JP2003076244A - Cleaning apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning apparatus whose cleaning brush with recovered toner stuck thereto can always be kept in a stuck toner-lessened state and which is small-sized and simple. SOLUTION: This cleaning apparatus CL1 is provided with a toner image carrier PR for carrying the toner stuck to the surface, the cleaning brush 1 for cleaning the residual toner stuck to the surface of the carrier PR, an electric field curtain producing member 2 for carrying the toner stuck to the brush 1 along the outer peripheral part of the brush 1 and another electric field curtain producing member 2 having electric field curtain producing electrodes for carrying the toner by an electric field curtain produced by applying electric field curtain producing voltage between the electric field curtain producing electrodes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning device for an image forming apparatus such as an electrophotographic copying machine or a laser printer, and more particularly to removing toner adhering to a toner adhering rotary member such as a photoconductor or an intermediate transfer member. The present invention relates to a cleaning device.

[0002]

2. Description of the Related Art Conventionally, an image forming apparatus using an electrophotographic system forms a toner image on a toner adhering rotary member through a process of charging, exposing, and developing the toner adhering rotary member, and then transferring and fixing the toner image. In the step, the toner image is transferred and fixed on the transfer material to form an image. In the transfer step, the residual toner remaining on the surface of the toner image carrier without being transferred to the transfer material is removed by the cleaning device.

FIG. 11 is an explanatory view of a conventional toner image carrier cleaning device. In FIG. 11, a cleaning device 02 that removes toner adhering to the surface of the toner image carrier 01 such as a photoconductor or an intermediate transfer member includes a cleaning brush 03, a flicker bar 04, and a discharge auger 05.
And a cleaning blade 06. The cleaning brush 03 is rotating in a direction in which the cleaning brush 03 contacts the toner image carrier 01 and rotates with the toner image carrier 01. A voltage having a polarity opposite to that of the toner is applied to the cleaning brush 03 by a voltage applying unit (not shown), and the residual toner remaining on the surface of the toner image carrier 01 is electrostatically adsorbed and removed. When the cleaning brush 03 to which the toner adheres comes in contact with the flicker bar 04 and then leaves, the adhered toner is repelled from the cleaning brush 03, and the repelled toner is discharged by a discharge auger 05 to a collection container (not shown). The residual toner that cannot be completely removed by the cleaning brush 03 is disposed on the downstream side of the cleaning brush 03 in the rotational direction of the toner image carrier 01, and is scraped off by the cleaning blade 06 that presses and contacts the toner image carrier 01.
The toner scraped off by the cleaning blade 06 adheres to the cleaning brush 03 and is discharged to the collection container by the discharge auger 05 as described above. Instead of the flicker bar 04, a cleaning brush 0
A cleaning device that collects toner by providing a toner collecting roll that contacts the toner 3 and transfers the toner on the brush and a scraper that scrapes the toner off the toner collecting roll is also known.

[0004]

In the conventional cleaning device 02 for removing the residual toner by the cleaning brush 03 and the cleaning blade 06, the flicker bar 0 is used to discharge the removed toner to the collecting container.
4 and a discharge auger 05 are required. in this case,
A drive member for driving the discharge auger 05 and a space for housing the flicker bar 04 and the discharge auger 05 are required. If a toner recovery roll or a scraper is provided instead of the flicker bar 04, more members will be required. Further, the cleaning device provided with the flicker bar 04 has a cleaning brush 0 in order to scrape off the toner adhering to the cleaning brush 03.
The cleaning brush 03 is configured to bend at the portion where 3 and the flicker bar 04 contact each other. Therefore, the cleaning brush 03 may be broken or the brush may have a peculiarity, which causes a decrease in cleaning ability and defective cleaning.

Further, the toner scraped off by the cleaning blade 06 may not fall and may be stored at the tip of the cleaning blade 06. At this time, the blade 0
A pressure contact area (Ni
When the foreign matter is caught in p), the foreign matter rubs the photosensitive body to cause scratches on the surface of the photosensitive body, or a gap is formed between the blade 06 and the toner image carrier 01. Then, the toner is conveyed to the downstream side of the image carrier 01 through the scratches or the gap (slip through), and a cleaning failure occurs. Further, if the tip of the blade 06 is chipped, the stored toner is conveyed to the downstream side of the toner image carrier 01, and cleaning failure occurs. As a measure against this cleaning failure, the blade 06
The force (line pressure) that presses the tip of the toner image carrier 01 against the toner image carrier 01 may be increased. However, if the force with which the blade 06 contacts the toner image carrier 01 is increased, the surface of the toner image carrier 01 is It becomes worn and deteriorates faster.

As a technique for solving the cleaning failure due to the stored toner, (J01) JP-A-7-140869.
Japanese Unexamined Patent Publication No. 2003-242242 discloses a cleaning device in which a rotatable paddle having flexible blades is provided and the blades rub near the tip of the blade. In the prior art described in the above publication (J01), since the blade is thick, the blade at the tip of the paddle does not reach the contact portion between the blade tip and the photoconductor, and the toner and foreign matter in the vicinity of the contact portion cannot be collected. There's a problem. In addition, there is a problem that the device becomes large due to the space for installing the rotatable paddle.
In recent years, there has been an increasing social demand for space-saving copiers and printers, and it has become necessary to reduce the number of parts and downsize them, but an image forming apparatus equipped with the above-mentioned cleaning device cannot meet this demand. Can not. Further, discarding the toner removed by the cleaning device is not preferable from the viewpoint of environmental protection, and also costs the toner for disposal.

In order to reduce the amount of waste toner, it has been attempted to use spherical toner having a high transfer efficiency, which is produced by an emulsion polymerization method, a suspension polymerization method or the like. However, because of the shape of the spherical toner, when the toner is stored at the tip of the cleaning blade, the toner tends to roll near the tip of the blade and easily enter between the blade tip and the toner adhering rotary member. That is, there is a problem that the above-mentioned toner scraping is more likely to occur than the conventional toner, and cleaning failure is likely to occur. As a technique for solving the problem of poor cleaning of spherical toner, (J02) JP-A-60-
131547, (J03) JP-A-5-333757.
Japanese Unexamined Patent Publication (Kokai) No. 8-254873 and (J04)
A technique is disclosed in which a pulverized toner is mixed with a spherical toner and used. In the prior arts described in each of the publications (J02) to (J04), the toner mixed with pulverized toner is used to reduce the spherical toner entering between the tip of the blade and the toner adhering rotary member. This is a technique for preventing defective cleaning. However, because multiple types of toner with different shapes and charge amounts are used, parameters such as applied bias at development / transfer, peripheral speed difference, cleaning blade pressure contact angle to the photoreceptor, bite amount, and fixing temperature are optimized. There is a problem in that it is difficult to set it to any value. In addition to the conventional technique, it is possible to increase the linear pressure between the toner-adhering rotary member and the cleaning blade, but the toner-adhering rotary member is worn by the cleaning blade and durability is reduced. Also,
A configuration in which a plurality of cleaning blades are provided for cleaning is conceivable, but this leads to an increase in the number of parts, a complicated shape of parts, and an increase in size of the apparatus.

[0008] As a technique for reducing the amount of toner discarded and for reducing the size by eliminating the auger of the cleaning device,
(J05) Japanese Unexamined Patent Application Publication No. 10-3197 and (J06) Japanese Unexamined Patent Application Publication No. 9-319278 disclose a cleaning device that electrically returns the toner on the brush that is electrically adsorbed to the photoconductor and collects it by a developing device. ing. However, in the conventional techniques described in the above-mentioned publications (J05) and (J06), when the toner is returned to the photoconductor and collected by the developing device, the surface of the photoconductor to which the toner adheres passes through a charged region. However, there is a problem that toner adheres to the charger and the charger is contaminated. Further, in the case of a color image forming apparatus, the toner may be reversely transferred from the intermediate transfer member to the photoconductor, and the color of the reverse transfer toner is different from the color of the transfer residual toner on the surface of the photoconductor. The adsorbed toner mixes colors. When the adsorbed mixed color toner is reversely transferred to the photoconductor and collected by the developing device, the toner in the developing device is mixed, and a defective toner image is formed by the mixed color toner during image formation. is there. When the toner is reused without being reverse-transferred to the photoconductor, a conveying device for conveying the toner collected in the toner collecting container to the developing device must be provided.

