning blade to a value within a predetermined range, the cleaning blade and the photoconductor are worn and the residual toner slips through. The balance can be made good.
In adjusting the coefficient of dynamic friction between the image carrier and the cleaning blade, conventionally, excessive addition of silicone oil to the image carrier or forming a surface hardened layer made of an isocyanate compound on the surface of the cleaning blade. However, it is possible to control accurately according to changes in ambient environmental conditions (temperature, humidity, rotation torque of the image carrier, deterioration of the cleaning blade, contents of the original to be imaged, etc.) It was difficult.

  Further, according to the cleaning device of the present invention, it is possible to sufficiently and effectively clean even spherical toner by providing a predetermined feedback circuit and controlling the driving power of the vibration applying member.

  The image forming apparatus according to another aspect of the present invention includes a cleaning blade and a vibration applying member for vibrating the cleaning blade, and the vibration applying member is brought into contact with the cleaning blade. By generating a predetermined traveling wave and collecting the scraped residual toner while moving it, not only non-spherical toner but also spherical toner can be cleaned sufficiently and effectively.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, what attached | subjected the same code | symbol in each drawing has the same structure or effect | action, The duplication description about these was abbreviate | omitted suitably.

1. Image Forming Apparatus (1) Basic Configuration FIG. 1 shows a basic configuration of an image forming apparatus according to the present invention. The image forming apparatus 10 includes a drum-type photoconductor 11 as an image carrier, and a primary charger 12 and an exposure device 13 are arranged around the photoconductor 11 along a rotation direction indicated by an arrow A. The developing device 14, the transfer charger 15, the separation charger 16, the cleaning device 17, and the static eliminator 18 are sequentially arranged.
Further, registration rollers 19a and 19b and a transfer conveyance path 21 are sequentially provided from the upstream side along the conveyance direction indicated by the arrow B, and toner is fixed to the most downstream portion of the transfer conveyance path 21 to be fixed on the sheet. A fixing device 22 including a fixing roller 22a and a pressure roller 22b is provided.
That is, in the image forming apparatus 10 having such a basic configuration, a vibration applying member 50, for example, a cleaning blade 17a including a piezoelectric element is brought into contact with the photoconductor 11 in the post-image forming process, so that a predetermined value is obtained. By collecting the residual toner scraped by the traveling wave while moving it, not only non-spherical toner but also spherical toner can be cleaned sufficiently and effectively.

(2) Operation Next, the basic operation of the image forming apparatus 10 will be described with reference to FIG.
First, the photosensitive member 11 of the image forming apparatus 10 is rotated at a predetermined process speed (circumferential speed) in a direction indicated by an arrow A by a driving unit (not shown), and the surface thereof is predetermined by a primary charger 12. Charge to polarity and potential. For example, in the case of the contact charging method, it is preferable to apply a DC voltage of about 1 to 2 kV and positively charge to 200 to 1,000 V.
Next, the exposure device 13 such as a laser or LED irradiates light through a reflection mirror or the like while performing light modulation according to image information, thereby exposing the surface of the photoreceptor 11. By this exposure, an electrostatic latent image is formed on the surface of the photoreceptor 11.

Next, the developer (toner) is developed by the developing device 14 based on the electrostatic latent image. In other words, toner is stored in the developing device 14, and by applying a predetermined developing bias to the developing sleeve 14a, the toner adheres corresponding to the electrostatic latent image on the surface of the photoreceptor 11, and the toner image Is formed.
That is, the recording material P is fed one by one from a paper feed cassette (not shown) along the conveyance direction indicated by the arrow B, and further fed by a pair of paper feed rollers (not shown), and then registered rollers. It contacts 19a, 19b. Therefore, after temporarily stopping, it is sent out by the registration rollers 19a and 19b in synchronism with the image formation on the photoconductor 11. The toner image can be reliably transferred onto the recording material P by being advanced along the transfer conveyance path 21 and applying a predetermined transfer bias to the photoconductor 11 and the transfer charger 15. .

Next, the recording material P after the toner image has been transferred is separated from the surface of the photoreceptor 11 by the separation charger 16 and conveyed to the fixing device 22. Here, the toner image is fixed on the surface by heat treatment and pressure treatment by the fixing roller 22a and the pressure roller 22b, and then discharged to the outside of the image forming apparatus 10 by a discharge roller (not shown).
On the other hand, the photoconductor 11 after the toner image transfer continues to rotate, and residual toner (adhered matter) that has not been transferred to the recording material P at the time of transfer is removed from the surface of the photoconductor 11 by the cleaning device 17 of the present invention. At the same time, the charge remaining on the surface of the photoconductor 11 is removed by the discharge of the static elimination light from the static eliminator 18, and the photoconductor 11 is used for the next image formation.
Details of the configuration and operation of the cleaning device 17 will be described later.

