JP2007155960A - Cleaning apparatus, cleaning method and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve both of cleaning performance for capturing depositions stuck to a member to be cleaned into a belt-like conductive brush and collection performance for collecting the depositions captured by the belt-like conductive brush into a collection roll. <P>SOLUTION: Since a contact part (nip part) between the belt-like conductive brush 102 formed by a shaft 104 having a diameter of 10.0 mm and a photoreceptor drum 12 is in high density, the cleaning performance for capturing remaining toner stuck to the photoreceptor drum 12 by the belt-like conductive brush 102 is high. On the other hand, density on the tip of a brush 112 on a contact part (nip part) between a belt-like conductive brush 102 formed by a shaft 106 having a diameter of 5.00 mm and a collection roll 120 is low, and thereby, collection performance for collecting the remaining toner captured by the belt-like conductive brush 102 by the collection roll 120 is high. Namely both the cleaning performance and the collection performance can be improved. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a cleaning device, a cleaning method, and an image forming apparatus.

  Conventionally, in an image forming apparatus that forms an image on a recording medium such as recording paper by an electrophotographic method such as a copying machine or a printer, as a cleaning device that removes residual toner remaining on the photosensitive drum without being transferred to the recording paper, A method is known in which a cleaning blade is pressed onto a photosensitive drum to scrape off and remove residual toner.

  In recent years, in order to perform high-definition image formation, a toner having a small particle size and a spherical shape, for example, a polymerized toner has been used. Such a small-diameter spherical toner slips through the cleaning blade described above.

Therefore, the residual toner is mechanically scraped off by a roll-like or belt-like conductive brush, and a bias voltage is applied to the conductive brush so that it is electrically attracted to the conductive brush and captured. The method to do is adopted. The residual toner captured by the conductive brush is collected electrically by the potential difference between the conductive brush and the collection roll by bringing the collection roll to which the bias voltage is applied into contact with the conductive brush, and further contacts the collection roll. The scraper is scraped off from the collecting roll and collected. (For example, refer to Patent Document 1 and Patent Document 2).
Japanese Patent Laid-Open No. 4-093974 JP-A-3-266878

  When cleaning the residual toner on the photoconductor, the higher the density of the conductive brush, the greater the chance of capturing the residual toner at the contact portion with the photoconductor, both mechanically and electrically. The cleaning performance to capture is improved. However, if the density is low, the chance of capturing the toner is reduced and the cleaning performance is lowered.

  On the other hand, the residual toner captured by the conductive brush from the photosensitive member may be adhered to the tip of the conductive brush or may slightly enter the brush.

  If the conductive brush has a high density, the residual toner that has slightly entered the inside of the brush is difficult to be collected because it is not easily caught between the brushes. Further, when the conductive brush has a high density, an electric field is not applied to the inside of the brush, so that it is difficult to collect.

  However, when the density is low, the distance between the brushes is wide, so that the brushes are easily pulled out. Further, since the electric field is applied to the relatively inside of the brushes, the brushes are easily collected.

  As described above, when the density of the conductive brush is increased, residual toner adhering to the photoconductor is easily captured, but it is difficult to collect the captured toner on the recovery roll. Conversely, if the density of the conductive brush is made low, it becomes difficult to capture the residual toner in the form of a photoconductor, but it becomes easy to collect the captured toner on a collecting roll.

  Therefore, there is a trade-off between the cleaning performance for capturing residual toner from the photoconductor to the conductive brush and the recovery performance for collecting residual toner from the conductive brush to the recovery roll. It was very difficult.

  The present invention has been made to solve the above-described problem, and has a cleaning performance for capturing deposits adhered to a member to be cleaned on a belt-like conductive brush, and a collection roll for deposits captured by the belt-like conductive brush. The purpose is to increase both the recovery performance and the recovery performance.

  The cleaning device according to claim 1 rotates in contact with a member to be cleaned, and rotates an endless belt-like conductive brush that captures deposits attached to the member to be cleaned, and the belt-like conductive brush. And a conductive recovery member that recovers deposits captured by the belt-shaped conductive brush by a potential difference from the belt-shaped conductive brush, and the belt-shaped conductive brush includes the member to be cleaned and the cleaning target member. The curvature of the contact portion is made smaller than the curvature of the contact portion with the conductive recovery member.

  In the cleaning device according to the first aspect, the rotating endless belt-like conductive brush is brought into contact with and captured by the member to be cleaned to which the adhered matter has adhered. The deposits captured by the belt-like conductive brush are collected by the conductive recovery member due to a potential difference from the belt-like conductive brush.

  Now, in the belt-like conductive belt, where the curvature is small (the curve is gentle), the spread of the tip of the brush is also small, and the density of the brush tip is high. On the contrary, in the portion where the curvature is large (the curve is steep), the spread of the brush tip becomes large, and the density of the brush tip becomes low.

  Therefore, by reducing the curvature of the contact portion of the belt-like conductive brush with the member to be cleaned and increasing the density of the brush tip, the adhering matter is captured at the contact portion between the belt-like conductive brush and the member to be cleaned. Opportunities are increased both mechanically and electrically, and the belt-like conductive brush increases the cleaning performance for capturing deposits.

  On the other hand, the adhering matter captured by the belt-like conductive brush may be either adhered to the tip of the brush or may slightly enter the brush.

  Deposits that have slightly entered the brush are easier to collect because the lower density of the brush tip tends to slip out of the brush.

  Furthermore, the electric field due to the potential difference between the conductive recovery member and the belt-like conductive brush does not reach the inside of the brush when the brush tip has a high density. However, if the brush tip has a low density, an electric field is applied to the relatively inner part of the brush, so that it is easy to collect the deposit that has entered the brush.

