JP2014048593A - Cleaning device and cleaning brush - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning device for preventing the contamination of an image forming apparatus by removing toner isolated and left on a recording medium after fixation and to provide a cleaning brush.SOLUTION: The cleaning device includes a cleaning member coming into contact with the surface of a surface-moving object to be cleaned, while being rotated, to remove the fine powder particles of the surface of the object to be cleaned, a support member arranged to face the cleaning member, in a contact state with the rear surface of the object to be cleaned, a cleaning-up member coming into contact with the cleaning member and removing the fine powder particles recovered to the cleaning member from the cleaning member, and a discharge member discharging the fine powder particles separated from the cleaning member by the cleaning-up member. The cleaning member is formed from pile fabric comprising a base fabric and a plurality of pile threads napped on the base fabric and when the diameter of the fine powder particle is defined as D1 and the fiber diameter of the pile thread is defined as D2, D2/D1≤2 is obtained.

Description

The present invention relates to a cleaning device and a cleaning brush.

In a high-speed image forming apparatus, flash light emission by a non-contact type flash lamp capable of applying high energy without affecting the conveyance of the recording medium as a means for providing fixing energy for melting the toner on the recording medium. A flash-fixing device using the above is used (Patent Document 1).

In the flash fixing device, since the recording medium is not inserted into a pressure contact portion that heats and pressurizes the recording medium, the driving of the fixing device does not affect the conveyance speed of the recording medium, and the recording medium can be prevented from being wrinkled or stretched. it can. Therefore, it is considered suitable for image formation at high speed and image formation on a wide recording medium.

Also known is a cleaning device that cleans the surface of the photoreceptor after transfer by bringing the tip of a loop pile brush made by weaving a plurality of brush threads into a loop on the base material in contact with the photoreceptor in a line contact state. (Patent Document 2).

JP 2010-230874 A Japanese Unexamined Patent Publication No. 1-116677

  SUMMARY OF THE INVENTION An object of the present invention is to provide a cleaning device and a cleaning brush that removes toner that remains isolated on a recording medium after fixing, and prevents contamination of an image forming apparatus.

In order to solve the above-mentioned problem, the cleaning device according to claim 1,
A cleaning member that rotates and contacts the surface of the object to be cleaned while rotating, and removes fine particles on the surface of the object to be cleaned;
A support member that is in contact with the back surface of the object to be cleaned and is disposed to face the cleaning member;
A cleaning member that contacts the cleaning member and removes the fine powder particles collected by the cleaning member from the cleaning member;
A discharge member that discharges the fine particles separated from the cleaning member by the cleaning member, and
The cleaning member is made of a pile fabric comprising a base fabric and a plurality of pile yarns raised on the base fabric, and when the fine particle diameter is D1, and the fiber diameter of the pile yarn is D2,
D2 / D1 ≦ 2.
It is characterized by that.

The invention according to claim 2 is the cleaning apparatus according to claim 1,
The pile yarn is raised in a loop on the base fabric,
It is characterized by that.

The invention according to claim 3 is the cleaning apparatus according to claim 1 or 2,
The pile yarn is made of inorganic fiber,
It is characterized by that.

The invention according to claim 4 is the cleaning apparatus according to claim 1 or 2,
The pile yarn is at least partly composed of divided fibers, and the fine fibers formed by dividing the divided fibers have a substantially polygonal cross-sectional shape, and a linear edge portion is formed,
It is characterized by that.

A fifth aspect of the present invention provides the cleaning apparatus according to any one of the first to fourth aspects,
The surface moving speed of the cleaning object that moves on the surface is Vp, the surface moving speed of the cleaning member that rotates and contacts the surface of the cleaning object and removes fine particles on the surface of the cleaning object is Vb, When
1.1 ≦ Vb / Vp ≦ 1.3,
It is characterized by that.

In order to solve the above-mentioned problem, the cleaning brush according to claim 6,
A cleaning brush used in the cleaning device according to any one of claims 1 to 5,
It consists of a pile fabric comprising a base fabric and a plurality of pile yarns raised on the base fabric, and when the fine particle diameter of the surface of the object to be cleaned is D1, and the fiber diameter of the pile yarn is D2,
D2 / D1 ≦ 2.
It is characterized by that.

  According to the present invention, it is possible to remove the toner that remains isolated on the recording medium after fixing, and to prevent the image forming apparatus from being contaminated.

1 is a schematic cross-sectional view illustrating an example of a schematic configuration of an image forming apparatus 100. FIG. (A) is a schematic cross-sectional view showing an example of the cleaning device 1, and (b) is a schematic view of isolated toner present on a sheet after fixing. It is a perspective view for demonstrating the structure of a brush roller. It is the expanded cross-section schematic diagram of the bristle which piled up the pile thread | yarn on the base fabric in the loop shape. (A) is an enlarged schematic cross-sectional view for explaining a contact state between the pile yarn tip of the cleaning device 2 of the comparative example and the isolated toner, and (b) is a diagram of the pile yarn tip and isolated toner of the cleaning device 1 according to the present embodiment. It is an expanded sectional schematic diagram explaining a contact state. (A) is an enlarged cross-sectional schematic diagram of a bristle obtained by raising a pile yarn composed of a plurality of split fibers in a loop shape, (b) is an enlarged cross-sectional schematic diagram showing an example of a cross-sectional shape of the split fibers, and (c) is It is an expanded sectional schematic diagram explaining the contact state of the loop front-end | tip part of pile yarn, and an isolated toner. It is a list which shows the performance evaluation test result about the cleaning apparatus 1 which concerns on 1st Embodiment, and the cleaning apparatus 1A which concerns on 2nd Embodiment.

