JP2003131536A - Image forming device and control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device which can securely clean a transfer member and does not causes any problems of toner scattering, an image memory, etc., even when toner of small particle size or toner of high sphericity is used and the transfer member is electrostatically cleaned. SOLUTION: The image forming device having a transfer member which transfers a formed toner image on a photoreceptor and a cleaning member which cleans toner on the photoreceptor is provided with an electrode member between members which electrostatically return residual toner sticking on the transfer member and mechanically clean the toner and is characterized in that the electrode member has a bias application means having bipolar output of positive and negative polarities, and a control means controlling the bias application.

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 used in a copying machine, a printer, etc. and a control method therefor.

[0002]

2. Description of the Related Art At present, in most image forming apparatuses which are required to have high image quality at high speed, an electrostatic latent image type image forming method centering on an electrophotographic method is adopted.

The reason therefor is that high-quality images can be stably obtained at high speed, and that they can be applied to color images and digital image formation. Therefore, it is considered that the electrostatic latent image type image forming method will continue to occupy a large amount in the future.

However, the performance demand level of the image forming technology in the market is high and is increasing year by year. Therefore, further improvement in performance is required even in the electrostatic latent image system.

Of these demands, needless to say, the biggest one is further improvement in image quality. As a countermeasure against this, it is effective to reduce the particle size of the toner and to make the particle size distribution and particle shape uniform. Is.

However, reducing the particle size of the toner, aligning the particle distribution, and the particle shape often cause other problems, and practical application is difficult without these measures.

Conventionally, as a method of cleaning the transfer residual toner on the photosensitive member, a method of pressing a blade-shaped elastic member against the surface of the photosensitive member to perform mechanical cleaning is known.

However, when the tip of the blade is worn, when a large amount of untransferred toner is present, such as when there is a transfer residual toner or a paper jam, the cleaning cannot be completed and slips through, resulting in poor cleaning. did. It is considered that this is because the tip of the blade brought into contact with the surface of the photoconductor vibrates due to the movement of the surface of the photoconductor and slips through a slight gap between the tip of the blade and the surface of the photoconductor.

As a countermeasure against the above, as a supplementary means in front of the cleaning blade, a rotating brush is brought into contact to mechanically scratch the toner on the photosensitive member to facilitate cleaning. The amount of toner that reaches the cleaning blade by adhering the semi-conductive elastic roller to the front and rotating it, and applying a bias of the opposite polarity to the toner at the time of development to adsorb the toner on the photoconductor to the roller. Have been proposed.

However, in recent years, toner particles have been reduced in particle size, and the sphericity has been increased by the production by a so-called polymerization method, so that high image quality can be obtained, but on the other hand, scratching by a brush is scratched. In addition, there are problems that the toner easily scatters, contaminates the inside of the machine, and stains the charging electrode around the cleaning means to cause uneven charging.

[0011]

In addition, for example, in an image forming apparatus in which a transfer member is a roller or the like and the cleaning thereof is performed electrostatically, the toner adhered to the transfer roller usually has a mixed polarity. Therefore, in order to electrostatically return these to the image bearing member (photosensitive member or intermediate transfer member), a method of alternately applying + and-bias is adopted. However, even if the toner charged to the opposite polarity to that at the time of development is returned to the image carrier, the polarity of the toner becomes the same as the bias applied to the roller as the cleaning assisting means,
Not only can it not be adsorbed to the cleaning assisting means, but the electrostatic attraction to the image carrier will increase, making cleaning even more difficult. As a ghost, there was a problem of appearing on the image.

That is, in the image forming apparatus employing the electrophotographic method, the cleaning means using the elastic blade is widely used as the cleaning means for the photosensitive member.
However, when a toner having a small particle size or a toner having a uniform particle size distribution and particle shape is used and the transfer member is also to be cleaned, the elastic blade cannot be sufficiently cleaned.

This causes deterioration of image quality due to color mixture, spots and pin poles. Further, if this state is continued for a long period of time, the toner remaining on the photoconductor or the like cannot be aggregated into a strong adhered substance, causing a so-called filming phenomenon, resulting in a significant deterioration in image quality.

