JPH0863071A - Image forming device - Google Patents

Abstract

PURPOSE: To improve image quality through the use of spherical toner and to excellently remove toner remaining on a toner image carrier by separating a cleaning blade from the toner image carrier at the timing of the completion of cleaning in a prescribed region on a first toner image carrier. CONSTITUTION: The toner T flocculated in the edge part of a rubber blade is removed therefrom in such a manner that the rubber blade 22a is released between images and the impact of the release of the blade is imparted, during a monochrome copying mode. For instance, the abutted state of the rubber blade 22a and an entrance seal on the intermediate transfer belt 19 is continued until a transfer to a paper sheet is completed and the cleaning of the next image forming region on the intermediate transfer belt 19 is completed. After that, the supply of a current to each solenoid is controlled to switch the rubber blade 22a and the entrance sealing member 22b to a separation state from the intermediate transfer belt 19 from the abutted state and then, to the abutted state before the transfer remaining toner region of the next image reaches the blade edge part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a facsimile and a printer, and more particularly to improving the cleaning property of a toner image carrier in an image forming apparatus using spherical toner. .

[0002]

2. Description of the Related Art Conventionally, for example, in an electrophotographic image forming apparatus, a toner image formed on a photoconductor as a latent image carrier is directly or indirectly passed through an intermediate transfer member such as an intermediate transfer belt. Then, an image is formed by transferring it onto a final toner image carrier such as transfer paper. The transfer residual toner remains on the surface of the photoconductor after the toner image is transferred onto the transfer paper or the intermediate transfer body, or on the surface of the intermediate transfer body after the toner image is transferred onto the transfer paper. Therefore, a cleaning device for removing the residual toner from the photoconductor and the intermediate transfer member is provided for repeated use. Various types of cleaning devices are known.

For example, in Japanese Patent Laid-Open No. 55-35345, there is an elastic cleaning blade which comes into contact with the surface of the image bearing member, and the suction opening end is close to the surface of the image bearing member so that the vicinity of the elastic cleaning blade contact portion is close. It has been disclosed that a suction means for forming a suction mechanism is provided in the above to enable highly efficient cleaning. Further, in Japanese Patent Laid-Open No. 2-95365, a cleaning blade is provided on the downstream side of the cleaning blade.
By making the tip of a seal member provided integrally with the photosensitive drum contact the photosensitive drum at all times, the area including the toner screw is made a sealed area, and the cleaning blade is separated from the photosensitive drum. What prevents the toner from scattering at that time is disclosed. In addition, JP-A-3-23483
In the publication, a brush roller slidably contacting the photosensitive member and the edge surface of the cleaning blade is rotatably provided, so that the toner blocked by the cleaning blade is less likely to accumulate on the edge surface. However, it is disclosed that the blocked toner is prevented from spilling out of the waste toner casing.

On the other hand, in order to improve the image quality, it has been proposed to use a spherical toner having a small particle size in an image forming apparatus.

[0005]

However, when such a spherical toner is used, in a cleaning device utilizing a cleaning blade, the contact portion between the cleaning blade and the photoconductor (hereinafter referred to as the blade). Toner accumulates on the edge, and the aggregated toner causes cleaning failure. It is considered that such defective cleaning with the spherical toner occurs due to the following reasons. That is, when the conventional amorphous toner is used, the toner shape is distorted and the particle size distribution is wide, so that the fluidity of the toner aggregate is relatively poor. Therefore, for example, as schematically shown in FIG. 6A, the aggregation degree of the toner blocked by the cleaning blade and accumulated at the blade edge portion is relatively small. Therefore, the agglomerated toner on the blade edge portion easily collapses, and the toner particles on the blade edge portion move / swap while collapsing appropriately during cleaning, and the toner blocked by the cleaning blade is appropriately collected from the edge portion into the cleaning device casing. Has been made. However, when the spherical toner is used, the toner shape is uniformly spherical and the particle size distribution is narrow. Therefore, for example, as shown schematically in FIG. Is closely packed. Further, since it is uniformly spherical, the curvature at the contact point between the toners in the toner aggregate is large and the adhesive force such as Van der Waals force or liquid bridging force is large as compared with the irregular toner. For this reason, the degree of aggregation of the toner accumulated at the blade edge portion is significantly larger than that of the irregular toner, and the toner easily accumulates at the blade edge portion. As a result, when a large amount of residual toner is present, it is considered that the aggregated toner accumulated here pushes up the cleaning blade and passes between the photoconductor and the cleaning blade.