Next, the present invention will be described in more detail with reference to the drawings with reference to embodiments and specific examples. However, the present invention is not limited to these embodiments and specific examples.
Also, in the description using the following drawings, it should be noted that the drawings are schematic and the ratio of each dimension and the like are different from the actual ones, and are necessary for the description for easy understanding. Illustrations other than the members are omitted as appropriate.

  In each of the illustrated embodiments, the cleaning device and the cleaning brush according to the present embodiment are applied to an image forming apparatus. Therefore, the cleaning mechanism according to the present embodiment will be described while explaining the schematic configuration of the image forming apparatus.

“First Embodiment”
(1) Overall Configuration and Operation of Image Forming Apparatus (1.1) Overall Configuration of Image Forming Apparatus FIG. 1 is a schematic cross-sectional view showing an example of a schematic configuration of an image forming apparatus 100 according to the present embodiment.
The image forming apparatus 100 is provided at one end of the image forming unit 110, the one end of the image forming unit 110 and supplying paper to the image forming unit 110, and the other end of the image forming unit 110 for printing. A paper discharge unit 130 that discharges the paper P, an operation information unit 140, and an image processing unit 150 that generates image information from print information transmitted from a host device.

  The image forming unit 110 includes a system control device 111, an exposure device 112, a photosensitive unit 113, a developing device 114, a transfer device 115, a paper transport device 116, a fixing device 117, and a cleaning device 1, and performs image processing. The image information received from the section 150 is formed as a toner image on the paper P sent from the paper feeding device 120.

The paper feeding device 120 includes a paper storage unit 121 and supplies paper to the image forming unit 110. In the present embodiment, the paper P as the recording medium is a continuous paper formed in a band shape. The continuous paper is formed with so-called perforations so as to be cut into a predetermined size after the image is recorded.
The paper P sent out from the paper storage unit 121 is transported to the transfer device 115 by the transport device 116a.
The transport device 116a includes transport rollers that rotate while pinching the paper P, and engages pins (not shown) with a plurality of feed holes provided at equal intervals along the longitudinal direction at both ends of the paper P. Carry while transporting.

  The paper discharge unit 130 discharges the paper P on which the image is output by the image forming unit 110. For this purpose, the paper discharge unit 130 includes a paper discharge tray 131 through which the paper P after image output is discharged, and the continuous paper on which the toner image is fixed is folded and stored at a predetermined perforation.

  The image forming unit 110 is provided with an operation information unit 140. The operation information unit 140 is used for inputting various settings and instructions and displaying information. That is, it corresponds to a so-called user interface, and is specifically configured by combining a liquid crystal display panel, various operation buttons, a touch panel, and the like.

(1.2) Configuration and Operation of Image Forming Unit In the image forming apparatus 100 having such a configuration, the sheet P fed from the sheet storage unit 121 of the sheet feeding device 120 in accordance with the timing of image formation is transferred to the image forming unit 110. It is sent to.

  The photoconductor unit 113 includes a photoconductor drum 113a as an image holding body that is rotationally driven. A charger 113b, an exposure device 112, a developing device 114, a transfer device 115, and a cleaning blade 113c are arranged along the rotation direction of the photosensitive drum 113a.

  The surface of the rotating photosensitive drum 113a is charged by the charger 113b, and an electrostatic latent image is formed by the latent image forming light emitted from the exposure device 112. The electrostatic latent image formed on the photosensitive drum 113a is developed as a toner image by the developing device 114.

When the toner image formed on the photosensitive drum 113a is conveyed to the transfer unit TR, the paper P is supplied from the paper feeding device 120 to the transfer unit TR in accordance with the timing.
A predetermined transfer voltage is applied to the transfer device 115 from a power supply device (not shown) controlled by the system control device 111, and the toner image on the photosensitive drum 113 a is transferred to the paper P.

Residual toner on the surface of the photosensitive drum 113a is removed by the cleaning blade 113c and collected in a waste toner container (not shown). Thereafter, the surface of the photosensitive drum 113a is recharged by the charger 113b.

  The fixing device 117 converts the light energy into heat energy by irradiating the flash onto the toner image transferred onto the paper P by the flash lamp 117a, and melts the toner with the heat. To settle.

The sheet on which the fixing is completed passes through the cleaning device 1 provided on the downstream side of the fixing device 117 and is sent to the paper discharge unit 130 by the transport device 116b.
The paper P sent to the paper discharge unit 130 is folded and stored in the paper discharge tray 131.

(1.3) Configuration and Operation of Cleaning Device FIG. 2A is a schematic cross-sectional view showing an example of the cleaning device 1 according to the present embodiment, and FIG. 2B is a diagram of toner existing on the paper P after fixing. It is an enlarged schematic diagram.
As shown in FIG. 2A, the cleaning device 1 is in contact with the brush roller 10 as an example of a cleaning member and the back surface of the paper P on which the toner image is fixed facing the brush roller 10. A backup roller 20 as an example of a support member that forms a nip portion N between the two and a waste toner collecting device 30 that collects toner scraped off by the pile yarn 12 of the brush roller 10.

