JP2015001701A - Cleaning device, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively recover foreign substances accumulated on the edge part of a blade of a cleaning device to suppress the foreign substances from passing through the blade.SOLUTION: A cleaning device 6 of an image forming apparatus A includes a blade (leveling blade 64 or cleaning blade 61) that is arranged opposite to a photoreceptor 1 and brought into contact with the outer peripheral surface of the photoreceptor 1, and a magnetic brush 63b that is arranged adjacent to the photoreceptor 1 on the upstream side of the blade when viewed in the direction of rotation of the photoreceptor 1, where the magnetic brush 63b forms a magnetic field with a range in which its bristles can reach the edge part of the blade, and changes the magnetic field to flow the bristles of the magnetic brush 63b.

Description

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

  2. Description of the Related Art Conventionally, in an electrophotographic image forming apparatus, an elastic blade (hereinafter referred to as a cleaning blade) made of urethane rubber or the like in a counter direction with respect to a rotation direction of a photoconductor in order to remove residual toner on the photoconductor after transfer. A cleaning device is known that performs cleaning by abutting. In such a cleaning device, for the purpose of improving transferability and cleaning properties, for example, as described in Patent Documents 1 and 2, a lubricant application unit that applies a lubricant onto a photoconductor with a brush roller Some are provided.

JP 2005-352009 A JP 2008-233193 A

In some cleaning systems including a lubricant application unit, a leveling blade is disposed for the purpose of stably leveling the lubricant applied by the lubricant application unit on the photoreceptor. However, if excessive lubricant accumulates on the edge of the leveling blade, and the accumulated mass of lubricant slips through the leveling blade, toner stains corresponding to the loss of the lubricant occur in the image background, and the image There is a problem that a phenomenon of deteriorating quality occurs.
The main cleaning blade also has a problem in that paper dust and toner accumulate on the blade edge, and if these lumps pass through the cleaning blade, poor cleaning and image contamination occur.

  Patent Document 1 describes a lubricant removing unit that removes the lubricant on the intermediate transfer belt. However, it is impossible to remove foreign matters such as lubricant and toner accumulated on the blade edge. Also in Patent Document 2, there is no description of a configuration for removing foreign matters such as lubricant and toner accumulated on the blade edge, and these cannot be removed effectively.

  An object of the present invention is to effectively collect foreign matter accumulated on the edge portion of a blade of a cleaning device and suppress slipping of the foreign matter from the blade.

In order to solve the above-mentioned problem, the invention described in claim 1
A cleaning device provided in an image forming apparatus having an image carrier,
A blade disposed opposite to the image carrier and in contact with an outer peripheral surface of the image carrier;
A magnetic brush disposed adjacent to the upstream side of the blade as viewed from the rotational direction of the image carrier;
With
The magnetic brush forms a magnetic field in a range in which the ears of the magnetic brush can come into contact with the edge portion of the blade, and the magnetic brush ears flow by changing the magnetic field.

The invention according to claim 2 is the invention according to claim 1,
The magnetic brush has a magnet roller provided with a plurality of magnetic poles arranged in the circumferential direction, and a cylindrical sleeve in which the magnet roller is disposed, and the sleeve and the image carrier are opposed to each other. The sleeve rotates so that the circumferential surface of the sleeve moves in the same direction as the circumferential surface of the image carrier, and the circumferential surface of the magnet roller is positioned at the position where the magnet roller and the image carrier face each other. The magnetic field is changed by rotating the magnet roller so as to move in the direction opposite to the peripheral surface of the carrier.

The invention according to claim 3 is the invention according to claim 1 or 2,
The blade is a cleaning blade for removing residual toner on the image carrier.

The invention according to claim 4 is the invention according to claim 1 or 2,
Having a lubricant application means for applying a lubricant to the image carrier;
The blade is a leveling blade that contacts the image carrier and smoothes the lubricant applied by the lubricant application means on the image carrier,
The magnetic brush is disposed between the lubricant applying means and the leveling blade.

The invention according to claim 5 is the invention according to any one of claims 1 to 4,
The ears of the magnetic brush are made of a dry two-component developer in which toner and carrier are mixed.

The invention according to claim 6 is the invention according to claim 5,
Replenishment means for replenishing the developer;
Discharging means for discharging the developer used in the magnetic brush;
Is provided.

The invention according to claim 7 is the invention according to claim 5 or 6,
As the developer, a developer discharged from a trickle developing device provided in the image forming apparatus is used.

The invention according to claim 8 is the invention according to any one of claims 1 to 7,
The blade is a plate-like member and has a notch at a corner on the magnetic brush side.

The invention according to claim 9 is the invention according to claim 4,
Tk <Tn, where Tk is the torque of the magnetic brush and the image carrier, and Tn is the torque of the blade and the image carrier.