Therefore, it is necessary to develop a technique capable of reliably cleaning the transfer member by using a toner having a small particle size or a toner having a uniform particle size distribution and a uniform particle shape and electrostatically cleaning the transfer member.

Further, in the method of electrostatically cleaning the transfer member, not only at the time of image formation but at the start and end of image formation, the toner accumulated on the transfer member is regularly cleaned. , It must be returned to the image carrier (photoconductor or intermediate transfer member). However, if this frequency is high, image formation will be hindered and productivity will be reduced. Therefore, it is necessary to accurately determine the timing at which cleaning is necessary and to perform cleaning only when necessary.

The present invention has been made to solve the above problems. An object of the first invention of the present invention is to reliably use a small particle size toner or a toner having a high sphericity to electrostatically clean a transfer member. An object of the present invention is to provide an image forming apparatus that does not cause the above problem.

A second object of the present invention is to further accurately determine the timing at which the transfer member needs to be cleaned, without causing problems such as image deterioration due to toner filming and stains on the back of the paper, and to perform image formation production. An object of the present invention is to provide an image forming apparatus in which the deterioration of the property is suppressed as much as possible.

[0018]

Means for Solving the Problems As a result of intensive studies by the inventors, it was found that the object of the present invention can be achieved by adopting any of the following constitutions.

[1] A latent image forming means for forming an electrostatic latent image on the electrophotographic photosensitive member, and a developing means for developing the electrostatic latent image to form a toner image are formed on the formed photosensitive member. In an image forming apparatus having a transfer member for transferring a toner image and a cleaning member for cleaning the toner on the photoconductor, the residual toner adhering to the transfer member is electrostatically returned to the photoconductor, and the toner is mechanically transferred from the transfer means. The electrode member is provided between the paths to the member to be cleaned, and
An image forming apparatus comprising: a bias applying unit that has a bipolar output and can apply a bias of an arbitrary polarity; and a control unit that controls the bias application.

[2] The image forming apparatus as described in [1], wherein the bias control of the electrode member is performed together with the bias control of the transfer member.

[3] At the time of cleaning, the electrode member outputs + polarity and the transfer member is biased with + polarity to the photosensitive member area where the bias of −polarity is applied to the transfer member during cleaning. The image forming apparatus according to [1], wherein the body region is controlled so as to output a negative polarity.

[4] In the control method of the image forming apparatus according to [1], the electrode member is + in the photoconductor region in which a bias of negative polarity is applied to the transfer member during cleaning.
The polarity of the transfer member is controlled so as to output the negative polarity to the photoconductor region to which the positive polarity bias is applied to the transfer member, and the bias of the transfer member at the time of performing electrostatic cleaning with the electrode member. Are controlled by a constant current, and the absolute value of the current value applied to the electrode member is controlled to be equal to or less than twice the absolute value of the current value applied to the transfer member.

[5] A latent image forming means for forming an electrostatic latent image on the electrophotographic photosensitive member and a developing means for developing the electrostatic latent image to form a toner image are provided. In an image forming apparatus having a first transfer member that transfers a toner image onto an intermediate transfer member and a second transfer member that transfers the toner image on the intermediate transfer member onto an image support, the residual toner on the second transfer member is removed. An electrode member is electrostatically returned to the intermediate transfer member, and an electrode member is provided in the path from the second transfer member to the cleaning member that mechanically cleans the toner. An image forming apparatus comprising: a bias applying unit capable of applying a bias having a polarity and a control unit controlling the bias application.

[6] The image forming apparatus according to [5], wherein the bias control of the electrode member is performed together with the bias control of the second transfer member.

[7] At the time of cleaning, the electrode member outputs + polarity and the second transfer member is applied with + polarity bias in the intermediate transfer body region where the negative polarity bias is applied to the second transfer member. The image forming apparatus according to [5], wherein control is performed so that negative polarity is output to the applied intermediate transfer member region.