As an example of the cleaning member, the waste toner collecting device 30 is in contact with the brush roller 10 to cause the pile yarn 12 of the brush roller 10 to flicker, and the fine powder removed from the brush roller 10 by the flicker 31. An auger 32 is provided as an example of a discharge member that conveys toner as particles to the outside of the cleaning device 1.

The brush roller 10 is for making physical contact with the paper P after fixing to remove unfixed or not sufficiently fixed toner remaining on the surface of the paper P.
The non-contact type flash fixing device in the image forming apparatus 100 is different from a heat roll fixing method in which toner is crushed by heat and pressure and fixed on a recording medium, and the toner is melted by absorbing flash light and converting it to heat. Fix to paper P.
However, in the heat roll fixing method, the toner is crushed, so that the wax in the toner easily oozes out. However, in the flash fixing method, the wax hardly oozes out and the fixing tends to be suppressed.

Therefore, the toner transferred onto the paper P has a large amount of heat generated by light absorption in an area where the image density is high in the image portion and there is no margin with the paper P, and the toner melts and soaks into the paper P. Although it is strongly fixed, an image region formed at a high spatial frequency, such as a halftone image or a line image, is a so-called fog toner or an image portion attached to a non-image portion in the development process. Since there are few adjacent toners, the amount of heat generated by light absorption is small, and fixing is performed in a state where the penetration into the paper P is not sufficient (see FIG. 2B).

Further, even in a region where the image density is high in the image portion, the fixing strength may not be sufficient in the peripheral region of the image.
In particular, the isolated toner T existing in units of one or several units has a small adhesion area with the surface of the paper P, and easily drops off from the surface of the paper P. There is a problem that the paper P is contaminated or when the output paper P is stored.

The cleaning device 1 according to the present embodiment is provided on the downstream side of the fixing device 117, physically contacts the fixed sheet P that moves on the surface, and at the tip of the pile yarn 12 of the brush roller 10 that is rotationally driven. The remaining unfixed or insufficiently fixed isolated toner T on the surface of the paper P is scraped off and removed.

The isolated toner T thus scraped off is transported to the waste toner collecting device 30 disposed downstream of the nip portion N between the brush roller 10 and the paper P along with the rotation of the brush roller 10, and from the brush roller 10 by the flicker 31. Removed and recovered. The collected toner is conveyed to the outside of the cleaning device 1 and discharged by an auger 32 provided at the bottom of the waste toner collecting device 30.

(2) Configuration of Brush Roller FIG. 3 is a perspective view for explaining the configuration of the brush roller 10.
The brush roller 10 is composed of a base cloth 11, brush hairs in which pile yarns 12 are raised in a loop shape on the base cloth 11, and a shaft 13 on a cylinder. As shown in FIG. It is wound into a shape and formed into a roller shape.

(2.1) Configuration of Base Fabric FIG. 4 is an enlarged schematic cross-sectional view of brush hairs obtained by raising pile yarns 12 in a loop shape on the base fabric 11.
The base fabric 11 is formed from a woven fabric obtained by weaving warp yarns 11a and weft yarns 11b. As the warp yarn 11a and the weft yarn 11b, yarns such as filament yarns and spun yarns made of fibers having high durability and flexibility, excellent wear resistance, and low dynamic friction coefficient are used.
Examples of such fibers include olefin resins such as ultra-high molecular weight polyethylene and polypropylene, amide resins such as aliphatic polyamide (nylon) and aromatic polyamide (aramid), and acrylic fibers such as polyacryl. Is mentioned. In addition, ester fibers such as polyethylene terephthalate, synthetic fibers made of fluororesin, semi-synthetic fibers such as rayon fibers and cupra fibers, natural fibers such as cotton, and the like.

The upper limit of the fineness of each of the warp yarn 11a and the weft yarn 11b is preferably 350 dtex, and more preferably 300 dtex. This is because the flexibility of the base fabric 11 decreases as the fineness increases. For example, when a brush roller is manufactured by winding brush hair around a small-diameter shaft, the base fabric 11 can respond flexibly. This is because the brush hair is easily peeled off, and there is a possibility that sufficient cleaning cannot be performed.
Further, as the fineness decreases, the strength of the base fabric 11 decreases, and there is a possibility that the base end portion of the pile yarn 12 cannot be tightened.
Therefore, the lower limit of the fineness of each of the warp yarn 11a and the weft yarn 11b is preferably 100 dtex, more preferably 150 dtex.

(2.2) Configuration of Pile Yarn As shown in FIG. 4, the pile yarn 12 is planted in a loop shape on the warp yarn 11 a and the weft yarn 11 b constituting the base fabric 11. That is, the pile yarn 12 woven in the base fabric 11 is fixed at both ends by tightening the base end portion with the warp yarn 11a and the weft yarn 11b of the base fabric 11, and the curved loop portion is covered. Rub against the surface of the cleaning body.
By forming the pile yarn 12 in a loop shape, the isolated toner T on the surface of the paper P after fixing as a member to be cleaned can be captured so as to be enclosed.

