JP2003066734A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of preventing the deterioration of a picture by securing the cleaning property and discharge erase property of an intermediate transfer body through a long period while avoiding the complication of structure. SOLUTION: An intermediate transfer belt 11 and an electricity removing roller 21 are rotatable at a relative speed at a mutual contact part. When setting the surface hardness of the discharge erase roller 21 to be H1, the surface hardness of the intermediate transfer belt 11 to be H2, the 10-point average roughness in the JIS standard B601 on the surface of the discharge erase roller 21 to be R1, and the 10-point average roughness in the JIS standard B601 on the surface of the intermediate transfer belt 11 to be R2, the relations of H1>H2 and R1>R2 are satisfied.

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 or a printer which employs an electrophotographic system, an electrostatic recording system or the like.

[0002]

2. Description of the Related Art Conventionally, various image forming apparatuses have been developed. In image forming apparatuses such as copying machines and laser beam printers, a toner image as a developer image is formed on the surface of a photosensitive drum which is a latent image carrier. In the system in which the toner image is formed and transferred to a recording material such as paper, the residual toner remaining on the surface of the photosensitive drum after the toner image is transferred is removed by a cleaning device.

On the other hand, even in a color copying machine equipped with an intermediate transfer member to enhance the selectivity of the recording material, the untransferred toner remaining on the intermediate transfer member is removed by a cleaning device for the intermediate transfer member. There is.

As the cleaning device as described above,
For example, a cleaning blade having an elastic portion such as urethane rubber formed in a plate shape is provided, and the edge of the cleaning blade scrapes off the residual toner adhering to the surface of the photosensitive drum with a predetermined pressure.

A cleaning device using this cleaning blade has a relatively simple structure and a small size, and is advantageous in terms of cost, and also has the advantage of being excellent in toner removal performance, and thus is widely used in practice. ing.

Further, in a high-quality color image forming apparatus which requires particularly high-speed and high-quality images, in order to minimize damage to the transfer body, it is necessary to use a cleaning blade rather than a cleaning blade.
There are some models that have introduced simple and light pressure type brush cleaners and cleaningless type.

[0007]

However, in the above-mentioned image forming apparatus, since the cleaning blade is brought into contact with the surface of the photosensitive drum, residual toner is strongly adhered to the cleaning blade as the image forming apparatus is used for a long period of time. There is a case where the particles adhere to cause so-called filming and deteriorate the image quality thereafter.

Further, in a recent image forming apparatus, when a general fixing device having a structure in which a transfer material is passed through a nip portion of a pair of rollers is used for fixing a toner image, the toner is prevented from adhering to the roller. To prevent this, apply silicone oil to the roller surface. This silicon oil adheres to the transfer device when the toner image on the second surface is transferred, and adheres to the intermediate transfer body when the image for the next page is formed.

The silicon oil adhering to the surface of the intermediate transfer member is partially transferred to the photosensitive drum which is in contact with the intermediate transfer member and adheres to it, resulting in poor charging due to oil contamination of the intermediate transfer member and slipping through the edge of the cleaning blade. Therefore, there is a problem that cleaning failure may occur.

Further, in order to achieve high image quality by using the structure provided with the transfer member, the cleaning mechanism is set to the transfer member as much as possible by using a toner of low pressure, simplification and high transfer efficiency. On the premise of this, cleanerless technology is being put to practical use. In this case, it is unavoidable that the ability to remove the charged products remaining on the intermediate transfer member, the transfer oil, the paper dust, the dust, and the like is unavoidable.

Further, if the contact pressure of the member for cleaning the toner on the intermediate transfer member is forcibly increased, the damage to the intermediate transfer member becomes large, and defects in image formation such as defective conveyance of the intermediate transfer member become remarkable. I don't like it.

Further, the retention of the electric memory by charging becomes a factor that hinders image defects and long-term stabilization of image quality, and has a drawback that residual charged toner on the intermediate transfer member is difficult to clean.

Further, since the model using the intermediate transfer member has a problem that the image quality is deteriorated by performing the transfer twice, the latent image bearing is carried out in order to enhance the transferability of the toner to the intermediate transfer member as much as possible. In general, the body and the intermediate transfer body are in constant contact with each other.

For example, in order to remove the residual charges on the intermediate transfer member, the contact pressure of the contact members such as the charge removing member and the cleaning member for removing the residual toner is made as small as possible,
It is an essential issue not to give vibrations to the intermediate transfer body and the latent image carrier, and during image formation, the rotation speed of the charge eliminating member is made variable to increase the relative speed with the latent image carrier to increase the relative speed. Increasing the polishing property of the surface is considered to be a factor that hinders the formation of high-quality images, and it has become difficult to achieve both cleaning of the intermediate transfer member and high-quality image formation.

Therefore, in the conventional image forming apparatus,
At the same time, without complicating the structure, prevent filming due to long-term use and cleaning failure due to adhesion of silicone oil during fixing, and ensure cleaning performance and charge removal property of transfer medium at the same time with a simple intermediate transfer medium cleaning device. It was difficult to achieve and prevent the deterioration of image quality.

