JP5169545B2 - Cleaning device, image forming apparatus, and process cartridge - Google Patents

Description

  The present invention relates to a cleaning device used in an image forming apparatus such as a copying machine, a facsimile machine, and a printer, and an image forming apparatus and a process cartridge provided with the same.

In recent years, an image forming apparatus is required to have high resolution so that a higher-precision and high-definition image can be formed, and there is a method of using a toner having a smaller particle diameter as one of means for achieving it. In order to improve the transfer rate, a spherical toner having a shape closer to a sphere has been used instead of a conventional irregular shape.
However, when a small particle size toner or a spherical toner is used, it is difficult to clean the residual toner remaining on the photoconductor because the particle size is small and the shape is spherical. In addition, there is a problem that a cleaning failure is likely to occur because the toner is easy to slip through the blade.

In order to deal with such problems, an electrostatic cleaning method has been proposed and used.
In the electrostatic cleaning method, toner is electrostatically adsorbed and cleaned by a cleaning member to which a voltage having a polarity opposite to that of the toner is applied.
As an example of this electrostatic cleaning method, as described in Patent Document 1, a cleaning bias having a polarity different from the original polarity of the toner is applied, and the residual toner on the image carrier is electrostatically applied. A cleaning member (cleaning brush) to be adsorbed and an upstream side of the cleaning member, scraping at least a part of the residual toner on the image carrier and applying a charging bias having the same polarity as the original polarity of the toner. The toner collecting member (conductive blade) and the toner collecting member are supported and the toner collected by the toner collecting member (conductive blade) is prevented from adhering to the cleaning member (cleaning brush). There is a cleaning device provided with a support part.
This cleaning device is constituted by a toner collecting member and a cleaning member, and the toner is scraped and charged by the collecting member and electrostatically adsorbed by a brush-like cleaning member to perform cleaning.
Further, as described in Patent Document 2, a conductive brush is disposed so as to contact and rub against the surface of the photoreceptor, and a collection roller is disposed in contact with the conductive brush. And a cleaning device in which a voltage is applied to both.
In this cleaning device, the toner is electrostatically removed from the photoreceptor by the conductive brush, and the toner adsorbed on the conductive brush is electrostatically transferred from the conductive brush to the collection roller.
The ones described in Patent Document 1 and Patent Document 2 remove toner by electrostatic attraction, and have better cleaning performance for small-diameter toner and spherical toner as compared with the blade cleaning method. can get.

JP 2004-271603 A JP 2005-265907 A

  However, the above-described cleaning device is suitable for small particle size toner and spherical toner, but since the removal of the toner from the toner carrier by electrostatic cleaning is performed by a single cleaning member, the cleaning device There is a limit to the performance, and there is a problem that when a high adhesion amount toner such as an untransferred toner or a P sensor pattern is left when a recording paper jam occurs, sufficient cleaning cannot be performed.

  The present invention has a cleaning device capable of improving the cleaning performance, reliably cleaning a high adhesion amount toner such as a recording paper jam or a P sensor pattern, and reducing the time during which image formation cannot be performed, and the same. An image forming apparatus and a process cartridge are provided.

The features of the present invention as means for solving the above-described problems are as follows.
The cleaning device of the present invention comprises:
In the cleaning device having a cleaning member voltages of different polarities are applied, the collecting member for collecting the toner on the cleaning member to the polarity of the toner to clean the toner remaining on the toner carrying member,
The cleaning member is disposed upstream of the recovery member in the moving direction of the toner carrier, the recovery member abuts on the toner carrier, and the recovery member has a voltage applied to the cleaning member. The recovery member cleans the toner on the toner carrier after a high voltage is applied and the toner adhering to the recovery member is removed .

  According to the present invention, in the cleaning device having the cleaning member for electrostatically cleaning the toner remaining on the toner carrier and the recovery member for electrostatically recovering the toner on the cleaning member, the recovery member also The toner can be electrostatically adsorbed from the toner carrier to perform cleaning, and the cleaning performance is improved.

Hereinafter, embodiments of the present invention will be described.
An embodiment in which the cleaning device of the present invention is applied to an intermediate transfer belt as a toner carrier as shown in FIGS. 1 and 2 will be described.
Note that the toner carrying member indicates all of the toner existing on the surface thereof. In addition to the toner carrying the toner image such as the photosensitive member and the intermediate transfer belt, the carrying belt for carrying the recording medium after transfer. Etc. are also included.
In FIG. 1, reference numeral 1 denotes an intermediate transfer belt, which is stretched between a polarity control counter electrode roller 2 and a driving roller 3.
Below the intermediate transfer belt 1, process cartridges 4 to 7 are arranged.
The process cartridges 4 to 7 are configured integrally with the photosensitive drums 8 to 11 and charging, exposure, developing, and cleaning devices that are process means necessary for image formation. A toner image having toners of different colors is formed on the photosensitive drums 8 to 11. As for the toners that the process cartridges 4 to 7 have, 4 is yellow, 5 is cyan, 6 is magenta, and 7 is black.
The photosensitive drums 8 to 11 are respectively arranged on the upper portions of the process cartridges 4 to 7 and are in contact with the lower surface of the lower portion of the intermediate transfer belt 1.
Counter electrode rollers 12 to 15 for transfer are arranged at positions inside the intermediate transfer belt 1 where the photosensitive drums 8 to 11 come into contact. The toner images are sequentially transferred to the intermediate transfer belt 1 at each contact portion between the photoconductors 8 to 11 and the intermediate transfer belt 1, and a color toner image in which the toner images overlap is formed on the intermediate transfer belt 1.
Reference numeral 16 denotes a secondary transfer roller for transferring a toner image from the intermediate transfer belt 1 to a recording medium, and reference numeral 17 denotes a P sensor pattern detector. A cleaning unit 18 removes residual toner on the intermediate transfer belt 1 after the secondary transfer.

FIG. 2 shows the cleaning unit 18.
In FIG. 2, the cleaning unit 18 is disposed so as to surround a portion where the intermediate transfer belt 1 is wound around the polarity control counter electrode roller 2 with an upper case 19 and a lower case 20. Is arranged.
In the cleaning unit 18, an entrance seal 21, a polarity control blade 22, a cleaning brush 23, and a collection roller 24 are arranged in the order of movement of the intermediate transfer belt 1.
Voltages are applied to the polarity control blade 22, the cleaning brush 23, and the collection roller 24 by power sources 25 to 27, respectively. The applied voltages are -2.5 kV for the polarity control blade 22, + 800V for the cleaning brush 23, and the collection roller. 24 is + 1200V.
Further, +2.2 kV is applied to the conductive blade 35 by the power source 28.
The polarity control blade 22 and the cleaning brush 23 are positioned opposite the polarity control counter electrode 2 across the intermediate transfer belt 1, and the collection roller 24 faces the collection roller counter electrode 31 across the intermediate transfer belt 1. It is in the position to do.
The polarity control counter electrode 2 and the recovery roller counter electrode 31 are each grounded, and the polarity control counter electrode 2 is grounded via a conductive bearing having a resistance 2a of 10 ³ Ω · cm.

The entrance seal 21 is for blocking the inside of the cleaning unit 18 from the outside. The entrance seal 21 is attached to the upper case 19 and is in contact with the intermediate transfer belt 1. The attachment direction does not scrape off the toner on the intermediate transfer belt 1. Thus, the movement of the intermediate transfer belt 1 is in the forward direction.
The polarity control blade 22 scrapes a part of the toner on the intermediate transfer belt 1 and charges the toner that passes without being scraped to a single polarity.
The polarity control blade 22 is attached to a polarity control blade holder 29 fixed to the polarity control blade stage 30.
The cleaning brush 23 is a brush-like one that rotates counterclockwise, and mechanically separates the toner on the intermediate transfer belt 1 and electrostatically adsorbs it for cleaning.
The collection roller 24 abuts on the cleaning brush 23 and electrostatically adsorbs and collects the toner adsorbed on the cleaning brush 23, and also abuts on the intermediate transfer belt 1 to remove the toner on the intermediate transfer belt 1. It is electrostatically attracted and cleaned.
For this purpose, the recovery roller counter electrode 31 is arranged at a position facing the intermediate transfer belt 1.