The length of the pile yarn 12 forming the loop from the base material to the top of the loop is not particularly limited, but if the loop is too long, the elasticity of the fiber is lost and the scraping property is lowered. On the other hand, if the length is too short, the formation of the loop is insufficient and the scraping effect is not exhibited, and the toner collection area is reduced.
Therefore, the length of the pile yarn 12 is 2 mm to 8 mm, more preferably 3 mm to 5 mm.

The flocking density of the pile yarn 12 is not particularly limited. However, if the flocking density is too low, the number of fibers that rub against the object to be cleaned is small, so that the scraping property is lowered and the collected deposits leak out. There is a risk of reducing the collection performance of such deposits.
On the other hand, if it is too high, the hardness of the brush increases, the sliding resistance of the pile yarn 12 with respect to the object to be cleaned increases, and the surface of the member to be cleaned may be damaged. Therefore, it is preferably 30,000 to 200,000 pieces / inch ² .

Each pile yarn 12 is formed so as to satisfy D2 / D1 ≦ 2, where D1 is a toner diameter as an example of fine particles on the object to be cleaned and D2 is a fiber diameter of each pile yarn 12. Yes.
Specifically, the toner diameter D1 is 5 μm to 9 μm, and the fiber diameter D2 of the pile yarn 12 is 9 μm to 12 μm.
In other words, a pile yarn 12 having a loop shape close to the particle size of toner, which is a fine powder particle on the surface of the object to be cleaned, is compared to a pile yarn having a cut end with a general fiber diameter of 20 μm to 50 μm. The toner is trapped so as to be enclosed.
The operation will be described later.

As a fiber used for the pile yarn 12, an inorganic fiber is suitable. Examples of inorganic fibers include glass fibers, rock fibers (basalt, andesite, etc.), metal fibers, metal oxide fibers, and the like.
These have strength, heat resistance, environmental resistance, etc. derived from the inorganic material constituting them, have a low coefficient of dynamic friction, and can suppress the conveyance resistance of the paper P after being fixed, which is the object to be cleaned.
In particular, since the paper P, which is a member to be cleaned, is heated to a high temperature by fixing, a stainless fiber having high heat resistance is more preferable.
The heat-resistant fiber can be coated with an inorganic material, particularly a metal oxide, to impart heat resistance and a low dynamic friction coefficient.

(2.3) Setting of Cleaning Device The contact amount (biting amount) of the brush roller 10 configured as described above with respect to the paper P may be equal to or less than the length of the pile yarn 12. However, if the contact amount is too small with respect to the length of the pile yarn 12, the contact area of the loop portion with the paper P becomes small, and the scraping property is deteriorated.
On the other hand, if the contact amount is too large, the frictional resistance between the pile yarn 12 and the paper P increases, and the conveying force of the paper P is hindered. Therefore, the contact amount (bite-in amount) of the brush roller 10 to the paper P is adjusted to be 0.5 mm to 3 mm, more preferably 1 mm to 2.5 mm.

The brush roller 10 in the cleaning device 1 captures the isolated toner T on the paper P so as to be in contact with the paper P moving on the downstream side at the nip portion N with the opposing backup roller 20 while rotating. Remove. Therefore, a speed difference is set with respect to the surface moving speed of the paper P that is the object to be cleaned.
When the surface moving speed of the paper P is Vp and the surface speed of the brush roller 10 is Vb, the speed ratio R (= Vb / Vp × 100%) is preferably 150% or less, more preferably 110%. Thru 130%.
The operation will be described later.

A bias voltage may be applied to the brush roller 10 using an external power supply device (not shown). Specifically, a bias voltage having a polarity opposite to the charging polarity of the toner image transferred onto the paper P is applied. For example, the set bias voltage is applied negatively when the toner polarity is positive, and positively when the toner polarity is negative.
Since the pile yarn 12 of the brush roller 10 is applied with a bias voltage having a polarity opposite to that of the toner to be captured, the cleaning action of the toner from the paper P is enhanced and the holding power of the captured toner is increased. The trapped toner can be prevented from falling off the brush roller 10 and falling onto the paper P.

(3) Operation / Effect of Cleaning Device FIG. 5A shows the tip of the pile yarn 12B and the isolated toner in the cleaning device 2 of the comparative example using the brush roller 10B made of the pile yarn 12B (cut pile yarn) whose tip is cut. FIG. 5B is an enlarged schematic cross-sectional view for explaining the contact state between the tip of the pile yarn 12 and the isolated toner T of the cleaning device 1 according to this embodiment.
Hereinafter, the operation of the cleaning device 1 of the present embodiment will be described, but before that, problems of the cleaning device 2 of the comparative example will be described with reference to the drawings. In the cleaning device 2 of the comparative example, the same reference numerals are given to the same components as in the present embodiment, and detailed description thereof will be omitted.

(3.1) Cleaning Device of Comparative Example Since there is little toner on the paper P that has passed through the non-contact type flash fixing device, the amount of heat generated by light absorption is small, and the paper P is sufficiently infiltrated. In this state, isolated toner is adhered in units of one or several units.
That is, as shown in FIG. 2B, the sheet P after fixing is not sufficiently soaked into the sheet P while maintaining the toner particle size transferred to the sheet P after development as shown in FIG. There is an isolated toner T that exists in an isolated state.