Further, in order to meet the recent demand for high durability and stability, the number of durable intermediate transfer members continues to increase, and the friction coefficient between the transfer member and the cleaning member increases with the progress of durability. In particular, many problems that are difficult to solve have come to be seen, such as waviness of the transfer belt system, color misregistration due to deformation, and machine down due to reverse rotation of the cleaning blade.

Therefore, the present invention provides an image forming apparatus capable of preventing the deterioration of the image quality while avoiding the complication of the structure and ensuring the cleaning property and the charge removing property of the intermediate transfer member for a long period of time. To aim.

[0018]

According to the present application, the above object is to provide a latent image bearing member carrying a latent image, and to apply the developer to the latent image bearing member to form the latent image with the developer image. And a transfer means for transferring the developer image on the latent image carrier to a recording material, and the transfer means receives the developer image from the latent image carrier and carries it. What is claimed is: 1. An image forming apparatus having a possible intermediate transfer member, wherein the developer image is transferred from the latent image carrier to a recording material through the intermediate transfer member, the intermediate transfer member being in contact with the intermediate transfer member. In an image forming apparatus provided with a rotatable static eliminator for static elimination, the intermediate transfer member and the static eliminator can rotate at a relative speed at their contact portions, and the surface hardness of the static eliminator is H1 and the surface hardness of the intermediate transfer member is H2, JIS standard B601 of the surface of the static eliminator
R10 is the average roughness of 10 points in J, and J of the surface of the intermediate transfer member.
This is achieved by the first invention in which the relationship of H1> H2 and R1> R2 is satisfied, where R2 is the 10-point average roughness in IS standard B601.

Further, according to the present invention, in the first aspect of the present invention, when at least one of the intermediate transfer body and the static eliminator rotates at a relative speed at the contact portion with each other, the intermediate transfer body and the static eliminator rotate. The present invention can also be achieved by the second invention in which the transfer means is set to have a higher peripheral speed than when the developer image is transferred from the intermediate transfer member to the recording material.

Further, according to the present application, in the first or second invention, the above-mentioned object is that the intermediate transfer member and the static eliminator rotate at a relative speed at their contact portions at a predetermined time interval. It is also achieved by the third invention that is.

Further, according to the present invention, in the above-mentioned object, in any one of the first to third inventions, the intermediate transfer member is such that the intermediate transfer member and the charge eliminator rotate at a relative speed at a contact portion with each other. This is also achieved by the fourth invention in which the rotation is stopped at the time.

Further, according to the present application, in the fourth aspect of the present invention, the static eliminator is configured so that when the intermediate transfer body and the static eliminator rotate at a relative speed at their contact portions, the transfer means performs the intermediate transfer. It is also achieved by the fifth invention in which the peripheral speed is set to be higher than when the developer image is transferred from the body to the recording material.

Further, according to the present invention, in the above-mentioned object, in any one of the first to third inventions, the static eliminator is such that the intermediate transfer member and the static eliminator rotate at a relative speed at a contact portion with each other. At this time, it is also achieved by the sixth invention in which the rotation is stopped.

Further, according to the present application, in the sixth aspect of the present invention, the intermediate transfer member is such that when the intermediate transfer member and the static eliminator rotate at a relative speed at their contact portions, the transfer means is an intermediate member. It is also achieved by the seventh invention in which the peripheral speed is set to be higher than when the developer image is transferred from the transfer body to the recording material.

Further, according to the present application, the above object is to provide a detection means for detecting at least one of temperature and humidity of the image forming apparatus main body in any one of the first to seventh inventions, It is also achieved by the eighth invention that the drive speed of at least one of the intermediate transfer member and the charge eliminator is changed based on the detection result of the detection means.

Further, according to the present application, the above object is based on the detection result of the detection means in the eighth invention.
The present invention can also be achieved by the ninth invention in which the drive start timing and drive end timing of at least one of the intermediate transfer member and the static eliminator are changed.

According to the present application, the above-mentioned object is provided with a detecting means for detecting at least one of the temperature and the humidity of the image forming apparatus main body in any one of the first to seventh inventions, The present invention can also be achieved by a tenth invention in which the drive start timing and drive end timing of at least one of the intermediate transfer member and the charge removing member is changed based on the detection result of the detection unit.

Further, according to the present application, the above-mentioned object is, in any one of the first to tenth inventions, when the latent image is formed on the latent image carrier and the transfer means is arranged on the intermediate transfer member. It is also achieved by the eleventh invention that the intermediate transfer member and the charge eliminating member are rotated at a relative speed at their contact portions except when the developer image is transferred onto the recording material.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be illustratively described in detail below with reference to the drawings. However,
The dimensions, materials, shapes, relative positions, and the like of the components described in this embodiment do not limit the scope of the present invention to them unless otherwise specified.

(First Embodiment) First, a first embodiment of an image forming apparatus according to the present invention will be described with reference to the drawings.

FIG. 1 is a partial configuration diagram of a first embodiment of an image forming apparatus according to the present invention.

The image forming apparatus shown in the figure is a four-color full-color copying machine, and a photosensitive drum 1 as a latent image carrier is provided inside an image forming apparatus main body (hereinafter referred to as an apparatus main body) 100.
The image forming units as the four developing units, that is, the first image forming unit 4 in order from the upstream side to the downstream side along the rotational transport direction A of
a, the second image forming unit 4b, the third image forming unit 4c, and the fourth image forming unit 4d.