An apparatus that uses an electric field curtain when the toner collected by a cleaning process in an image forming apparatus is conveyed to a developing apparatus is disclosed in JP-A-8-30160. Further, (J08) Japanese Patent Laid-Open No. 2001-122436 discloses a technique using an electric field curtain in a toner conveying device for supplying toner to a developing device. The above-mentioned publications (J07) and (J08) describe the technique of utilizing the electric field curtain when the toner is conveyed to the developing device, but do not describe the use of the electric field curtain in the cleaning device. A general cleaning device of an image forming apparatus includes a cleaner container, a cleaning brush that collects toner on a toner image carrier, a toner transport auger, and a member that moves toner from the cleaning brush to the toner transport auger ( A flicker bar or a recovery roll and a member such as a scraper for scraping off the toner on the surface of the recovery roll). In such a cleaning device, it is possible to use an electric field curtain instead of the toner carrying auger. However, even if the toner-transporting auger is replaced with the toner-transporting electric field curtain in the cleaning device, a cleaning brush and a member for moving the toner from the cleaning brush to the toner-transporting electric field curtain must be arranged in the cleaner container. Therefore, it is difficult to reduce the size of the cleaning device to a large extent.

In view of the above-mentioned problems (and examination), the present invention has the following contents (O01) to (O04). (O01) To provide a small and simple cleaning device that can always hold a cleaning brush to which collected toner adheres in a state where the amount of adhered toner is small. (O02) To enable the toner attached to the cleaning brush to be conveyed to a predetermined place by a small and simple toner conveying mechanism. (O03) To provide a simple and space-saving cleaning device that does not require a flicker bar, an auger, etc., so that a high-quality image without image defects can be obtained for a long period of time. (O04) To provide a cleaning device capable of preventing cleaning failure even when spherical toner is used.

[0011]

The present invention devised to solve the above problems will now be described. The elements of the present invention are to facilitate correspondence with the elements of the embodiments described later. Note that the reference numerals of the elements of the embodiments are enclosed in parentheses. The reason why the present invention is described in association with the reference numerals of the embodiments described later is to facilitate the understanding of the present invention and not to limit the scope of the present invention to the embodiments. (Present invention) In order to solve the above-mentioned subject, the cleaning device of the present invention is provided with the following constituent requirements (A01)-(A04). (A01) Toner adhering rotary member (PR, B, T2b) having a surface to which toner is adhered, (A02) Toner adhering rotary member (PR, B, T2b) is brought into contact with the toner adhering rotary member (PR). , B, T2b) cleaning brush (6) for cleaning the residual toner adhering to the surface, (A03) for carrying the toner adhering to the cleaning brush (6) along the outer peripheral portion of the cleaning brush (6). Electric field curtain generating members (8, 8 ',) arranged on the outer peripheral portion of the cleaning brush (6).
(20, 25), (A04) A plurality of electric field curtain generating electrodes supported by electrode supporting members (8a, 20a, 25a) arranged along the toner conveying direction and arranged at intervals in the toner conveying direction ( 8b, 8b ', 20b, 25
b) and the plurality of electric field curtain generating electrodes (8b, 8)
b ', 20b, 25b) coating layer (8
c, 20c, 25c), and the covering layer (8c, by the electric field curtain generated when the electric field curtain generating voltage is applied to each of the plurality of electric field curtain generating electrodes (8b, 8b ', 20b, 25b). 20c, 25c) The electric field curtain generating member (8, 8 ', 20, 25) for carrying the toner near the surface in the toner carrying direction.

(Operation of the Present Invention) In the cleaning device of the present invention having the above-mentioned structure, the cleaning brush (6)
Comes into contact with the surface of the toner-adhering rotary member (PR, B, T2b) to contact the toner-adhering rotary member (PR, B, T2).
b) Clean the residual toner adhering to the surface. The electric field curtain generating members (8, 8 ', 20, 25) arranged along the outer periphery of the cleaning brush (6) are
Each of the plurality of electric field curtain generating electrodes (8b, 8b ', 2)
0b, 25b) causes the electric field curtain generated when an electric field curtain generating voltage is applied to the coating layer (8c, 2b).
0c, 25c) toner near the surface (toner attached to the cleaning brush (6)) is conveyed in the toner conveying direction.

Therefore, the electric field curtain generating member (8,
Since 8 ', 20, 25) conveys the toner attached to the cleaning brush (6), it is possible to remove the toner without providing a flicker bar, a toner conveying auger, and members for driving and supporting them. it can. Further, since a space for arranging each member such as a flicker bar is not required, it is possible to provide a space-saving and small cleaning device (CL1, CL2, CL3). Since the cleaning brush (6) is not damaged by the flicker bar, it is possible to provide a high-quality image with no image defects for a long period of time.

Further, the cleaning apparatus of the present invention can have the following constituent requirements (B01) to (B04). (B01) Toner adhering rotary member (PR, B, T2b) having a surface to which toner adheres, (B02) The toner adhering rotary member (PR, B, T2b) abutting on the surface of the toner adhering rotary member (PR, (B, T2b) Cleaning blade (7) having a blade tip portion for scraping off the residual toner adhering to the surface, (B03) The toner attaching rotary member (PR, B, T2) scraped by the blade tip portion.
b) In order to convey the toner accumulated on the surface to the upstream side in the rotational direction of the surface of the toner adhering rotary member (PR, B, T2b) from the tip of the blade, the toner adhering rotary member (P
R, B, T2b) electric field curtain generating members (8, 8 ', 20, 25) arranged on the back side, (B04) electrode supporting members (8a, 20a,) arranged along the toner conveying direction.
25a) and a plurality of electric field curtain generating electrodes (8b, 8) arranged at intervals in the toner conveying direction.
b ', 20b, 25b) and a coating layer (8c, 20c, 25c) for coating the surfaces of the plurality of electric field curtain generating electrodes (8b, 8b', 20b, 25b), and each of the plurality of electric fields Curtain generating electrodes (8b, 8b ', 20b,
The coating layer (8c, 20c, 2) is generated by the electric field curtain generated by the electric field curtain generating voltage applied to 25b).
5c) The electric field curtain generating member (8, 8 ', 20, 2) for carrying the toner near the surface in the toner carrying direction.
5).

In the cleaning device (CL1, CL2, CL3) of the present invention having the above structure, the blade tip portion of the cleaning blade (7) is in contact with the surface of the toner adhering rotary member (PR, B, T2b). The residual toner adhering to the surface of the toner adhering rotary member (PR, B, T2b) is scraped off. The toner in the vicinity of the surface of the coating layer (8c, 20c, 25c) contains a plurality of electric field curtain generating electrodes (8).
b, 8b ', 20b, 25b) and the electric field curtain generated when the electric field curtain generation voltage is applied, the conveying force in the toner conveying direction (the upstream side of the toner adhering rotary member (PR, B, T2b) in the rotational direction). Receive. That is, the electric field curtain generating members (8, 8 ', 20, 25) arranged on the back surface side of the toner adhering rotating member (PR, B, T2b).
Of the toner adhering rotary member (P, B, T2b) scraped off by the tip of the blade and accumulated on the surface of the toner adhering rotary member (PR, B, T2b) than the tip of the blade.
R, B, T2b) The surface is conveyed upstream in the rotational direction.