In order to solve the above problems, a cleaning method using a brush or a blade edge cleaning device using suction, and a mylar used as a mechanism for removing toner adhering to the tip of a conventional cleaning blade. Although it is possible to use a cleaning member such as −, the cleaning method using a brush and the blade edge cleaning device using suction increase the cost. In addition, a blade edge cleaning device using a cleaning member such as mylar is a counter
In the case of the method, instead of scratching the blade edge,
There is a risk of causing defective turning.

The present invention has been made in view of the above problems. A spherical toner is used as a toner to improve the image quality, and the toner remains on a toner image carrier such as a latent image carrier or an intermediate transfer member. An object of the present invention is to provide an image forming apparatus that can clean toner well.

[0008]

In order to achieve the above object, an image forming apparatus according to a first aspect of the present invention is configured such that a toner image is formed on a first toner image carrier and then the toner image is formed on the second toner image carrier. In the image forming apparatus, the toner image is transferred onto the second toner image carrier to form a toner image on the second toner image carrier, and the residual toner is removed from the first toner image carrier after the transfer using a cleaning blade. The cleaning blade moves to the contact / separation drive unit that is formed of toner and that causes the cleaning blade to contact and separate from the first toner image carrier, and the cleaning blade moves to the first position at the timing when cleaning of a predetermined area on the first toner image carrier is completed. One control means for controlling the contact / separation drive means is provided so as to be separated from one toner image carrier.

Further, in the image forming apparatus of the second aspect, after the toner image is formed on the first toner image carrier, the toner image is transferred to the second toner image carrier and is then transferred on the second toner image carrier. In an image forming apparatus for forming a toner image and removing residual toner from the first toner image carrier after the transfer using a cleaning blade, the toner image is formed by spherical toner, and the first toner image carrier is A drive device that drives the moving direction to be switchable, a toner image transfer from the first toner image carrier to the second toner image carrier is not performed, and
And a control means for controlling the driving device so that the first toner image carrier moves in a direction opposite to that during the transfer when the cleaning of the predetermined area on the toner image carrier is completed. It is a feature.

Further, the image forming apparatus of claim 3 is the image forming apparatus of claim 2, wherein the first toner image carrier moves during the transfer of the toner image from the first toner image carrier to the second toner image carrier. A contact member that is counter-contacted to the surface of the first toner image carrier in the direction of movement of the first toner image carrier, which is opposite to the direction of transfer, is provided on the upstream side of the cleaning blade contact portion. , The reverse movement is performed until the surface portion of the first toner image carrier located at the cleaning blade contact portion at the time of starting the movement in the reverse direction passes through the contact portion of the contact member. It is characterized in that the above-mentioned control means is configured so as to allow the above.

[0011]

In the image forming apparatus according to the present invention, the contact / separation drive means is arranged so that the cleaning blade is separated from the first toner image carrier at the timing when the cleaning of the predetermined area on the first toner image carrier is completed. To control. Due to the impact of the cleaning blade when it is separated from the first toner image carrier, the agglomerated toner at the blade edge is destroyed and the toner is removed from the edge. The cleaning blade separated here is brought into contact with the surface of the first toner image carrier again until the area on the first toner image carrier on which the toner image for transfer is formed is opposed.

According to another aspect of the image forming apparatus of the present invention, the toner image is not transferred from the first toner image carrier to the second toner image carrier, and the predetermined toner image on the first toner image carrier is not transferred. When you finish cleaning the area,
The drive device is controlled so that the first toner image carrier moves in the direction opposite to that during the transfer. Aggregated toner is removed from the blade edge portion by the surface of the first toner image carrier moving in the opposite direction. The toner removed from the edge portion and adhering to the surface of the first toner image carrier is removed from the surface of the first toner image carrier by an appropriate toner removing unit.