As shown in FIG. 1, the first to fourth image forming portions 4a to 4d are provided with a photosensitive drum 1 which is a drum type electrophotographic photosensitive member as a latent image carrier. As the photosensitive drum 1, a photosensitive layer having a carrier generating layer (CGL) and a carrier transporting layer (CTL) is formed on a surface of a cylindrical aluminum substrate by a coating 1, a JIS surface roughness so that the CTL thickness is 40 μm. The average Rz (10-point average), which is (B601), was 2 μm or less in the initial state.

The photosensitive drum 1 is rotatably supported by the main body 100 of the apparatus, and a driving means (not shown).
Is driven to rotate in the direction of arrow A at a process speed of 120 mm / sec. The photosensitive drum 1 has an outer diameter of 80 m.
m was used.

A primary charger 2 is arranged in proximity to the photosensitive drum 1, and the surface of the photosensitive drum 1 is uniformly charged by the primary charger 2. The surface of the photosensitive drum 1 after being charged is exposed by an optical system (not shown) arranged above the image forming unit to form an electrostatic latent image, and then is exposed by the blank exposing unit 3.

Subsequently, the toner in the developer is attached to the electrostatic latent image by the first to fourth image forming portions 4a to 4d,
The electrostatic latent image is developed as a toner image. As the developer, a two-component developer mainly containing a silicon-based toner and a ferrite-based carrier was used.

This toner image is a photosensitive drum 1 and a linear pressure on the photosensitive drum 1 (one obtained by dividing the member pressure applied in the thrust direction by the length in the drum thrust direction).
When the photosensitive drum 1 and the intermediate transfer belt 11, which is an intermediate transfer member that rotates in the forward direction, are pressed at N / cm and come to a transfer portion where they come into contact and face each other, they are formed by the pre-charged intermediate transfer belt 11. The action of the electric field causes the transfer from the photosensitive drum 1 to the intermediate transfer belt 11 in the form of electrostatic attraction.

Here, the contact pressure of the charge eliminating roller 21 as the charge eliminating member against the intermediate transfer belt 11 during image formation is P1,
When the contact pressure is P2 during non-image formation, P1 = P2>
We are satisfied with 0. Further, the static elimination roller 21 is provided with a static elimination roller facing earth member 22 at a position facing the static elimination roller 21.

In the above-mentioned intermediate transfer belt 11, EPDM rubber, chloroprene rubber, epichlorohydrin rubber, silicone rubber, NBR rubber, or modified rubber thereof is used as a belt layer material.

As the material of the surface layer, a material containing a fluororesin (for example, from the viewpoint of high releasability and low coefficient of friction) (for example,
Materials containing PVDF, PTFE, tetrafluoroethylene, etc.) are used.

FIG. 2 shows a partially enlarged view of the intermediate transfer belt 11 shown in FIG.

In the present embodiment, as shown in FIG. 2, EP is added to the base layer 11a which constitutes the intermediate transfer belt 11.
Using DM rubber, the base layer 11a was coated with a coating in which PVDF resin was dispersed to form a surface layer 11b.

EPDM rubber is used for the base layer constituting the static elimination roller 21, and carbon is dispersed and internally added as a conductive filler to this belt layer to obtain an average surface roughness of hardness 40 degrees (Asker C load 4.9 N). A product having a thickness of 10 μm to 20 μm was used as a surface layer that abuts on the intermediate transfer belt 11.

The roller surface layer facing the intermediate transfer belt 11 was also made of the same material, and was a member for holding the charge due to the charge removal as the ground. Both rollers have an outer diameter of 16 m
m, the thrust length 306, the contact pressure of the charge eliminating member to the intermediate transfer belt 11 was 3.92 N, and the average surface roughness was 2 μm to 4 μm.

The intermediate transfer belt 11 has a primary transfer bias roller 8, a support roller 9 facing the photosensitive drum 1, a counter roller 10 facing the secondary transfer bias roller 12, and a counter roller 19 facing the cleaning blade 16 indicated by an arrow B. It is hung so that it can be conveyed and rotated. In the present embodiment, the intermediate transfer belt 11, the primary transfer bias roller 8, the support roller 9, the secondary transfer bias roller 12, the counter roller 10 and the like constitute a transfer unit.

A cleaning blade 16 as a cleaning means for the intermediate transfer belt 11 was brought into contact with the intermediate transfer belt 11 in the forward direction with respect to the conveying rotation direction. As the material of the cleaning blade 16, polyurethane rubber was used.

After the toner image is transferred, the residual toner remaining on the surface of the photosensitive drum 1 without being transferred to the recording material P is scraped off and removed by the cleaning blade 17 of the cleaning device 5, and further by the pre-exposure lamp 15. The residual charges are removed, and the next image is formed.

The photosensitive drum 1 on which the first toner image is formed by the first image forming unit 4a as described above is conveyed and rotated, and the second image forming unit 4b and the third image forming unit 4 are rotated.
c, and the fourth image forming section 4d carries out multiple development of toner images in the same manner as in the case of the first image forming section 4a.