Therefore, the toner accumulated at the tip of the blade receives the force of being conveyed in the conveying direction by the electric field curtain, so that the amount of toner accumulated at the tip of the blade is kept small. That is, toner is less likely to pass through (slip through) the tip of the blade, and cleaning failure can be prevented. Even if the toner is spherical toner,
Since the amount of toner stored in the blade tip portion is small, the toner does not roll and slip through, and cleaning failure can be prevented without using multiple types of toner or increasing the linear pressure of the blade (7). . As a result,
The toner on the image carrier (PR, B, T2b) is sufficiently removed, and it is possible to provide a high-quality image without image defects for a long period of time.

Further, the cleaning device (CL
1, CL2, CL3) are the following constituent requirements (C01) to (C01)
It is also possible to provide 04). (C01) Toner adhering rotary member (PR, B, T2b) having a surface to which the toner adheres, (C02) The toner adhering rotary member (PR, B, T2b) is brought into contact with the surface of the toner adhering rotary member (PR, (B, T2b) Cleaning blade (7) having a blade tip portion for scraping off the residual toner adhering to the surface, (C03) The cleaning blade (7) is disposed on the tip surface of the cleaning blade (7) and scraped by the blade tip portion. An electric field curtain generating member (8, 8 ',) that conveys toner along the tip surface of the cleaning blade (7) in a direction away from the surface of the toner image carrier.
20, 25), (C04) A plurality of electric field curtain generating electrodes (8a, 20a, 25a) supported by the electrode supporting members (8a, 20a, 25a) arranged along the toner conveying direction and arranged at intervals in the toner conveying direction. 8b, 8b ', 20b, 25
b) and the plurality of electric field curtain generating electrodes (8b, 20)
b, 25b) coating layers (8c, 8c ',
20c, 25c) and the coating layers (8c, 20c, 25c) by the electric field curtain generated by the electric field curtain generating voltage applied to each of the plurality of electric field curtain generating electrodes (8b, 8b ', 20b, 25b). ) The electric field curtain generating member (8, 8 ', 20, 25) for carrying the toner near the surface in the toner carrying direction.

In the cleaning device (CL1, CL2, CL3) of the present invention having the above structure, the toner adhering rotary member (PR, B, T2b) has a surface to which the toner adheres. The blade tip portion of the cleaning blade (7) is brought into contact with the surface of the toner adhering rotary member (PR, B, T2b) and the toner adhering rotary member (PR, B, T2).
b) Scrape off the residual toner adhering to the surface. The electric field curtain generating member (8, 8 ', 20, 25) disposed on the tip surface of the cleaning blade (7) is applied when an electric field curtain generating voltage is applied to each of the plurality of electric field curtain generating electrodes (25b). By the generated electric field curtain, the toner scraped off by the blade tip portion is conveyed along the tip surface of the cleaning blade (7) in a direction away from the surface of the toner adhering rotary member (PR, B, T2b).

Therefore, since the toner accumulated at the tip of the blade is conveyed by the electric field curtain, the amount of toner accumulated at the tip of the blade is kept small. That is, the toner passes (slips) through the tip of the blade.
And the cleaning failure can be prevented. Even if the toner is spherical toner, the amount of toner stored in the blade tip is small, so the toner does not roll and slip through, and measures such as using multiple types of toner and increasing the linear pressure of the blade (7) are taken. It can be cleaned without taking any action. As a result, the image carrier (PR,
The toner on B, T2b) is sufficiently removed, and a high-quality image without image defects can be provided for a long period of time.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION (Embodiments) Next, specific examples (embodiments) of the embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments. Absent.
In order to facilitate understanding of the following description, in the drawings, the front-rear direction is the X-axis direction, the left-right direction is the Y-axis direction, and the up-down direction is the Z-axis direction, and arrows X, -X, Y, -Y, Z,-
The direction indicated by Z or the indicated side is defined as front, rear, left, right, upper, lower, or front, rear, left, right, upper, lower. In addition, in the figure, "○" in "○" means an arrow from the back of the paper to the front, and "○" in "○" indicates the front of the paper. Shall mean the arrow from to the back.

(Embodiment 1) FIG. 1 is an illustration of an image forming apparatus having a cleaning device according to Embodiment 1 of the present invention.
In FIG. 1, an image forming apparatus U composed of a copying machine
An automatic document feeder U2 is placed on the upper surface of the platen glass PG at the upper end of 1. The automatic document feeder U2
Has an original feed tray TG1 on which a plurality of originals Gi to be copied are stacked and placed. Each of the plurality of documents Gi placed on the document feeding tray TG1 sequentially passes through the copy position on the platen glass PG and passes through the document discharging tray T.
It is configured to be discharged to G2. The automatic document feeder U2 has a hinge shaft (not shown) provided at its rear end portion (-X end portion) and extending in the left-right direction.
It is rotatable with respect to 1, and is rotated upward when the operator manually places the document Gi on the platen glass PG.

The image forming apparatus U1 has a UI (user interface) through which the user inputs and operates an operation command signal such as copy start. An IIT (image input terminal) as a document reading device arranged below the transparent platen glass PG on the upper surface of the image forming apparatus U1 has an exposure system registration sensor (platen registration sensor) Sp arranged at a platen registration position (OPT position). And an exposure optical system A. The movement and stop of the exposure optical system A are controlled by the detection signal of the exposure system registration sensor Sp, and are normally stopped at the home position. Reflected light from the document Gi that has passed the exposure position on the upper surface of the platen glass PG by the automatic document feeder U2 or a document manually placed on the platen glass PG is transmitted through the exposure optical system A to a CCD (solid-state imaging device). Element) R (red), G
(Green) and B (blue) electrical signals are converted.

The IPS (Image Processing System) converts the RGB electrical signals input from the CCD into K (black), Y (yellow), M (magenta), and C (cyan) image data, and temporarily. And outputs the image data to the laser drive circuit DL as image data for forming a latent image at a predetermined timing. Laser drive circuit D
L outputs a laser drive signal to ROS (latent image forming device) according to the input image data. The operations of the IPS and the laser drive circuit DL are controlled by a controller C composed of a microcomputer.

The image carrier PR (toner adhering rotary member) is rotating in the direction of arrow Ya, and the surface thereof is a charging roll.
After being uniformly charged by the (charge roll) CR, the laser beam L of the ROS (latent image forming device) exposes and scans the latent image writing position Q1 to form an electrostatic latent image. When forming a full-color image, K (black), Y
Electrostatic latent images corresponding to four color images of (yellow), M (magenta), and C (cyan) are sequentially formed, and in the case of a monochrome image, only electrostatic latent images corresponding to K (black) image are formed. To be done.

The surface of the image carrier PR on which the electrostatic latent image is formed is rotationally moved and sequentially passes through the developing area Q2 and the primary transfer area Q3. The rotary type developing device G sequentially rotates and moves to the developing area Q2 as the rotation shaft Ga rotates.
It has four color developing units GK, GY, GM and GC of (black), Y (yellow), M (magenta) and C (cyan). The developing units GK, GY, GM, and GC of the respective colors have a developing roll GR that conveys the developer to the developing area Q2, and form an electrostatic latent image on the image carrier PR passing through the developing area Q2. Develop into a toner image. Each of the developing units GK, GY,
The cartridge mounting portions Hk and H are provided on the developing containers of GM and GC.
Toners of respective colors are replenished from toner replenishing cartridges (not shown) mounted on y, Hm, and Hc (see FIG. 1). Such a rotary developing device is described in, for example, Japanese Patent Application Laid-Open Nos. 12-131942 and 12-231250.

Below the image carrier PR, an intermediate transfer belt B (toner adhering rotating member) and a belt driving roll R are provided.
d, tension roll Rt, walking roll Rw,
A plurality of belt support rolls (Rd, Rd, including idler roll (free roll) Rf and backup roll T2a
Rt, Rw, Rf, T2a) and the primary transfer roll T1
And a belt frame (not shown) that supports them. The intermediate transfer belt B is supported by the belt supporting rolls (Rd, Rt, Rw, Rf, T2a) so as to be rotatable and movable in the arrow Yb direction.