An image forming apparatus according to the invention of claim 10 is provided.
The cleaning apparatus as described in any one of Claims 1-9 is provided.

  According to the present invention, it is possible to effectively collect foreign matter accumulated on the edge portion of the blade of the cleaning device, and to suppress the passage of foreign matter from the blade.

1 is a diagram illustrating a schematic configuration example of an image forming apparatus. It is a figure which shows the relationship between a developing device and a cleaning apparatus. It is a figure which shows the principal part structure of a cleaning apparatus. It is a figure which expands and shows the edge part vicinity of the leveling blade of a cleaning apparatus. It is a figure for demonstrating the motion of the developer in a magnetic brush. It is arrow sectional drawing in the CC line of FIG. It is a figure which shows the structural example of the cleaning apparatus of a comparative example. It is a figure which shows an example of the braid | blade which has a notch in an edge part. It is a figure which shows the cleaning apparatus of a modification.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the scope of the invention is not limited to the illustrated examples.

[Configuration of Image Forming Apparatus A]
First, the overall configuration of the image forming apparatus A according to the present invention will be described.
FIG. 1 is a schematic cross-sectional configuration diagram of an image forming apparatus A in the present embodiment. In each figure, the direction from the front side to the back side of the image forming apparatus A is shown as the y direction, and the direction orthogonal to the y direction (paper transport direction) is shown as the x direction. Moreover, except for FIG. 6, the arrow attached | subjected to each part to rotate shows the rotation direction.

  As shown in FIG. 1, the image forming apparatus A reads an image from a document, forms a read image on a sheet P and outputs it, page data including image data from an external device, and each image data. A print function for receiving a job including the image forming conditions, and forming and outputting an image on the paper P based on the received job. As shown in FIG. 1, the image forming apparatus A includes an image reading unit 10, a printing unit 20, a control unit 30, and the like.

  The image reading unit 10 includes an automatic document feeder 11 called an ADF (Auto Document Feeder) and a reading unit 12. The automatic document feeder 11 is provided in the upper part of the main body of the image forming apparatus A. The automatic document feeder 11 includes a plurality of conveyance rollers, and conveys the document d placed on the document tray T1 onto a contact glass that is a reading surface of the reading unit 12.

  The reading unit 12 includes a scanner provided with a light source, a lens, a contact glass, an image sensor 12a, and the like. The reading unit 12 forms an image of the reflected light of the light irradiated on the document d and photoelectrically converts the image of the document. Image data (analog signal) is generated by reading and photoelectric conversion. Here, the image means not only image data such as graphics and photographs but also text data such as characters and symbols.

  The image data read by the image reading unit 10 is output to an image processing unit (not shown), subjected to various image processing, and then yellow (Y), magenta (M), cyan (C), black (K ) And is output to the exposure devices 3Y, 3M, 3C, and 3K of the image forming unit 23.

  The printing unit 20 includes a paper feeding unit 21, a paper feeding / conveying unit 22, an image forming unit 23, a fixing unit 24, a carry-out unit 25, and the like.

  The paper feed unit 21 includes a plurality of paper feed trays 21a, paper feed means 21b, a manual feed tray T2, and the like. In the paper feed tray 21a, various types of paper P such as standard paper, special paper, insertion paper, etc., identified for each paper feed tray 21a based on the amount and size of the paper are stored for each preset type. Yes. The paper P stored in the paper feed tray 21a is transported one by one from the top to the paper feed transport unit 22 by the paper feed unit 21b. The manual feed tray T2 can be loaded with various types of paper P according to the user's needs. The sheets P stacked on the manual feed tray T2 are conveyed one by one from the top toward the sheet feeding / conveying section 22 by the sheet feeding roller.

  The sheet feeding / conveying unit 22 conveys the sheet P conveyed from the sheet feeding tray 21a or the manual feed tray T2 to the secondary transfer roller 22b via a plurality of intermediate rollers, registration rollers 22a, and the like. Further, the paper feeding / conveying unit 22 conveys the sheet P on which the single-sided image formation processing has been performed to the double-sided conveyance path by the conveyance path switching plate, and again conveys the sheet P to the secondary transfer roller 22b via the intermediate roller and the registration roller 22a. The toner images transferred to an intermediate transfer belt 23b described later are collectively transferred onto the paper P by the secondary transfer roller 22b.

  When the image forming unit 23 forms an image of a maximum of four colors (yellow (Y), magenta (M), cyan (C), and black (K)), each image can be filled with toner of different colors. The image forming units 23Y, 23M, 23C, and 23K, a cleaning unit 23a, and an intermediate transfer belt 23b are provided.