However, the first to fourth image forming sections 4a to 4d are used.
The toner color of the toner image developed by
Toner images of four colors are collectively transferred onto the intermediate transfer belt 11 by the primary transfer bias roller 8, and the recording material P is transferred onto the secondary transfer bias roller 8 so as to match the timing with the toner composite image on the intermediate transfer belt 11. The toner composite image is collectively transferred to the recording material P where the toner image is fixed on the recording material P via the recording material conveyance path 18 to obtain a copy image.

At this time, the surface of the fixing roller of the fixing means 14 is coated with, for example, silicone oil as a release agent so that the toner on the recording material P does not adhere to the surface of the fixing roller.

The recording material P on which the toner image is formed on the front surface (first surface) passes above the non-wrapper and is discharged onto a paper discharge tray (not shown) when the image is formed on one side. It
As a result, when the image formation is performed on both sides, the recording material P having the toner image fixed on the first side is not discharged to the discharge tray by the switching of the flapper (not shown), and is re-disposed downward. It is guided to a paper feeding means (not shown).

Then, after being turned upside down by an inverting device (not shown), after the toner image is transferred again to the second surface,
The image is fixed by the fixing means 14, passes through the upper part of the flapper, and is discharged onto the paper discharge tray to complete the image formation.

After that, the photosensitive drum 1 performs a three-rotation idle rotation operation (post-rotation), and at the same time, the intermediate transfer belt 11 which is in forward contact with the photosensitive drum 1 also performs a predetermined rotation operation.

The operation of the first embodiment of the image forming apparatus according to the present invention described above will be described with reference to FIG. FIG. 3 shows a diagram of an operation sequence of the first embodiment of the image forming apparatus according to the present invention described above.

As shown in FIG. 3, the rotational process speed of the intermediate transfer belt 11 is 120 mm in order to generate a rotational speed difference between the intermediate transfer belt 11 and the charge eliminating roller 21, which is a feature of the present invention. / Sec to 160 mm
The speed was increased to / sec.

Further, a charge of minus 3 KV was applied to the charge eliminating roller 21 during the idling operation. Here, the static elimination roller 21
Contacts the intermediate transfer belt 11 in the forward direction.

Due to the relative speed thus generated, a frictional force is generated between the intermediate transfer belt 11 and the static elimination roller 21, the intermediate transfer belt 11 and the static elimination roller 21 perform an operation of mutually polishing each other, and the static elimination roller 21. By vibrating due to the applied voltage, it is possible to remove foreign matter such as scraps and dust of the residual toner belt accumulated on the surface of the intermediate transfer belt 11 and the surface of the charge eliminating roller 21 due to the accumulation of the number of times of image formation, and it is possible to form a high quality and stable image Could be achieved.

Incidentally, in the present embodiment, the contact pressure of the cleaning blade 16 contacting the intermediate transfer belt 11 is 0.196 N / cm, and the environmental condition is high temperature and high humidity.
According to the results of the endurance experiment in the environment test room at 75 ° C at 75 ° C, conventionally, at the time of 30,000 sheets, image defective toner fusion spots / streaks and oil streak cleaning defects, which are considered to be due to charged products, occurred. It was confirmed that the good condition was maintained even after 35,000 sheets had passed.

In this experiment, evaluation was carried out by continuously copying an image with an image ratio of about 25% by A4 size transverse feed in the endurance mode.

In the present embodiment, the case where the intermediate transfer belt 11 is used as the intermediate transfer body has been described, but as the intermediate transfer body, for example, as shown in FIG. 5, a cylindrical intermediate transfer drum 20 is used. Also, the same effect as above was confirmed.

This intermediate transfer drum 20 is endless, and by including a rubber, elastomer, or sponge layer in any one of the layers, the surface of the intermediate transfer drum 20 can have appropriate elasticity. Compared to the intermediate transfer belt 11 of the transfer belt system, the device for suppressing the increase in damage to the photosensitive drum 1 is added.

(Second Embodiment) Next, a second embodiment of the image forming apparatus according to the present invention will be described. Since the configuration of the second embodiment is substantially the same as the configuration of the first embodiment described with reference to FIG. 1 described above, detailed description of the configuration will be omitted.

The purpose of this second embodiment is to avoid the constant input of the sequence as in the first embodiment during non-image formation, and to set a certain number of copy intervals at the intervals of the above first embodiment. The aim is to improve the image quality and stability by utilizing the improvement of the polishing ability using the relative speed, which is the main focus.

The operation sequence of the second embodiment will be described with reference to FIG. FIG. 4 shows an operation sequence diagram of the second embodiment of the image forming apparatus according to the present invention.

However, as shown in FIG. 4, in this operation sequence, the number of polishing is naturally reduced as compared with the first embodiment, and this reduction is not covered by another means. Therefore, in the present embodiment,
The process speed of one rotation of the intermediate transfer belt 11 in the non-image forming apparatus is increased to 200 mm / sec from 120 mm / sec at the time of image formation, and at the same time, the charge eliminating roller 2 is used.
Rotation process speed of 1 is also from 120 mm / sec to 150
This was achieved by pushing up to mm / sec and increasing the number of times of polishing between the intermediate transfer belt 11 and the charge eliminating roller 21.

The present embodiment is particularly effective for an image forming apparatus that does not have a double-sided continuous copy version. In the executed sequence, the sequence of the present embodiment is input once every 5,000 copies. The present inventors have made an effort to achieve a long life of the intermediate transfer belt 11 and the charge eliminating roller 21 without increasing the number of polishing times unnecessarily.