Particularly, in the image forming apparatus of claim 3,
As the toner removing means, the first toner is provided upstream of the cleaning blade contact portion in the moving direction of the first toner image carrier during the transfer of the toner image from the first toner image carrier to the second toner image carrier. An abutting member is used which comes into counter-contact with the surface of the image carrier in the moving direction of the first toner image carrier in the direction opposite to that during the transfer. That is, when the movement of the opposite direction is started, the surface portion of the first toner image carrier located at the cleaning blade contact portion is moved in the opposite direction until it passes the contact portion of the corresponding contact member. Then, the agglomerated toner adhering to this portion is scraped off from the surface of the first toner image carrier by the contact member.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to an electrophotographic color copying machine which is an image forming apparatus will be described below. FIG. 1 is a schematic configuration diagram of a color copying machine according to this embodiment. This color copying apparatus includes a color image reading apparatus (hereinafter referred to as a color scanner) 1 that reads a color image of an original document and a color image recording apparatus (hereinafter referred to as a color printer) 2 that records the read color image on a transfer paper. I have it.

The color scanner 1 includes a document table 3
The image of the original document is imaged on the color sensor 7 through the illumination lamp 4, the mirror group 5 and the lens 6, and the color image information of the original document 3 is displayed, for example, in blue (Blu, hereinafter B) and green (Green, Green, Hereinafter referred to as G), red (R
ed, hereinafter referred to as R) is read for each color-separated light and converted into an electrical image signal. And this color scanner 1
On the basis of the B, G, and R color-separated image signal intensity levels obtained in step 1, color conversion processing is performed by an image processing unit (not shown),
Color image data of black (hereinafter, referred to as Bk), cyan (Cyan, hereinafter referred to as C), magenta (Magenta, hereinafter referred to as M), and yellow (Yellow, hereinafter referred to as Y) are obtained.

The color printer 2 forms a four-color image on transfer paper based on the color image data. Therefore, the photosensitive member 9 as a latent image carrier is provided,
Around it, a writing optical unit 8 as a latent image forming unit, a photoconductor cleaning unit (including a pre-cleaning static eliminator) 10, a static eliminator 11, a charger 12, an electrometer 13 as a surface potential detecting unit, and a color developing device. Bk developing device 14, C developing device 15, M developing device 16, and Y
A developing device 17, an intermediate transfer belt 19 and the like are arranged. Further, a paper transfer unit 29 for transferring the toner image from the intermediate transfer belt 19 to the transfer paper as a final toner image carrier, and a fixing device 2 for fixing the toner image on the transfer paper.
Eight and so on.

The optical unit 8 comprises a laser and its light emission drive control section (not shown), a polygon mirror and its rotation motor, an f / θ lens, etc., and converts color image data from the color scanner 1 into an optical signal. After conversion, optical writing corresponding to the original image is performed, and an electrostatic latent image is formed on the photoconductor 9 that is uniformly charged by the charger 12 while being rotationally driven counterclockwise.

Hereinafter, an outline of the copying operation will be described by taking an example in which the operation order of latent image formation and development (color image formation order) is Bk, C, M, and Y (however, the image formation order is limited to this. Not a thing). When the copy operation is started,
The Bk image data starts to be read by the color scanner 1 at a predetermined timing, and latent image formation by optical writing with a laser beam starts based on the image data (hereinafter, an electrostatic latent image based on the Bk image data is referred to as a Bk latent image).
C, M, and Y are referred to as C latent image, M latent image, and Y latent image, respectively. This Bk latent image is developed with Bk toner of the Bk developing device 14.