The particle size of the toner used in the electrophotographic image forming apparatus is normally 5 μm to 9 μm. In the image forming apparatus 100 using the flash fixing type fixing device, the isolated toner T is also developed after being developed. The toner particle size as transferred onto P is substantially maintained.
On the other hand, when a cut pile yarn is used as the brush roller 10B of the cleaning device 2, the fiber diameter D2 of the raw yarn constituting the pile yarn 12B is normally 20 μm to 50 μm.
Therefore, as schematically shown in FIG. 5A, the break edge (EG) which is the tip of the pile yarn 12B is in point contact with the paper P, and is present on the paper P in an isolated manner so that the paper P penetrates. For the isolated toner T that is not sufficient, the scraping force cannot be sufficiently applied.

On the other hand, since the fiber diameter of the pile yarn 12B is thick and firm, if the broken edge makes point contact with the paper P, the surface of the paper P may be damaged.
Further, since the paper P and the toner image immediately after being fixed by the fixing device 117 are not fixed by being sufficiently cooled, the toner image fixed on the paper P may be damaged.
Further, the conveyance resistance of the paper P is increased, and there is a possibility that the accommodation of the paper P in the paper discharge tray 131 is hindered.

(3.2) Cleaning Device According to the Present Embodiment As shown in FIG. 5B, the cleaning device 1 according to the present embodiment is provided on the downstream side of the fixing device 117, and the sheet P after fixing moves on the surface. And the remaining unfixed or unfixed toner on the surface of the paper P is scraped off at the tip of the pile yarn 12 raised in a loop shape of the brush roller 10 that is driven to rotate. .
The pile yarn 12 is fastened with the warp yarn 11a and the weft yarn 11b of the base fabric 11, whereby both ends are fixed, and the curved loop portion rubs against the surface of the object to be cleaned.
Then, as shown in FIG. 5 (b), the pile yarn 12 forms a loop shape, and the loop tip portion captures the isolated toner T on the surface of the sheet P after fixing as a member to be cleaned. .

Each pile yarn 12 is formed to satisfy D2 / D1 ≦ 2, where D1 is a toner diameter and D2 is a fiber diameter of each pile yarn 12.
Specifically, the toner diameter D1 is 5 μm to 9 μm, and as shown in FIG. 2B, the toner P is sufficiently infiltrated into the paper P while maintaining the toner particle diameter substantially as shown in FIG. It exists in an isolated state.
Since the fiber diameter D2 of the pile yarn 12 is formed as 9 μm to 12 μm, each pile yarn 12 is in direct contact with the isolated toner T, and only the isolated toner T is infiltrated on the paper P with insufficient penetration. Drop off from the paper P after fixing.
In addition, since the tip of the pile yarn comes into contact with the sheet P moving on the surface in a loop shape, an increase in sheet conveyance resistance can be suppressed.

When the toner used in the image forming apparatus 100 has a small particle diameter, for example, 5 μm, the pile yarn 12 desirably has a fiber diameter D2 that is as small as the toner.
Therefore, when the toner diameter is D1 and the fiber diameter of each pile yarn 12 is D2, it is more preferable that D2 / D1 ≦ 1 is satisfied (see Example 3).

The toner after fixing that has fallen off the paper P after fixing is solidified and collected in the brush bristles constituted by the pile yarns 12, 12,... So as to be surrounded by the loop tip of the pile yarn 12. .
Then, along with the rotation of the collected brush roller 10, it is conveyed to the waste toner collecting device 30, and comes into contact with the brush roller 10 to flicker the pile yarn 12 of the brush roller 10 from the pile yarn 12 by the flicker 31. break away. The toner removed from the brush roller 10 by the flicker 31 is conveyed to the outside of the cleaning device 1 by the auger 32.

Further, as the fiber used for the pile yarn 12, inorganic fiber, that is, glass fiber, rock fiber (basalt, andesite, etc.), metal fiber, metal oxide fiber, etc. are used. Along with strength, heat resistance, environmental resistance and the like derived from inorganic substances, the coefficient of dynamic friction is low, and the conveyance resistance of the fixed sheet P, which is the object to be cleaned, can be suppressed.
In particular, when the sheet P is a continuous sheet having a perforation, a non-contact type flash fixing device that does not affect the conveyance of the recording medium is used, so the conveyance resistance of the sheet P after fixing is reduced. Among inorganic fibers, stainless steel fibers are preferable because of their low coefficient of dynamic friction.
In addition, when the stainless steel fiber is used, the paper P that is the object to be cleaned is heated to a high temperature due to fixing, so even if a very fine fiber of 10 μm to 18 μm is used, Heat resistance is high and the heat resistance as the brush roller 10 can be maintained.