When forming a full-color image, the electrostatic latent image of the first color is formed at the latent image writing position Q1, and the toner image Tn of the first color is formed in the developing area Q2.
The toner image Tn is electrostatically primarily transferred onto the intermediate transfer belt B by the primary transfer roll T1 when passing through the primary transfer area Q3. Thereafter, in the same manner, the second image is transferred onto the intermediate transfer belt B carrying the first color toner image Tn.
The toner images Tn of the colors, the third color, and the fourth color are sequentially superposed and primary-transferred, and finally a full-color multiple toner image is formed on the intermediate transfer belt B. When forming a monochromatic monocolor image, only one developing device is used, and the monochromatic toner image is primarily transferred onto the intermediate transfer belt B. After the primary transfer, the surface of the image carrier PR has an image carrier cleaner CL1.
It is cleaned by (cleaning device).

Below the backup roll T2a, a secondary transfer roll T2b is provided.
It is movably arranged between a position separated from 2a and a position in contact therewith. The backup roll T2a
The secondary transfer roll T2b constitutes a secondary transfer device T2. The intermediate transfer belt B supported by the backup roll T2a and the pressure contact region of the secondary transfer roll T2b form a secondary transfer region Q4. A secondary transfer voltage having a polarity opposite to the charging polarity of the toner used in the developing device G is supplied from the power supply circuit E to the secondary transfer roll T2b, and the power supply circuit E is controlled by the controller C.

The recording sheets S accommodated in the paper feed tray TR1 or TR2 are taken out by the pickup roll Rp at a predetermined timing, separated one by one by the separation roll Rs, and are conveyed by the plurality of transport rolls Ra of the paper feed path SH1. Is conveyed to the registration roll Rr. The cash register roll Rr
The recording sheet S conveyed to the pre-transfer sheet guide S is timed to move the primary-transferred multiple toner image or single-color toner image to the secondary transfer area Q4.
The sheet is conveyed from G1 to the secondary transfer area Q4. In the secondary transfer area Q4, the secondary transfer device T2 electrostatically secondarily transfers the toner image on the intermediate transfer belt B onto the recording sheet S. The intermediate transfer belt B after the secondary transfer is a belt cleaner C.
The residual toner is removed by L2 (cleaning device). The image carrier PR, the charging roll CR, the developing device G,
Maintenance transfer roll T1, intermediate transfer belt B, secondary transfer device T
2. A toner image forming apparatus (PR + CR + G + T1 + B + T) that transfers and forms a toner image on the recording sheet S by using 2 or the like.
2) is configured.

The secondary transfer roll T2b and the belt cleaner CL2 are arranged so as to be able to come into contact with (separate from and contact with) the intermediate transfer belt B, and when a color image is formed, the final color is not fixed. The toner image is separated from the intermediate transfer belt B until the toner image is primarily transferred to the intermediate transfer belt B. The secondary transfer roll cleaner CL3
The (cleaning device) moves to and from the intermediate transfer belt B together with the secondary transfer roll T2b.

The recording sheet S to which the toner image is secondarily transferred has the post-transfer sheet guide SG2 and the sheet conveying belt B.
The sheet H is conveyed to the fixing area Q5. The fixing region Q5 is a region (nip) where the heating roll Fh and the pressure roll Fp of the fixing device F are in pressure contact with each other, and the recording sheet S passing through the fixing region Q5 is heated and fixed by the fixing device F. On the outer peripheral surface of the heating roll Fh, the oil for peeling the sheet is applied by the oil applying roll Fa on the upstream side in the rotation direction from the fixing area Q5. Around the heating roll Fh and the pressure roll Fp, a cleaning member Fb for cleaning the surface of the heating roll Fh is arranged in contact with the downstream side of the fixing region Q5 in the rotation direction.

In FIG. 1, the sheet discharge path SH2 is provided on the downstream side of the fixing area Q5 for fixing the toner image on the recording sheet S.
Is provided, and the sheet reversing path SH3 is connected to the sheet discharging path SH2. A switching gate GT1 is provided at a branch point of the sheet discharging path SH2 and the sheet inverting path SH3.
Is provided. The recording sheet S conveyed to the sheet discharge path SH2 is conveyed to the sheet discharge roller Rh by a plurality of conveying rollers Ra, and is discharged to the sheet discharge tray TR3 from the sheet discharge port Ka formed at the upper end of the image forming apparatus U1. It The sheet circulation path SH3 is provided in the sheet inversion path SH3.
4 are connected, and a mylar gate GT2 formed of a sheet-shaped member is provided at the connection portion. The mylar gate GT2 allows the recording sheet S conveyed through the sheet inversion path SH3 from the switching gate GT1 to pass through as it is, and the recording sheet S that has once passed and then switched back is directed to the sheet circulation path SH4 side. Dodge The recording sheet S conveyed to the sheet circulation path SH4 is retransmitted to the transfer area Q4 through the paper feed path SH1. The sheet conveying path SH is constituted by the elements indicated by the reference signs SH1 to SH4.

(Cleaning Device) FIG. 2 is a sectional view of the image carrier cleaner (image carrier cleaning device) according to the first embodiment of the present invention. 3A and 3B are explanatory views of the image carrier cleaner and the toner conveying path, FIG. 3A is a perspective view, and FIG. 3B is a sectional view taken along line IIIB-IIIB of FIG. 3A. 4A and 4B are explanatory views of an electric field curtain generating member and a member that supports the electric field curtain generating member. FIG. 4A is a perspective view and FIG. 4B is FIG. 4A.
FIG. 4C is a development view of the electric field curtain generating member when viewed from the IVB direction in FIG. 4C, and FIG. The image carrier cleaner CL1 and the belt cleaner CL
The second and second transfer roll cleaners CL3 have substantially the same structure. Below, only the structure and operation of the image carrier cleaner CL1 will be described, and description of the other parts will be omitted.

2 to 4, the case main body 1 of the image carrier cleaner CL1 is formed in a rectangular tube shape with the left side surface (-Y side surface) opened, and the left end portion (-Y end portion) of the upper surface is downward. The blade supporting portion 1a is bent (see FIG. 2) to form a blade supporting portion 1a. In FIG. 3, a plate-shaped case front portion 2
On the rear surface (-X surface) of the rectangular tube type case body 1
Has a rectangular tube-shaped protrusion 2a that fits inside the front end (+ X end) (see FIG. 3B). The front surface of the case body 1 is closed by the case front portion 2. An upper curtain support 2b1 and a lower curtain support 2b2 are provided above and below the rear end (-X end) of the protrusion 2a.

In FIG. 3, the rear part 3 of the case having the shape of a square tube is
On the front wall (+ X surface wall), a rectangular tubular rear projection 3a that fits inside the rear end (−X end) of the case body 1 is provided.
(See FIG. 3B). The case rear part 3 is fitted to the case body 1 and the rear surface of the case body 1 is closed by the rear protrusion 3a. A circular hole 3b is formed in the center of the front wall of the case rear part 3, and a drawer opening 3c (see FIG. 3A) is formed on the front left part of the top wall (+ Z surface wall) of the case rear part 3. Has been formed. A toner discharge cylinder 4 fixed to the main body of the image forming apparatus U1 is fitted and connected below the case rear portion 3 (-Z direction). The toner discharge cylinder 4 has the same diameter as that of the case rear portion 3 at the connecting portion with the case rear portion 3, and has a small diameter at a position away from the connecting portion. The toner discharge cylinder 4 is connected to a toner collection box (not shown), and the toner collected by the cleaner CL1 is discharged to the toner collection box and discarded. It is also possible to connect the toner discharge cylinder 4 to a developing device and reuse the toner collected by the cleaner CL1. The case body 1, the case front portion 2 and the case rear portion 3
A cleaner container is constituted by the cleaner container, and the cleaner container is a frame (not shown) of the main body of the image forming apparatus U1.
Supported by.