The polarity control blade stay 30 is provided with a cleaning brush scattering prevention seal 32 that comes into contact with the cleaning brush 23, thereby blocking between the cleaning brush 23 and the polarity control blade stay 30.
Zinc stearate 34 urged upward by a compression spring 33 from below is pressed against the cleaning brush 23, and the zinc stearate 34 is applied to the intermediate transfer belt 1 through the cleaning brush 23.
Zinc stearate 34 is a lubricant for reducing the friction coefficient of the intermediate transfer belt 1 and increasing the transfer rate of the toner image.
The toner on the collection roller 24 is scraped off by the conductive blade 35 and removed.
The conductive blade 35 is attached to a conductive blade holder 36 fixed to a conductive blade stage 37.

  The parts other than the upper case 19 and the lower case 20 of the cleaning unit 18 include an entrance seal 21, a polarity control blade 22, a polarity control blade holder 29, a polarity control blade stage 30, a cleaning brush scattering prevention seal 32, and a cleaning brush 23. The recovery roller 24, the conductive blade 35, the conductive blade holder 36, and the conductive blade stage 37 are surrounded. As a result, a blocking space 38 is formed in the cleaning unit 18 to prevent the toner removed from the intermediate transfer belt 1 from adhering to the intermediate transfer belt 1 again.

  Reference numeral 39 denotes a toner discharge screw disposed on the bottom surface of the lower case 20 of the cleaning unit 18 for discharging the toner removed from the intermediate transfer belt 1 to the outside.

Next, the configuration of each member will be described in detail.
In the present embodiment, as the intermediate transfer belt 1, a synthetic resin such as polyimide, polycarbonate, polyester, or polypropylene, or various rubbers containing a suitable amount of a conductive agent such as carbon black is used.
The intermediate transfer belt 1 has a volume resistance of 10 ¹¹ Ω · cm and a linear velocity of 138 mm / s.
Further, an intermediate transfer belt 1 having elasticity can be used, and silicone rubber, NBR, H-NBR, CR, EPDM, urethane rubber or the like is used as the main base material of the conductive elastic layer. The material for the conductive protective layer is not particularly limited as long as it can achieve the objectives of reducing frictional resistance, stability of electrical characteristics to the environment, and improving residual toner cleaning performance by reducing surface roughness. Fluorine resin polymers such as ethylene (PTFE), copolymers of tetrafluoroethylene and perfluoroalkyl vinyl ether (PFA), PVdF, alcohol-soluble nylon, silicone resin, silane coupler, urethane resin emulsions and organic solvents In addition, a dissolved / dispersed paint can be used.
These protective layers can be provided by dip coating, spray coating, electrostatic coating, roll coating, or the like. Furthermore, by subjecting the protective layer to surface treatment or polishing, it is possible to improve mold release properties, conductivity, wear resistance, surface cleaning properties, and the like.

The polarity control blade 22 is a plate-like material bonded on a sheet metal, and is made of conductive urethane rubber, a thickness of 2.4 mm, and a protruding amount of 7 mm. The polarity control blade 22 has a hardness of 60 to 80 with a JIS-A hardness meter and a rebound resilience of 30%, but other values are possible. The electric resistance is 10 ^{6 to 8} Ω · cm. The polarity control blade 22 is in contact with the intermediate transfer belt 1 at a counter, the contact angle is 20 degrees, the contact pressure is 20 g / cm, and the amount of biting into the intermediate transfer belt 1 is 0.8 mm.

The cleaning brush 23 is made of conductive polyester and has a hair length of 4 mm.
The amount of biting into the transfer belt 1 is 1 mm, the rotation direction is counterclockwise in FIG. 2, the linear velocity is 138 mm / s (the same linear velocity as the transfer belt 1), and the brush yarn resistance is 10 ⁷ Ω · cm. The brush flocking density is 100,000 / inch ² , the brush form is inclined toward the downstream side in the brush rotation direction, and Φ is 14.
Specifically, the cleaning brush 23 has a core in which a conductive portion 231a as shown in FIG. 3 is wrapped with an insulating layer 231b in order to reduce charge injection into the toner between the intermediate transfer belt 1 and the cleaning brush 23. The sheath-structure fiber 231 is configured to incline the core-sheath structure fiber 231 toward the downstream side in the rotation direction of the intermediate transfer belt 1.
By inclining the core-sheath structure fiber 231 of the cleaning brush 23 in this manner, the contact probability between the toner and the cut surface where the conductive portion 231a is exposed from the core-sheath structure fiber 231 is reduced as shown in FIG. It is intended to reduce charge injection into the device.

The collection roller 24 is obtained by winding a PVDF tube (thickness: 100 μm) around a SUS core metal, and providing a surface UV coat layer (thickness: 5 μm) as an insulating layer thereon, and has a diameter of Φ14 mm.
The collection roller 24 rotates in the counterclockwise direction in FIG. 2, and the direction linear velocity is 138 mm / s.
The reason why the PVDF tube is wound around the metal core and the insulating layer is provided on the surface layer is to reduce the charge injection into the toner between the cleaning brush 23 and the collection roller 24.

The recovery roller counter electrode roller 31 is configured by winding urethane foam rubber of 1 mm around a core metal Φ5 mm (the outer shape is Φ7 mm). The volume resistance value of the foamed urethane rubber is 10 ⁴ Ω · cm or less, and the roller hardness is 44 degrees with an Asker C hardness meter.
Further, both sides of a bearing (not shown) are pressed against the recovery roller counter electrode roller 31 by 300 g springs in the direction of the recovery roller 24, and a pressure of 10 g / cm per unit length in the direction of the recovery roller 24. It has been added.

The conductive blade 35 is a plate-shaped member bonded on a sheet metal, and is made of conductive urethane rubber, a thickness of 2.8 mm, and a protruding amount of 7 mm. The conductive blade 35 has a hardness of 60-80 with a JIS-A hardness meter and a rebound resilience of 30%, but other values are possible. The electric resistance is 10 ^{6 to 8} Ω · cm.
The conductive blade 35 contacts the collection roller 24 at a counter, the contact angle is 20 degrees, the contact pressure is 20 g / cm, and the amount of biting into the collection roller 24 is 0.6 mm.

The entrance seal 21 and the anti-scattering seal 32 for the cleaning brush are made of polyurethane rubber having a thickness of 0.2 mm, and the protruding amount is 7 mm, which are in contact with the intermediate transfer belt 1, the cleaning brush 23, and the recovery roller 24, respectively. The contact angle is 11 degrees, and the amount of biting is 1 mm.
In such a configuration, when a print button of an operation unit (not shown) of the image forming apparatus is pressed, an operation necessary for image formation is started.

When the image forming operation is started, the drive roller 3 in FIG. 1 rotates in the counterclockwise direction indicated by the arrow, and the intermediate transfer belt 1 moves in the counterclockwise direction indicated by the arrow.
In each of the process cartridges 4 to 7, charging, latent image formation, development, and cleaning necessary for image formation are started, and a toner image is formed on each of the photosensitive drums 8 to 11, and each of the photosensitive drums 8 to 11. Each toner image is sequentially transferred onto the intermediate transfer belt 1 at each contact portion between the intermediate transfer belt 1 and the intermediate transfer belt 1.
The toner image is superimposed and transferred in the order of yellow, 5 cyan, 6 magenta, and 7 black 30 in the process cartridge 4 at the left end, and is transferred to a recording sheet by the secondary transfer roller 16 and is fixed to a fixing unit (not shown). )) And discharged out of the device.
The toner that is not transferred onto the paper in the secondary transfer and remains on the intermediate transfer belt 1 is transported to the cleaning unit 18 by the movement of the intermediate transfer belt 1 to be cleaned, and the next image formation is started again.