The toner image formed on the photosensitive member 9 is transferred onto the surface of the intermediate transfer belt 19 which is driven at the same speed as the photosensitive member (hereinafter, the toner image transfer from the photosensitive member to the intermediate transfer belt is referred to as belt transfer). . The intermediate transfer belt 19 is stretched around a drive roller 21, a belt transfer bias roller 20, and a group of driven rollers, and is drive-controlled by a drive motor (not shown) as described later. Then, the belt transfer is performed by applying a predetermined bias voltage to the belt transfer bias roller 20 while the photoconductor 9 and the intermediate transfer belt 19 are in contact with each other.

On the side of the photoreceptor 9, the process B is followed by the process C. That is, C image data reading by the color scanner 1 is started at a predetermined timing, and C latent image formation is performed by laser light writing with the image data. The C developing device 15 develops the C latent image with C toner. In each of the steps M and Y, the operations of reading image data, forming a latent image, and developing are performed in the same manner as the steps Bk and C described above.

Then, on the intermediate transfer belt 19, the Bk, C, M, and Y toner images sequentially formed on the photoconductor 9 are sequentially aligned on the same surface to form a belt transfer image of four-color overlapping. To do. As a method of driving the intermediate transfer belt 19 for the four-color overlapping belt transfer on the intermediate transfer belt 19, there are a plurality of operation methods after the belt transfer of the Bk toner image of the first color is completed to the end. You can think of the street. In this example, the following quick return method is adopted. That is, in the quick return method, when the belt transfer of the Bk toner image is completed, the intermediate transfer belt 19 is separated from the surface of the photoconductor 9 and the forward movement is stopped, and at the same time, the high speed return is performed in the opposite direction. This high-speed return is stopped after the front end position of the Bk image on the surface of the intermediate transfer belt 19 passes through the belt transfer equivalent position in the opposite direction and further moves by a preset distance. This puts it in a standby state. Next, when the front end portion of the C toner image on the photoconductor 9 side reaches a predetermined position before the belt transfer position, the intermediate transfer belt 19 is restarted in the forward direction. Further, the intermediate transfer belt 19 is brought into contact with the surface of the photoconductor 9 again. Also in this case, the C image is transferred under the condition that it is accurately overlapped with the Bk image on the surface of the intermediate transfer belt 19. After that, the same operation is performed to proceed to the Y and M image process to obtain a belt transfer image of four colors. Subsequent to the belt transfer process for the Y toner image of the fourth color, the toner is moved forward at the same speed without returning, and the four-color superimposed toner image on the surface of the intermediate transfer belt 19 is collectively transferred onto the transfer paper.

The paper transfer unit 5 for bulk transfer from the intermediate transfer belt 19 to the transfer paper is composed of a paper transfer bias roller 23a, a roller cleaning blade 23b, and a contact / separation mechanism 23c from the belt. . The bias roller 23a is usually separated from the surface of the intermediate transfer belt 19 and comes in contact with and separated from the surface of the intermediate transfer belt 19 at a timing when the superimposed images of four colors are collectively transferred to the transfer paper. The intermediate transfer belt 19 is operated by the mechanism 23c.
Is pressed by. At the same time, a predetermined bias voltage is applied to the roller 23a to transfer it to the paper. The transfer paper is fed by the paper feed roller or the registration roller 29 at the timing when the front end of the four-color superimposed image on the intermediate transfer belt surface reaches the paper transfer position.

The transfer paper on which the four-color superposed toner images have been collectively transferred from the intermediate transfer belt surface is conveyed to the fixing device 9 by the paper conveying unit, and the toner images are formed on the fixing roller and the pressure roller which are controlled at a predetermined temperature. It is fused and fixed and carried out to a copy tray to obtain a full-color copy.

The surface of the photosensitive member 9 after the belt transfer is cleaned by the photosensitive member cleaning unit 10,
In addition, the static elimination lamp 11 uniformly eliminates static electricity.

The transfer residual toner on the intermediate transfer belt 19 after the toner image is transferred onto the transfer paper 24 is removed by the belt cleaning unit 22, and the surface of the intermediate transfer belt 19 is cleaned. The belt cleaning unit 22 in this embodiment includes an inlet seal 22b,
A rubber blade 22a and a belt contacting / separating mechanism which will be described later in detail, and the like, which is downstream of the facing portion of the paper transfer unit 29 in the forward direction of the intermediate transfer belt 19 and facing the photoconductor 9. It is arranged so as to face the surface of the intermediate transfer belt 19 at a more upstream position.