2 to 4, a cleaning brush 6 is arranged inside the cleaner container, and a brush shaft 6a of the cleaning brush 6 is attached to the front portion 2 of the case.
And a rear surface wall (-X surface wall) 3d of the case rear portion 3 are rotatably supported via bearings (FIG. 3).
(See B). A gear (not shown) is fixed to the rear end (-X end) of the brush shaft 6a, and is rotated by a motor (not shown). The cleaning brush 6 is rotationally driven by the motor in a direction in which the cleaning brush 6 is rotated along with the image carrier PR, and is in contact with the image carrier PR to collect the transfer residual toner on the image carrier PR (FIG. 2). reference). Figure 2
In the cleaning blade 7 made of an elastic member, its base end is held by the blade supporting portion 1a of the case body 1, and its tip is arranged so as to come into contact with the image carrier PR. An area (blade contact area) where the cleaning blade 7 and the image carrier PR contact each other is downstream of a contact area (brush contact area) between the cleaning brush 6 and the image carrier PR in a rotation direction of the image carrier PR. The transfer residual toner which is set to the side and which is not collected by the cleaning brush 6 is scraped off by the cleaning blade 7.

2 to 4, a cylindrical shape in which the image carrier PR side (-Y side) is opened in the front-rear direction so as to contact the tip of the cleaning brush 6 along the outer periphery thereof. The electric field curtain generating member 8 is provided. The electrode supporting member 8a of the electric field curtain generating member 8 is made of an insulating member, and a plurality of electrodes 8b (electric field curtain generating electrodes) made of a conductive member are provided on the upper surface of the electrode supporting member 8a at equal intervals in the front-back direction (X-axis direction). , And are arranged in parallel. The coating layer 8c formed of an insulating member is
It is arranged so as to cover the upper surfaces of the electrode supporting member 8a and the electrode 8b (see FIG. 4C).

In FIG. 4B, the end of the electrode 8b is connected to the lead lines 8d, 8e, 8f at the upper end (+ Z side end) of the open portion of the electric field curtain generating member 8. The electrode (the frontmost electrode) on the frontmost side (+ X side) of the electrodes 8b is connected to the first lead wire 8d, and the electrode (second electrode) adjacent to the frontmost electrode and the rear side (-X side) is the first electrode. An electrode (third electrode) adjacent to the second electrode on the rear side of the second lead wire 8e is connected to the third lead wire 8f.
The electrode adjacent to the rear side of the third electrode is connected to the first lead wire 8d, and similarly every other two electrodes are connected to the respective lead wires 8d, 8e, 8f. The lead lines 8d, 8e, and 8f are sandwiched between the electrode supporting member 8a and the coating layer 8c between the electric field curtain generating portion and the rear end portion (-) of the electric field curtain generating member 8 along the upper end portion. It is arranged so as to extend to the (X end). At the rear end portion of the upper end portion of the electric field curtain generating member 8, the lead wires 8 are provided.
A sheet-shaped lead wire 8g is formed in which d, 8e, and 8f are insulated from each other and bundled together. The electrode support member 8a, the electrode 8b, the coating layer 8c, the lead wire 8d
The electric field curtain generating member 8 is constituted by 8f and the sheet-shaped lead wire 8g.

2 to 4, the outer peripheral surface of the electrode supporting member 8a is fixed to the curtain supporting member 9, and the electric field curtain generating member 8 having low rigidity is reinforced and supported. The front portion of the curtain support member 9 is vertically supported by the pair of curtain support portions 2b1 and 2b2,
The rear portion penetrates the circular hole 3b and is supported by the peripheral surface thereof (see FIG. 3B). In addition, the electric field curtain generating member 8 and the curtain supporting member 9 are configured to be rearward (−X direction) longer than the cleaning brush 6, and a rear end (−X end) of the cleaning brush 6 has a rear wall (−). It is arranged so that a gap is formed between the X-plane wall) 3d (see FIG. 3B).

FIGS. 5A and 5B are explanatory views for explaining how toner is conveyed by the electric field curtain, FIG. 5A is an operation explanatory view, and FIG. 5B is a view showing a supply voltage supplied to the electric field curtain generation member. The sheet-shaped lead wire 8g is drawn to the outside of the cleaner from the drawer port 3c of the case rear portion 3 and is connected to the electric field curtain generating power supply circuit PU. The first to third lead lines 8d to 8f are supplied with first to third electric field curtain generation voltages CH1 to CH3 from the electric field curtain generation power supply circuit PU (see FIG. 5A). The electric field curtain generation power supply circuit PU applies the voltage supplied from the power supply circuit E to each electric field curtain generation voltage C.
It is converted into H1, CH2 and CH3 and supplied. Example 1
Then, the electric field curtain generation voltages CH1, CH2, C
H3 is set so as to be supplied during the execution period of the image forming operation (job).

In FIG. 5, each electric field curtain generation voltage CH supplied from the electric field curtain generation power supply circuit PU.
1, CH2, and CH3 are pulse-shaped AC voltages of the same shape whose phases are delayed by 1/3 cycle, and the time during which a high voltage (positive (+) voltage) is supplied is low by 1/3 cycle. The time during which the voltage (negative (−) voltage) is supplied is set to 2/3 cycles (see FIG. 5B).

Therefore, the lead lines 8d, 8e,
When a high voltage is supplied to the electrode 8b to which one of the lead wires 8f is connected, a low voltage is supplied to the electrode 8b to which the other two lead wires are connected. Since an electric field is generated between the electrodes to which different voltages are supplied, a periodic electric field distribution (in the direction in which the electrodes 8b are arranged) is formed on the surface of the coating layer 8c of the electric field curtain generating member 8 having the above configuration. An electric field curtain having an electric field distribution formed by repeatedly arranging electric fields of the same shape is generated. The electric field distribution of the electric field curtain moves along the direction in which the electrodes 8b are arranged. Since the electrodes 8b of the electric field curtain generating member 8 are arranged in parallel with each other, the electric field distribution of the electric field curtain is from the front side (+ X side) to the rear side (−X side) in the direction of arrow 15 (see FIG. 5A). Move along. If the supplied voltage is not three-phase (for example, a four-phase power supply), the number of lead wires and the distance between electrodes connected to the lead wires (4
It can be adapted by changing every 3 lines in case of phase power supply.

(Operation of Embodiment 1) FIG. 6 is an explanatory view showing the arrangement of electrodes of the electric field curtain generating member of Embodiment 1 and the direction in which toner is conveyed by the electric field curtain of this electrode arrangement. In the cleaning device (CL1, CL2, CL3) of the present invention having the above configuration, the cleaning brush 1 performs cleaning by adhering the toner adhering to the toner adhering rotary member (PR, B, T2b) to the cleaning brush 6. . The toner attached to the cleaning brush 6 receives an electric force by the electric field curtain generated on the surface of the coating layer 8c of the electric field curtain generating member 8 arranged so as to be substantially in contact with the cleaning brush 6.

5 and 6, FIG. 5B of the first embodiment.
When the applied voltage shown in Fig. 5 is used, the toner having a negative (-) charging polarity is generated by the electric field curtain (electric field curtain on which the electric field distribution moves) on the electric field curtain generating member 8 in the moving direction (Fig. 5A). And in the direction of arrow 15 in FIG. 6). Since the electric field curtain generating member 8 and the curtain supporting member 9 are configured to be longer on the rear side (−X side) than the cleaning brush 6 (see FIG. 3B), the rear end portion (−X end portion) of the cleaning brush 6 is formed. The toner conveyed to ()) is separated from the cleaning brush 6 by the electric field curtain and is conveyed to the rear end portion (−X end portion) on the surface of the electric field curtain generating member 8. The toner conveyed to the rear end of the electric field curtain generating member 8 is not further conveyed by an electric force, but is pushed by the toner conveyed later and is discharged to the toner discharge cylinder 4. It should be noted that foreign matters such as carriers having a positive (+) charge polarity are
The electric field curtain conveys the toner in the conveying direction (direction of arrow 15 in FIGS. 5A and 6).