  Therefore, by increasing the curvature of the contact portion of the belt-like conductive brush with the conductive recovery member and reducing the density of the brush tip, the conductive recovery member increases the recovery capability of recovering the deposits. Yes.

  As described above, both the cleaning performance for capturing the deposits from the member to be cleaned by the belt-like conductive brush and the recovery performance for collecting the deposit from the belt-like conductive brush to the conductive recovery member are both high.

  The belt-like conductive brush and the conductive recovery member need not be insulative and may be so-called semiconductive. Alternatively, a conductive or semiconductive coating may be applied. In short, it is sufficient that a predetermined potential difference is provided between the belt-like conductive brush and the conductive recovery member.

  A cleaning device according to a second aspect is characterized in that, in the configuration according to the first aspect, a curvature of a contact portion of the belt-like conductive brush with the member to be cleaned is substantially zero.

  In the image forming apparatus according to the second aspect, the curvature of the contact portion of the belt-like conductive brush with the member to be cleaned is substantially zero. A curvature of approximately 0 means that the curve is straight without being curved. Therefore, the portion where the curvature is substantially 0 has the highest density because the tip of the brush does not spread. That is, the cleaning performance with which the belt-like conductive brush captures deposits is the highest.

  According to a third aspect of the present invention, there is provided the cleaning device according to the first or second aspect, wherein the conductive recovery member is a rotating recovery roll, and the contact member that scrapes off deposits collected by the recovery roll. It is characterized by having.

  In the image forming apparatus according to the third aspect, the collection roll collects the deposits captured by the belt-like conductive brush, and the contact member scrapes off the deposits collected by the collection roll. Therefore, the collection capability of the collection roll is maintained high.

  According to a fourth aspect of the present invention, there is provided an image forming apparatus comprising the cleaning device according to any one of the first to third aspects, wherein the toner image formed on the image carrier is finally transferred to a recording medium. The belt-shaped conductive brush of the cleaning device is in contact with the member to be cleaned, to which the toner that has not been transferred to the recording medium has finally adhered, and the toner adhering to the member to be cleaned is removed. The conductive collecting member collects the toner captured and captured by the belt-like conductive brush by a potential difference from the belt-like conductive brush.

  In the image forming apparatus according to the fourth aspect, the toner image formed on the image carrier is finally transferred to the recording medium. Then, the belt-like conductive brush of the cleaning device comes into contact with the member to be cleaned to which the toner that has not been transferred to the recording medium finally adheres, and the toner adhering to the member to be cleaned is captured, thereby the belt-like conductive property. The toner collected by the brush is collected by the conductive collecting member due to a potential difference from the belt-like conductive brush.

  Thus, both the cleaning performance for capturing toner from the member to be cleaned by the belt-shaped conductive brush and the recovery performance for recovering toner from the belt-shaped conductive brush to the conductive recovery member are both enhanced.

  Therefore, for example, even when continuously printing high image density images and the like that generate a large amount of toner that is not finally transferred to the recording medium, the belt-like conductive brush captures sufficiently, and furthermore, a large amount of belt-like conductive material. Even if the brush captures the toner, the conductive recovery member can be sufficiently recovered.

  The image forming apparatus according to claim 5 is the configuration according to claim 4, wherein the member to be cleaned is the image carrier, and the belt-like conductive brush is in contact with the image carrier. It is characterized by.

  In the image forming apparatus according to the fifth aspect, the belt-like conductive brush captures and cleans the toner that has finally adhered to the image carrier and has not been transferred to the recording medium.

  According to a sixth aspect of the present invention, in the configuration of the fourth aspect, the image forming apparatus includes a conveying belt that conveys the recording medium, and the member to be cleaned is the conveying belt, and the belt-shaped conductive member is connected to the conveying belt. It is characterized by the contact of the sex brush.

  In the image formation according to the sixth aspect, the belt-like conductive brush captures and cleans the toner that has adhered to the conveyance belt that conveys the recording medium and is not finally transferred to the recording medium.

  According to a seventh aspect of the present invention, in the configuration of the fourth aspect, the image forming apparatus includes an intermediate transfer body onto which the toner image formed on the image carrier is transferred, and the member to be cleaned is the intermediate transfer body. The belt-like conductive brush is in contact with the intermediate transfer member.

  The image forming apparatus according to claim 7, wherein the toner that is not transferred to the recording medium that is attached to the intermediate transfer body onto which the toner image formed on the image carrier is transferred is removed from the belt-like conductive brush. Has captured and cleaned.

  An image forming apparatus according to claim 8 is the structure according to claim 4, wherein an intermediate transfer belt is brought into contact with the image carrier, and a toner image formed on the image carrier is transferred to the intermediate transfer belt. The first transfer member is provided, and the member to be cleaned is the first transfer member, and the belt-like conductive brush is in contact with the transfer member.

  The image forming apparatus according to claim 8, wherein the intermediate transfer belt is brought into contact with the image carrier and the toner image formed on the image carrier is attached to the first transfer member that is transferred to the intermediate transfer belt. The toner that has not been transferred to the recording medium is captured and cleaned by a belt-like conductive brush.

  According to a ninth aspect of the present invention, in the configuration of the fourth aspect, the image forming apparatus includes a second transfer member that transfers a toner image to the recording medium, and the member to be cleaned is the second transfer member, The belt-like conductive brush is in contact with the second transfer member.

  In the image forming apparatus according to claim 9, the belt-like conductive brush captures the toner that has adhered to the second transfer member that transfers the toner image to the recording medium and has not been finally transferred to the recording medium. Cleaning.