Next, toner cleaning on the intermediate transfer belt 1 will be described with reference to FIG.
The toner remaining on the intermediate transfer belt 1 without being transferred to the paper in the secondary transfer is conveyed by the movement of the intermediate transfer belt 1 and passes through the entrance seal 21. Since the entrance seal 21 is disposed so as not to scrape off the toner image on the intermediate transfer belt 1, the residual toner on the intermediate transfer belt is not cleaned at this time.

After the toner on the intermediate transfer belt 1 passes through the entrance seal 21, a part of the toner is scraped off when passing the position of the polarity control blade 22, and the toner remaining without being scraped off passes through the polarity control blade 22. pass.
The toner on the intermediate transfer belt 1 before passing through the polarity control blade 22 undergoes secondary transfer, and the toner charge amount distribution (q / d distribution) is + polarity as shown in FIG. 4a (before polarity control). And -polar ones are mixed.
The toner charge amount distribution (q / d distribution) was measured with an E-spurt analyzer manufactured by Hosokawa Micron. The vertical axis of the charge amount distribution chart shows the ratio to the number collected, and the horizontal axis represents one toner. Represents the amount of charge. If the q / d distribution is closer to one side with “0” as a boundary, it indicates that the polarity can be controlled.

Since a voltage of −2.5 kV is applied to the polarity control blade 22, as shown in FIG. 4B (after polarity control), the toner passes through the polarity control blade 22 by charge injection or discharge. Is charged.
The toner scraped off by the polarity control blade 22 falls into the blocking space 38 (on the left side of the polarity control blade 22 in FIG. 2), and is discharged out of the cleaning unit 18 by the toner discharge screw 39 to be accommodated (not shown). ).

The negatively charged toner that has passed through the polarity control blade 22 is conveyed to the position of the cleaning brush 23 by the movement of the intermediate transfer belt 1.
Since the cleaning brush 23 is rotating in the direction opposite to the moving direction of the intermediate transfer belt 1 and +800 V is applied, the surface of the intermediate transfer belt 1 is rubbed by the cleaning brush 23 and is applied onto the intermediate transfer belt 1. The toner is separated from the surface and moved to the cleaning brush 23 by electrostatic action.

The toner moved from the intermediate transfer belt 1 to the cleaning brush 23 is conveyed to a contact position with the collection roller 24 by the rotation of the cleaning brush 23.
Since the collection roller 24 rotates in the same direction as the cleaning brush 23 and a voltage of +1.2 kV higher than that of the cleaning brush 23 is applied, the toner on the cleaning brush 23 acts electrostatically at this contact position. To move onto the collection roller 24.

The toner on the collection roller 24 is scraped off by the conductive blade 35.
As described above, the toner on the intermediate transfer belt 1 is moved from the intermediate transfer belt 1 onto the cleaning brush 23 by electrostatic action, and the intermediate transfer belt 1 is cleaned. However, the cleaning brush 23 cannot clean the toner completely. The toner that passes while remaining on the intermediate transfer belt 1 is cleaned by the collection roller 24.

The collection roller 24 is in contact with the intermediate transfer belt 1 while facing the collection roller counter electrode roller 31 with the intermediate transfer belt 1 interposed therebetween, and a voltage of +1.2 kV is applied thereto. The remaining toner moves from the intermediate transfer belt 1 to the collecting roller 24.
Thus, the toner on the intermediate transfer belt 1 that has passed through the cleaning brush 23 is cleaned by the recovery roller 24.
The toner that has moved from the intermediate transfer belt 1 onto the collecting roller 24 is scraped off by the conductive blade 35.
As described above, the intermediate transfer belt 1 is also cleaned by the collection roller 24.

Here, the voltage applied to the cleaning brush 23 and the collection roller 24 will be described.
FIG. 5 shows the relationship between the voltage applied to the cleaning brush 23 when the toner adhesion amount on the intermediate transfer belt 1 is about 0.4 mg / cm ² and the cleaning residual ID after cleaning by the cleaning brush 23. The horizontal axis represents the voltage applied to the cleaning brush 23, and the vertical axis represents the remaining cleaning ID.
The cleaning residual ID indicates a state after the toner on the toner carrier is cleaned with a cleaning brush or the like.
In the present embodiment such as FIG. 2, the cleaning residual ID is, specifically, the toner on the toner carrier after cleaning is tape-transferred with Scotch tape (registered trademark) and pasted on paper, and the reflection density is determined. Measured with a spectrocolorimeter (X-light manufactured by Amtec), while only the scotch tape was attached to paper, and the reflection density was measured with a spectrocolorimeter in the same manner. This is a value obtained by subtracting the reflection density value of only the tape.

  There is a correlation between the remaining cleaning ID and the number of toners, and the value of the remaining cleaning ID increases as the number of toners increases. Therefore, the cleaning property can be determined by the remaining cleaning ID.

Since cleaning with the cleaning brush 23 moves the toner with a potential difference, in principle, the higher the voltage applied to the cleaning brush 23, the better the cleaning performance.
However, as the voltage applied to the cleaning brush 23 is increased, the current flowing from the cleaning brush 23 to the polarity control counter electrode 2 increases, thereby increasing the current flowing into the toner.
When the current flowing into the toner increases, the toner is charged toward the applied voltage polarity side of the cleaning brush 23 (this is generally considered as charge injection), and finally the toner charging polarity is applied to the cleaning brush. The polarity of the applied voltage is the same.
When the charging polarity of the toner becomes the same as that of the cleaning brush 23, a repulsive force acts between the cleaning brush 23 and the toner. As a result, the toner remains on the intermediate transfer belt 1 or the cleaning brush 23 rotates and the intermediate transfer is performed. When it meets the belt 1 again, it adheres to the intermediate transfer belt 1 again (usually referred to as “reverse adhesion”), resulting in residual cleaning toner.
The range where the cleaning brush applied voltage in FIG. 5 is +1300 V or more is this region.
In this embodiment, the voltage applied to the cleaning brush 23 is set to +800 V instead of the vicinity of +1000 V having the best cleaning property shown in FIG.
The reason is as follows.
The reverse adhesion described above occurs similarly between the collection roller 24 and the intermediate transfer belt 1. In other words, when the voltage applied to the collection roller 24 is +1300 V or more, reverse adhesion toner is generated even between the collection roller. Therefore, the voltage applied to the collection roller 24 must be lower than + 1300V.
Also, a potential difference of 400 V is required to move about 0.4 mg / cm ² of toner from the cleaning brush 23 to the collection roller 24.
Therefore, in this embodiment, the applied voltage to the collection roller 24 is +1200 V, and the applied voltage to the cleaning brush 23 is +800 V.

As described above, the voltages applied to the cleaning brush 23 and the collection roller 24 are the regions where the cleaning of the intermediate transfer belt 1 is favorably performed by the cleaning brush 23 and the collection roller 24, and the intermediate transfer belt 1, the cleaning brush 23, and the like. There is no reverse adhesion of the toner to the collection roller 24, and the voltage is such that the toner is collected from the cleaning brush 23 to the collection roller 24.
By setting the applied voltage in this way, the toner from the cleaning brush 23 and the toner from the intermediate transfer belt 1 move to the collection roller 24, and the intermediate transfer belt 1 is also cleaned by the collection roller 24.

  Next, details when the charging polarity of the toner passing through the polarity control blade 22 to which a voltage of −2.5 kV having the same polarity as that of the toner is applied will be described.

As described above, the polarity control blade 22 is arranged in counter contact with an electric resistance of 10 ^{6 to 8} Ω · cm, a contact pressure with the intermediate transfer belt 1 of 20 g / cm.
As shown in FIG. 6, the polarity of the toner passing through the polarity control blade 22 is −2.0 kV, −− by “friction charging”, “charge injection”, “discharge”, etc. by the intermediate transfer belt 1 and the polarity control blade 22. According to the applied voltage values of 2.5 kV and −3.0 kV, the polarity of the residual toner is shifted to the negative side, which is the normal charging polarity of the toner.
In the polarity control blade 22, as shown in FIG. 7, a so-called stick slip is generated in which the contact state of the tip changes from the state indicated by L to the state indicated by M in the rotation direction of the intermediate transfer belt 1.
Toner slip occurs when the tip of the polarity control blade 22 is in the L state in the figure.