  The image forming unit 23Y includes a charging device 2Y, an exposure device 3Y, a developing device 4Y, a primary transfer roller 5Y, a cleaning device 6Y, and a conveying screw 7Y arranged around a photoreceptor 1Y as an image carrier, and yellow (Y ).

  Specifically, an electrostatic latent image is formed by irradiating light corresponding to yellow (Y) image data from the exposure device 3Y to the photoreceptor 1Y charged by the charging device 2Y. As shown in FIG. 2, the developing device 4Y is filled with a dry two-component developer (developer D) containing yellow (Y) toner and a carrier, and the developing device 4Y forms an electrostatic latent image. The electrostatic latent image is developed by attaching a charged toner to the surface of the photoreceptor 1Y. The photoreceptor 1Y to which the toner is attached by the developing device 4Y is transferred to the intermediate transfer belt 23b while being rotated at a constant speed to the transfer position where the primary transfer roller 5Y is disposed. After the toner is transferred to the intermediate transfer belt 23b, the cleaning device 6Y removes residual toner and the like on the surface of the photoreceptor 1Y. Further, the cleaning device 6Y applies a lubricant to the photoreceptor 1Y from which the residual toner has been removed, and smoothes it with a smoothing blade 64.

Here, as shown in FIG. 2, the developing device 4Y includes a supply means 41 for supplying a developer, a supply screw 42, a stirring screw 43, and a developing roller 44 that conveys toner charged on the photoreceptor 1Y. And so on. Each part constituting the developing device 4Y is long along the axial direction of the photosensitive member 1, and the length in the axial direction is at least longer than the printing width.
The developing device 4Y is replenished little by little by the replenishing means 41, and the developer D accommodated in the housing 40 is stirred and circulated by the supply screw 42 and the stirring screw 43 to be supplied to the developing roller 44, and the developer. This is a so-called known trickle developing type developing device that discharges the developer D, which has become excessive due to the replenishment of the developer D, to the outside of the developing device 4Y due to overflow.
The developing device 4Y is connected to the conveying screw 7Y as shown in FIG. The conveying screw 7Y is connected to a replenishment port 641 (see FIG. 6) of the lubricant recovery device 63 of the cleaning device 6Y, and the developer D discharged from the developing device 4Y is transferred to the lubricant recovery device 63 of the cleaning device 6Y. Transport. In FIG. 1, illustration of the conveying screws 7Y, 7M, 7C, and 7K is omitted. In FIG. 2, the charging device 2Y is not shown.

  The image forming units 23M, 23C, and 23K have the same configuration as the image forming unit 23Y, and form magenta (M), cyan (C), and black (K) images, respectively.

The intermediate transfer belt 23b is a semiconductive endless belt that is suspended and supported rotatably by a plurality of rollers, and is driven to rotate as the rollers rotate.
The intermediate transfer belt 23b is pressure-bonded to the photoreceptors 1Y, 1M, 1C, and 1K by the primary transfer rollers 5Y, 5M, 5C, and 5K of the image forming units 23Y, 23M, 23C, and 23K. As a result, the toner of each color developed on the surface of each of the photoreceptors 1Y, 1M, 1C, and 1K is sequentially transferred to the intermediate transfer belt 23b at the transfer positions by the primary transfer rollers 5Y, 5M, 5C, and 5K. The toner image is transferred onto the paper P at the transfer position (secondary transfer position) by the next transfer roller 22b. The intermediate transfer belt 23b transfers the toner image onto the paper P by the secondary transfer roller 22b, and then separates the paper P in curvature and electrostatically. The toner remaining on the intermediate transfer belt 23b is removed by the cleaning unit 23a.

  The fixing unit 24 includes a heating roller 24 a having a heat source and a pressure roller 24 b that presses against the heating roller 24 a to form a nip portion N, and heat-fixes the toner image transferred to the paper P.

  The paper P on which the toner image is fixed is sandwiched between the paper discharge rollers of the carry-out unit 25 and is carried out from the carry-out port to the paper discharge tray T3.

  The control unit 30 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The CPU of the control unit 30 is connected to a drive unit or the like (drive motor or the like) of each unit of the image forming apparatus A, reads out a program stored in the ROM, expands it in the RAM, and executes an image according to the expanded program. The operation of the forming apparatus A is centrally controlled.

[Configuration of Cleaning Device 6]
Next, the cleaning device 6 that is characteristic of the image forming apparatus A will be described in detail. In the following description, each color photoconductor 1Y, 1M, 1C, 1K, charging device 2Y, 2M, 2C, 2K, exposure device 3Y, 3M, 3C, 3K, developing device 4Y, 4M, 4C, 4K, primary transfer roller 5Y, 5M, 5C, and 5K, cleaning devices 6Y, 6M, 6C, and 6K, and conveying screws 7Y, 7M, 7C, and 7K are collectively referred to as a photoreceptor 1, a charging device 2, an exposure device 3, a developing device 4, and a primary. These are referred to as a transfer roller 5, a cleaning device 6, and a conveying screw 7.