Incidentally, in the prior art, image blurring toner streaks and spots due to poor charging occurred at 20,000 sheets or less at 32 ° C. and 75% under an environment of high temperature and high humidity. In the above, it was confirmed that the single-sided A4 size lateral feed and the intermittent copying of one sheet maintained the cleaning property up to 40,000 sheets.

(Third Embodiment) Next, a third embodiment of the image forming apparatus according to the present invention will be described with reference to FIGS.

FIG. 5 shows a partial configuration diagram of the third embodiment of the image forming apparatus according to the present invention, and FIG. 6 is a diagram of an operation sequence of the third embodiment of the image forming apparatus according to the present invention. Indicates.

However, among the members shown in FIG. 5, the same members as those shown in FIG. 1 are designated by the same reference numerals, and the detailed description thereof will be omitted.

As shown in FIG. 5, the third embodiment of the image forming apparatus according to the present invention is different from the first embodiment of the image forming apparatus according to the present invention as described above. Instead of the intermediate transfer belt 11 used in the embodiment, the intermediate transfer drum 20 is used, and the other points are the same.

The purpose of this embodiment is the same as that of the second embodiment described above, but is particularly suitable for an image forming apparatus using a toner on the intermediate transfer drum 20 in which the toner is very easily fused. It is valid.

As an experimental evaluation of this embodiment, an external additive in the toner used in the first embodiment and the second embodiment (particularly, as a cleaning aid, is added as a lubricant and an abrasive). In a system in which twice the amount of strontium titanate was added, a strong fusion substance (commonly known as filming) was generated in the portion corresponding to the white background portion of the image forming portion as the number of copies accumulated. . The number of generated sheets was 20,000 or less under the environment of high temperature and high humidity of 32 ° C. and 75%.

Therefore, as is apparent from the operation sequence shown in FIG. 6, in order to make the polishing property stronger than that in the above-described second embodiment, non-image formation before and after image formation is performed. At some times, the static elimination roller 21 is stopped and only the intermediate transfer drum 20 has a process speed of 120 mm / sec.
It was possible to remove the filming firmly adhered to the intermediate transfer drum by rotating the intermediate transfer drum by generating the polishing force between the charge removal roller and the intermediate transfer drum of the first and second embodiments. . At this time, it was single-sided, A4 size horizontal feed, and intermittent copy for one sheet.

In this embodiment, in consideration of avoiding damage to the intermediate transfer drum 20 and the static elimination roller 21,
The sequence was set to operate every 1000 sheets.

Here, the intermediate transfer drum used had a surface Asker hardness of about 30 degrees and an average surface layer roughness Rz of 5 μm or less.

(Fourth Embodiment) Next, a fourth embodiment of the image forming apparatus according to the present invention will be described.

The present embodiment further improves the effect of the above-described third embodiment, and particularly corresponds to a high-speed color copying machine having a faster process speed than the image forming apparatus described in the third embodiment. It was done.

Therefore, its structure is similar to that shown in FIG. Further, FIGS. 7 and 8 show sequence diagrams of the fourth embodiment.

In this embodiment, the process speed is 16
It was applied to a high-speed copying machine with a high speed of 0 mm / sec. A drum having a diameter of 180 mm was used in response to the increased speed (see FIG. 7).

As the experimental evaluation, the same evaluation mode as in the above-mentioned third embodiment was used.
Although filming occurred in 1,000 copies, in the present embodiment, the process speed of the photosensitive drum 1 during non-image formation is set to the process speed (V1
= 120 mm / sec) V2 greater than 180 mm /
With the time being set to sec, the filming adhered more firmly than in the third embodiment can be removed in a state where the charge eliminating roller 21 is stopped.

Incidentally, the sequence of this embodiment is 50
It was thrown in every 00 sheets, and the target of 20,000 sheets could be achieved. At this time, A4 size transverse feed and one sheet were intermittently copied.

Further, as a form in which the completely similar effect can be confirmed, conversely, during non-image formation, the intermediate transfer drum 20 is stopped, and the rotation process speed of the charge eliminating roller 21 is changed to the process speed (V3) during image formation. It is possible to obtain substantially the same effect as described above even in the state where V4 = 180 mm / sec, which is larger than (= 120 mm / sec). The image used had a duty ratio of 25% (see FIG. 8).

Here, during non-image formation, during the period when the intermediate transfer drum 20 is stopped rotating, the conveyance rotation speed of the charge eliminating roller 21 is V3, and the conveyance rotation speed during image formation is V4.
Then, V3> V4.

(Fifth Embodiment) Next, a fifth embodiment of the image forming apparatus according to the present invention will be described.

The configuration of this fifth embodiment is similar to that of FIG.
The configuration is the same as that of the first embodiment described with reference to FIG. The operation sequence of the fifth embodiment will be described with reference to FIGS. 9, 10 and 11. FIG. 9, FIG. 10 and FIG. 11 show operation sequence diagrams of the fifth embodiment of the image forming apparatus according to the present invention.

The object of the present embodiment is to provide an image forming apparatus in which a process design is performed in which the amount of externally added components in the toner is reduced in order to reduce the occurrence of filming or the like. The main purpose is to suppress the occurrence of defects.