When the toner is sandwiched between the polarity control blade 22 and the intermediate transfer belt 1 while slipping through, current flows into the toner with the voltage applied to the polarity control blade 22, and the toner is charged to the polarity on the applied voltage side. And pass through the polarity control blade 22.
It is considered that the change in the charging polarity of the toner in such a state is due to charge injection into the toner.

It has been confirmed that the potential on the surface of the intermediate transfer belt 1 after transfer varies in a range of approximately −100 V to +100 V, although it varies slightly depending on transfer conditions.
When the applied voltage to the polarity control blade 22 is “−2 kV”, if the surface potential of the intermediate transfer belt 1 is −100 V, the potential difference becomes 1900 V, so that discharge starts, and as a result, the polarity control blade 22 passes. The q / d distribution of the later toner shifts to the negative side.

In addition, before and after the contact position of the polarity control blade 22 with the intermediate transfer belt 1, the polarity control blade 22 and the transfer belt 1 form two wedge portions, an entrance and an exit. The toner is charged with the same polarity as the applied voltage by the discharge of the formed minute gap portion.
Since the wedge portion on the entrance side of the polarity control blade 22 mechanically scrapes off the toner and becomes contaminated with toner over time, the discharge of the minute gap portion is mainly performed on the wedge portion on the exit side.

In this way, the charging polarity of the toner changes when passing through the polarity control blade 22.
Then, the toner whose polarity is set to the negative polarity side and passed through the polarity control blade 22 is electrostatically removed by the cleaning brush 23 to which a voltage having a polarity opposite to the charging polarity of the toner is applied.
The applied voltage to each part such as the polarity control blade 22, the cleaning brush 23, the collection roller 24, the conductive blade 35, etc. can be of the reverse polarity as described above depending on the design requirements.

  Next, cleaning when a high adhesion amount toner such as untransferred toner or P sensor pattern at the time of recording paper jam remains on the intermediate transfer belt 1 will be described.

As the cleaning object of the cleaning brush 23, toners with various adhesion amounts and charge amounts are conveyed. By way of example concrete adhesion amount, the usual amount of deposition in the secondary transfer residual toner from about 0.05 mg / ^cm 2, P sensor pattern toner adhesion amount of about 0.6 mg / cm ^2, after the recording paper jam For the secondary untransferred toner, the adhesion amount is about 0.6 mg / cm ² or the like.

The P sensor pattern toner image is a 10-step 1.5 cm × 1.65 cm square pattern. For example, the first step is “0.03 mg / cm ² ” and the last step is “0.6 mg”. / Cm ² ”, it is formed in a square shape in which the toner adhesion amount gradually increases.
The toner amount of the P sensor pattern formed on the intermediate transfer belt 1 is detected by the P sensor pattern detector 17 shown in FIG. 1, and the result is fed back to the charging roller applied voltage and the developing bias and developed. The toner adhesion amount is controlled to be constant.
Since the normal image formation is temporarily interrupted when the P sensor pattern toner image is formed, the secondary transfer onto the recording paper is not performed. Therefore, the amount of toner after the primary transfer that has been primarily transferred from the photoconductors 8 to 11 to the intermediate transfer belt 1 is conveyed to the cleaning unit 18 while remaining attached on the intermediate transfer belt 1.

  Further, when a recording paper jam occurs after the primary transfer, the same amount of toner as the P sensor pattern is conveyed to the cleaning unit 18. In the case of this recording paper jam, unlike the case of the P sensor pattern, in the extreme case, the entire surface may become solid, and the total amount of toner conveyed to the cleaning unit 18 may increase.

When such a large amount of toner is conveyed by the intermediate transfer belt 1, the toner on the intermediate transfer belt 1 is first scraped off by the polarity control blade 22.
When the polarity control blade 22 is new, most of the toner is scraped off by the polarity control blade 22. However, as time passes, the polarity control blade 22 gradually wears the contact portion with the intermediate transfer belt 1 and inputs. The amount of toner gradually increases. When the wear progresses and is extreme, most of the toner may pass.

The cleaning brush 23 has a cleaning capacity. For example, if the capacity is such that the attached amount can be cleaned to about 0.4 mg / cm 2, if it is more than that, the cleaning cannot be completed, and it passes through while remaining on the intermediate transfer belt 1.
That is, in this case, when the adhesion amount is about 0.6 mg / cm ^{2 as in} the case of the P sensor pattern toner or the secondary untransferred toner after the recording paper jam, the worst case is 0.2 mg / cm ^2. The toner of cm ² will pass through the cleaning brush 23.
In the present embodiment, as shown in FIG. 2, the recovery roller 24 is brought into contact with the intermediate transfer belt 1, and the intermediate transfer belt 1 is also cleaned by the recovery roller 24. The toner that has passed through the cleaning brush 23 can be cleaned.

Specifically, the embodiment shown in FIG. 2 has a linear relationship between the toner adhesion amount and the cleaning residual ID as shown in FIG. 8, and the toner adhesion amount when the cleaning residual ID is 0.02. Is about 0.1 mg / cm ² .
As shown in FIG. 5 when the toner adhesion amount on the intermediate transfer belt 1 is about 0.4 mg / cm ² , when the applied voltage to the cleaning brush 23 is +800 V, the cleaning remaining ID after passing through the cleaning brush 23 is about At 0.02, the toner adhesion amount is about 0.1 mg / cm ² .
Therefore, as described above, when the toner adhesion amount on the intermediate transfer belt 1 is about 0.6 mg / cm ^{2 as in} the case of the P sensor pattern toner or the secondary untransferred toner after jamming, the cleaning is performed. After passing through the brush 23, about 0.3 mg / cm ² of toner remains on the intermediate transfer belt 1.
Since + 1200V is applied to the collection roller 24 and + 800V is applied to the cleaning brush 23, and the potential difference between them is 400V, the cleaning brush 23 cleans and adsorbs the intermediate transfer belt 1 by this potential difference. Most of the toner of / cm ² moves to the collection roller 24.
The toner on the collection roller 24 is scraped off by the conductive blade 35.

About 0.3 mg / cm ² of toner remaining on the intermediate transfer belt 1 after passing through the cleaning brush 23 is carried to the position of the recovery roller 24 by the movement of the intermediate transfer belt 1.
Since the collection roller 24 is in contact with the intermediate transfer belt 1 and a voltage of +1200 V is applied, approximately 0.3 mg / cm ² of toner remaining on the intermediate transfer belt 1 is collected from the intermediate transfer belt 1 to the collection roller. 24 and adheres to the collecting roller 24.
Thus, the toner on the intermediate transfer belt 1 that has passed through the cleaning brush 23 is also cleaned by the collection roller 24.

When the toner on the intermediate transfer belt 1 is cleaned by the recovery roller 24, the recovery roller 24 comes into contact with the cleaning brush 23 after the intermediate transfer belt 1 is cleaned by the recovery roller 24.
As a result, the toner on the cleaning brush 23 is moved onto the collection roller 24 in a state where the toner from the intermediate transfer belt 1 is adhered to the collection roller 24. Therefore, the toner movement from the cleaning brush 23 is performed on the collection roller 24. This is slightly less than that in which no toner is attached to the toner.

In this case, the toner that has not moved to the collection roller 24 is temporarily held by the cleaning brush 23. However, the cleaning brush 23 may be cleaned even if it temporarily holds about 0.4 mg / cm ² of toner. There is no effect on the property, and the above-described state of a high adhesion amount of the toner does not occur continuously, so there is almost no effect due to this.
For the toner temporarily held on the cleaning brush 23, a current flows between the intermediate transfer belt 1 and the cleaning brush 23, and between the cleaning brush 23 and the collection roller 24. If the toner stays for a long time, the reverse polarity occurs, which reverses to the same polarity as the applied voltage and adheres again to the intermediate transfer belt 1 as described above. Since the toner moves to the collecting roller 24 in a short time, there is almost no influence of this.