FIG. 3 schematically shows a main configuration of the cleaning device 6.
As shown in FIG. 3, a cleaning blade 61, a lubricant application device 62, a lubricant recovery device 63, and a leveling blade 64 are arranged in this order along the rotation direction of the photosensitive member 1 in the housing 60 of the cleaning device 6. It is provided side by side. Each of the parts constituting the cleaning device 6 is elongated along the axial direction of the photosensitive member 1, and the length in the axial direction is at least longer than the printing width.

  The cleaning blade 61 is provided on the downstream side of the transfer position by the primary transfer roller 5 and on the upstream side of the lubricant application device 62 in the rotation direction of the photosensitive member 1. The cleaning blade 61 is a thin plate member made of, for example, urethane rubber. One end of the cleaning blade 61 is in contact with the surface of the photoreceptor 1 and scrapes off and removes toner remaining on the surface of the photoreceptor 1.

The lubricant application device (lubricant application means) 62 is provided on the downstream side of the cleaning blade 61 and the upstream side of the lubricant recovery device 63 as viewed in the rotational direction of the photoreceptor 1. The lubricant application device 62 includes a brush roller 62a and a solid lubricant 62b.
The brush roller 62a preferably has conductive hair bristles and is provided so as to contact the surface of the photoreceptor 1 and the solid lubricant 62b. As shown by arrows in FIG. 3, the brush roller 62a rotates so that its peripheral surface moves in a direction opposite to the peripheral surface of the photosensitive member 1, and scrapes the lubricant little by little from the solid lubricant 62b. 1 is applied continuously.
The solid lubricant 62b is formed in a plate shape that has a solid hydrophobic material such as steering acid zinc (Zn-St) as a main component and extends in the rotation axis direction of the photoreceptor 1. The solid lubricant 62b is held by a holding member (not shown) and is pressed against the brush roller 62a via the holding member by a pressure member such as a spring 62c attached to the housing 60 of the cleaning device 6.

  The lubricant recovery device 63 is provided on the downstream side of the lubricant application device 62 and on the upstream side of the leveling blade 64 in the rotational direction of the photoreceptor 1. The lubricant collecting device 63 includes a magnetic brush 63b, a circulating screw 63c, a regulating plate 63d, and the like in the casing 63a, and collects the lubricant deposited on the edge portion of the leveling blade 64 using the developer D. To do. Details will be described later.

  The leveling blade 64 is provided adjacent to the downstream side of the lubricant recovery device 63 in the rotational direction of the photosensitive member 1. The leveling blade 64 is a thin plate member made of, for example, urethane rubber. One end of the leveling blade 64 is in contact with the surface of the photosensitive member 1, and the lubricant applied to the surface of the photosensitive member 1 is leveled to fix the lubricant powder on the photosensitive member 1. A powder film is formed.

FIG. 4 shows a partially enlarged view near the edge portion of the leveling blade 64.
In the leveling blade 64, as shown in FIG. 4, excessive lubricant that has not been fixed to the photoreceptor 1 is accumulated on the edge portion due to the scraping action of the leveling blade 64 (in FIG. The agent is denoted by St). When a certain amount of the lubricant St is deposited on the edge portion, the lubricant St slips through, and the image is stained. Therefore, in the image forming apparatus A, the lubricant recovery device 63 is provided in the vicinity of the edge portion of the leveling blade 64, and the lubricant St deposited on the edge portion of the leveling blade 64 is removed and recovered, and the lubricant St slips through. I try to suppress it.

Hereinafter, the configuration and operation of the lubricant recovery device 63 will be described in detail.
As shown in FIG. 3, the casing 63a of the lubricant recovery device 63 is provided with a supply port 641 (see FIG. 6) for supplying the developer D transported by the transport screw 7 into the casing 63a. (Supplying means). The developer D supplied from the supply port 641 is used for the magnetic brush 63b. The amount of the developer D supplied to the photoreceptor 1 side is regulated by the regulation plate 63d so as to be an appropriate amount. Further, the casing 63a is provided with a discharge port 642 (see FIG. 6) for discharging the developer D to the outside of the lubricant recovery device 63.