2. Cleaning Device (1) Basic Structure Next, the basic structure of the cleaning device 17 will be described in detail with reference to FIG. FIG. 2 is a schematic perspective view of the cleaning device 17 arranged in parallel with the axial direction of the photoconductor 11.
The cleaning device 17 includes a vibration applying member 50 that generates a traveling wave along the edge of the cleaning blade. The reason for this is that by generating such traveling waves, even if the scraped residual toner is a spherical toner as shown in FIG. 2, it can be efficiently recovered while moving the residual toner. Because.
That is, as represented by an arrow B in FIG. 2, the residual toner 20 scraped off from the photoconductor 11 due to the traveling wave is directed toward the piezoelectric element 50 located in the direction opposite to the traveling direction of the traveling wave. Be transported.
Therefore, it can collide with the collection wall 17e in the vicinity of the vibration applying member 50 and can be efficiently accommodated in the toner collection unit 17c. Even before reaching the vicinity of the vibration applying member 50, a part of the toner scraped off by the cleaning blade can be accommodated in the toner recovery unit 17c.
The toner dropped into the toner recovery unit 17c is transported in the axial direction of the photosensitive member 11 by a toner transport screw in the toner recovery unit 17c (not shown), to the left in FIG. 2, and finally the toner recovery unit 17c. The toner is collected from the end portion into a toner collecting container (not shown) through a toner collecting path (not shown).

  Here, a bolt-clamped Langevin type vibrator can be used as the vibration imparting member 50, and as shown in FIG. 3, a metal plate 62 is sandwiched from above and below by a pair of piezoelectric elements 60 and 61, for example, PZT. It is also preferable to configure as'. This is because with such a configuration, the piezoelectric element as the vibration applying member to be brought into contact with the cleaning blade 17a can be further reduced in size.

(2) Arrangement Position of Vibration Applying Member As shown in FIG. 2, in the cleaning device 17, it is preferable that the vibration applying member 50 is brought into contact with the end portion of the cleaning blade 17a.
This is because when the vibration applying member is brought into contact with the central portion of the cleaning blade, the toner moves toward the center of the cleaning blade, but the toner accumulates in the central portion of the blade. This is because it may be difficult to remove the toner from the contact portion of the photoconductor.

In addition, as shown in FIG. 2, even if only one vibration applying member (piezoelectric element) 50 is disposed at the end of the cleaning blade 17a, an effect can be produced. When a metal, ceramic, or resin with high hardness that absorbs little energy is used, traveling waves may not easily occur due to the influence of reflected waves.
In this case, as shown in FIG. 4, it is preferable to arrange a plurality of vibration applying members 50 at the ends of the cleaning blade 17a. Although different from FIG. 4, it is also possible to arrange them at both ends.
At this time, the adjacent vibration applying members are arranged apart by a distance of λ / 4 of the wavelength of the standing wave generated by the vibration applying member so that the combined wave of the standing waves generated by each vibration forms a traveling wave, Further, it is preferable that the stationary wave generated by at least the adjacent vibration applying member generates a portion having a spatial shift of λ / 4 (λ: wavelength) and a phase shifted by π / 2.
More specifically, when the cleaning blade is made of a rubber material, the traveling wave speed traveling through the cleaning blade is about 1,800 m / sec. Therefore, if the vibration frequency of the vibration applying member (piezoelectric element) is 30 kHz, the wavelength of the standing wave is about 6 cm, and the interval between adjacent vibration applying members is about 1.5 cm.
Further, when an iron thin plate (thickness of about 0.2 mm) is used for the cleaning blade, the traveling wave speed traveling through the cleaning blade is about 6,000 m / sec. Accordingly, if the vibration frequency of the vibration applying member is 30 kHz, the wavelength of the standing wave is about 20 cm, and the interval between adjacent vibration applying members is about 5 cm.

Further, as shown in FIG. 2, it is preferable that the vibration applying member 50 is brought into contact with the blade surface of the cleaning blade 17a.
The reason for this is that the spherical member can be sufficiently and effectively cleaned by a predetermined traveling wave by bringing the vibration applying member into contact with the blade surface in this way. In other words, the vibration imparting member is brought into contact with the blade surface, which is a surface for scraping the residual toner on the cleaning blade, to effectively vibrate the cleaning toner including the surface of the cleaning blade in one direction. It can be recovered while being moved to.