Components of external additives in toner (especially abrasives)
It is advantageous to reduce damage to the photoconductor (durability, scratches, etc.) and delay the occurrence of image defects such as vertical streaks due to scratches to extend the life of the photoconductor.
On the other hand, the abrasion amount of the photoconductor is reduced, and the removal ability of the fusion products that hinder the charging ability of the photoconductor or the transfer body is deteriorated, and abnormal images such as fusion stripes and spots are generated on the image. I will let you.

Here, in this embodiment, as a countermeasure, especially in a high-temperature and high-humidity environment, a polishing force increasing sequence between the intermediate transfer belt 11 and the discharging roller 21 seen in the above-described first embodiment and the like. While incorporating
In order to improve the polishing power over the sequence other than in the high temperature and high humidity environment, a sequence in which the polishing power is changed according to the environmental conditions in the apparatus is introduced.

On the contrary, when the polishing force is not required so much, for example, in a low temperature and low humidity environment, the polishing force is prevented from operating more than necessary, and the life around the transfer belt is unnecessarily reduced. I tried not to.

In the embodiment, the environmental conditions are divided into three categories, and I (internal temperature 20 ° C to less than 30 ° C, humidity 10% to
Less than 60%), II (internal temperature 30 ° C to 45 ° C, humidity 60)
% To less than 80%), III (internal temperature 45 ° C or higher, humidity 8)
0% or more).

The other combinations were assigned to the categories with humidity values.

Under the environmental conditions of Category I, the process speed of the intermediate transfer belt in the above-described first embodiment during non-image formation was 140 mm / sec (see FIG. 9).

Under the environmental condition of Category II, the same sequence as that of the above-described first embodiment is used (see FIG. 10).
That is, the process speed during non-image formation of the intermediate transfer belt was set to 160 mm / sec.

Under the environmental conditions of Category III, the process speed of the intermediate transfer belt 11 during non-image formation in the above-described first embodiment was 180 mm / sec (see FIG. 11).

As a result, it is possible to increase the polishing force between the intermediate transfer belt 11 and the charge eliminating roller 21 in association with the environmental conditions, with respect to the fusion streaks and spots that tend to occur due to high temperature and high humidity. It has become possible to create a high-quality image stabilization sequence.

Further, the same effect as described above can be achieved by forming a sequence corresponding to another environmental condition.

Corresponding to the environment classification in the image forming apparatus described above, in section I, the rotation speed of the intermediate transfer belt was set to 3 rotations. In Category II, the rotation speed of the intermediate transfer belt was set to four. In Category III, the rotation speed of the intermediate transfer belt was set to 5 times.

However, in the image forming apparatus according to the present invention, the number of rotations of the intermediate transfer belt is not limited to these numbers and may be changed appropriately.

As described above, the same effect as described above was achieved by making the number of rotations of the intermediate transfer belt 11, that is, the time during which the charge-removing roller 21 is contact-polished, to correspond to the environmental condition.

Incidentally, according to the conventional example, at 32 ° C. and 75% under a high temperature and high humidity environment, under the condition that the external additive strontium titanate content in the toner is 0.2% (wt%),
When the number of copies is 15,000 or less, the fusion streak and spots were generated when the power was turned on at the start of work. However, the relative speed and the photosensitive drum rotation speed (polishing time) were increased in this embodiment. It was confirmed that both of them prevented fusion streaks and spots on more than 20,000 sheets. At this time, A4 lateral feed, image duty ratio of 6%, and one-sheet intermittent copying.

Here, according to the environment, the control of the rotational speed or the rotational speed of the intermediate transfer belt 11 during non-image formation is controlled by a control circuit (not shown). As the control transmission system, a condition detected by a temperature / humidity sensor (not shown) serving as a detection unit arranged in the sheet feeding unit of the image forming apparatus used in the present invention is converted into a signal and converted into a signal. It is transmitted to the arithmetic circuit and sent to the intermediate transfer belt drive motor control circuit to control the rotation of the intermediate transfer belt.

[0103]

As described above, according to the first invention of the present application, the intermediate transfer member and the charge eliminator whose surface hardness and surface roughness are optimized are relatively in contact with each other. Since it can rotate at a high speed, the surface of the intermediate transfer member and the static eliminator are abraded by the friction between the intermediate transfer member and the static eliminator. The quality can be secured and the deterioration of the image quality can be prevented.

According to the second invention of the present application,
The intermediate transfer body and the static eliminator, whose surface hardness and surface roughness are optimized, are rotatable at the contacting parts at a relative speed, and at least one of the intermediate transfer body and the static eliminator is the intermediate transfer body. When the body and the charge eliminator rotate at the relative speed at the contact portion, the peripheral speed is set to be higher than that when the transfer means transfers the developer image from the intermediate transfer body to the recording material. The surface of each other is abraded by rubbing between the body and the static eliminator, thereby avoiding the complication of the structure and more effectively ensuring the cleaning property and the static erasing property of the intermediate transfer member for a long period of time. Can be prevented from deteriorating.