The magnetic brush 63b of the lubricant recovery device 63 is formed of a non-magnetic stainless steel or aluminum material, and has a cylindrical sleeve 631 processed to have a rough surface (for example, sandblasting), and a shaft inside the sleeve 631. The recovery roller 630 includes a magnet roller 632 inserted along the direction.
The sleeve 631 is kept in non-contact with the photoreceptor 1 by abutting rollers (not shown), and the circumferential surface thereof is in the same direction as the circumferential surface of the photoreceptor 1 at a position facing the photoreceptor 1. Rotate to move.
The magnet roller 632 is provided such that a plurality of magnetic poles are arranged in the circumferential direction (S pole and N pole are alternately arranged), and the circumferential surface of the magnet roller 632 is opposite to the photoreceptor 1 and the sleeve 631 in a position facing the photoreceptor 1. Rotate to move to. The magnet roller 632 forms a magnetic field in a range in which the ears of the magnetic brush 63 b are leveled and can contact the edge portion of the blade 64.
Developer D forms spikes of magnetic brush 63b in accordance with the magnetic field formed by magnet roller 632. The sleeve 631 and the magnet roller 632 are rotated based on the drive of a drive motor (not shown) according to the control of the control unit 30.

  As the ears of the magnetic brush 63b, the effect of recovering the lubricant can be obtained by using only the magnetic carrier. However, since the carrier is composed of iron powder, magnetite, ferrite particles and the like and is hard, there is a possibility that the lubricant on the photoreceptor 1 may be completely removed. On the other hand, the toner has a smaller particle size and lower hardness than the carrier. Therefore, by using a dry two-component developer in which toner and carrier are mixed in the magnetic brush 63b, it is possible to suppress the carrier from directly hitting the photoconductor 1, and to leave the lubricant on the surface of the photoconductor 1 while leveling blade 64. It is possible to remove the lubricant St deposited on the edge portion of each of the above. Further, by using the developer D discharged from the developing device 4 as the developer used for the ears of the magnetic brush 63b, the developer D discharged from the developing device 4 can be effectively used.

The sleeve 631 rotates so that its peripheral surface moves in the same direction as the peripheral surface of the photoconductor 1 at a position facing the photoconductor 1, and the magnet roller 632 is opposite to the sleeve 631 (that is, opposes the photoconductor 1). The magnetic field formed by the magnetic poles of the magnet roller 632 changes when the rotation is performed so that the circumferential surface moves in the direction opposite to the circumferential surface of the photoreceptor 1. This change in the magnetic field acts such that each particle of the developer D forming the ears of the magnetic brush 63b draws an elliptical arc indicated by a dotted line in FIG. The individual particles forming the spikes of the developer D are conveyed in the rotation direction by the rotation of the sleeve 631 while rotating so as to draw an arc shown in FIG. 5 on the peripheral surface of the sleeve 631. Note that FIG. 5 shows only a part of one row of arcs in the cross section of the sleeve 631, but the developer D rotates to draw a plurality of rows of arcs in the axial direction of the sleeve 631. In this way, it is possible to penetrate the edge of the leveling blade 64 while flowing the ears of the magnetic brush 63b.
The lubricant St deposited on the edge portion of the leveling blade 64 is in mechanical contact with the developer D that has entered the edge portion and adheres to the surface of the developer D, whereby the rotation direction of the sleeve 631 together with the developer D is increased. And is collected in the lubricant collecting device 63.

  As described above, in the lubricant recovery device 63, the ears (developer D) of the magnetic brush 63b are caused to flow and penetrate into the edge portion of the leveling blade 64, and the lubricant St is adhered to the developer D to develop the developer. Since it is collected together with D, the lubricant St deposited on the edge portion of the leveling blade 64 can be effectively removed and collected, and image smear due to slipping of the lubricant can be suppressed.

Here, if the torque between the magnetic brush 63b and the photosensitive member 1 is Tk, and the torque between the leveling blade 64 and the photosensitive member 1 is Tn, Tk <Tn is set. The torque Tk between the magnetic brush 63b and the photoconductor 1 is such that when the developer D comes into contact with the photoconductor 1 due to the rotation of the collection roller 630 of the magnetic brush 63b while the photoconductor 1 is rotating, the photoconductor 1 is rotated. It is the force that acts on. The torque Tn between the leveling blade 64 and the photoconductor 1 is a force that acts on the photoconductor 1 when the leveling blade 64 contacts when the photoconductor 1 is rotating. For example, Tk = 0.12 N / m and Tn = 0.23 N / m are set.
When the torque Tk between the lubricant recovery device 63 and the photoconductor 1 is larger than the torque Tn between the leveling blade 64 and the photoconductor 1, the lubricant applied to the surface of the photoconductor 1 is recovered by the lubricant recovery device 63. As a result, the lubricant is insufficiently supplied to the photoreceptor 1. By setting Tk <Tn, such supply shortage of lubricant can be suppressed.