Thus, the toner from the cleaning brush 23 and the toner on the intermediate transfer belt 1 move to the collection roller 24, and the toner on the collection roller 24 is scraped off by the conductive blade 35.
Note that when the toner is scraped off by the conductive blade 35 on the surface of the collection roller 24, the surface potential of the collection roller 24 is lowered. The reason for this is that when the toner having a charge attached to the surface of the collecting roller 24 is scraped off by the conductive blade 35, a peeling discharge occurs and gives a negative charge to the high resistance layer or the insulating layer of the collecting roller 24. Alternatively, it is considered that a negative charge is given to the surface layer of the collecting roller 24 due to toner adhesion, and the given charge remains even if the conductive blade 13 scrapes off the toner.
In order to cope with this decrease in surface potential, a voltage higher than the voltage applied to the collection roller 24 is applied to the conductive blade 35 in contact with the surface of the collection roller 24.
That is, toner movement from the intermediate transfer belt 1 to the cleaning brush 23 and from the cleaning brush 23 to the collecting roller 24 is performed by a potential gradient. However, when the surface potential of the collecting roller 24 decreases as described above, the surface potential of the collecting roller 24 is decreased. Therefore, the potential difference between the recovery roller 24 and the cleaning brush 23 is reduced, and toner movement from the cleaning brush 23 to the recovery roller 24 is reduced.
When the toner movement from the cleaning brush 23 to the collection roller 24 is reduced, the toner accumulates in the cleaning brush 23 and the cleaning property is deteriorated.
In the embodiment of FIG. 2, there is a potential difference equal to or higher than the discharge start voltage between the surface of the collection roller 24 having a high resistance surface layer or insulating layer and the conductive blade 35. The discharge roller surface 24 is charged by discharge and charge injection at the gap, and the potential difference from the cleaning brush 23 is maintained.
Further, the surface of the collection roller 24 is charged by discharge and charge injection, and when the potential of the surface of the collection roller 24 increases, the discharge gradually decreases, and when it reaches a certain potential, the discharge is stopped.
In FIG. 2, such an applied voltage condition is set.
As described above, in the embodiment shown in FIG. 2, the recovery roller 24 is brought into contact with the intermediate transfer belt 1, the recovery roller counter electrode 31 is disposed across the intermediate transfer belt 1, and the recovery roller 24 is moved to the cleaning brush 23. Since a voltage of 1200 V, which is higher than the applied voltage of 800 V, is applied, the toner from the cleaning brush 23 and the toner on the intermediate transfer belt 1 move to the recovery roller 24, and the intermediate transfer belt is also moved by the recovery roller 24. 1 cleaning is performed.
Thus, even when a high adhesion amount toner such as untransferred toner or P sensor pattern at the time of recording paper jam remains on the intermediate transfer belt 1, sufficient cleaning can be performed.

Next, the toner removed from the intermediate transfer belt 1 will be described.
Normally, it is known that when toner is scraped off from a toner image carrier with a cleaning blade, the toner flies up and scatters. When the toner on the intermediate transfer belt 1 is scraped off with the polarity control blade 22, and the conductive property is increased. When the toner on the collection roller 24 is scraped off by the blade 35, it is in a scattered state.
The toner scraped off by the polarity control blade 22 or the conductive blade 35 naturally falls and falls to the toner discharge screw 39 and is discharged to the cleaning unit 18 by the toner discharge screw 39. Similarly, when rotating and discharging the toner out of the cleaning unit 18, the toner rises and is scattered.

In this way, the toner rises and floats in a scattered state especially when it is mechanically removed or moved, but the floating toner moves even from a slight gap, and therefore when the cleaning brush scattering prevention seal 32 is not provided. Adheres to the surface of the intermediate transfer belt 1 after passing through the polarity control blade 22 from the gap between the cleaning brush 23 and the polarity control blade stay 30.
The toner usually has a charge when adhering to the toner image carrier with an electrostatic force, but once separated, the charge is lost and becomes uncharged (no charge).
Therefore, most of the toner adhering to the surface of the intermediate transfer belt 1 from the gap between the cleaning brush 23 and the polarity control blade stay 30 is uncharged toner and reaches the position of the cleaning brush 23 by the movement of the intermediate transfer belt 1. The toner to be treated had a polarity-controlled -polar toner as shown in FIG. 9a (before the cleaning brush) and the q / p distribution of two peaks of the non-polar toner as shown in b (uncharged toner). Become toner.

Since the cleaning brush 23 moves the toner with a potential gradient between the intermediate transfer belt 1 and the cleaning brush 23, the uncharged toner does not move toward the cleaning brush 23 but passes through the position of the cleaning brush 23.
Since the non-charged toner has no electrostatic force binding force, the adhesion force to the intermediate transfer belt 1 is weak, and therefore, the mechanical force of the cleaning brush 23 slightly scrapes off the intermediate transfer belt 1. Most of them pass through the position of the cleaning brush 23 and directly enter the next transfer process.

The toner of each color exists in the transfer residual toner on the intermediate transfer belt 1, and the next transfer is performed on the cleaning residual toner in the next transfer step. As a result, a color different from the color of the desired image information, or an abnormal image due to a so-called cleaning defect in which an image is not formed is formed on the intermediate transfer belt 1.
Therefore, the gap between the polarity control blade stay 30 and the cleaning brush 23 in FIG. 2 is closed by the cleaning brush scattering prevention seal 32, so that the scattered toner does not adhere to the surface of the intermediate transfer belt 1 and such an abnormality occurs. Generation of an image can be prevented.

Another example of the configuration of the collection roller 24 will be described.
The toner on the collection roller 24 is mechanically scraped off using the conductive blade 35. However, in the case of a spherical toner, it is difficult to remove the toner as in the conventional case. In order to cope with this, the structure of the collection roller 24 may be as follows.
That is, the collection roller 24 only needs to have a function of transferring the toner adhering to the cleaning brush 23 to the collection roller 24 by a potential gradient between the cleaning brush 23 and the collection roller 24, and the intermediate transfer belt 1 and the photoreceptor 8. Unlike ~ 11, there are few restrictions on the material. Therefore, spherical toner can be easily removed by coating the surface of the collection roller 24 with a material having a low coefficient of friction, or winding a tube with a low coefficient of friction around a metal roller to reduce the coefficient of friction of the surface of the collection roller 24. .
Specifically, the recovery roller 24 may be formed by winding a fluorine coating, PVDF, or PFA tube.

  As the photoreceptor used in this embodiment, for example, a conductive support is heated to 50 ° C. to 400 ° C., and a vacuum deposition method, a sputtering method, an ion plating method, a thermal CVD method, a photo CVD method is applied on the support. An amorphous silicon photoreceptor having a photoconductive layer made of a-Si formed by a film forming method such as a plasma CVD method can be used. As the formation method, a plasma CVD method, that is, a method in which a source gas is decomposed by direct current, high frequency or microwave glow discharge to form an a-Si deposited film on a support is preferred. It is used.

FIG. 10 is a block diagram showing a second embodiment of the cleaning device. Unlike the configuration of the first embodiment shown in FIG. 2, a cleaning brush counter electrode 40 is provided as a counter electrode dedicated to the cleaning brush 23. Is. 10, the same components as those in FIG. 2 are denoted by the same reference numerals.
Since the counter electrode 2 for polarity control is provided with the counter electrode 40 for the cleaning brush,
It is arranged at a position facing only the polarity control blade 22.
The counter electrode 40 for the cleaning brush is composed of a Φ7 mm metal roller and is grounded.
In the embodiment of FIG. 2, the counter electrodes of the polarity control blade 22 and the cleaning brush 23 are also used as the same polarity control counter electrode 2.
In this case, when a high voltage (−polarity) is applied to the polarity control blade 22, the current flowing from the cleaning brush 23 to the polarity control counter electrode 2 increases, thereby increasing the current flowing into the toner as described above. As a result, the toner charging polarity becomes the same as the voltage applied to the cleaning brush 23, the reverse adhesion increases, and the cleaning performance by the downstream cleaning brush 23 or the collection roller 24 may deteriorate.
This is because when the high voltage is applied to the polarity control blade 22, the polarity control counter electrode 2 has a potential (−polarity) due to the resistance 2 a of the conductive bearing connected to the polarity control counter electrode 2. This is probably because the potential difference between the cleaning brush 23 and the polarity control counter electrode 2 increases.
Also, when the current value changes due to contamination of the polarity control blade 2 with toner or a change with time, the cleaning brush 23 is affected and the cleaning property is changed.
Therefore, as in the embodiment of FIG. 10, the cleaning brush counter electrode 40 that is the counter electrode of the cleaning brush 23 is provided separately from the polarity control counter electrode 2 that is the counter electrode of the polarity control blade 22. Problem is solved and the cleaning property is improved.