Further, according to the third invention of the present application, the intermediate transfer member and the charge eliminator, whose surface hardness and surface roughness are optimized, can rotate at their contact portions at a relative speed. At the same time, the intermediate transfer member and the static eliminator
At a predetermined time interval, since they rotate at a relative speed at the contacting portions with each other, the surface of each other is polished by the sliding friction between the intermediate transfer body and the static eliminator while reducing the load on the intermediate transfer body and the static eliminator, More effectively while avoiding the complexity of the structure,
It is possible to secure the cleaning property and the charge removing property of the intermediate transfer member for a long period of time and prevent the deterioration of the image quality.

According to the fourth invention of the present application,
The intermediate transfer body and the static eliminator, whose surface hardness and surface roughness are optimized, are rotatable at the contacting portions at a relative speed, and the intermediate transfer body and the static eliminator are mutually Since the rotation is stopped when rotating at a relative speed at the contact portion, it is possible to improve the cleaning property and the charge removing property of the intermediate transfer member by improving the relative speed of the intermediate transfer member and the charge removing member. It is possible to prevent the deterioration of image quality by ensuring the cleaning property and the charge removal property of the intermediate transfer member for a long period of time while avoiding the complication of the structure because the surfaces of each other are polished by the rubbing against the charge removal member. it can.

Further, according to the fifth invention of the present application, the intermediate transfer member and the charge eliminator, whose surface hardness and surface roughness are optimized, can rotate at their contact portions at a relative speed. In addition, when the charge eliminator rotates at a relative speed at the contact portion between the intermediate transfer member and the charge eliminator, the transfer means rotates faster than when the developer image is transferred from the intermediate transfer member to the recording material. Since the speed is set, the surfaces of the intermediate transfer member and the static eliminator are rubbed against each other by polishing, thereby avoiding the complication of the structure and more effectively cleaning the intermediate transfer member for a long period of time. It is possible to prevent deterioration of the image quality by ensuring the charge resistance and the charge removal property.

According to the sixth invention of the present application,
The intermediate transfer body and the static eliminator, whose surface hardness and surface roughness are optimized, are rotatable at the contacting parts at a relative speed, and the static eliminator contacts the intermediate transfer body and the static eliminator. When rotating with relative speed in the section,
Since the rotation is stopped, the relative speed of the intermediate transfer member and the static eliminator is improved, and the cleaning property and the static eliminator of the intermediate transfer member are improved, and the mutual transfer is performed by the friction between the intermediate transfer member and the static eliminator. It is possible to prevent the deterioration of the image quality by polishing the surface of the intermediate transfer member and ensuring the cleaning property and the charge removal property of the intermediate transfer member for a long period of time while avoiding the complication of the structure.

Further, according to the seventh invention of the present application, the intermediate transfer member and the charge eliminator, whose surface hardness and surface roughness are optimized, can rotate at their contact portions at a relative speed. In addition, when the intermediate transfer body rotates at a relative speed at the contact portion between the intermediate transfer body and the static eliminator, it is faster than when the transfer means transfers the developer image from the intermediate transfer body to the recording material. Since it is set to the peripheral speed,
The surfaces of the intermediate transfer member and the static eliminator are rubbed with each other by rubbing, thereby avoiding the structure from becoming complicated and more effectively ensuring the cleaning property and the static erasing property of the intermediate transfer member for a long period of time. It is possible to prevent deterioration of image quality.

According to the eighth invention of the present application,
The intermediate transfer member and the static eliminator, the surface hardness and surface roughness of which are optimized, are rotatable at the contacting portions at a relative speed, and the intermediate transfer member and the charge eliminator are detected based on the detection result by the detecting means. Since the drive speed of at least one of the static eliminator is changed, the surface of each of them is polished by sliding friction between the intertransfer member and the static eliminator, if necessary, to complicate the structure. While avoiding, it is possible to more effectively ensure the cleaning property and the charge removing property of the intermediate transfer member for a long period of time, and prevent the deterioration of the image quality.

Further, according to the ninth invention of the present application, the intermediate transfer member and the charge eliminator, whose surface hardness and surface roughness are optimized, can rotate at their contact portions at a relative speed. At the same time, the timing for starting and ending the driving of at least one of the intermediate transfer member and the static eliminator is changed based on the detection result of the detection unit. The surface of each other is abraded by the rubbing between the charge-removing member and the static eliminator, and while avoiding the complication of the structure, the cleaning property and the charge-removing property of the intermediate transfer member are more effectively ensured for a long period of time, and the image quality is improved. It is possible to prevent deterioration.

According to the tenth invention of the present application,
The intermediate transfer member and the static eliminator, the surface hardness and surface roughness of which are optimized, are rotatable at the contacting portions at a relative speed, and the intermediate transfer member and the charge eliminator are detected based on the detection result by the detecting means. Since the timing of driving start and driving end of at least one of the static eliminator is changed, the surface of each other is polished by sliding friction between the intertransfer member and the static eliminator, if necessary. While avoiding the complication of the structure, it is possible to more effectively ensure the cleaning property and the charge removing property of the intermediate transfer member for a long period of time, and prevent the deterioration of the image quality.