The brush roller 10 is rotationally driven with a speed difference with respect to the surface moving speed of the paper P that is the object to be cleaned. When the surface moving speed of the paper P is Vp and the surface speed of the brush roller 10 is Vb, the speed ratio R (= Vb / Vp × 100%) is preferably 150% or less, more preferably 110%. Thru 130%.
That is, the brush roller 10 in the cleaning device 1 contacts the surface movement of the paper P, which is the object to be cleaned, in the forward direction (in the same direction) at a surface speed 10% to 30% faster than the paper P.
When the speed ratio is small, there is little opportunity for the loop portion of the pile yarn 12 constituting the brush roller 10 to contact the isolated toner T, and a sufficient cleaning action cannot be obtained.
On the other hand, when the speed ratio is too large, the loop portion of the pile yarn 12 often comes into contact with the isolated toner T and the cleaning action increases, but the captured and removed toner is scattered from the brush roller 10 more. In addition, the paper P and the toner image on the paper P may be damaged.
When the brush roller 10 is rotated and brought into contact with the transport direction of the paper P (reverse direction), the cleaning action increases, but the transport resistance of the paper P increases, and the paper P discharge tray. In addition to hindering the storage capacity of the paper 131, there is a risk of damaging the paper P and the toner image on the paper P.

“Second Embodiment”
The basic configuration of the cleaning device 1A according to this embodiment is the same as that of the cleaning device 1 according to the first embodiment, and a pile yarn 12A of a brush roller 10A as an example of a cleaning member is configured by a plurality of split fibers 12a. Is different.
In the following description, components common to the cleaning device 1A according to the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

(1) Configuration of pile yarn Fig. 6 (a) is an enlarged schematic sectional view showing an example in which the pile yarn 12A is constituted by a plurality of split fibers 12a, 12a, ..., Fig. 6 (b) is a pile yarn 12A. FIG. 6C is an enlarged cross-sectional schematic diagram showing an example of the cross-sectional shape of the divided portion, and FIG. It is.
In the brush roller 10A, when at least a part of the plurality of pile yarns 12A has a toner diameter D1, and the fiber diameters of the divided fibers 12a, 12a,... Constituting each pile yarn 12A are D2, D2 / D1 ≦ 2 is satisfied.

As will be described later, the split fibers 12a, 12a,... Have a sufficiently small fiber diameter of, for example, 5 μm to 9 μm, compared to a normal cut pile yarn having a fiber diameter D2 of 20 μm to 50 μm. be able to. When the toner used in the image forming apparatus 100 has a small particle diameter, for example, 5 μm, it is desirable that the pile yarn 12A has a fiber diameter D2 that is as small as the isolated toner T.
Therefore, when the toner diameter is D1, and the fiber diameters of the split fibers 12a, 12a,... Constituting each pile yarn 12A are D2, it is more preferable that D2 / D1 ≦ 1 is satisfied. .
Moreover, the pile yarn 12A does not necessarily need to be formed in a loop shape, and may be a cut pile yarn (see Example 4 and Example 5).

The split fibers 12a are fibers obtained by a composite spinning method in which a plurality of nozzles are used, materials are discharged from these nozzles in a molten state, and spinning is performed while being combined. Therefore, it is preferable to use a synthetic resin capable of composite spinning as the material of the split fiber 12a. In addition to this, the durability and flexibility are high, and it has appropriate heat resistance, excellent wear resistance, and a dynamic friction coefficient. It is more preferable to use a synthetic resin having a low value.

Examples of such synthetic resins include ester resins such as polyester and polyethylene terephthalate, and amide resins such as aliphatic polyamide (nylon) and aromatic polyamide (aramid). In addition, olefin resins such as ultra-high molecular weight polyethylene and polypropylene, acrylic resins such as polyacryl, etc., fluorine such as tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), etc. Resins etc. are also mentioned.

As shown in FIG. 6B, the divided fiber 12a has a substantially polygonal cross-sectional shape, and has at least one edge with an angle of less than 90 degrees to form a linear edge portion.
In addition, the polygonal shape does not necessarily need to be comprised only by the straight line, and the substantially polygonal shape which has a circular arc in part may be sufficient as it.

The divided fiber 12a divided from one pile yarn 12A has a toner diameter of D1, and the divided fibers 12a, 12a,... Constituting the respective pile yarn 12A have a fiber diameter of D2, D2 / D1 ≦ It is divided to satisfy 2.
Specifically, the toner diameter D1 is 5 μm to 9 μm, and the fiber diameter D2 of the split fibers 12a of the pile yarn 12A is 5 μm.

(2) Operation / Effect of Cleaning Device The cleaning device 1A of the present embodiment is provided on the downstream side of the fixing device 117, and is a brush roller that is rotationally driven in physical contact with the fixed sheet P that moves on the surface. The remaining unfixed or not sufficiently fixed toner on the surface of the paper P is scraped off at the tip of the pile yarn 12A raised in a loop shape of 10A.
In the pile yarn 12A, the base end portions of the plurality of split fibers 12a, 12a,... Are fastened with the warp yarn 11a and the weft yarn 11b of the base fabric 11, so that both end portions are fixed and the curved loop portion is covered. Rub against the surface of the cleaning body.
Then, as shown in FIG. 6A, the pile yarn 12 </ b> A forms a loop so that the isolated toner T on the surface of the paper P after fixing as a member to be cleaned is captured so as to be enclosed.