Therefore, the cleaning device of the first embodiment (image carrier cleaner CL1, belt cleaners CL2 and CL2)
The secondary transfer roll cleaner CL3) removes the residual toner attached to the surface of the toner adhering rotary member (the image carrier PR and the intermediate transfer belt B) or the secondary transfer roll T2b with the cleaning brush 6, and the electric field curtain generating member 8 It can be conveyed to the toner discharge path 4. That is, a member for removing or repelling toner from the cleaning brush 6 such as a flicker bar, or a conveying device such as an auger for conveying the removed toner is not required, and a cleaning device having a very simple structure and low cost is provided. can do. Further, since a member such as a flicker bar that strongly comes into contact with the brush is not provided, damage to the brush 6 due to breakage of the brush or habit of the brush can be reduced, the toner recovery efficiency of the brush 6 can be maintained, and cleaning failure can be prevented. Can be prevented. Further, the cleaning device, which has been increased in size because a space for arranging members such as an auger was required, can be made very compact and space-saving.

In order to confirm the effect of the first embodiment, a test for confirming the recoverability of the toner on the brush by the electric field curtain was conducted. The cleaning brush 6 is an acrylic insulating brush with a diameter of 14 mm (where the distance between the tips of the brushes is the largest in the cross section), 30 denier bristles, a density of 20,000 brushes / inch ² , and a length of 5 mm.
I used the one. The cleaning brush 6 is configured to rotate in the same direction as the photoconductor at a speed 1.1 times the rotation speed of the photoconductor. When the cleaning brush 6 contacts the electric field curtain generating member 8, a portion 0.5 mm from the tip of the brush 6 is set to contact the electric field curtain generating member 8. When the tips of the brushes 6 are brought into contact with each other, the amount of contact is preferably set in the range of 0 mm to 3 mm due to the stress on the cleaning brush 6, and the cleaning brush 6 and the electric field curtain generating member 8
It is also possible to set not to contact.

As the electric field curtain generating member 8, the electrode 8b is used.
Has a thickness (size in the Z-axis direction) of 18 μm, a width of electrode 8b (size in the X-axis direction) is 500 μm, and an electrode interval (electrode 8).
b distance between each other) 100 μm, thickness of coating layer 8c 2
The one having a thickness of 5 μm was used. Also, the voltage supplied from the electric field curtain generating power source PU has a frequency of 30 Hz and Vpp.
A pulsed voltage having a (difference between the maximum value and the minimum value of the voltage) of 1.6 kV and an offset (a voltage serving as a reference of the deviation between the maximum voltage and the minimum voltage) of 0 V was used. The tip of the cleaning blade 7 is brought into contact with the image carrier PR by 1.1 mm, the linear pressure is 3.5 gf / cm, and the BSA (blade setting angle, the angle the blade makes with the tangential direction of the image carrier) is 25 °. Set to. Further, as the toner, a spherical toner having a diameter of 5.5 μm obtained by an emulsion polymerization method, which is difficult to clean, was used. Then, the test was conducted in an environmental laboratory where the temperature was 10 ° C and the humidity was 15%.
The printing was performed by printing a predetermined full color pattern on paper.

Under the above conditions, the following two tests were conducted. A cleaning device including a cleaning blade 7, a cleaning brush 6, a flicker bar, and a transport auger (prior art, see FIG. 11). A cleaning device including a cleaning blade 7, a cleaning brush 6, and an electric field curtain generating member 8 (see Embodiment 1 and FIG. 2). In the test, the flicker bar is set so as to bite into the cleaning brush by 1 mm. Although a printing test was performed on 50,000 sheets, no inconvenience occurred on the image with either of the cleaning devices, but when the brush after the test was observed with a microscope, the tip of the brush was cut or broken. Mostly seen in cleaning equipment.

As a result of this test, the ability of the cleaning device having the electric field curtain generating member 8 to clean the cleaning brush is equivalent to that of the cleaning device having the flicker bar, and the stress (load) on the cleaning brush 6 is small. It was confirmed that space saving is possible because no auger for transportation is required.

(Embodiment 2) FIG. 7 is a sectional view of an image bearing member cleaner according to Embodiment 1 of the present invention and corresponds to FIG. 2 of Embodiment 1. FIG. 8 is an explanatory diagram showing an array of electrodes of the electric field curtain generating member of Example 2 of the present invention and a direction in which toner is conveyed by the electric field curtain of this electrode array, and corresponds to FIG. 6 of Example 1. It is a figure. In the description of the second embodiment, constituent elements corresponding to those of the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. The second embodiment is the same as the first embodiment in the following points.
However, in other respects, the configuration is similar to that of the first embodiment.

In FIG. 7, the image carrier cleaner CL1 '
(The same applies to the belt cleaner CL2 'and the 2 o'clock transfer roll cleaner CL3') is a semi-cylindrical electric field curtain generating member instead of the electric field curtain generating member 8 and the curtain supporting member 9 of the image carrier cleaner CL1 of the first embodiment. 8'and a semi-cylindrical support cylinder 9 '. In FIG. 8, the plurality of electrodes 8b 'of the semi-cylindrical electric field curtain generating member 8'of the second embodiment are arranged to be inclined with respect to the front-back direction (X-axis direction) and parallel to each other. By this arrangement of the electrode 8b ', the toner is moved from the lower side (-Z direction) to the upper side (+ Z direction) while the toner discharge path 4 is being moved.
As a result, the toner is conveyed in the direction from the lower front side (the -Z axis side on the + X axis side) to the upper rear side (the + Z axis side on the -X axis side) as indicated by arrow 15 '. Example 2
In the semi-cylindrical electric field curtain generating member 8 ', since the toner is conveyed from the lower side to the upper side by the arrangement of the electrodes 8b', the opened both ends are imaged like the electric field curtain generating member 8 of the first embodiment. It is not necessary to configure the cleaning brush 6 close to the carrier PR, and the cleaning brush 6 has a semi-cylindrical shape that contacts the outer periphery from the lower end to the upper end. In addition, in order to increase the contact area between the cleaning brush 6 and the electric field curtain generating member 8 ', the same shape as that of the first embodiment can be used.

(Operation of the Second Embodiment) The cleaning devices CL1 ', CL2', CL3 'of the second embodiment having the above-mentioned structure.
The cleaning brush 6 removes the residual toner adhering to the surface of the toner adhering rotary member (the image carrier PR, the intermediate transfer belt B and the secondary transfer roll T2b), and the toner is conveyed by the electric field curtain generating member 8 to be discharged to the toner discharge path. 4 can be transported. That is, a member for removing toner from the cleaning brush 6 and a conveying device such as an auger are not required, and a cleaning device having a very simple structure and low cost can be provided. Further, since a member such as a flicker bar that strongly comes into contact with the brush is not provided, damage to the brush 6 due to breakage of the brush or habit of the brush can be reduced, the toner recovery efficiency of the brush 6 can be maintained, and cleaning failure can be prevented. Can be prevented. Furthermore, since a space for installing the transfer device is not required, it is possible to provide a cleaning device that is much more compact and space-saving than the conventional one.

(Embodiment 3) FIG. 9 is an enlarged explanatory view of a main part of a cleaning blade of an intermediate transfer belt cleaner according to Embodiment 3 of the present invention. In the description of the third embodiment, constituent elements corresponding to those of the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. The third embodiment differs from the first embodiment in the following points, but is configured similarly to the first embodiment in other points.

In FIG. 9, a cylindrical electric field curtain generating member 20 is fixed to the outer peripheral surface of the belt driving roll Rd, and the belt driving roll Rd and the arrow AL (see FIG. 9).
Is rotating in the direction of. Cylindrical electric field curtain generating member 2
0 is composed of an electrode supporting member 20a, a plurality of electrodes 20b, and a coating layer 20c. An electric field curtain generating voltage is supplied to the cylindrical electric field curtain generating member 20 by a lead wire (not shown). The electric field curtain generation voltage generates an electric field curtain that moves the toner and the like on the intermediate transfer belt toward the upstream side (the direction of arrow 21 in FIG. 9) in the moving direction of the intermediate transfer belt B. The position (blade contact position) where the cleaning blade 7 and the intermediate transfer belt B contact each other is set within the range where the intermediate transfer belt B and the electric field curtain generating member 20 contact each other. It is set so that the force of the electric field curtain acts on the upstream side.