2 and 3 show an example of the contact / separation mechanism, and FIG. 2 (a) is an explanatory view showing a state in which the rubber blade 22 and the inlet seal member 22b are brought into contact with the intermediate transfer belt 19, FIG. 2B is an explanatory view showing a state in which the rubber blade 22 and the entrance seal member 22b are separated from the intermediate transfer belt 19, and FIG. 3 is a plan view of some components of the dynamic contact / separation mechanism. In this example, the rubber blade 22a is attached to the blade contacting / separating bracket 30 swingable around the bracket rotation fulcrum 30a so as to serve as a counter in the forward direction of the intermediate transfer belt 19. One end of the bracket is urged by a cleaning blade pressing spring 30b having one end locked to the structure of the belt cleaning unit 22 so that the tip of the rubber blade 22a abuts on the surface of the intermediate transfer belt 19. The cleaning blade pressing spring 30b
A cleaning blade latch solenoid 32 is provided to separate the rubber blade 22a from the intermediate transfer belt 19 against the pressing biasing force. As shown in the plan view of FIG. 3, the plunger 32a of the solenoid is connected by a connecting link 33 to a cleaning blade releasing link lever 34 which is swingable around a link lever rotation fulcrum 34a. A roller 35 is rotatably attached to one end of the cleaning blade release link lever 34. The roller 35 comes into contact with a part of the blade contacting / separating bracket 30 by swinging the cleaning blade release link lever 34 in the direction of arrow A in FIG. 3, and resists the pressing biasing force of the cleaning blade pressing spring 30b. The blade contacting / separating bracket 30 is swung to separate the rubber blade 22a from the intermediate transfer belt 19.
The cleaning blade latch solenoid 32 in the illustrated example is in a state in which the plunger 32a is pulled into the main body when current is not supplied, and the plunger 32a is released by flowing current (projected from the solenoid main body). State).

On the other hand, the entrance seal member 22b is attached to the entrance seal contact / separation bracket 31 which is swingable around the entrance seal member rotation fulcrum 31a so as to perform trading in the forward direction of the intermediate transfer belt 19.
The center of gravity of the bracket and the entrance seal 22b is set so that the swing position where the tip of the entrance seal member 22b contacts the surface of the intermediate transfer belt 19 is taken by its own weight. A biasing means may be used instead of or in addition to such a center of gravity setting. An entrance seal latch solenoid 36 is provided to separate the entrance seal member 22b from the intermediate transfer belt 19. The solenoid is swingable about a lever rotation fulcrum 37a, and is connected to one end of an inlet seal release lever 37 which is always biased counterclockwise by a lever release spring 38. The other end of the lever comes into contact with the pin 31b planted in the bracket 31 for bringing in and out the inlet seal by the swing of the lever by the latch solenoid 36 for the inlet seal, and swings the bracket to bring the inlet seal member 22b. Is separated from the intermediate transfer belt 19. The inlet seal latch solenoid 36 in the illustrated example is also in a state in which the plunger is pulled into the main body when current is not supplied, and the plunger is released by passing current (state protruding from the solenoid main body). I take the.

By the contacting / separating mechanism described above, the entrance seal 22b and the rubber blade 22a are provided with the intermediate transfer belt while the second color, the third color, and the fourth color are belt-transferred after the first color Bk image is belt-transferred. 19 is separated from the surface of the intermediate transfer belt so as not to disturb the toner image on 19 (current supply to the cleaning blade latch solenoid 32 and the entrance seal latch solenoid 36 is stopped), and the intermediate after the batch transfer to the transfer paper is performed. The transfer belt surface is pressed against the intermediate transfer belt 19 again at the cleaning timing (current is supplied to the cleaning blade latch solenoid 32 and the inlet seal latch solenoid 36). (Hereinafter, margin)

At the time of repeat copying, the operation of the color scanner and the image formation on the photosensitive member 9 are continued from the Y (fourth color) image process for the first sheet, and then Bk (first color) for the second sheet at a predetermined timing. Proceed to the imaging process. In the intermediate transfer belt 19, the second Bk toner image is formed in the area where the surface of the intermediate transfer belt 19 is cleaned by the rubber blade 22a after the batch transfer process of the first four-color superimposed image onto the transfer paper. To be transferred to the belt. After that, the same operation as the first sheet is performed.