[8] In the control method of the image forming apparatus according to [5], the electrode member outputs a + polarity to the intermediate transfer body region where the − transfer bias is applied to the second transfer member during cleaning. , The second transfer member is controlled so that the negative polarity is output to the intermediate transfer body region to which the positive bias is applied to the second transfer member, and the second transfer member is subjected to electrostatic cleaning with the electrode member. Both biases are controlled by a constant current, and the absolute value of the current value applied to the electrode member is the second
A control method characterized in that the current value applied to the transfer member is controlled to not more than twice the absolute value of the current value.

[0027]

[9] The image forming apparatus as described in [1] or [5], wherein a polymerization method toner is used.

[10] A latent image forming means for forming an electrostatic latent image on the electrophotographic photosensitive member, and a developing means for developing the electrostatic latent image to form a toner image are formed on the formed photosensitive member. In an image forming apparatus having a transfer means for primary transfer of a toner image to an intermediate transfer body and further secondary transfer to an image support, a backup member for suspending a belt-shaped intermediate transfer body from the back side and a backup member facing the backup member are provided. In an image forming apparatus including a secondary transfer member arranged as a unit and a bias applying unit for generating an electric field between the both members, residual toner adhering to the secondary transfer member is electrostatically transferred to an intermediate transfer member. The electrode member is provided between the transfer member and a member for mechanically cleaning the toner, and the electrode member is provided outside the sheet passing width of the image support in the width direction of the secondary transfer member and inside the developing sleeve width of the developing means. Position of the secondary transfer member An image forming apparatus comprising a detection unit for detecting a toner adhesion amount.

[11] Bias applying means is connected to the backup member in order to generate an electric field between the backup member and the secondary transfer member arranged opposite thereto.
In addition, the secondary transfer member side is grounded [1
0] The image forming apparatus described in [1].

[12] The secondary transfer member is a roller having at least a semiconductive layer [1]
0] The image forming apparatus described in [1].

[13] A cleaning operation of the secondary transfer member is controlled based on the information on the toner adhesion amount of the secondary transfer member and the sheet passing width of the image support [10].
The image forming apparatus described.

[14] In the method of controlling the image forming apparatus according to [10], the width of the image support passed through during the image forming operation is switched from the width of the image support previously passed through. At this time, if the width of the image support after switching is narrower than the width of the image support previously passed through, the image forming operation is continued without performing the cleaning operation of the secondary transfer member, and after switching. Is wider than the previous paper passing width, and when the toner adhesion amount detecting means of the secondary transfer member detects the toner adhesion more than the specified value, the image forming operation is interrupted and the secondary transfer member is cleaned. A control method characterized in that the image forming operation is restarted, and if the prescribed value is not reached, the image forming operation is continued without cleaning the secondary transfer member.

The above [1]-

Invention of [9] and [10]
In the inventions [14] to [14], the former is sometimes referred to as the first invention and the latter is sometimes referred to as the second invention because the basic structure is slightly different.

In the present invention, the image bearing member means a member carrying (holding) a toner image, and is typically an electrophotographic photoreceptor (sometimes referred to simply as a photoreceptor).
And an intermediate transfer member. The intermediate transfer member is for temporarily carrying the toner image formed by toner development, and the image support is for carrying the final image.

Usually, the intermediate transfer member is made of polyimide, silicone rubber or a resin film which does not expand or contract, and the like, and the image support is plain paper, processed paper or the like.

The transfer member is typically a transfer roller, and is a member for bringing an intermediate transfer member or an image support into contact with an image carrier and applying a bias electric field to perform transfer in a toner image transfer process. is there. In the present invention, the term “transfer member” simply refers to a member (primary transfer member) for transferring from a photoconductor to an intermediate transfer member or an image support, and the term “secondary transfer member” refers to an image transfer from an intermediate transfer member. Refers to the member that causes transfer to the body. Further, the electrode member is a member that can apply an alternating electric field, and usually has a shape in which conductive elastic rubber is wound around a core metal, like the transfer member, but is not limited to this and may be a brush-shaped member. The pad may be in the form of a pad, the bias applying means is a high-voltage power supply, and the control means is for controlling the voltage, the cycle, etc. of the bias application.