  The cleaning method according to claim 10 is the cleaning method of the cleaning device according to any one of claims 1 to 3, wherein a potential difference between the belt-like conductive brush and the member to be cleaned is determined. A cleaning process in which the belt-shaped conductive brush captures deposits adhering to the member to be cleaned, and a potential difference between the belt-shaped conductive brush and the conductive recovery member. And a recovery step of recovering the kimono by the conductive recovery member.

  In the cleaning method according to the tenth aspect, since the curvature of the contact portion of the belt-like conductive brush with the member to be cleaned is made small and the brush tip is made high in density, the cleaning performance in the cleaning process is high. Furthermore, since the curvature of the contact portion of the belt-like conductive brush with the conductive recovery member is increased and the density of the brush tip is reduced, the recovery capability of the recovery process is high. That is, both the cleaning process and the recovery process have high performance.

  The cleaning method according to claim 11 is a cleaning method for a member to be cleaned of the image forming apparatus according to any one of claims 4 to 9, wherein the belt-shaped conductive brush and the member to be cleaned are provided. And a cleaning process in which the belt-shaped conductive brush captures toner adhering to the member to be cleaned by a potential difference between the belt-shaped conductive brush and the conductive recovery member. And a collecting step for collecting the toner captured by the conductive collecting member.

  In the cleaning method according to the eleventh aspect, since the curvature of the contact portion of the belt-like conductive brush with the member to be cleaned is made small and the brush tip is made high in density, the cleaning performance in the cleaning process is high. Furthermore, since the curvature of the contact portion of the belt-like conductive brush with the conductive recovery member is increased and the density of the brush tip is reduced, the recovery capability of the recovery process is high. That is, both the cleaning process and the recovery process have high performance.

  As described above, according to the present invention, the belt-shaped conductive brush, the member to be cleaned, and the member to be cleaned are reduced by reducing the curvature of the contact portion of the belt-shaped conductive brush with the member to be cleaned and by increasing the density of the brush tip. Increase the chances of capturing deposits at the contact area of both the mechanical and electrical surfaces to increase the cleaning performance, increase the curvature of the contact area of the belt-like conductive brush with the conductive recovery member, and increase the density of the brush tip. The collection capacity is increased by lowering the density. That is, both the cleaning performance for capturing the deposit from the member to be cleaned by the belt-like conductive brush and the recovery performance for collecting the deposit from the belt-like conductive brush to the conductive recovery member are both high.

  FIG. 1 shows an image forming apparatus 01 according to the first embodiment of the present invention. The image forming apparatus 01 performs image processing based on color image information sent from an image data input device such as a personal computer (not shown), and forms a color image on the recording paper P by an electrophotographic method.

  The image forming apparatus 01 includes image forming units 10Y, 10M, 10C, and 10K that form toner images of respective colors of yellow (Y), magenta (M), cyan (C), and black (K). In the following, when it is necessary to distinguish YMCK, description will be made by adding any of Y, M, C, and K after the reference. When YMCK does not need to be distinguished, Y, M, C, K is omitted.

  The image forming units 10Y, 10M, 10C, and 10K are arranged so that the image forming units 10Y, 10M, 10C, and 10K move in the traveling direction of the endless intermediate transfer belt 30 that is stretched by the backup roll 34 and the plurality of stretch rolls 32. They are arranged in series in the order of 10K. Further, the intermediate transfer belt 30 is provided with primary transfer rolls 16Y, which are arranged to face the photosensitive drums 12Y, 12M, 12C, and 12K as image carriers of the image forming units 10Y, 10M, 10C, and 10K, respectively. It is inserted between 16M, 16C and 16K.

  Next, the configuration of each of the image forming units 10Y, 10M, 10C, and 10K and the image forming operation will be described using the image forming unit 10Y that forms a yellow toner image as a representative.

  As shown in FIG. 2, the surface of the photosensitive drum 12Y is uniformly charged by the contact charger 13Y. Next, image exposure L corresponding to the yellow image is performed by the exposure device 14Y, and an electrostatic latent image corresponding to the yellow image is formed on the surface of the photosensitive drum 12Y.

  The developing device 15Y includes a developing roll 18Y. The developing roll 18Y is a so-called mag roll having a magnet built therein. A developer is carried on the surface of the developing roll 18Y. The developer is composed of toner and carrier, and the carrier is magnetic particles such as ferrite powder or iron powder. The carrier controls the charge polarity and charge amount of the toner and forms a magnetic brush on the developing roll 18Y to carry the toner to the vicinity of the electrostatic latent image.

  The electrostatic latent image corresponding to the yellow image is developed by applying a developing bias to the developing roll 18Y of the developing device 15Y, and becomes a yellow toner image. The yellow toner image is primarily transferred onto the intermediate transfer belt 30 by the pressing force of the primary transfer roll 16Y and the electrostatic attraction force by the transfer bias applied to the primary transfer roll 16Y. The surface of the photosensitive drum 12Y is charged again by the contact charger 13Y for the next image forming cycle.

  Note that in the primary transfer, the entire yellow toner image is not transferred to the intermediate transfer belt 30, and a part thereof remains on the photosensitive drum 12Y as residual yellow toner. The residual yellow toner remaining on the photosensitive drum 12Y is removed by a cleaning device 100 (details will be described later).

  As shown in FIG. 1, in the image forming apparatus 01, the image forming process similar to the above is performed at the timing in consideration of the relative positions of the image forming units 10Y, 10M, 10C, and 10K. This is also performed in the units 10Y, 10M, 10C, and 10K, and the Y, M, C, and K color toner images are sequentially superimposed on the intermediate transfer belt 30 to form a full color toner image.