Further, according to the eleventh invention of the present application, the intermediate transfer member and the charge eliminator, whose surface hardness and surface roughness are optimized, can rotate at a relative speed at their contact portions. In addition, when the latent image is formed on the latent image carrier and when the transfer means is not transferring the developer image from the intermediate transfer body to the recording material, the intermediate transfer body and the neutralizer contact each other. Since the parts rotate at a relative speed, the surfaces of the intermediate transfer member and the static eliminator are abraded by the friction between the intermediate transfer member and the static eliminator. Therefore, it is possible to secure the cleaning property and the charge removing property of the intermediate transfer member and prevent the deterioration of the image quality.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a schematic configuration of an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a partial step view of an intermediate transfer member provided in the image forming apparatus of FIG.

FIG. 3 is a diagram for explaining the operations of the intermediate transfer member and the static eliminator in the first embodiment of the present invention.

FIG. 4 is a diagram for explaining operations of an intermediate transfer body and a charge eliminator according to the second embodiment of the present invention.

FIG. 5 is a schematic sectional view showing a schematic configuration of an image forming apparatus according to a third embodiment of the present invention.

FIG. 6 is a diagram for explaining operations of an intermediate transfer body and a charge eliminator according to the third embodiment of the present invention.

FIG. 7 is a diagram for explaining operations of an intermediate transfer member and a charge eliminator in a fourth embodiment of the present invention.

FIG. 8 is a diagram for explaining operations of an intermediate transfer member and a charge eliminator in a fourth embodiment of the present invention.

FIG. 9 is a diagram for explaining the operations of the intermediate transfer body and the static eliminator in the fifth embodiment of the present invention.

FIG. 10 is a diagram for explaining the operations of the intermediate transfer body and the static eliminator in the fifth embodiment of the invention.

FIG. 11 is a diagram for explaining the operations of the intermediate transfer member and the static eliminator in the fifth embodiment of the present invention.

[Explanation of symbols]

1 Photosensitive drum (latent image carrier) 4a, 4b, 4c, 4d Image forming section (developing means) 11 Intermediate transfer belt (intermediate transfer member) 20 Intermediate transfer drum (intermediate transfer body) 21 Static eliminator roller (static eliminator) P recording material

Claims (11)

[Claims] 1. A latent image carrier carrying a latent image, developing means for visualizing the latent image as a developer image by applying a developer to the latent image carrier, and a latent image carrier on the latent image carrier. A transfer means for transferring the developer image onto the recording material, wherein the transfer means has a rotatable intermediate transfer member for receiving and carrying the developer image from the latent image carrier, An image forming apparatus for transferring the developer image from the latent image carrier to a recording material via an image forming apparatus, comprising: a rotatable charge eliminator that contacts an intermediate transfer body and neutralizes the intermediate transfer body, The intermediate transfer member and the static eliminator can rotate at a relative speed at their contact portions, and the surface hardness of the static eliminator is H1,
Assuming that the surface hardness of the intermediate transfer body is H2, the 10-point average roughness of the surface of the static eliminator according to JIS standard B601 is R1, and the 10-point average roughness of the surface of the intermediate transfer body according to JIS standard B601 is R2, H1> An image forming apparatus characterized by satisfying a relationship of H2 and R1> R2. 2. At least one of the intermediate transfer member and the static eliminator is a developer image from the intermediate transfer member onto the recording material when the intermediate transfer member and the static eliminator rotate at a relative speed at their contact portions. The image forming apparatus according to claim 1, wherein the peripheral speed is set to be higher than that when transferring the image. 3. The image forming apparatus according to claim 1, wherein the intermediate transfer member and the static eliminator rotate at a contact portion at a relative speed at a predetermined time interval. . 4. The intermediate transfer body stops rotating when the intermediate transfer body and the static eliminator rotate at a relative speed at their contact portions with each other. The image forming apparatus according to item 1. 5. The static eliminator is faster than the transfer means transferring the developer image from the intermediate transfer body onto the recording material when the intermediate transfer body and the static eliminator rotate at a relative speed at their contact portions. The image forming apparatus according to claim 4, wherein the peripheral speed is set. 6. The static eliminator stops rotating when the intermediate transfer member and the static eliminator rotate at a relative speed at their contact portions with each other. The image forming apparatus described. 7. The intermediate transfer member is more effective than the transfer unit transferring the developer image from the intermediate transfer member to the recording material when the intermediate transfer member and the charge eliminator rotate at a relative speed at their contact portions. 7. A high peripheral speed is set.
The image forming apparatus according to item 1. 8. A detection unit for detecting at least one of temperature and humidity of an image forming apparatus main body, and based on a detection result by the detection unit, a driving speed of at least one of an intermediate transfer member and a static eliminator. The image forming apparatus according to any one of claims 1 to 7, wherein the image forming apparatus is configured to be changed. 9. The driving start timing and the driving end timing of at least one of the intermediate transfer member and the static eliminator are changed based on the detection result of the detection unit. Image forming apparatus. 10. A detection means for detecting at least one of temperature and humidity of an image forming apparatus main body, and based on a detection result by the detection means, start driving of at least one of an intermediate transfer body and a static eliminator. The image forming apparatus according to any one of claims 1 to 7, wherein a timing of driving end is changed. 11. The intermediate transfer body and the static eliminator contact each other except when a latent image is formed on the latent image carrier and when the transfer means transfers the developer image from the intermediate transfer body to the recording material. The image forming apparatus according to claim 1, wherein the image forming apparatus is configured to rotate at a relative speed.