Further, as shown in FIG. 2, an extension 17d is provided in the lateral direction of the cleaning blade 17a so that the lateral width of the cleaning blade 17a is longer than the lateral width of the photosensitive member 11, and the extension 17d of the cleaning blade It is preferable to bring the vibration applying member 50 into contact.
This is because the toner can be effectively collected from the end of the photosensitive member by bringing the vibration applying member into contact with the extension in this manner.

(3) Traveling Wave As shown in FIG. 5, in the cleaning device 17, after the traveling wave is generated by the vibration applying member 50, it is preferably attenuated while propagating along the edge of the cleaning blade.
This is because the generation of a reflected wave can be suppressed by generating a traveling wave and attenuating its amplitude. Conversely, if it is a stationary wave whose amplitude does not attenuate, a reflected wave is likely to be generated, and it is difficult to collect the residual toner while moving it in one direction.

In terms of the degree of attenuation, it is more preferable that the wave function disappears at the end of the cleaning blade. However, it is preferable to attenuate so that, for example, the value is about 30% or less of the initial amplitude.
Further, in order to generate a traveling wave and obtain an excellent recovery effect for the residual toner, the frequency of the vibration applying member is set to a value in the range of 20 to 60 kHz, and the hardness of the cleaning blade is 85 ° or more. It is preferable to set the value of.

(4) Coefficient of dynamic friction (μ)
Further, in the cleaning device 17, a traveling wave is generated by the vibration applying member 50 while controlling the driving power, so that the dynamic friction coefficient (μ) between the photosensitive member defined by the following formula and the cleaning blade is set to 0. characterized in that a value within the range of 2 to 1.5.
Coefficient of dynamic friction (μ) = (T2−T1) / (F · r)
T2: Rotational torque (kgf · cm) of the photoconductor with the cleaning blade in pressure contact
T1: Rotational torque (kgf · cm) of the photoconductor with the pressure contact of the cleaning blade released
F: Load of the cleaning blade (kgf)
r: Radius of the photoreceptor (cm)

In this regard, the reason will be described in more detail with reference to FIG. That is, in FIG. 6, the horizontal axis indicates the driving power (W) of the piezoelectric element, and the vertical axis indicates the dynamic friction coefficient (μ) defined by the above equation. As can be understood from the characteristics shown in FIG. 6, the dynamic friction coefficient (μ) varies greatly depending on the driving power (W) of the piezoelectric element, and can be controlled within a predetermined range.
On the other hand, if the dynamic friction coefficient (μ) exceeds 1.5, the cleaning blade may squeeze, chatter or roll up easily.
Therefore, for example, by setting the driving power of the piezoelectric element to about 2 W or more, the upper limit value of the dynamic friction coefficient (μ) is preferably set to 1.5 or less, and in order to suppress wear of the photoreceptor, the piezoelectric element It is more preferable to set the dynamic friction coefficient (μ) to 0.7 or less by setting the driving power (W) to about 3 W or more.
However, when the dynamic friction coefficient (μ) becomes excessively small, residual toner may slip through depending on the configuration of the cleaning blade. Accordingly, in order to prevent the residual toner from slipping through regardless of the configuration of the cleaning blade, it is preferable that the dynamic friction coefficient (μ) is 0.2 or more with respect to the lower limit value of the dynamic friction coefficient (μ). When the dynamic friction coefficient (μ) is less than 0.2, depending on the conditions of the image forming apparatus, it is not possible to sufficiently remove charged products and the like deposited and adhered to the surface of the photoconductor, and the photoconductor The charging performance may be adversely affected.
Therefore, in order to reliably remove the charged product, the dynamic friction coefficient (μ) is more preferably 0.5 or more.

(5) Feedback Circuit As shown in FIG. 7, it is preferable that the cleaning device 17 measures the value of the dynamic friction coefficient and controls the driving power of the vibration applying member by the feedback circuit.
This is because a spherical toner can be sufficiently and effectively cleaned by providing a predetermined feedback circuit and controlling the driving power of the vibration applying member based on the value of the dynamic friction coefficient. is there.
That is, the rotational torque (T1) of the photoconductor in a state where the pressure contact of the cleaning blade is released by the torque detector 17h provided between the photoconductor 11 and the motor 17i, and the photoconductor in the state where the cleaning blade is pressed And the dynamic friction coefficient (μ) between the photosensitive member and the cleaning blade is calculated from the measured rotational torque value, and the obtained dynamic friction coefficient (μ) value is calculated. Therefore, it is preferable to adjust the driving power of the vibration applying member by a feedback circuit.