  Then, a full color toner image is collectively collected from the intermediate transfer belt 30 by the electrostatic attraction force of the secondary transfer roll 36 to which a transfer bias is applied to the recording paper P conveyed to the secondary transfer position A at a predetermined timing. Then, the image is transferred onto the recording paper P.

  The recording paper P to which the full-color toner image has been transferred is separated from the intermediate transfer belt 30, and then conveyed to the fixing device 31, where the full-color toner image is fixed to the recording paper P by heat and pressure.

  The residual toner on the intermediate transfer belt 30 that has not been transferred to the recording paper P is collected by the intermediate transfer belt cleaner 33.

  Next, specifications of main members and main electrical specifications are described.

Photoconductor drum 12: Organic photoconductor having a diameter of about 30.0 mm Distance between centers of the photoconductor drum: about 100 mm
Contact charger 13: charging roll made of a semiconductive roll
DC + AC contact charging system
V _PP = 1.5 kv (AC component voltage value, Peak to Peak)
Frequency = 1.0 kHz (AC component voltage waveform)
V _DC = −520v (DC component voltage value)
Exposure device 14: Laser wavelength = 780 nm
Development method: Two-component development
Development bias: V _DC = −400 v (DC component voltage value)
V _PP = 1.5 kv (AC component voltage value, Peak to Peak)
Frequency = 6.0 kHz (AC component voltage waveform)
Developing roll 18: Sleeve diameter = φ16.0 mm
Sleeve rotation speed = 208 mm / s
Development gap (space between the photosensitive drum 12 and the development roll 18): 0.3 mm
Intermediate transfer belt 30: made of polyimide, process speed: about 104 mm / second, surface potential: background portion (charging potential) V ₀ = −500 v
Image part (electrostatic latent image part, post-exposure potential) V _L = −200v
Primary transfer roll 16: transfer bias + 500v to + 1000v
Secondary transfer roll 36: transfer bias + 1600v
Next, the cleaning device 100 will be described.

  As shown in FIGS. 2 and 3, in the cleaning device 100, an endless belt-like conductive brush 102 is stretched around a shaft 104 having a diameter of 10.0 mm and a shaft 106 having a diameter of 5.0 mm.

The belt-like conductive brush 102 has a brush 112 planted on the surface of an endless belt-like conductive base belt 109. The brush 112 is made of conductive nylon, and the density of flocking is 2.0 denier and 240 kf / inch ² . The brush length is about 3.0 mm. (See also FIG. 4). The belt-like conductive brush 102 is so-called semiconductive having a predetermined resistance value.

  The belt-like conductive brush 102 is in contact with the photosensitive drum 12 and the metal recovery roll 120. A shaft 104 having a diameter of 10.0 mm is used inside a portion that forms a contact portion (NIP portion) between the photosensitive drum 12 and the belt-like conductive brush 102. Further, a shaft 106 having a diameter of 5.0 mm is used inside a portion that forms a contact portion (NIP portion) between the belt-like conductive brush 102 and the collection roll 120.

  The collection roll 120 is rotated by a drive mechanism (not shown), and the scraper 122 is in contact therewith.

  One of the shaft 104 and the shaft 106 is rotationally driven by a drive mechanism (not shown). The belt-like conductive brush 102 is rotated and moved at a higher speed than the photosensitive drum 12.

  A predetermined bias voltage (for example, about +500 V) is applied to the belt-like conductive belt 102. A predetermined bias voltage (for example, about +1000 v) is also applied to the collection roll 120.

  Since the belt-like conductive belt 102 is semiconductive having a predetermined resistance value, a potential difference can be provided between the belt-like conductive belt 102 and the collection roll 120.

  Then, the residual toner remaining on the photosensitive drum 12 is scraped off by the belt-like conductive brush 102, and is applied to the belt-like conductive belt 102 by the potential difference between the photosensitive drum 12 and the belt-like conductive belt 102. Residual toner is captured and removed from the photosensitive drum 12 by being electrically attached.

  The residual toner captured by the belt-like conductive belt 102 is moved to the collecting roll 120 and collected by the potential difference between the collecting roll 120 and the belt-like conductive belt 102.

  The residual toner collected by the collection roll 120 is scraped off by the scraper 122. The residual toner thus scraped off is stored in the housing 101 (see FIG. 2) of the cleaning device 100. The residual toner inside the casing 101 is conveyed by the auger 124 and sent to a waste toner storage unit (not shown).

  Next, the operation of the present invention will be described.

As described above, the belt-like conductive brush 102 has the brush 112 planted on the surface of the endless belt-like conductive base belt 109. The brush 112 is made of conductive nylon and has a density of 2.0 denier and 240 kf / inch ² . The brush length is about 3.0 mm.

  As shown in FIG. 3, the curvature (see FIG. 4A) of the contact portion (NIP portion) between the belt-like conductive brush 102 formed by the shaft 104 having a diameter of 10.0 mm and the photosensitive drum 12 has a diameter (see FIG. 4A). It is smaller than the curvature (see FIG. 4B) of the contact portion (NIP portion) between the belt-like conductive brush 102 formed by the 5.0 mm shaft 106 and the collection roll 120.

  Now, when the brush length and brush density are the same and the curvature (shaft diameter) is different, as shown in FIG. 4 (A), the curvature is as shown in FIG. 4 (A). The smaller one (the one with the larger shaft diameter) has a high density because the tip of the brush 112 does not spread so much. On the other hand, as shown in FIG. 4B, the one with the larger curvature (the one with the smaller shaft diameter) has a low density because the tip of the brush 112 spreads greatly.