The above is the description of the copy mode for obtaining four full colors, but in the case of the three-color copy mode and the two-color copy mode, the same operation as above is performed for the designated color and the number of times. .

In the case of the monochromatic copy mode, only the developing unit for the color is kept in the developing operation state until the predetermined number of sheets are finished, and the intermediate transfer belt 19 is kept in contact with the surface of the photosensitive member 9. Drive in the forward direction at a constant speed to perform the copy operation. During the copying operation in the single color copy mode, the surface of the intermediate transfer belt 19 after the toner image transferred on the belt is transferred onto the transfer paper passes through the belt cleaning unit 22. Therefore, from the viewpoint of not disturbing the toner image before transfer to the transfer, the rubber blade 22a and the entrance seal 22b of the belt cleaning unit 22.
Need not be separated from the intermediate transfer belt 19, and the copying operation can be performed while the surface of the intermediate transfer belt 19 is kept in contact.

However, each developing device 14, 15, 16, 1
7, especially continuous copying is often done in single color mode,
In the Bk developing device, spherical toner (for example, 5 to 7.5) is used.
When spherical toner with a diameter within the range of μm) is used,
As described with reference to FIG. 6B, the spherical toner aggregates on the rubber blade edge portion, and the cleaning performance is deteriorated. For example, if about 10 sheets of monochromatic copy are made with spherical toner, cleaning failure occurs.

Therefore, in the present embodiment, during the single-color copy mode, the toner T aggregated on the edge portion of the rubber blade as shown in FIG. 4 (a) is transferred to the rubber between the images as shown in FIG. 4 (b). The blade 22a is released to give an impact for releasing the blade to remove it from the rubber blade edge.
For example, the contact state of the rubber blade 22a and the entrance seal with respect to the intermediate transfer belt 19 is continued until the paper transfer is completed and the cleaning for the next image forming area on the intermediate transfer belt 19 is completed, and then, as shown in FIG. The control means controls the current supply to the solenoids 32 and 36 to switch the rubber blade 22a and the inlet seal member 22b from the contact state to the intermediate transfer belt 19 to the separated state. Then, the transfer residual toner area of the next image is switched to the contact state before reaching the blade edge portion.

Here, in the above embodiment, the rubber blade 2
Agglomerated toner was removed from the rubber blade edge portion by using the impact when releasing 2a from the intermediate transfer belt 19. Instead of this, the intermediate transfer belt 19 was removed as shown in FIGS. 5 (a) and 5 (b). It is also possible to remove the aggregated toner from the edge portion of the rubber blade by temporarily performing the reverse operation between the images. As shown in FIG. 5C, this reversal causes the toner removed from the edge of the rubber blade to reach the contact portion of the entrance seal member 22b, and is removed from the intermediate transfer belt 19 by the entrance seal member 22b. It is desirable to do up to. Instead of the removal by the entrance seal member 22b, any other belt cleaning member may be used. When the intermediate transfer belt 19 is rotated in the reverse direction, the intermediate transfer belt 19 and the paper transfer roller 23a are separated from each other. When the aggregated toner is removed from the intermediate transfer belt 19, the normal forward rotation operation is resumed, and the belt transfer of the next image is performed.

[0035]

According to the image forming apparatus of the first aspect, the first
When the cleaning of the predetermined area on the toner image carrier is completed, the cleaning blade is separated from the first toner image carrier, and the impact at the time of this separation destroys the aggregated toner at the edge of the blade to remove the toner from the edge. Since spherical toner is used as the toner, the image quality can be improved, and the toner remaining on the toner image carrier such as a latent image carrier or an intermediate transfer member can be cleaned well.