Next, a method for adjusting the driving power of the vibration applying member (piezoelectric element) by the feedback circuit and controlling the value of the dynamic friction coefficient will be described with reference to the flowchart shown in FIG.
First, image formation is started, and an initial driving power value (P ₀ ) of the piezoelectric element is set as shown in S1. In this example, the initial drive power value (P ₀ ) is set to 6W.
Next, the operation of the piezoelectric element is started as shown in S2, and the rotation of the photosensitive member is started as shown in S3.
Next, as shown in S4, the rotational torque of the photosensitive member is measured, and the dynamic friction coefficient (μ) is calculated by calculation. That is, the rotational torque (T1) of the photoconductor with the pressure contact of the cleaning blade released and the rotational torque (T2) of the photoconductor with the pressure contact of the cleaning blade are measured, respectively. The dynamic friction coefficient (μ) is calculated by calculation. The rotational torque of the photoconductor with the pressure contact of the cleaning blade released may be stored in a storage device of the image forming apparatus and used.
When measuring the rotational torque (T2) of the photoconductor with the cleaning blade pressed, the angle (contact angle) between the cleaning blade and the photoconductor is set to 5 to 30 in accordance with the actual press contact conditions. It is preferable to press the cleaning blade against the photoreceptor so that the linear pressure is 10 to 50 g / cm.

Next, as shown in S5, it is determined that the dynamic friction coefficient (μ) is a value equal to or less than a predetermined value. In this example, when it is determined that the dynamic friction coefficient (μ) is 0.7 or less, the process proceeds to the next step S6, but it is determined that the dynamic friction coefficient (μ) exceeds 0.7. If so, the process proceeds to S8, which is the implementation of the feedback circuit.
That is, as shown in S8, after increasing the driving power of the piezoelectric element, the process returns to S4 as the previous step. Then, the steps S4, S5 and S8 are repeated, and the driving power of the piezoelectric element is adjusted so that the dynamic friction coefficient (μ) becomes a value of 0.7 or less.

Next, after confirming that the dynamic friction coefficient (μ) is equal to or less than a predetermined value (0.7), it is determined that the dynamic friction coefficient (μ) is equal to or greater than the predetermined value as shown in S7. . In this example, if it is determined that the dynamic friction coefficient (μ) is a value of 0.5 or more, the process proceeds to the final step, but if it is determined that the dynamic friction coefficient (μ) is less than 0.5, The process proceeds to S9, which is another feedback circuit implementation.
That is, as shown in S9, after the drive power of the piezoelectric element is reduced, the process returns to S6 as the previous step. Then, the steps S6, S7 and S9 are repeated, and the driving power of the piezoelectric element is adjusted so that the dynamic friction coefficient (μ) becomes a value of 0.5 or more.
As described above, by adjusting the driving power of the piezoelectric element and controlling the value of the coefficient of dynamic friction, even when the surrounding environmental conditions change, the cleaning blade and the photosensitive member can be quickly and accurately adjusted. A good balance between wear and residual toner slip can be achieved.

(6) Toner In configuring the cleaning device, it is preferable that the applied toner has an average circularity defined by the following formula of 0.8 or more.
Average circularity = 4πA / L ²
(A: toner projected area (μm ² ), L: toner peripheral length (μm))
This is because the residual toner can be sufficiently and effectively cleaned by having a predetermined average circularity. In other words, if the circularity is excessively small, the fluidity is extremely lowered and the effect of moving along the blade edge may not be sufficiently exhibited.
The average circularity can be measured by a flow type particle image analyzer, for example, FPIA-1000 (manufactured by Sysmex Corporation).
In measuring the average circularity, for example, a projection image of 1,000 to 10,000 toner particles in a water dispersion state is projected, and the above-described projection area (A) and perimeter length (L) are set. It is preferable to calculate as an average value.

According to the cleaning device and the image forming apparatus including the cleaning device according to the present invention, the residual toner attached to the surface of the photosensitive member in the image forming apparatus is efficiently recovered even when the toner is not only spherical but also spherical. And excellent image formation can be performed over a long period of time.
In addition, even if the surrounding environmental conditions have changed by adjusting the driving power of the piezoelectric element and controlling the value of the coefficient of dynamic friction between the photoconductor and the cleaning blade within a predetermined range, Uniform image formation can be performed over a long period of time.