(Operation of Third Embodiment) In the cleaning device of the third embodiment having the above configuration, the residual toner is conveyed to the area where the cleaning blade 7 and the intermediate transfer belt B come into contact with each other (the blade contact area). In addition, the electric field curtain generated by the cylindrical electric field curtain 20 causes an arrow 21
(See FIG. 9). That is, since the residual toner receives a force in the direction of the arrow 21 which is opposite to the rotation direction Yb of the intermediate transfer belt, the accumulated toner itself vibrates or the toner collides with each other. In this way, the disturbed toner is separated from the intermediate transfer belt B by its own weight and floats in the form of a cloud in the air. The cloud-shaped toner falls due to the action of gravity, is adsorbed by the cleaning brush 6 installed below (-Z axis direction), and is collected. Further, the amount of the toner that has not entered the cloud shape and has entered the blade contact area is significantly reduced, and further, the toner is disturbed by the electric field curtain and the attraction force between the toner and the intermediate transfer belt B is reduced. It can be easily scraped off by the cleaning blade 7.

Since the electric field curtain can cloud not only toner but also foreign matters such as carriers, foreign matters such as carriers enter the blade contact area,
Cleaning failure due to storage can be prevented.

On the other hand, even if a spherical toner which is hard to be scraped off by the cleaning blade 7 is used while having a high transfer rate, the amount of the spherical toner entering the contact area is greatly reduced by the above-mentioned action. Thus, it is possible to prevent the toner from rolling and scraping to the downstream side of the contact area. Therefore, the spherical toner can be collected without mixing a plurality of toners or increasing the linear pressure between the cleaning blade 7 and the intermediate transfer belt B. Therefore, since it is not necessary to increase the linear pressure, it is possible to reduce wear and deterioration of the intermediate transfer belt B due to the contact of the cleaning blade 7, and it is possible to prevent cleaning failure. Also, by using spherical toner having a high transfer rate, the amount of toner to be discarded can be reduced.

Therefore, it is possible to prevent the cleaning failure even when the spherical toner which is difficult to clean is used, and it is possible to provide the cleaning device which has the same structure as that of the first and second embodiments and which is low in cost and space-saving.
Although the cylindrical electric field curtain generating member 20 is provided on the outer periphery of the belt driving roll Rd in the third embodiment, the electric field curtain generating member independent of the belt driving roll is brought into contact with the inside of the intermediate transfer belt B. It is also possible to provide. Further, if the electric field curtain can be generated on the toner image carrying surface of the intermediate transfer belt B, the electric field curtain generating member does not need to have a cylindrical shape, but can have, for example, a belt shape or a sheet shape. Furthermore, in the cleaning device of the third embodiment, the cleaning brush 6 or the cylindrical electric field curtain generating member may be replaced with a conventional toner transferring auger.

A test was conducted to confirm the effect of the third embodiment. As the cylindrical electric field curtain generating member 20, the thickness of the electrode 20b (size in the Z-axis direction) is 18 μm, the width of the electrode 2b (size in the X-axis direction) is 500 μm, and the electrode interval (distance between the electrodes 20b). ) 100 μm, coating layer 2
0c having a thickness of 25 μm was used. In addition, the voltage supplied from the power source PU for generating the electric field curtain has a frequency of 30
Hz, Vpp (difference between maximum value and minimum value of voltage) is 1.6k
A pulsed voltage with V and an offset of 0V was used. The intermediate transfer belt B has a volume resistance of 10 ⁶ logΩ · cm,
A surface resistance of 10 ⁶ logΩ / □ and a thickness of 1 mm was used.

The tip of the cleaning blade 7 is brought into contact with the intermediate transfer belt B by 1.1 mm, and the linear pressure is 2.35 gf /
In cm, the BSA (blade set angle) was set to 17 °. Further, as the toner, a spherical toner having a diameter of 5.5 μm obtained by an emulsion polymerization method, which is difficult to clean, was used. Then, the test was carried out by printing a predetermined full color pattern on P paper in an environmental laboratory where the temperature was 10 ° C. and the humidity was 15%.

Under each of the above settings and conditions, the following two tests were conducted. A cleaning device including only the cleaning blade 7. A cleaning device including a cleaning blade 7 and a cylindrical electric field curtain generating member 20. As a result of the above-mentioned two tests, the cleaning device having the above-mentioned configuration caused a cleaning failure at the time of printing about 100,000 sheets, while the cleaning device having the above-mentioned configuration produced 500,000 printed sheets. At that time, no cleaning failure occurred. As a result, it was confirmed that the cleaning device including the electric field curtain generating member 20 reduces defective cleaning.

(Fourth Embodiment) FIG. 10 shows a fourth embodiment of the present invention.
FIG. 7 is an enlarged explanatory view of a main part of a cleaning blade of the intermediate transfer belt cleaner of FIG. In the description of the fourth embodiment, constituent elements corresponding to those of the third embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. The fourth embodiment differs from the third embodiment in the following points, but is configured similarly to the third embodiment in other points.

In FIG. 10, in the belt cleaner of the fourth embodiment, the sheet-shaped electric field curtain generating member 25 is fixed to the front end surface of the cleaning blade 7. Like the electric field curtain generating member 8, the sheet-shaped electric field curtain generating member 25 includes an electrode supporting member 25a, a plurality of electrodes 25b, and a coating layer 25c. The electrodes 25b of the sheet-shaped electric field curtain generating member 25 extend in the front-rear direction (X-axis direction) and are arranged in parallel with each other. The sheet-like electric field curtain generating member 25 is supplied with an electric field curtain generating voltage for generating an electric field curtain for moving the toner in the direction of arrow 26 by a lead wire (not shown).

(Operation of Fourth Embodiment) In the cleaning device of the fourth embodiment having the above configuration, the cleaning blade 7
The toner scraped off by the electric field curtain generated by the sheet-shaped electric field curtain generating member 25 is moved along the front end surface of the cleaning blade 7 by the intermediate transfer belt B.
It is conveyed in a direction away from the surface (direction of arrow 26).
Although the toner conveyed to the lower end portion (−Z end portion) of the sheet-like electric field curtain generating member 25 is not further conveyed,
The toner is pushed out by the toner conveyed later, falls from the end portion by the action of gravity, and is adsorbed by the cleaning brush 6 and discharged. Therefore, the toner in the contact area between the cleaning blade 7 and the intermediate transfer belt B is
Since it is transported by the electric field curtain, it does not accumulate in the contact area. At the same time, foreign matter such as carriers entering the contact area is also conveyed from the contact area,
Cleaning failure can be prevented.

Even when a spherical toner that is difficult to clean is used, the spherical toner is conveyed by the electric field curtain, so that the spherical toner does not accumulate in the contact area and it is possible to prevent defective cleaning due to slipping through the contact area. it can. Therefore, it is possible to prevent defective cleaning even when spherical toner that is difficult to clean is used, and it is possible to provide a low-cost and space-saving cleaning device with a simple configuration as in the first and second embodiments.
In place of the cleaning blade 7 of the third embodiment,
By using the sheet-shaped electric field curtain generating member 25 of Example 4, it is possible to more efficiently convey the toner in the contact area and prevent cleaning failure. Further, the cleaning device provided with the sheet-shaped electric field curtain generating member 25 on the cleaning blade of the fourth embodiment is the same as the third embodiment.
Since it is not necessary to provide the electric field curtain generating member inside the belt as described above, the present invention can be applied to the image carrier cleaner CL1 and the secondary transfer belt cleaner CL3. Further, the cleaning blade 7 and the electric field curtain generating member 25 of the fourth embodiment can be applied to the cleaning blade portion of the conventional cleaning device.