FIG. 11 shows an embodiment in which plate-like ones are used as the cleaning brush counter electrode and the recovery roller counter electrode.
In FIG. 11, the cleaning brush counter electrode 41 and the recovery roller counter electrode 42 are fixedly attached in a plate-like curved shape, and are formed of conductive urethane rubber having a thickness t = 1.5 mm. The transfer belt 1 is hit by the belly.
The electric resistance value of the conductive urethane rubber is 10 ^{6 to 8} Ω · cm or less, and the hardness is 60 ° to 80 ° with an Asker C hardness meter.
The pressure is applied to the intermediate transfer belt 1 from both ends by springs on a support plate (not shown).

FIG. 12 is a configuration diagram showing a third embodiment of the cleaning device, in which the collection roller 24 is arranged upstream of the cleaning brush 23.
In FIG. 12, the same components as those in FIG. 2 or 10 are denoted by the same reference numerals.
In FIG. 12, the positions of the collection roller 24, the cleaning brush 23, and related members are switched, and accordingly, a toner discharge guide 41 and an outlet seal 42 are provided.
The toner discharge guide 41 is for guiding the toner scraped from the collection roller 24 by the conductive blade 35 toward the toner discharge screw 39, and is attached to the lower case 10.
The outlet seal 42 is for blocking the inside of the cleaning unit 18 from the outside and preventing the toner from the cleaning brush 23 from floating on the intermediate transfer belt 1, and is attached to the lower case 10. Yes.
Further, a recovery roller scattering prevention seal 43 is attached to the polarity control blade stage 30 in place of the cleaning brush scattering prevention seal 32.
The outlet seal 42 and the recovery roller scattering prevention seal 43 have the same configuration as the inlet seal 21 or the cleaning brush scattering prevention seal 32. The toner discharge guide 41 is also made of the same material.

In the embodiment shown in FIG. 12, the negatively charged toner that has passed through the polarity control blade 22 is transported to the contact position with the recovery roller 24 by the movement of the intermediate transfer belt 1, and the intermediate transfer belt at this contact position. The toner on 1 is moved onto the collection roller 24 by electrostatic action, and cleaning by the collection roller 24 is performed.
The toner that has passed through the intermediate transfer belt 1 without being completely cleaned by the collecting roller 24 is conveyed to the position of the cleaning brush 23 and cleaned by the cleaning brush 23.
The toner moved from the intermediate transfer belt 1 to the cleaning brush 23 is conveyed to a contact position with the collection roller 24 by the rotation of the cleaning brush 23, and moves onto the collection roller 24 by electrostatic action at this contact position.
The toner that has moved from the cleaning brush 23 onto the collection roller 24 and the toner that has moved from the intermediate transfer belt 1 onto the collection roller 24 are scraped off by the conductive blade 35.

FIG. 13 is a configuration diagram showing a fourth embodiment of the cleaning device, in which a photosensitive drum is used as a toner carrier to be cleaned.
In FIG. 13, reference numeral 46 denotes a photosensitive drum, and a cleaning unit 47 is disposed on a part of the peripheral surface of the photosensitive drum 46.
The cleaning unit 47 is disposed so that a part of the peripheral surface of the photosensitive drum 46 is surrounded by a case 48, and a cleaning configuration is disposed inside.
In FIG. 13, the same components as those in FIG. 2, FIG. 10, or FIG.
In the case 48 of the cleaning unit 47, the entrance seal 21, the polarity control blade 22, the cleaning brush 23, and the recovery are arranged in the order of rotation of the photosensitive drum 46 in the order of movement of the entrance seal 21 and the intermediate transfer belt 1. A roller 24 is arranged.
The entrance seal 21 is attached to the case 48, and the polarity control blade 22 is attached to a polarity control blade holder 29 fixed to the polarity control blade stay 30.
The polarity control blade stay 30 is provided with a cleaning brush scattering prevention seal 32 that comes into contact with the cleaning brush 23, thereby blocking between the cleaning brush 23 and the polarity control blade stay 30.
The conductive blade 35 is attached to a conductive blade holder 36 fixed to a conductive blade stay 37.
33 is a compression spring, 34 is zinc stearate, 25-28 is a power source for the voltage to be applied, and 39 is a toner discharge screw.
The parts other than the case 48 of the cleaning unit 47 are the entrance seal 21, the polarity control blade 22, the polarity control blade holder 29, the cleaning brush scattering prevention seal 32, the cleaning brush 23, the recovery roller 24, the conductive blade 35, and the conductive blade. By being surrounded by the holder 36, a blocking space 49 is formed in the cleaning unit 47, and the toner removed from the photosensitive drum 46 is prevented from adhering to the photosensitive drum 46 again.

  In the embodiment shown in FIG. 13, the recovery roller 20 may be the above, but a foamed polyurethane layer is provided on the outer layer of the core metal of Φ8 mm, and further a PVDF tube (thickness 100 μm) and an insulating layer are provided on the outer layer. A layer composed of a certain surface UV coat layer (thickness: 5 μm) is suitable. This configuration can also be used in the embodiment shown in FIG. 2, FIG. 10, or FIG.

In the embodiment of FIG. 13, the opposing electrodes of the polarity control blade 22, the cleaning brush 23, and the recovery roller 24 are the photosensitive drum 46, but the photosensitive drum 46 is an insulator, and the voltage applied corresponding to this is the insulator. The flowing current is different, and the flowing current is extremely small.
Specifically, an example of the applied voltage and current value in the embodiment of FIG. 13 is as follows: for the polarity control blade 22, an applied voltage of −1.0 kV and a current value of 20 μA, for the cleaning brush 23, an applied voltage of +300 V and a current value of 3 μA, The recovery roller 24 has an applied voltage of +700 V and a current value of 5 μA.
An example of the embodiment shown in FIG. 2 is as follows. For the polarity control blade 22, the applied voltage is −2.5 kV and the current value is 50 μA. For the cleaning brush 23, the applied voltage is +800 V and the current value is 18 μA. The applied voltage is +1200 V and the current value is 2 to 5 μA.
10 or 11, the polarity control blade 22 has an applied voltage of −2.5 kV and a current value of 50 μA. The cleaning brush 23 has an applied voltage of +800 V and a current value of 8 μA. The roller 24 has an applied voltage of +1200 V and a current value of 15 μA.
In such a configuration, the photosensitive drum 44 is cleaned by the cleaning brush 23 and the collection roller 24.

FIG. 14 shows an embodiment in which the cleaning device of the present invention is used in a color image forming apparatus having one photosensitive member, a plurality of developing devices and an intermediate transfer belt.
In FIG. 14, a photosensitive drum 101 is disposed in a housing (not shown) of the image forming apparatus 100, and a charging roller 102, yellow, magenta, cyan, and black developing devices 103 to 106 and an intermediate portion are disposed around the photosensitive drum 101. A transfer device 107, a photoconductor cleaning unit 108, a static elimination lamp 109, and a light shielding plate 110 are disposed.
An exposure device (not shown) for exposing with a laser beam 111 is disposed above the photosensitive drum 101. A conveying belt 112 that conveys the recording paper after transfer is disposed below.
The photoconductor cleaning unit 108 performs cleaning of the photoconductor drum 101, and may have the same configuration as the cleaning device 47 of the embodiment shown in FIG.
The intermediate transfer device 107 transfers a toner image by an intermediate transfer belt 113 stretched by a plurality of rollers. The toner image of each color is transferred from the photosensitive drum 101 at a contact position with the photosensitive drum 101. A color toner image obtained by superimposing the color toner images is transferred to the recording paper P at the position of the secondary transfer roller 114.
Reference numeral 115 denotes an intermediate transfer belt cleaning unit, which may have the same configuration as the cleaning unit 18 of the embodiment shown in FIG. 2, FIG. 10 or FIG. Reference numeral 116 denotes a counter electrode of the intermediate transfer belt cleaning unit 115, which is illustrated in a simplified manner.