1 is a diagram provided for explaining a schematic configuration of an image forming apparatus according to the present invention. It is a longitudinal cross-sectional view which shows schematic structure of the cleaning apparatus which concerns on this invention. It is a figure provided in order to demonstrate an example of a piezoelectric element. It is a figure provided in order to demonstrate the arrangement | positioning method of a vibration provision member. It is a figure provided in order to demonstrate the attenuation | damping condition of a traveling wave. It is a figure provided in order to demonstrate the dynamic friction coefficient between a photoconductor and a cleaning blade. It is a figure provided in order to demonstrate the measuring method of a dynamic friction coefficient. It is a flowchart regarding the drive electric power control of a piezoelectric element. It is a figure provided in order to demonstrate the conventional cleaning blade (the 1). It is a figure provided in order to demonstrate the conventional cleaning blade (the 2). It is a figure provided in order to demonstrate the conventional cleaning blade (the 3). It is a figure provided in order to demonstrate the conventional particle removal apparatus.

Explanation of symbols

10: Image forming device 11: Photoconductor 12: Primary charger 13: Exposure device 14: Developer 15: Transfer charger 16: Separation charger 17: Cleaning device 17a: Cleaning blade 19a, 19b: Feed roller 20: Residual Toner 21: Conveying belt 22: Fixing device 22a: Fixing roller 22b: Pressure roller 50: Vibration applying member (piezoelectric element)

Claims (8)

A cleaning blade for scraping and removing the toner remaining on the surface of the image carrier, and a traveling wave along the edge of the cleaning blade in contact with the cleaning blade and moving the scraped residual toner A vibration applying member for collecting , a cleaning device comprising:
The linear pressure of the cleaning blade with respect to the image carrier is set to a value within the range of 10 to 50 g / cm,
The driving power of the vibration applying member is controlled, and the dynamic friction coefficient (μ) defined by the following formula between the image carrier and the cleaning blade is set to a value in the range of 0.2 to 1.5. cleaning apparatus, characterized in that.
Coefficient of dynamic friction (μ) = (T2−T1) / (F · r)
T2: Rotational torque (kgf · cm) of the image carrier with the cleaning blade in pressure contact
T1: Rotational torque (kgf · cm) of the image carrier in a state where the pressure contact of the cleaning blade is released
F: Load of the cleaning blade (kgf)
r: radius of image carrier (cm)   The cleaning apparatus according to claim 1, wherein the vibration applying member is brought into contact with an end portion of the cleaning blade.   The cleaning apparatus according to claim 1, wherein the vibration applying member is brought into contact with a blade surface of the cleaning blade.   The cleaning device according to claim 1, wherein the vibration applying member is a piezoelectric element. A plurality of the vibration imparting members are provided, the interval between adjacent vibration imparting members is λ / 4 (λ: the wavelength of the standing wave generated by the vibration imparting member), and the phase of the standing wave generated in the adjacent vibration imparting member is π / The cleaning device according to claim 1, wherein the cleaning device is shifted by two.   An extension is provided in a lateral direction of the cleaning blade so that the lateral width of the cleaning blade is longer than the lateral width of the photosensitive member, and the vibration applying member is brought into contact with the extension of the cleaning blade. The cleaning device according to any one of claims 1 to 5. The cleaning apparatus according to claim 1 , wherein a feedback circuit for controlling the value of the dynamic friction coefficient is provided to control driving power of the vibration applying member. An image forming apparatus provided with a cleaning device,
The cleaning device scrapes off the image carrier to remove residual toner, and generates a traveling wave along the edge of the cleaning blade in contact with the cleaning blade to move the scraped residual toner. A vibration imparting member for collecting while collecting ,
The linear pressure of the cleaning blade with respect to the image carrier is set to a value within the range of 10 to 50 g / cm,
The driving power of the vibration applying member is controlled, and the dynamic friction coefficient (μ) defined by the following formula between the image carrier and the cleaning blade is set to a value in the range of 0.2 to 1.5. image forming apparatus characterized by.
Coefficient of dynamic friction (μ) = (T2−T1) / (F · r)
T2: Rotational torque (kgf · cm) of the image carrier with the cleaning blade in pressure contact
T1: Rotational torque (kgf · cm) of the image carrier in a state where the pressure contact of the cleaning blade is released
F: Load of the cleaning blade (kgf)
r: radius of image carrier (cm)

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