(Modifications) The embodiments of the present invention have been described in detail above, but the present invention is not limited to the above-mentioned embodiments, and is within the scope of the gist of the present invention described in the claims. Thus, various changes can be made. A modified embodiment of the present invention is illustrated below. (H01) In each of the embodiments described above, the rotary developing device is used as the developing device, but other developing devices such as a tandem developing device can also be used. (H02) In each of the above-described embodiments, the voltage supplied to each electric field curtain generating member is a three-phase voltage, but a voltage other than the three-phase voltage set so that the toner can be efficiently transported, such as a four-phase voltage, Six-phase voltages can also be used. (H03) In each of the above-described embodiments, the voltage supplied to the electric field curtain generating member is a pulse voltage, but a voltage other than a pulse voltage that is set so that a sufficient carrying force is obtained, for example, a sine wave voltage. Voltage can also be used. (H04) In each of the above-described embodiments, the member (supporting cylinder 3 or the like) that supports the electric field curtain generating member is provided, but the structure of the electric field curtain generating member is changed (for example, the electrode supporting member 2a is configured to be thick, It is also possible to omit the supporting member by using a material having high rigidity. (H05) In each of the above-described embodiments, the cleaning brush 1 and the electric field curtain generating member 2 are brought into contact with each other. However, a gap is provided between the cleaning brush 1 and the electric field curtain generating member 2 as long as the toner can be conveyed by the electric field curtain. Can be provided. (H06) In each of the above-described embodiments, the cleaning brush 1 is made of an insulating brush. However, when the cleaning brush 1 is made of a conductive brush, a bias having a polarity opposite to that of the toner is applied to the brush shaft 1a, and the cleaning brush 1 It is also possible to charge the toner with a polarity opposite to that of the toner, and electrostatically adsorb the toner on the surface of the image carrier PR for cleaning.

[0067]

The above-described cleaning device of the present invention has the following effects (E01) to (E04). (E01) It is possible to provide a small-sized and simple cleaning device that can always hold a cleaning brush to which collected toner adheres in a state where the amount of adhered toner is small. (E02) The toner attached to the cleaning brush can be conveyed to a predetermined place by a small and simple toner conveying mechanism. (E03) By providing a simple and space-saving cleaning device that does not require a flicker bar or an auger, it is possible to obtain a high-quality image without image defects for a long period of time. (E04) It is possible to provide a cleaning device capable of preventing defective cleaning even when spherical toner is used.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an image forming apparatus including a cleaning device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of an image carrier cleaner (cleaning device for a toner adhering rotating member) according to the first embodiment of the present invention.

3A and 3B are explanatory views of an image carrier cleaner and a toner conveyance path, FIG. 3A is a perspective view, and FIG. 3B is II of FIG. 3A.
It is a IB-IIIB sectional view taken on the line.

FIG. 4 is an explanatory diagram of an electric field curtain generating member and a member that supports the electric field curtain generating member.
Is a perspective view, FIG. 4B is a development view of the electric field curtain generating member when viewed from the IVB direction of FIG. 4A, and FIG. 4C is an IVC of FIG. 4B.
-IVC line sectional drawing.

5A and 5B are explanatory views for explaining a state where toner is conveyed by an electric field curtain, FIG. 5A is an operation explanatory view, and FIG. 5B is a view showing a supply voltage supplied to an electric field curtain generation member. .

FIG. 6 is an explanatory diagram showing an array of electrodes of the electric field curtain generating member according to the first embodiment and a direction in which toner is conveyed by the electric field curtain of the electrode array.

FIG. 7 is a cross-sectional view of the image carrier cleaner according to the first embodiment of the present invention, and is a view corresponding to FIG. 2 of the first embodiment.

FIG. 8 is an explanatory diagram showing an array of electrodes of an electric field curtain generating member according to a second embodiment of the present invention and a direction in which toner is conveyed by the electric field curtain of the electrode array. It is a figure corresponding to FIG.

FIG. 9 is an enlarged explanatory view of a main part of the cleaning blade of the intermediate transfer belt cleaner according to the third embodiment of the present invention.

FIG. 10 is an enlarged explanatory view of a main part of the cleaning blade of the intermediate transfer belt cleaner according to the fourth embodiment of the present invention.

FIG. 11 is an explanatory diagram of a conventional toner-adhering rotating member cleaning device.

[Explanation of symbols]

PR, B, T2b ... Toner adhering rotary member, 6 ... Cleaning brush, 7 ... Cleaning blade, 8, 8 ', 2
0,25 ... Electric field curtain generating member, 8a, 20a, 25
a ... Electrode supporting member, 8b, 8b ', 20b, 25b ... Electric field curtain generating electrode, 8c, 20c, 25c ... Coating layer.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2H134 GA01 GA05 GA06 GB02 HB01                       HB08 HB09 HB11 HD07 HD11                       HD16 JA01 KF02 KJ02                 2H200 GA23 GA34 GA44 GA47 GB22                       GB25 HA02 HA28 HB12 HB22                       JA02 JC03 JC07 JC12 LB02                       LB03 LB08 LB09 LB12 LB13                       LB17 LB38 NA03

Claims (3)

[Claims] 1. A cleaning device having the following constituent features (A01) to (A04), (A01) a toner adhering rotary member having a surface to which toner adheres, and (A0)
2) A cleaning brush for cleaning the residual toner adhering to the surface of the toner adhering rotary member by contacting the surface of the toner adhering rotary member, and (A03) cleaning the toner adhering to the cleaning brush along the outer peripheral portion of the cleaning brush. An electric field curtain generating member disposed on the outer peripheral portion of the cleaning brush for transporting, (A04) supported by an electrode supporting member disposed along the toner transporting direction, and spaced apart in the toner transporting direction. A plurality of electric field curtain generating electrodes, and a coating layer that covers the surface of the plurality of electric field curtain generating electrodes, by an electric field curtain generated when an electric field curtain generating voltage is applied to each of the plurality of electric field curtain generating electrodes. The electric field curtain generating member that conveys toner near the surface of the coating layer in the toner conveying direction. 2. A cleaning device having the following constituent features (B01) to (B04), (B01) a toner adhering rotary member having a surface to which toner adheres, and (B0)
2) A cleaning blade having a blade tip portion that abuts on the surface of the toner adhering rotary member to scrape off the residual toner adhering to the surface of the toner adhering rotary member, and (B03) the toner adhering rotation scraped off by the blade tip portion. An electric field curtain generating member disposed on the back side of the toner adhering rotary member to convey the toner accumulated on the surface of the member to the upstream side in the rotation direction of the surface of the toner adhering rotary member rather than the tip of the blade, (B04) toner conveying A plurality of electric field curtain generating electrodes supported by electrode supporting members arranged along the direction and arranged at intervals in the toner transport direction, and a coating layer that covers the surface of the plurality of electric field curtain generating electrodes. And having an electric field curtain generated when an electric field curtain generating voltage is applied to each of the plurality of electric field curtain generating electrodes. The electric field curtain generating member for conveying the toner in the covering layer near the surface of the toner conveying direction. 3. A cleaning device comprising the following constituents (C01) to (C04), (C01) a toner adhering rotary member having a surface on which toner adheres, and (C0)
2) A cleaning blade having a blade tip portion that abuts on the surface of the toner adhering rotary member and scrapes off the residual toner adhering to the surface of the toner adhering rotary member, (C03) is disposed on the tip surface of the cleaning blade, and the blade is An electric field curtain generating member that conveys the toner scraped off by the tip portion in a direction away from the surface of the toner image carrier along the tip surface of the cleaning blade, (C
04) A plurality of electric field curtain generating electrodes supported by electrode supporting members arranged along the toner conveying direction and arranged at intervals in the toner conveying direction, and covering the surfaces of the plurality of electric field curtain generating electrodes. A coating layer, and the electric field curtain generating member that conveys toner near the surface of the coating layer in the toner conveying direction by an electric field curtain generated when an electric field curtain generating voltage is applied to each of the plurality of electric field curtain generating electrodes. .