First, the first aspect of the present invention will be described. With the above-described structure, not only the toner returning to the image carrier is disturbed by a roller or a brush, but also the electrode member is electrostatically charged. Because it can be absorbed
It is possible to suppress toner scattering and reduce the amount of toner that reaches a mechanically cleaning member such as an elastic blade for cleaning. Toners with different polarities can be adsorbed by the electrode member, but if they are not completely adsorbed, they are biased with the opposite polarity to the polarities of the toner, weakening the electrostatic adhesion force to the image carrier and mechanically The cleaning by the member to be cleaned is surely performed.

Further, regarding the second aspect of the present invention, the first point is that by electrostatically removing toner stains on the secondary transfer member, there is no problem such as filming and the configuration can be simplified. It is similar to the invention.

By providing a sensor for detecting the amount of toner adhering to the secondary transfer member at an appropriate position, it is possible to know how dirty the secondary transfer member is due to the toner. Further, by avoiding the high voltage source from coming near the sensor, malfunction due to noise, sensor stain due to electric field, sensor destruction due to leak current can be prevented, and stain on the secondary transfer member can be accurately grasped. Moreover, since the cleaning operation is carried out based on the information of the width of the image support and the contamination of the secondary transfer member, it is possible to suppress the decrease in productivity of image formation.

Here, the detection means for detecting the toner adhesion amount is usually a reflection density detection sensor, and when this value is less than the specified value, its output and the adhesion amount to the transfer member are previously measured. The relationship is obtained, and the case where the adhered amount is a value that does not stain the image support visually even if it is transferred to the image support is indicated.

[0041]

BEST MODE FOR CARRYING OUT THE INVENTION First, the structure of the first invention and the components used therein will be described.

FIG. 1 is a sectional view of a structure for explaining an embodiment of the first invention of the present invention.

The photosensitive member 1 has a diameter of 80 mm, 150 mm /
It has a drum-shaped base body that rotates clockwise in sec. Reference numeral 2 is a transfer member, which is a transfer roller having a diameter of 20 mm in which a conductive elastic rubber is wound around a core metal, and 3 is an electrode member before cleaning, which is a roller having a diameter of 16 mm and in which a conductive elastic rubber is wound around a core metal. is there. The scraper 10 is a member for scraping off the toner from the electrode member 3.
Reference numeral 4 denotes a member that is mechanically cleaned, and a typical example thereof is a blade that uses elastic rubber.

Although not shown, the photosensitive member is first uniformly charged, and then imagewise exposed to form an electrostatic latent image, which is developed with toner for developing an electrostatic latent image to form a toner image. It When the photoconductor 1 rotates and reaches the transfer member 2, the toner image is transferred to the image support 6 by the transfer member. The toner image is then fixed to the image support (not shown),
On the other hand, the toner that has not been transferred and remains on the photosensitive member is cleaned and prepared for the next image formation.

In cleaning the transfer member, the transfer member 2 and the electrode member 3 have the same axial length, and both are applied with a ± alternating electric field from a high voltage power source. In this example, the current values are both ± 30 μA, and the conditions for applying the current are preferably as shown in the time chart of FIG. In addition, a,
b is, for example, the time for one rotation of the transfer member (transfer roller).

That is, the transfer member 2 is formed on the surface of the photoreceptor 1 of FIG.
A bias is applied so that the position in contact with the electrode member 3 is shifted by the time t until it contacts the electrode member 3 and an opposite electric field is obtained. As a result, the toner adhering to the transfer member is attracted to the photoconductor and subsequently to the electrode member. The toner attached to the electrode member is scraped off and collected by a scraper member or the like.

At this time, if a constant voltage is used as the bias applied to the transfer member and the electrode member, the cleaning performance will change when the resistance value of the transfer member and the electrode member changes due to environmental changes and changes over time. It is preferable to use an electric current.

Further, when the current value applied to the electrode member is too large, a large potential unevenness is created on the photosensitive member or the intermediate transfer member, and it is not possible to correct it to a uniform potential in the next charging or transfer process. Since unevenness may occur on the upper side, it is preferable that c ′ ≦ 2 × c and d ′ ≦ 2 × d, and more preferably c ′ = c and d ′ = d. However, c and d represent the current values of the ± bipolar bias applied to the transfer member in absolute values, and c ′,
Similarly, d'is a bias applied to the electrode member.