Further, according to the image forming apparatus of the second or third aspect, the toner image transfer from the first toner image carrier to the second toner image carrier is not performed, and the first toner image carrier is not transferred. When the cleaning of the predetermined area is completed, the first toner image carrier is moved in the opposite direction to that during the transfer, and the surface of the first toner image carrier moving in the opposite direction causes the blade edge portion to move. Since the aggregated toner is removed, the spherical toner can be used as the toner to improve the image quality, and the toner remaining on the toner image carrier such as the latent image carrier or the intermediate transfer member can be satisfactorily cleaned.

Particularly, according to the image forming apparatus of the third aspect, the surface portion of the first toner image carrier located at the cleaning blade contact portion at the time of starting the movement in the opposite direction,
The reverse movement is performed until the contact member passes through the contact portion, and the agglomerated toner adhering to this portion is scraped off from the surface of the first toner image carrier by the contact member. It is possible to prevent the once removed toner from aggregating again at the contact portion during the subsequent transfer.

[Brief description of drawings]

FIG. 1 is a front view showing a schematic configuration of a color copying machine according to an embodiment.

2A and 2B are explanatory views of the operation of a contact / separation mechanism in a belt cleaning unit of the color copying machine.

FIG. 3 is a plan view of some components of the contact / separation mechanism.

4A and 4B are explanatory views of the operation of the embodiment.

5A to 5C are explanatory views of the operation of another embodiment.

6A and 6B are explanatory views of the problems of the present invention.

[Explanation of symbols]

 9 photoconductor 19 intermediate transfer belt 22 belt cleaning unit 22a rubber blade 22b entrance seal member 30 blade contact / separation bracket 30a bracket rotation fulcrum 30b cleaning blade pressing spring 31 entrance seal contact / separation bracket 31a entrance seal member rotation fulcrum 31b pin 32 Latch solenoid for cleaning blade 32a Plunger 33 Connection link 34 Cleaning blade release link lever 34a Link lever rotation fulcrum 35 Roller 36 Entrance seal latch solenoid 37a Lever rotation fulcrum 37 Entrance seal release lever 38 Lever release spring

Claims (3)

[Claims] 1. A toner image is formed on a first toner image carrier and then the toner image is transferred to a second toner image carrier to form a second toner image carrier.
In an image forming apparatus for forming a toner image on a toner image carrier and removing residual toner from the first toner image carrier after the transfer using a cleaning blade, a toner image is formed by spherical toner, The cleaning blade moves from the first toner image carrier to the contact / separation drive unit that moves the cleaning blade toward and away from the first toner image carrier, and at the timing when the cleaning of a predetermined area on the first toner image carrier is completed. An image forming apparatus comprising: a control unit that controls the contact / separation drive unit so as to be separated from each other. 2. A toner image is formed on a first toner image carrier and then the toner image is transferred to a second toner image carrier to form a second toner image carrier.
In an image forming apparatus for forming a toner image on a toner image carrier and removing residual toner from the first toner image carrier after the transfer using a cleaning blade, a toner image is formed by spherical toner, A drive device for driving the first toner image carrier so that the moving direction can be switched, and a toner image transfer from the first toner image carrier to the second toner image carrier is not performed, and on the first toner image carrier. When the cleaning of the predetermined area of
An image forming apparatus comprising: a control unit that controls the driving device so that the toner image carrier moves in a direction opposite to that during the transfer. 3. An upstream side of the cleaning blade contact portion in the moving direction of the first toner image carrier during the transfer of the toner image from the first toner image carrier to the second toner image carrier,
An abutting member that counter-contacts the surface of the first toner image carrier in the moving direction of the first toner image carrier in the direction opposite to that during the transfer is provided, and the cleaning blade is used when starting the movement in the opposite direction. The control means is configured so that the surface portion of the first toner image carrier located at the contact portion moves in the opposite direction until it passes through the contact portion of the contact member. The image forming apparatus according to claim 2.