  The developer D (including the lubricant St) collected by the magnetic brush 63b is circulated and conveyed in the apparatus by the circulation screw 63c (the circulation screw 63c1 and the circulation screw 63c2), and is supplied to the magnetic brush 63b. However, as the developer D is repeatedly used and the lubricant St adheres to the surface, the recovery ability of the developer D decreases. Therefore, the lubricant recovery device 63 includes a mechanism (discharge means) for discharging the developer D including the developer D used by the magnetic brush 63b in an amount replenished from the conveying screw 7.

  6 is a cross-sectional view taken along line CC in FIG. As shown in FIG. 6, the inside of the casing 63 a is divided into an upper chamber 661 and a lower chamber 662 across a barrier 665. The right side of FIG. 6 is the front side of the apparatus, and the left side is the rear side of the apparatus.

In the upper chamber 661, the circulation screw 63c1 is provided so as to face the collection roller 630 and its axial direction is parallel to the axial direction of the collection roller 630. The upper chamber 661 protrudes from the lower chamber 662 on the front side of the apparatus, and a discharge port 642 for discharging the developer D is provided at the protruding portion.
In the lower chamber 662, a circulation screw 63c2 is provided so that its axial direction is parallel to the circulation screw 63c1. The lower chamber 662 is provided with a replenishing port 641 for the developer D, and the developer D discharged from the developing device 4 is replenished into the casing 63 a through the replenishing port 641.

The upper chamber 661 and the lower chamber 662 are connected by a first communication portion 663 and a second communication portion 664, and are routed by arrows in FIG. 6 via the first communication portion 663 and the second communication portion 664. The developer D is circulated and conveyed by the circulation screw 63c1 and the circulation screw 63c2.
Specifically, the circulating screw 63c2 conveys the developer D replenished from the replenishing port 641 and the developer D sent from the first communication portion 663 to the rear side of the apparatus while stirring the developer D. The developer D conveyed to the rear side of the apparatus is sent to the upper chamber 661 through the second communication portion 664. The circulation screw 63c1 in the upper chamber 661 supplies the developer D being conveyed to the recovery roller 630 while conveying the developer D sent via the second communication portion 664 from the apparatus rear side to the apparatus front side. The circulation screw 63c1 takes in the developer D collected by the collection roller 630 and conveys it to the front side of the apparatus. The developer D transported to the front side of the apparatus is sent to the lower chamber 662 by the reverse winding blade R via the first communication portion 663 and transported through the circulation path, but is transported in the casing 63a by replenishment of the developer D. When the developer D exceeds a predetermined amount, the developer D passes through the reverse winding blade R and further enters the protruding portion on the front side of the apparatus, and is discharged to the outside of the lubricant collecting apparatus 63 through the discharge port 642. The discharged developer D is collected in the collection tank 65.

  As described above, in the lubricant recovery device 63, the developer D is replenished as needed from the developing device 4 and supplied to the recovery roller 630, and the developer D increased by the replenishment is discharged from the lubricant recovery device 63. Therefore, it is possible to suppress a decrease in the recovery ability of the lubricant.

[Evaluation of lubricant slip-through suppression]
In order to confirm the effect of the above embodiment, an evaluation experiment for suppressing slipping of the lubricant leveling blade 64 (hereinafter referred to as lubricant slipping) in the image forming apparatus A including the cleaning device 6 of the present embodiment was performed. .

  Specifically, the image forming apparatus A (Example) provided with the cleaning device 6 of the above embodiment and the image forming apparatus (cleaning device not provided with the lubricant recovery device 63) shown in FIG. In Comparative Example), 20000 A3 size and 1% coverage test images were printed, and the cleaning device was operated for each printing, and image smear due to slipping of lubricant in each finished test image. The presence or absence was visually observed. Then, for each of the example and the comparative example, the section occurrence rates of image stains caused by slipping of the lubricant were tabulated.

The evaluation experiment was performed in a high-temperature and high-humidity environment (temperature 30 ° C., humidity 80%) in which the occurrence of slipping of the lubricant becomes significant.
The configurations of the photoreceptor 1 and the cleaning device 6 used in the evaluation experiment are shown below. In addition, although the lubricant collection | recovery apparatus 63 is not provided in the cleaning apparatus of a comparative example, the structure other than that used was the same as what is shown below.
<Photoconductor>
Photosensitive drum diameter: φ60mm
Photoconductor rotation speed: 100 rpm
<Cleaning device>
Cleaning blade: Urethane rubber blade Thickness t = 2mm
Counter contact, contact force 20N, contact angle 15 °
Lubricant application brush: Outer diameter 16mm Counter contact
Conductive polyester fiber
Rotational speed Photoreceptor speed ratio 0.5
Lubricant type: Zinc stearate Leveling blade: Urethane rubber blade Thickness t = 2mm
Counter contact, contact force 20N, contact angle 15 °