  Therefore, the contact portion (NIP portion) between the belt-shaped conductive brush 102 formed by the shaft 104 having a diameter of 10.0 mm and the photosensitive drum 12 is the belt-shaped conductive formed by the shaft 106 having a diameter of 5.0 mm. From the contact portion (NIP portion) between the conductive brush 102 and the collection roll 120, the density of the tip of the brush 112 becomes high.

  In the case of the present embodiment, the density of the tip of the brush 112 at a portion with a small curvature (FIG. 4A) is about 1 of the density of the tip of the brush 112 at a portion with a large curvature (FIG. 4B). .4 times.

  When cleaning the residual toner on the photosensitive drum 12 with the belt-like conductive brush 102, the higher the density of the tip of the brush 112 is, the more the residual toner remains on the contact portion (NIP portion) with the photosensitive drum 12. Since the chance of capturing the toner increases both mechanically and electrically, the cleaning performance is improved.

  On the other hand, the residual toner captured by the belt-like conductive brush 102 from the photosensitive drum 12 remains attached to the tip portion of the brush 112, and inside the brush 112 (in the root direction) as shown in FIG. There is a residual toner T slightly entering the toner.

  FIG. 20 conceptually illustrates an electric field E generated by a potential difference between the belt-like conductive brush 102 and the collection roll 120. Since the brush 112 and the brush 112 are at the same potential, no electric field is applied between the brush 112 and the brush 112. Therefore, as can be seen by comparing FIG. 20A and FIG. 20B, the electric field E does not reach the inside of the brush when the tip of the brush 102 is dense (FIG. 20A). If the density is low, it takes up to the relatively inside of the brush 112 (FIG. 20B). In other words, the lower the density of the tip of the brush 112, the more the electric field is applied to the inside of the brush.

  From this, the residual toner remaining on the tip portion of the brush 112 is subjected to an electric field generated by the potential difference between the belt-like conductive brush 102 and the collection roll 120 regardless of the brush density, so regardless of the brush density, It can be seen that it can be collected on the collecting roll 120 relatively easily.

  However, as shown in FIGS. 5A and 20A, the residual toner T slightly entering the inside of the brush 112 does not apply an electric field to the inside of the brush when the density of the tip of the brush 112 is high. Therefore, it is difficult to recover, but as shown in FIG. 5B and FIG. 20B, it can be seen that when the density is low, an electric field is applied to the inside relatively, so that it is easy to recover.

  Further, the residual toner T slightly entering the inside of the belt-like conductive brush 102 has a lower density at the tip of the brush 112 than in FIG. 5A where the density at the tip of the brush 112 is higher. In the case of 5 (B), the space between the brushes 112 spreads out more easily, and the recovery becomes easier.

  As described above, in this embodiment, as shown in FIG. 4A, the contact portion (NIP portion) between the belt-like conductive brush 102 formed by the shaft 104 having a diameter of 10.0 mm and the photosensitive drum 12. Has a high density at the tip of the brush 112 and high cleaning performance. Further, as shown in FIG. 4B, the contact portion (NIP portion) between the belt-like conductive brush 102 and the collection roll 120 formed by the shaft 106 having a diameter of 5.0 mm is the density of the tip of the brush 112. Has a low density and high recovery performance.

  That is, the cleaning performance for capturing the residual toner adhering to the photosensitive drum 12 on the belt-shaped conductive brush 102 and the recovery performance for recovering the residual toner captured by the belt-shaped conductive brush 102 on the recovery roll 120. Both are high.

  In a high-temperature and high-humidity environment, if the bias voltage applied to the belt-like conductive brush 102 is increased, charge injection occurs in the toner and the polarity is reversed, resulting in a reduction in cleaning performance. It cannot be applied. Therefore, in order to ensure the cleaning performance in a high temperature and high humidity environment, the belt density of the belt-like conductive brush 102 must be increased. However, conventionally, when the brush density is increased, the collecting ability of the collecting roller is reduced, so that a high image density image with a large amount of residual toner is continuously printed, and the belt-like conductive brush removes a large amount of residual toner. When captured, the recovery roller could not be recovered sufficiently. For this reason, residual toner may accumulate on the belt-like conductive brush and cause a cleaning failure.

  However, in the present embodiment, even if the brush density of the belt-like conductive brush 102 is increased to ensure the cleaning performance in a high temperature and high humidity environment, as described above, the contact portion (NIP portion) with the collection roll 120 ) Is increased to reduce the density of the tip of the brush 112 to increase the collection performance, so that no collection failure (cleaning failure) occurs.

  Next, the experimental results of the operational effects in this embodiment will be described.

  First, the experimental method will be described.

  (1) The collection roll 120 and the scraper 122 are removed, and the toner is allowed to enter the belt-like conductive brush 102 for a predetermined time. The amount of toner that has entered the belt-like conductive brush 102 during this predetermined time is defined as [predetermined toner amount].

  (2) Measure the amount of toner that could not be captured and slipped through the belt-like conductive brush 102.

  (3) Calculate the cleaning rate. Specifically, the [amount of toner captured by the belt-like conductive brush 102] is calculated by subtracting the [amount of toner that could not be captured] from the [amount of predetermined amount of toner]. Next, when [the amount of toner captured by the belt-like conductive brush 102] is divided by the first [amount of toner of a predetermined amount], the cleaning efficiency is obtained.

  (4) The collection roll 120 and the scraper 122 are mounted, and the amount of toner collected from the belt-like conductive brush 102 is measured within a predetermined time.

  (5) Calculate the recovery efficiency. Specifically, the recovery efficiency is obtained by dividing [the amount of collected toner] by [the amount of toner captured by the belt-like conductive brush 102].