The toner diameter D1 is 5 μm to 9 μm, and the fiber diameter D2 of the split fiber 12a of the pile yarn 12A is 5 μm.
Further, the divided fiber 12a has a substantially polygonal cross-sectional shape, and has at least one edge with an angle of less than 90 degrees to form a linear edge portion.
Therefore, as shown in the enlarged schematic cross-sectional view of FIG. 6C, the split fibers 12a are more easily inserted between the isolated toner T on the paper P and the paper P, and the surface of the paper P and the surface are fixed. The toner adhering to the non-image part can be scraped and collected without damaging the image part.
In addition, since the tip end portion of the pile yarn comes into contact with the sheet P moving on the surface in a loop shape, an increase in sheet conveyance resistance can be suppressed.

The split fibers 12a are composite-spun using a synthetic resin having heat resistance, excellent wear resistance, and a low dynamic friction coefficient.
Specifically, ester resins such as polyester and polyethylene terephthalate, amide resins such as aliphatic polyamide (nylon) and aromatic polyamide (aramid), olefin resins such as ultra-high molecular weight polyethylene and polypropylene, and polyacryl And the like, and acrylic resins such as tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) and polytetrafluoroethylene (PTFE).
Therefore, it is possible to suppress the conveyance resistance of the sheet P after fixing, which is a member to be cleaned.
In particular, when the sheet P is a continuous sheet having a perforation, a non-contact type flash fixing device that does not affect the conveyance of the recording medium is used, so the conveyance resistance of the sheet P after fixing is reduced. The above-described synthetic resin is suitable because it has excellent wear resistance and a low coefficient of dynamic friction.
Further, the sheet P heated by the fixing and having a high temperature and the toner image on the sheet P are less likely to be damaged, which is preferable.

In order to confirm the effects of the cleaning device 1 according to the first embodiment and the cleaning device 1A according to the second embodiment, a performance evaluation test is performed on paper transportability, cleaning performance of the isolated toner T, and scattering of the captured toner. Went. The results are shown in FIG.
"Evaluation criteria for paper transportability"
◯: The sheet conveyance resistance is small, and the sheet accommodation in the sheet discharge tray 131 is not hindered.
Δ: The paper accommodation in the paper discharge tray 131 is somewhat disturbed by the paper conveyance resistance.
X: The paper accommodation in the paper discharge tray 131 is hindered by the paper conveyance resistance.
"Evaluation criteria for cleaning properties"
A: Isolated toner T after fixing can be scraped off.
○: The isolated toner T after fixing can be scraped and removed to some extent.
Δ: A part of the isolated toner T after the fixing can be scraped off and removed.
X: The isolated toner T after fixing cannot be scraped off and removed.
"Evaluation criteria for toner scattering"
○: The scraped isolated toner T is held and transported, and there is no scattering to the surroundings.
X: The isolated toner T that has been scraped off cannot be held when being transported and is scattered around.

"Example 1, Example 3"
In Example 1, a brush roller 10 in which a pile yarn 12 made of stainless fiber having a fiber diameter D2 of 12 μm was formed in a loop shape was used. For the image forming apparatus 100, toner having a toner diameter D1 of 9 μm was used. That is, D2 / D1 = 1.33.
A brush roller 10 having a hair length of 4.5 mm and a flocking density of 120 kF / inch ² has a contact amount of 1.0 mm, a surface moving speed ratio Vb / Vp = 1.3, no bias applied voltage, and a rotation direction in a forward direction. Used as.
In Example 3, a brush roller 10 having a loop shape of pile yarn 12 made of basalt fiber having a fiber diameter D2 of 9 μm was used. For the image forming apparatus 100, toner having a toner diameter D1 of 5 μm was used. That is, D2 / D1 = 1.80.
A brush roller 10 having a bristle length of 4.5 mm, a flocking density of 150 kF / inch ² has a contact amount of 1.0 mm, a surface moving speed ratio Vb / Vp = 1.3, no bias applied voltage, and a rotational direction is forward. Used as.

  As shown in FIG. 7, in the first and third embodiments, the isolated toner T after fixing on the paper P can be scraped and removed without hindering the paper storage capacity in the paper discharge tray 131, and the scraped isolated It was confirmed that scattering around the toner T did not occur.

"Example 2, Example 4, Example 5"
Example 2 is different from Example 1 only in that the surface movement speed ratio Vb / Vp is Vb / Vp = 1.1.
In Example 4, a brush roller 10A of cut pile yarn composed of split fibers 12a having a fiber diameter D2 of 5 μm was used. For the image forming apparatus 100, toner having a toner diameter D1 of 9 μm was used. That is, D2 / D1 = 0.56.
A brush roller 10A having a hair length of 4.0 mm, a flocking density of 300 kF / inch ² is brought into contact with an amount of 1.0 mm, a surface moving speed ratio Vb / Vp = 1.3, no bias applied voltage, and a rotation direction is forward. Used as.
Example 5 is a cut pile yarn brush roller 10A having a split fiber 12a with a fiber diameter D2 of 5 μm and a flocking density of 250 kF / inch ² and a conductive acrylic fiber with a fiber diameter D2 of 25 μm and a flocking density of 100 kF / inch ^2. A cut-pile yarn brush roller 10A comprising a contact amount of 1.0 mm, a surface moving speed ratio Vb / Vp = 1.3, no bias applied voltage, and a rotational direction as a forward direction, respectively. For the image forming apparatus 100, toner having a toner diameter D1 of 5 μm was used.