Lubricant recovery device: SUS sleeve, 4-pole magnet roller
Outside diameter φ10mm
4-pole common magnetic force Magnetic flux density 50mT
Sleeve rotation speed Photoconductor speed
Magnet roller rotation speed 1000rpm
Developer Trickle development device discharge developer
Toner density 6.5%
Regulated version Magnetic regulation Carrying amount 300g / m ²
Circulating screw outer diameter φ8mm, Pitch 15mm
Gaps between photoconductor and sleeve 0.7mm

Table 1 shows the results of an evaluation experiment for suppressing the lubricant slipping through the above-described lubricant.

  As shown in Table 1, in the cleaning device of the comparative example in which the lubricant recovery device is not provided, image contamination due to lubricant slipping continuously occurs, whereas the lubricant recovery device of the present embodiment In the cleaning device 6 provided with the above, image smear due to slipping through the lubricant did not occur. In other words, it was verified that the cleaning device 6 of the present embodiment can suppress the slipping of the lubricant by including the lubricant recovery device 63.

The above embodiment may be modified examples 1 and 2 below.
[Modification 1]
As the leveling blade 64, as shown in FIG. 8, a blade having a notch at the corner on the magnetic brush 63b side may be used. In this way, the developer D can easily enter the edge portion of the leveling blade 64, and the developer D and the lubricant St that have entered the edge portion can be more easily recovered.

[Modification 2]
In the above-described embodiment, the case where the recovery device having the magnetic brush 63b is used as the lubricant recovery device has been described as an example. However, in the cleaning device 6, as shown in FIG. In view of this, a recovery device having the same configuration as the lubricant recovery device 63 may be provided adjacent to the upstream side of the cleaning blade 61. This collection device is provided in the vicinity of the cleaning blade 61 so that the ears of the magnetic brush 63 b can contact the edge of the cleaning blade 61. Thus, by providing a recovery device having the same configuration as the lubricant recovery device 63 adjacent to the upstream side of the cleaning blade 61, the ears of the cleaning blade 61 are allowed to enter while flowing the ears of the magnetic brush 63b. Therefore, the toner deposited on the edge portion of the cleaning blade 61 can be effectively removed and collected, and image contamination due to slipping of the toner cleaning blade 61 can be suppressed. In the second modification, it is preferable that the edge of the cleaning blade 61 has a notch as in the first modification.

As described above, the cleaning device 6 of the image forming apparatus A according to the present embodiment is disposed so as to face the photoreceptor 1 and is a blade (equalizing blade 64 or cleaning blade) that contacts the outer peripheral surface of the photoreceptor 1. 61) and a magnetic brush 63b disposed adjacent to the upstream side of the blade as viewed from the rotation direction of the photosensitive member 1, and the magnetic brush 63b has a magnetic field in a range in which the ear can contact the edge portion of the blade. The ears of the magnetic brush 63b are made to flow by changing the magnetic field.
Accordingly, the ears (developer D) of the magnetic brush 63b are allowed to flow into the edge of the blade while flowing, and foreign matters such as lubricant St and toner can be attached to the developer D and collected together with the developer D. Therefore, the foreign matter accumulated on the edge portion of the leveling blade 64 can be effectively removed and collected, and image contamination due to the passage of the foreign matter from the blade can be suppressed.

  For example, the sleeve 631 rotates so that the circumferential surface of the sleeve 631 moves in the same direction as the circumferential surface of the photoconductor 1 at a position where the sleeve 631 of the magnetic brush 63 b and the photoconductor 1 face each other, and the magnet roller 632 and the photoconductor 1. When the magnet roller 632 rotates so that the circumferential surface of the magnet roller 632 moves in the direction opposite to the circumferential surface of the photoconductor 1 at a position where the magnetic fields face each other, the magnetic field can be changed.

  Further, by using a dry two-component developer in which toner and a carrier are mixed as the ears of the magnetic brush 63b, it is possible to suppress the carrier from directly hitting the photoreceptor 1. For this reason, for example, it is possible to remove foreign matters accumulated on the edge portion of the blade while leaving the lubricant applied to the surface of the photoreceptor 1.

  Further, since a replenishing means for replenishing the developer and a discharging means for discharging the developer D used in the magnetic brush 63b are provided, the developer D used in the magnetic brush 63b can be replaced, and development is performed. It is possible to suppress a decrease in recovery capability due to the agent D.

  Further, by using the developer discharged from the trickle developing type developing device 4 provided in the image forming apparatus A as the developer D used for the magnetic brush 63b, the developer D discharged from the developing device 4 is effectively used. Can be used.