When image formation is performed in the image forming apparatus 100 shown in FIG. 14, the photosensitive drum 101 rotates counterclockwise as indicated by an arrow, charging by the charging roller 102, latent image formation by the laser light 111, and each developing device 103 To 106, and a toner image is formed on the photosensitive drum 101.
This series of processes is sequentially performed for each color of yellow, magenta, cyan, and black, and a toner image for each color is sequentially formed.
Simultaneously with the rotation of the photosensitive drum 101, the intermediate transfer belt 113 rotates in the clockwise direction indicated by the arrow, and each time a toner image of each color is formed, the toner image is sequentially superimposed on the same position on the intermediate transfer belt 1113. Transferred to form a color toner image.
The color toner image on the intermediate transfer belt 113 is transferred onto the recording paper P that has been transported by the transport belt 112 at the position of the secondary transfer roller 114, and is then fixed and discharged (not shown). Discharged to the top.
The transfer residual toner remaining on the surface of the photoconductor 101 is removed by the photoconductor cleaning unit 108, and the transfer residual toner remaining on the surface of the intermediate transfer belt 113 is removed by the intermediate transfer belt cleaning unit 115. .

FIG. 15 shows an embodiment in which the cleaning device of the present invention is used for a photoreceptor and a paper transport belt of an image forming apparatus.
In FIG. 15, a photosensitive drum 201 is disposed in a casing (not shown) of the image forming apparatus 200, and a charging roller 202, a developing device 203, a transfer roller 204, a photosensitive member cleaning unit 205, and a charge eliminating device are disposed around the photosensitive drum 201. A lamp 206 and a light shielding plate 207 are arranged.
Reference numeral 208 denotes laser light emitted from an exposure apparatus (not shown).
Reference numerals 209 and 210 denote an upper registration roller and a lower registration roller for conveying recording paper from a paper feed cassette (not shown), and 211 and 212 denote recording paper in a transfer area between the photosensitive drum 201 and the transfer roller. It is a guide plate to guide.
Reference numeral 213 denotes a conveyance belt for conveying the recording paper after transfer, and 214 denotes a conveyance belt cleaning unit.

The photoconductor cleaning unit 205 is for cleaning the photoconductor drum 201, and may have the same configuration as the cleaning device 47 of the embodiment shown in FIG.
The conveyor belt cleaning unit 214 can be of the same configuration as the cleaning unit 18 of the embodiment shown in FIG. 2, FIG. 10 or FIG. 12, or can be used in a simplified manner such as omitting the polarity control function. Can do.
In the image forming apparatus shown in FIG. 15, when image formation is performed, the photosensitive drum 101 rotates counterclockwise as indicated by an arrow, is charged by the charging roller 202, latent image is formed by the laser beam 208, and the developing device 203. Development is performed, and a toner image is formed on the photosensitive drum 201.
In synchronization with image formation, a recording sheet is fed from a sheet feeding cassette (not shown) by an upper registration roller 209 and a lower registration roller 210 and passes between guide plates 211 and 212 between the photosensitive drum 201 and the transfer roller. Is fed to the transfer area.
The toner image on the photosensitive drum 201 is transferred onto a recording sheet in a transfer region, conveyed to a fixing device (not illustrated) by a conveying belt 213 that conveys the recording sheet after transfer, and a discharge tray (not illustrated) after fixing. ) Discharged on top.
The transfer residual toner remaining on the surface of the photoconductor 201 is removed by the photoconductor cleaning unit 205. Further, the toner adhering to the transport belt 213 is removed by the transport belt cleaning unit 214.

The cleaning of the conveyance belt 213 will be described. In the case of the configuration shown in FIG. 15, when a recording paper jam occurs, the toner image on the photosensitive drum 201 is transferred to the conveyance belt 213, and the conveyance belt 213. May get dirty. In addition, low-charge toner or positively-charged toner in the developing device may adhere between the papers on the photosensitive drum 201. In this case, the toner adhering between the papers is transported by the conveyor belt 213. The transfer belt 213 may be soiled.
For this reason, toner may adhere to the conveyor belt, and the adhered toner is removed by the conveyor belt cleaning unit 115.

FIG. 16 shows an embodiment of a process cartridge using the cleaning device of the present invention.
In FIG. 16, reference numeral 301 denotes a photosensitive drum, 302 denotes a charging roller, 303 denotes a developing unit, and 304 denotes a cleaning unit. These are integrally supported in a frame 305 and are detachable from the main body of the image forming apparatus. A cartridge 300 is configured. Reference numeral 306 denotes a laser beam.
As the cleaning unit 304, one having the same configuration as the cleaning device 47 of the embodiment shown in FIG. 13 can be used.
The process cartridge 300 shown in FIG. 16 may be used as the process cartridges 4 to 7 shown in FIG.
In FIG. 16, other process means of the photosensitive drum 301 and the cleaning unit 304 are also integrally supported. However, the process cartridge 300 is at least supported by the photosensitive drum 301 and the cleaning unit 304. I just need it.

As described above, in this embodiment, in order to clean the toner remaining on the intermediate transfer belt, the photosensitive drum, and the conveyance belt, which are toner carriers, a cleaning in which a voltage having a polarity different from the polarity of the toner is applied. In a cleaning device having a cleaning brush as a member and a recovery roller as a recovery member for recovering toner on the cleaning brush, the recovery roller contacts an intermediate transfer belt or the like as a toner carrier, and the recovery roller A voltage higher than the voltage applied to the brush is applied, and the collection roller cleans the toner such as the intermediate transfer belt .
Accordingly, the cleaning performance is enhanced because the intermediate transfer belt, which is a toner carrier, is also cleaned by the collection roller.

The voltage applied to each of the cleaning brush and the collection roller is a voltage in a region where the toner such as the intermediate transfer belt is cleaned by the cleaning brush and the collection roller, and the cleaning brush or the collection roller and the intermediate transfer belt, etc. Since the toner does not cause reverse adhesion and the toner moves from the cleaning brush to the collecting roller, the toner can be well cleaned without reverse adhesion and the toner can be collected well. Done.
Further, since the potential difference between the intermediate transfer belt or the like and the collection roller is larger than the potential difference between the cleaning brush and the collection roller, the collection function by the collection roller and the cleaning by the collection roller are favorably performed.

In addition, the cleaning brush is disposed upstream of the recovery roller in the moving direction of the intermediate transfer belt, etc., the toner from the cleaning brush moves to the recovery roller, and after the toner adhering to the recovery roller is removed, the toner from the intermediate transfer belt, etc. Since the toner moves to the collecting roller, it is less affected by the toner from the cleaning brush and can be effectively cleaned by the collecting roller.
Further, the recovery roller is disposed upstream of the cleaning brush in the moving direction of the intermediate transfer belt, etc., and the toner from the intermediate transfer belt moves to the recovery roller, and after the toner adhering to the recovery roller is removed, the toner from the cleaning brush By moving the toner to the collecting roller, the collecting by the collecting roller from the cleaning brush can be effectively performed without being affected by the toner from the intermediate transfer belt or the like.
In addition, the collection roller is brought into contact with the intermediate transfer belt or the like, and the collection roller counter electrode is disposed with the intermediate transfer belt or the like interposed therebetween, thereby forming a potential gradient between the collection roller and the intermediate transfer belt. And the function of cleaning by the collecting roller can be enhanced.
In addition, a polarity control member is provided upstream of the cleaning brush and the collection roller in the moving direction of the intermediate transfer belt, etc., and a voltage having a polarity different from the polarity of the cleaning brush and the collection roller is applied to the polarity control member. Thus, the polarity of the toner is controlled, so that cleaning can be performed satisfactorily.