  As shown in FIG. 7, in the second embodiment, the fourth embodiment, and the fifth embodiment, the paper storage capacity of the paper discharge tray 131 is not hindered, and the scraped-off isolated toner T does not scatter around. Was confirmed. Further, although the isolated toner T after fixing on the paper P could be scraped and removed to some extent, it was confirmed that the cleaning performance was slightly inferior compared with the first and third embodiments.

“Comparative Example 1 and Comparative Example 2”
Comparative Example 1 differs from Example 1 only in that the surface movement speed ratio Vb / Vp is Vb / Vp = 1.5.
Comparative Example 1 differs from Example 1 only in that the surface movement speed ratio Vb / Vp is Vb / Vp = −0.1, that is, the rotation direction is the reverse direction.
As shown in FIG. 7, in Comparative Examples 1 and 2, it was confirmed that the storage capacity of the paper discharge tray 131 was hindered and the scattered isolated toner T was scattered around. Further, the isolated toner T after fixing on the paper P was partially scraped and removed, but it was confirmed that the cleaning property was inferior to that of the first and third embodiments.

“Comparative Example 3, Comparative Example 4”
Comparative Example 3 is a conductive acrylic fiber having a fiber diameter D2 of 44 μm, a flocking density of 60 kF / inch ² , a cut pile yarn brush roller 10B having a hair length of 5.0 mm, a contact amount of 0.5 mm, and a surface movement speed ratio. Vb / Vp = 1.3, there was a bias applied voltage, and the rotation direction was used as the forward direction. For the image forming apparatus 100, toner having a toner diameter D1 of 9 μm was used. That is, D2 / D1 = 4.89.
Comparative Example 4 is a conductive acrylic fiber having a fiber diameter D2 of 25 μm, a flocking density of 60 kF / inch ² and a cut pile yarn brush roller 10B having a hair length of 5.0 mm. Vb / Vp = 1.3, there was a bias applied voltage, and the rotation direction was used as the forward direction. For the image forming apparatus 100, toner having a toner diameter D1 of 9 μm was used. That is, D2 / D1 = 2.78.
As shown in FIG. 7, in Comparative Examples 3 and 4, it can be confirmed that the storage of the paper in the paper discharge tray 131 is somewhat disturbed, and the isolated toner T after fixing on the paper P cannot be scraped off and removed. It was. Therefore, toner scattering did not occur.

As mentioned above, although embodiment concerning this invention was explained in full detail, this invention is not limited to the said embodiment, A various change is made within the range of the summary of this invention described in the claim. Is possible.

DESCRIPTION OF SYMBOLS 1, 1A, 2 ... Cleaning apparatus 10, 10A, 10B ... Brush roller 11 ... Base cloth 11a ... Warp yarn 11b ... Weft yarn 12, 12A, 12B ... Pile yarn 12a ... Split fiber 13 ... shaft 20 ... backup roller 30 ... waste toner collecting device 31 ... flicker 32 ... auger 100 ... image forming device 110 ... image forming unit 111 ... system Control device 112 ... Exposure device 113 ... Photoconductor unit 113a ... Photoconductor drum 113b ... Charger 113c ... Cleaning blade 114 ... Developing device 115 ... Transfer devices 116a, 116b ..Paper transport device 117 fixing device 117a flash lamp
DESCRIPTION OF SYMBOLS 120 ... Paper feeder 121 ... Paper storage part 130 ... Paper discharge part 131 ... Paper discharge tray D1 ... Toner diameter D2 ... Fiber diameter P ... Paper T ... Isolation toner

Claims (6)

A cleaning member that rotates and contacts the surface of the object to be cleaned while rotating, and removes fine particles on the surface of the object to be cleaned;
A support member that is in contact with the back surface of the object to be cleaned and is disposed to face the cleaning member;
A cleaning member that contacts the cleaning member and removes the fine powder particles collected by the cleaning member from the cleaning member;
A discharge member that discharges the fine particles separated from the cleaning member by the cleaning member, and
The cleaning member is made of a pile fabric comprising a base fabric and a plurality of pile yarns raised on the base fabric, and when the fine particle diameter is D1, and the fiber diameter of the pile yarn is D2,
D2 / D1 ≦ 2.
A cleaning device. The pile yarn is raised in a loop on the base fabric,
The cleaning apparatus according to claim 1. The pile yarn is made of inorganic fiber,
The cleaning apparatus according to claim 1 or 2, wherein The pile yarn is at least partly composed of divided fibers, and the fine fibers formed by dividing the divided fibers have a substantially polygonal cross-sectional shape, and a linear edge portion is formed,
The cleaning apparatus according to claim 1 or 2, wherein The surface moving speed of the cleaning object that moves on the surface is Vp, the surface moving speed of the cleaning member that rotates and contacts the surface of the cleaning object and removes fine particles on the surface of the cleaning object is Vb, When
1.1 ≦ Vb / Vp ≦ 1.3,
The cleaning apparatus according to claim 1, wherein A cleaning brush used in the cleaning device according to any one of claims 1 to 5,
It consists of a pile fabric comprising a base fabric and a plurality of pile yarns raised on the base fabric, and when the fine particle diameter of the surface of the object to be cleaned is D1, and the fiber diameter of the pile yarn is D2,
D2 / D1 ≦ 2.
A cleaning brush characterized by that.

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