  In addition to the cleaning device 100 (see FIG. 3) of the present embodiment, this experiment is performed in a strip-shaped conductive brush having the same specifications (material, brush length, brush density, etc.) as the belt-shaped conductive brush 102 shown in FIG. 90, a cleaning device 98 (referred to as Comparative Example 1) provided with a conductive brush roll 95 (see FIG. 6) spirally wound around a shaft 94 having a diameter of 10.0 mm, and a diameter of 5.0 mm shown in FIG. A similar experiment was conducted with a cleaning device 99 (referred to as Comparative Example 2) provided with a conductive brush roll 97 (see FIG. 6) spirally wound around the shaft 96.

  The curvature of the contact portion (see FIG. 4A) between the photosensitive drum 12 and the belt-like conductive belt 102 and the curvature of the conductive brush roll 95 are substantially the same, and the density of the tip of the brush is also the same. Almost the same and high density. Similarly, the curvature of the contact portion (see FIG. 4B) between the belt-like conductive brush 102 and the collection roll 120 and the curvature of the conductive brush roll 97 are substantially the same, and the density of the tip of the brush is also the same. Almost the same and low density.

  Further, the same voltage as in this embodiment was applied to the belt-like conductive brush 102 and the conductive brush rolls 95 and 97.

  The experimental results are shown in the graph of FIG. 9 and the table of FIG.

  As can be seen from the graph and the table, the conductive brush roll 95 of Comparative Example 1 (see FIG. 7) has a high density, and therefore, compared with the conductive brush roll 97 of Comparative Example 2 (see FIG. 8). The cleaning efficiency is high and satisfies the target value of 99%, but the recovery efficiency is lower than that of Comparative Example 2 and has not yet reached 80% of the target value.

  Conversely, since the conductive brush roll 95 (see FIG. 8) of Comparative Example 2 has a low density, the cleaning efficiency has not yet achieved the target value of 99%, but the recovery efficiency of 80% satisfies the target value.

  On the other hand, in the cleaning device 100 of this embodiment (see FIG. 3), the density of the brush tip of the contact portion (NIP portion) with the photosensitive drum 12 is high, and the contact portion (NIP) with the collection roll 120 is high. The density of the tip of the brush is low. Therefore, the target value can be achieved for both the cleaning efficiency and the recovery efficiency.

  That is, it can be seen that the cleaning device 100 of the present embodiment has a cleaning performance equivalent to that of the cleaning device 98 of Comparative Example 1 and a recovery capability equivalent to that of the cleaning device 99 of Comparative Example 2.

  A plurality of cleaning devices may be provided. For example, the untransferred toner remaining on the photosensitive drum 12 and the intermediate transfer belt 30 without being transferred has a large positive polarity, but the toner transferred to the intermediate transfer belt 30 on the upstream side is offset to the downstream photosensitive drum 12. There may be many reverse transfer toners having reverse polarity. Accordingly, as shown in FIG. 19, a positive electrode cleaning device in which the polarity of the bias voltage applied to the belt-like conductive brush 102 and the collecting roll 120 is changed so that residual toner of both positive polarity and reverse polarity can be cleaned. Two cleaning devices 802 for reverse polarity to 801 may be provided.

  In the present embodiment, the curvature of the contact portion (NIP portion) between the photosensitive drum 12 and the belt-like conductive belt 102 is determined by the contact portion (NIP portion) between the belt-like conductive brush 102 and the collection roll 120. As a method of making it smaller than the curvature, it has been realized by using shafts 106 and 104 having different diameters, but is not limited thereto.

  Next, a modified example of the cleaning device 100 will be described.

  First, the first modification will be described.

  As shown in FIG. 11, in the cleaning device 200 according to the first modification, the belt-like conductive brush 102 is stretched around sheet metals 204 and 206 having semicircular R surfaces 204A and 206A, not a shaft. In this case, the belt-like conductive brush 102 is configured to rotate following the rotation of the photosensitive drum 12.

  The curvature of the R surface 204A of the sheet metal 204 is the same as that of the shaft 104 having a diameter of 10.0. Further, the curvature of the R surface 206A of the sheet metal 206 is the same as that of the shaft 106 having a diameter of 5.0. Therefore, it has cleaning performance and recovery performance substantially equivalent to the cleaning device 100.

  Next, a second modification will be described.

  As shown in FIG. 12, in the cleaning device 300 of the second modified example, the belt-like conductive brush 102 is stretched around sheet metals 304 and 306 having R surfaces 304A and 306A, not a shaft.

  Now, the curvature of the R surface 304A of the sheet metal 304 is smaller than that of the first modification. Therefore, the density of the tip of the brush 112 is higher. That is, the cleaning ability is higher.

  Further, the R surface 306A of the sheet metal 306 is composed of a plurality of curved surfaces, and the curvature increases toward the tip. Therefore, the density of the tip of the brush 112 is lower. That is, the collection capacity is higher.

  Next, a third modification will be described.

  As shown in FIG. 13, in the cleaning device 400 of the third modified example, the belt-like conductive brush 102 is stretched around the sheet metals 404 and 306 instead of the shaft. The sheet metal 306 is the same as in the second modification.

  Although R is formed at both ends of the sheet metal 404, the contact portion (NIP portion) between the photosensitive drum 12 and the belt-like conductive belt 102 is a straight line (the curvature is 0). Therefore, the density of the tip of the brush 112 is further increased. That is, the cleaning ability is even higher.

  In the first to third modifications, only one of them may be a shaft and the other may be a driving roll, and may be driven to rotate with a speed difference instead of driven rotation.

  Next, a fourth modification will be described.

  As shown in FIG. 14, in the cleaning device 500 of the fourth modified example, a belt-shaped conductive brush 102 is stretched around three shafts 502, 504, and 506 as a whole in a substantially triangular shape. The belt-like conductive belt 102 is in contact with the photosensitive drum 12 between the shaft 502 and the shaft 504.