Further, since the cleaning member is a brush and the recovery member is a roller, these provide functions suitable for cleaning by the cleaning member and for recovery and cleaning by the recovery member.
Further, since a blocking space for collecting the toner removed from the intermediate transfer belt or the like is formed in the cleaning device, it is possible to prevent the collected floating toner from adhering to the intermediate transfer belt or the like.
In addition, the cleaning device is formed in a unit shape that includes a case that surrounds the cleaning brush and the collection roller that are in contact with the intermediate transfer belt, etc., so that the cleaning device can be handled easily and a blocking space is formed. Can be easily formed.
Further, since the toner carrier is an intermediate transfer belt, a photoconductor, and a recording paper conveyance belt, the application range of the cleaning device is widened and the function of the cleaning device is exhibited.

Further, by using this cleaning device in an image forming device having a cleaning device that removes residual toner generated in the means that comes into contact with toner in the image forming process, an image forming device with good cleaning quality can be obtained.
Further, by using this cleaning device for the process cartridge, a process cartridge with good cleaning quality can be obtained.

1 is a schematic configuration diagram illustrating an embodiment in which a cleaning device of the present invention is used for an intermediate transfer belt of a color image forming apparatus having a plurality of process units. It is a block diagram which shows 1st Embodiment of the cleaning apparatus of this invention. It is a schematic diagram which shows the slanted hair (fiber is inclined with respect to the axis | shaft) state of the core-sheath structure fiber of a cleaning brush. It is a figure which shows the toner charge amount distribution (q / d distribution) before and behind a polarity control blade. It is a figure which shows the relationship between a cleaning brush applied voltage and cleaning residual ID. It is a figure which shows the relationship between a polarity control blade application voltage and the toner charge amount distribution (q / d distribution) after polarity control. It is a figure which shows the state of the stick slip of a polarity control blade. FIG. 6 is a diagram illustrating a relationship between a cleaning residual ID and a toner adhesion amount. FIG. 6 is a diagram illustrating a toner charge amount distribution (q / d distribution) when uncharged toner adheres to an intermediate transfer belt. It is a block diagram which shows 2nd Embodiment of the cleaning apparatus of this invention. It is a block diagram which shows embodiment using the plate-shaped thing as a counter electrode for cleaning brushes, and a counter electrode for collection | recovery rollers. It is a block diagram which shows 3rd Embodiment of the cleaning apparatus of this invention. It is a block diagram which shows 4th Embodiment of the cleaning apparatus of this invention. 1 illustrates an embodiment in which the cleaning device of the present invention is used in a color image forming apparatus having one photosensitive member, a plurality of developing devices, and an intermediate transfer belt. 1 illustrates an embodiment in which the cleaning device of the present invention is used for a photoreceptor and a paper transport belt of an image forming apparatus. 1 illustrates an embodiment of a process cartridge using a cleaning device of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Intermediate transfer belt 2 Opposite electrode roller for polarity control 2a Resistance 3 Drive rollers 4-7 Process cartridges 8-11 Photoconductive drums 12-15 Counter electrode roller 16 Secondary transfer roller 17 P sensor pattern detector 18 Cleaning unit 19 Upper case 20 Lower case 21 Entrance seal 22 Polarity control blade 23 Cleaning brush 231 Core-sheath structure fiber 231a Conductive portion 231b Insulating layer 24 Collection roller 25-28 Power supply 29 Polarity control blade holder 30 Polarity control blade stage
31 Counter electrode roller for recovery roller 32 Anti-scattering seal for cleaning brush 33 Compression spring 34 Zinc stearate 35 Conductive blade 36 Conductive blade holder 37 Steer for conductive blade
38 Blocking space 39 Toner discharge screw
40 Cleaning brush counter electrode 42 Recovery roller counter electrode 43 Toner discharge guide 44 Exit seal 45 Recovery roller scattering prevention seal 46 Photosensitive drum 47 Cleaning unit 48 Case 49 Shut-off space 100 Image forming apparatus 101 Photosensitive drum 102 Charging roller 103 To 106 Developing device 107 Intermediate transfer device 108 Cleaning unit 109 for photosensitive member Static elimination lamp 110 Light shielding plate 111 Laser beam 112 Conveying belt 112
113 Intermediate transfer belt 113
114 Secondary transfer roller P Recording paper 115 Intermediate transfer belt cleaning unit 116 Counter electrode 200 of intermediate transfer belt cleaning unit Image forming apparatus 201 Photosensitive drum 202 Charging roller 203 Developing device 204 Transfer roller 205 Photoconductor cleaning unit 206 Static neutralization Lamp 207 Shielding plate 208 Laser beam 209 Upper registration roller 210 Lower registration rollers 211, 212 Guide plate 213 Conveying belt 214 Conveying belt cleaning unit 300 Process cartridge 301 Photosensitive drum 302 Charging roller 303 Developer 304 Cleaning unit 305 Frame 306 Laser light

Claims (11)

In the cleaning device having a cleaning member voltages of different polarities are applied, the collecting member for collecting the toner on the cleaning member to the polarity of the toner to clean the toner remaining on the toner carrying member,
The cleaning member is disposed upstream of the recovery member in the moving direction of the toner carrier, the recovery member abuts on the toner carrier, and the recovery member has a voltage applied to the cleaning member. A cleaning device , wherein a high voltage is applied, and after the toner adhering to the recovery member is removed, the recovery member cleans the toner on the toner carrier . The cleaning device according to claim 1,
The voltage applied to each of the cleaning member and the collection member is a voltage region where the cleaning member and the collection member and the cleaning of the toner on the toner carrying member is performed, the cleaning member or the collection member cleaning device comprising said that toner carrying reverse adhesion not occur in the toner with the body, and moves from the cleaning member of the toner to the collecting member is a voltage to be performed with. The cleaning device according to claim 1 or 2,
Cleaning device potential difference between the collecting member and the toner carrying member, being larger than the potential difference between the cleaning member and the collection member. In the cleaning device according to any one of claims 1 to 3,
Cleaning apparatus, characterized in that a collecting member facing the electrode at a position facing the collecting member across the toner carrying member. In the cleaning device according to any one of claims 1 to 4,
The toner carrier polarity control member is provided in the moving direction of the upstream position, a voltage of a different polarity is applied to the polarity of the cleaning member and the collecting member to the polarity control member relative to said cleaning member and said collecting member cleaning apparatus characterized by being Ru is. In the cleaning device according to any one of claims 1 to 5,
The cleaning member is a brush, a cleaning device, characterized in that said collecting member is a roller. In the cleaning device according to any one of claims 1 to 6,
A cleaning device, wherein a blocking space for collecting the toner removed from the toner carrier is formed in the cleaning device. In the cleaning device according to any one of claims 1 to 7,
A cleaning device the cleaning device, characterized in that said is in contact with the toner carrying member formed on the cleaning member and said surround the recovery member units like having a case shape. In the cleaning device according to any one of claims 1 to 8,
The cleaning device , wherein the toner carrier is any one of an intermediate transfer belt, a photosensitive member, and a recording paper transport belt . And the latent image bearing member, a latent image forming means for forming an electrostatic latent image on said image bearing member,
A developing means for forming a developed toner image an electrostatic latent image on the latent image carrier with toner,
A transfer unit for transferring the transfer member or a recording medium the toner image on the image bearing member,
An image forming apparatus having a cleaning unit that removes residual toner generated in a unit that comes into contact with toner in an image forming process.
Examples cleaning device, an image forming apparatus characterized by using the cleaning device according to any one of claims 1-9. In the process cartridge that integrally supports the latent image carrier and at least the cleaning device and is detachable from the image forming apparatus main body,
Examples cleaning device, process cartridge characterized by using a cleaning device according to any one of claims 1-9.

Images