  In addition, by providing a notch at the corner of the blade on the magnetic brush 63b side, the developer D can easily enter the edge of the blade, and the developer D and foreign matter that have entered the edge can be more easily removed. Can be recovered.

  Further, if the torque of the magnetic brush 63b and the photosensitive member 1 is Tk, and the torque of the blade (equalizing blade 64) and the photosensitive member 1 is Tn, the necessary lubrication for the surface of the photosensitive member 1 is set by setting Tk <Tn. It is possible to prevent the agent from being completely removed by the magnetic brush 63b.

  Note that the description in the above embodiment shows a preferred example of the image forming apparatus according to the present invention, and the present invention is not limited to this.

  For example, in the above embodiment and Modifications 1 and 2, the photoconductor 1 is described as an image carrier. However, in the cleaning device (cleaning unit 23a) that removes foreign matter on the intermediate transfer belt 23b as an image carrier. The present invention can also be applied.

  In addition, the detailed configuration and detailed operation of the image forming apparatus A can be changed as appropriate without departing from the spirit of the present invention.

1 (1Y, 1M, 1C, 1K) Photosensitive drum 2 (2Y, 2M, 2C, 2K) Charging device 3 (3Y, 3M, 3C, 3K) Exposure device 4 (4Y, 4M, 4C, 4K) Developing device 5 (5Y, 5M, 5C, 5K) Primary transfer roller 6 (6Y, 6M, 6C, 6K) Cleaning device 10 Image reading unit 11 Automatic document feeding unit 12 Reading unit 20 Printing unit 21 Paper feeding unit 21a Paper feeding tray 21b Paper feeding Means 22 Paper feeding / conveying unit 22a Registration roller 22b Secondary transfer roller 23 Image forming unit 23a Cleaning unit 23b Intermediate transfer belt 24 Fixing unit 24a Heating roller 24b Pressure roller 25 Unloading unit 61 Cleaning blade 62 Lubricant coating device 63 Lubricant recovery device Device 63a Casing 63b Magnetic brush 630 Recovery roller 631 Sleeve 632 Magnet roller -63c Circulating screw 641 Replenishment port 642 Discharge port 661 Upper chamber 662 Lower chamber 63d Regulating plate 64 Leveling blade A Image forming apparatus d Document P Paper D Developer St Lubricant T1 Document tray T2 Manual feed tray T3 Paper discharge tray

Claims (10)

A cleaning device provided in an image forming apparatus having an image carrier,
A blade disposed opposite to the image carrier and in contact with an outer peripheral surface of the image carrier;
A magnetic brush disposed adjacent to the upstream side of the blade as viewed from the rotational direction of the image carrier;
With
The said magnetic brush is a cleaning apparatus which forms the magnetic field of the range which the said brush brush can contact the edge part of the said blade, and makes the said brush brush flow by changing the said magnetic field.   The magnetic brush has a magnet roller provided with a plurality of magnetic poles arranged in the circumferential direction, and a cylindrical sleeve in which the magnet roller is disposed, and the sleeve and the image carrier are opposed to each other. The sleeve rotates so that the circumferential surface of the sleeve moves in the same direction as the circumferential surface of the image carrier, and the circumferential surface of the magnet roller is positioned at the position where the magnet roller and the image carrier face each other. The cleaning apparatus according to claim 1, wherein the magnetic field is changed by rotating the magnet roller so as to move in a direction opposite to the circumferential surface of the carrier.   The cleaning device according to claim 1, wherein the blade is a cleaning blade for removing residual toner on the image carrier. Having a lubricant application means for applying a lubricant to the image carrier;
The blade is a leveling blade that contacts the image carrier and smoothes the lubricant applied by the lubricant application means on the image carrier,
The cleaning device according to claim 1, wherein the magnetic brush is disposed between the lubricant applying unit and the leveling blade.   The cleaning device according to claim 1, wherein the ears of the magnetic brush are made of a dry two-component developer in which toner and a carrier are mixed. Replenishment means for replenishing the developer;
Discharging means for discharging the developer used in the magnetic brush;
A cleaning device according to claim 5.   The cleaning device according to claim 5, wherein the developer discharged from a trickle developing device provided in the image forming apparatus is used as the developer.   The said blade is a plate-shaped member, Comprising: The cleaning apparatus as described in any one of Claims 1-7 which has a notch in the corner | angular part by the side of the said magnetic brush.   5. The cleaning device according to claim 4, wherein Tk <Tn, where Tk is a torque of the magnetic brush and the image carrier, and Tn is a torque of the blade and the image carrier.   An image forming apparatus comprising the cleaning device according to claim 1.