  With such a configuration, the contact portion (NIP portion) between the photosensitive drum 12 and the belt-like conductive belt 102 becomes a straight line (the curvature is 0) as in the third modification. Therefore, the density of the tip of the brush is further increased. That is, the cleaning ability is even higher.

  Next, a fifth modification will be described.

  As shown in FIG. 15, in the cleaning device 600 of the fifth modified example, a belt-like conductive brush 102 is stretched around two shafts 604 and 606. The belt-like conductive belt 102 is in contact with the photosensitive drum 12 between the shaft 604 and the shaft 606.

  Even in such a configuration, the contact portion (NIP portion) between the photosensitive drum 12 and the belt-like conductive belt 102 is a straight line (the curvature is 0) as in the third and fourth modifications. Therefore, the density of the tip of the brush is further increased. That is, the cleaning ability is even higher.

  Next, the image forming apparatus 02 according to the second embodiment of the present invention will be described. In addition, the same code | symbol and the same member name are attached | subjected to the member same as 1st embodiment, and the overlapping description is abbreviate | omitted.

  As shown in FIG. 16, unlike the first embodiment, the residual toner on the photosensitive drum 12 is cleaned by a cleaning device 60 that is scraped off by a cleaning blade 62.

  Further, the cleaning of the intermediate transfer belt 30 is performed by the cleaning device 110. The cleaning device 110 differs from the cleaning device 100 described in the first embodiment except that the voltage specifications applied to the belt-like conductive belt 102 and the recovery roll 120 are the same except for the configuration. Omitted.

  As in the first embodiment, this embodiment also has a cleaning performance for capturing the residual toner adhering to the intermediate transfer belt 30 by the belt-like conductive brush 102 and collects the residual toner captured by the belt-like conductive brush 102. Both the recovery performance that the roll 120 recovers are enhanced.

  Further, as in the first embodiment, the residual toner on the photosensitive drum 12 may be cleaned by the cleaning device 100.

  Next, the image forming apparatus 03 according to the third embodiment of the present invention will be described. In addition, the same code | symbol and the same member name are attached | subjected to the member same as 1st embodiment, and the overlapping description is abbreviate | omitted.

  A conveying belt 70 that conveys the recording paper P is inserted between the photosensitive drums 12Y, 12M, 12C, and 12K and the transfer rolls 72Y, 72M, 72C, and 72K that are arranged to face each other. The conveyor belt 70 is stretched by a plurality of stretching rolls 74 and is rotationally moved in a predetermined direction. Then, the color toner images on the photosensitive drum 12 are directly transferred and superimposed on the recording paper P conveyed by the conveyance belt 70 to form a full color toner image.

  Residual toner on the photosensitive drum 12 is cleaned by a cleaning device 60 including a cleaning blade 62.

  Now, most of the residual toner that has not been transferred to the recording paper P is cleaned by the cleaning device 60. However, residual toner that has slipped through slightly adheres to the conveyance belt 70. Further, when the recording paper P is not transported due to a jam or the like, the toner adheres to the transport belt 70. Further, toner floating in the air also adheres to the conveyance belt 70.

  The toner adhering to the conveyance belt 70 in this way is cleaned by the cleaning device 111. The cleaning device 111 also has the same configuration as the cleaning device 100 described in the first embodiment except that the voltage specifications applied to the belt-like conductive belt 102 and the collection roll 120 are the same. Omitted.

  Similarly to the first embodiment, in this embodiment, the cleaning performance of collecting the toner attached to the conveyance belt 70 by the belt-like conductive brush 102 and the toner collected by the belt-like conductive brush 102 are collected by the collecting roll 120. Both the recovery performance and the recovery performance are enhanced.

  As in the first embodiment, the residual toner on the photosensitive drum 12 may be cleaned by the cleaning device 100.

  Next, an image forming apparatus 05 according to a fourth embodiment of the present invention will be described. In addition, the same code | symbol and the same member name are attached | subjected to the member same as 1st embodiment, and the overlapping description is abbreviate | omitted.

  As shown in FIG. 17, the photosensitive drum 12 is provided with each color developing device 7Y, 7M, 7Y, 7K, and a toner image of each color is formed by a rotary developing device 155 that rotates about a rotating shaft 156. Is done. Then, the respective color toners are transferred to the intermediate transfer belt 530 in order and superimposed to form a full-color toner image, which is transferred onto the recording paper P all at once.

  Note that an intermediate transfer belt 530 is inserted between the primary transfer roll 516 arranged to face the photosensitive drum. Further, when the recording paper P passes between the backup roll 534 and the secondary transfer roll 536, the full color toner image is transferred.

  Then, the primary transfer roll 516 is cleaned by the cleaning device 112. Further, the secondary transfer roll 536 is cleaned by the cleaning device 113.

The cleaning devices 112 and 113 also have the same configuration as the cleaning device 100 described in the first embodiment, except that the voltage specifications applied to the belt-like conductive belt 102 and the collection roll 120 are different. Therefore, for example, toner that has not been transferred to the recording paper P due to a jam or the like adheres to the secondary transfer roll 536. Further, toner floating in the air also adheres to the secondary transfer roll 536. Further, the toner floating in the air also adheres to the primary transfer roll 516.

  The toner adhering to the primary transfer roll 516 and the secondary transfer roll 536 in this way is cleaned by the cleaning devices 112 and 113.

  Also, in the present embodiment, both the cleaning performance and the recovery performance are improved as in the first embodiment.

  As in the first embodiment, the residual toner on the photosensitive drum 12 may be cleaned by the cleaning device 100.

  Although illustration is omitted, the same cleaning apparatus as in the first to fifth modifications of the first embodiment can also be applied in the second to fourth embodiments.

  In addition, this invention is not limited to the said embodiment.

  For example, the present invention can be applied to the removal of deposits other than toner, for example, paper dust that comes out of the recording paper P and adheres.

1 is a diagram schematically illustrating an image forming apparatus according to a first embodiment of the present invention. It is a figure which shows an image forming unit typically. It is a figure which shows the cleaning apparatus of this invention typically. (A) of the cleaning apparatus of this invention is an enlarged view of the contact part of an electroconductive brush and a photoreceptor drum, (B) is an enlarged view of the contact part of an electroconductive brush and a collection | recovery roll. 4A is an enlarged view of FIG. 4A, and FIG. 4B is an enlarged view of FIG. 4B, each showing a state in which residual toner has entered slightly inside the brush. It is explanatory drawing explaining the creation method of the conductive brush roll with which the comparative example 1 and the comparative example 2 are provided. It is a figure which shows the cleaning apparatus of the comparative example 1 typically. It is a figure which shows the cleaning apparatus of the comparative example 2 typically. It is a graph which shows an experimental result. It is a table | surface which shows an experimental result. It is a figure which shows typically the cleaning apparatus of a 1st modification. It is a figure which shows typically the cleaning apparatus of a 2nd modification. It is a figure which shows typically the cleaning apparatus of a 3rd modification. It is a figure which shows typically the cleaning apparatus of a 4th modification. It is a figure which shows typically the cleaning apparatus of a 5th modification. It is a figure which shows typically the image forming apparatus concerning 2nd embodiment of this invention. It is a figure which shows typically the image forming apparatus concerning 3rd embodiment of this invention. It is a figure which shows typically the image forming apparatus concerning 4th embodiment of this invention. It is a figure which shows the example which provided two cleaning apparatuses. An electric field generated by a potential difference between the belt-like conductive brush and the collecting roller is conceptually shown, (A) shows a case where the brush is high density, and (B) shows a case where the brush is low density.

Explanation of symbols

01 Image forming apparatus 12 Photosensitive drum (image carrier)
30 Intermediate transfer belt (intermediate transfer member)
70 Conveying belt 100 Cleaning device 102 Belt-shaped conductive brush 120 Recovery roll 122 Scraper (contact member)
516 Primary transfer roll (first transfer member)
530 Intermediate transfer belt 536 Secondary transfer roll (second transfer member)
P Recording paper (recording medium)

Claims (11)

An endless belt-like conductive brush that rotates in contact with the member to be cleaned and captures the adhering matter adhering to the member to be cleaned;
A conductive recovery member that comes into contact with the belt-like conductive brush and collects deposits captured by the belt-like conductive brush by a potential difference from the belt-like conductive brush;
With
The belt-shaped conductive brush has a curvature of a contact portion with the member to be cleaned smaller than a curvature of a contact portion with the conductive recovery member.   The cleaning device according to claim 1, wherein a curvature of a contact portion of the belt-shaped conductive brush with the member to be cleaned is set to approximately zero. The conductive recovery member is a rotating recovery roll;
The cleaning device according to claim 1, further comprising a contact member that scrapes off the deposits collected by the collecting roll. An image forming apparatus comprising the cleaning device according to any one of claims 1 to 3, and finally transferring a toner image formed on an image carrier to a recording medium,
The belt-like conductive brush of the cleaning device comes into contact with the member to be cleaned to which the toner that has not been transferred to the recording medium finally adheres, and the toner adhering to the member to be cleaned is captured, and the belt An image forming apparatus, wherein the conductive collecting member collects the toner captured by the conductive brush by a potential difference from the belt-shaped conductive brush.   The image forming apparatus according to claim 4, wherein the member to be cleaned is the image carrier, and the belt-like conductive brush is in contact with the image carrier. A transport belt for transporting the recording medium;
The image forming apparatus according to claim 4, wherein the member to be cleaned is the conveyor belt, and the belt-like conductive brush is in contact with the conveyor belt. An intermediate transfer member to which a toner image formed on the image carrier is transferred;
The image forming apparatus according to claim 4, wherein the member to be cleaned is the intermediate rolling member, and the belt-like conductive brush is in contact with the intermediate transfer member. A first transfer member for bringing the intermediate transfer belt into contact with the image carrier and transferring a toner image formed on the image carrier to the intermediate transfer belt;
The image forming apparatus according to claim 4, wherein the member to be cleaned is the first transfer member, and the belt-like conductive brush is in contact with the first transfer member. A second transfer member for transferring a toner image to the recording medium;
The image forming apparatus according to claim 4, wherein the member to be cleaned is the second transfer member, and the belt-like conductive brush is in contact with the second transfer member. A cleaning method for a cleaning device according to any one of claims 1 to 3,
A cleaning step in which the belt-like conductive brush captures an adhering matter adhering to the member to be cleaned due to a potential difference between the belt-like conductive brush and the member to be cleaned;
A recovery step in which the conductive recovery member recovers the deposits captured by the member to be cleaned due to a potential difference between the belt-shaped conductive brush and the conductive recovery member;
A cleaning method comprising: A method for cleaning a member to be cleaned of an image forming apparatus according to any one of claims 4 to 9,
A cleaning step in which the belt-like conductive brush captures toner adhering to the member to be cleaned due to a potential difference between the belt-like conductive brush and the member to be cleaned;
A collection step in which the conductive collection member collects toner captured by the member to be cleaned due to a potential difference between the belt-like conductive brush and the conductive collection member;
A cleaning method comprising:

Images