Similarly, in FIG. 3, the image carrier is the intermediate transfer member 1.
FIG. 1 is a sectional view illustrating a configuration in which the toner attached to the secondary transfer member 12 is transferred to the intermediate transfer member and then cleaned by the electrode member 13 before cleaning and the mechanically cleaning member 14. There is.

In this case, the bias voltage application method is preferably the same as that shown in FIG.

Next, the second invention of the present invention will be described with reference to embodiments. FIG. 4 is a cross-sectional view of the configuration of an image forming apparatus having a sensor that detects the toner adhesion state of the secondary transfer member.

Although not shown, a latent image forming means and a developing means are provided around the photosensitive member 1, and 5 is a developing sleeve in the developing means. The toner image formed on the photoconductor 1 rotating counterclockwise by these is transferred to the intermediate transfer body 11 by the transfer member 2 (in this case, the primary transfer member), and then the secondary transfer member 12 is transferred. Is transferred to the image support 6. Reference numeral 15 is a backup member (backup roller) for pressing the intermediate transfer member 11 against the secondary transfer member, and 16 is a sensor for detecting the toner adhesion state of the secondary transfer member. Further, the toner returned to the intermediate transfer member is cleaned by the electrode member 13 before cleaning and the mechanically cleaning member 14.

FIG. 5 shows the relationship between the length of the image forming apparatus shown in FIG. 4 in the image forming width direction and the positional relationship in order to explain the method of installing the sensor.

In the present invention, the sensor is installed inside the width of the developing sleeve 5, outside the width of the image support, and inside the width of the secondary transfer member. As a result, the state of the residual adhered toner on the secondary transfer member can be accurately grasped, and whether the cleaning is necessary or not even if the image support to be passed next has a wider width. You can decide

When the secondary transfer member is cleaned, the toner attached to the secondary transfer member must be biased back to the intermediate transfer member 11 side, but the bias voltage is actually applied. Any of the secondary transfer member 12 and the backup member 15 may be used. Figure 6
Is a high-voltage power supply 17 for applying a bias to the secondary transfer member 12.
With the attached (Fig. 6 (a)) and the backup member 1
FIG. 6 shows the case of being attached to No. 5 (FIG. 6B).

The latent image forming means in the present invention is usually composed of a charging means for uniformly charging the photoreceptor and an exposing means for exposing the uniformly charged photoreceptor in an imagewise manner. Of course, a so-called tandem type color image forming apparatus having a plurality of these and sequentially forming and transferring toner images may be used.

The technology and requirements relating to the constituent features of the present invention, the toner used, the image forming apparatus and the like will be described below.

1. Photoreceptor The photoreceptor in the present invention may be either an organic or inorganic photoreceptor as long as it is a so-called electrophotographic photoreceptor, and is not particularly limited. However, the most widely used in recent years is an organic photoconductor (OPC).

The organic photoreceptor usually uses a phthalocyanine pigment, a perylene pigment or the like as a charge generating substance. Fine particles of these pigments are dispersed in a resin and then applied to form a charge generating layer. A laminate type is used which is used as a substance and is coated with a resin to form a charge transport layer.

2. Charging means, image exposing means, developing means What is usually used in an electrophotographic image forming apparatus can be used in the present invention.

That is, the charging means is a corotron, a scorotron type corona charger, a roller charger, a brush charger or the like.

A semiconductor laser light source, an LED light source, or the like is used as the image exposure means, and these are exposed in a beam or spot shape to imagewise expose the uniformly charged surface of the photoreceptor to form a latent image.

The developing means may be of a one-component or two-component developing system, and these may be any developing device capable of using the developer described later.

3. Toner Used in the Present Invention The toner used in the present invention preferably has a small particle size, a narrow particle size distribution, and a uniform shape.

As for the particle diameter of the toner, specifically, it is preferable that the volume average particle diameter is 3 to 8 μm. If the thickness is less than 3 μm, the charging may not be sufficiently performed, and the toner may be scattered to deteriorate the image quality and adversely affect the human body. If it exceeds 8 μm, the image quality may not be good. The volume average particle size can be measured by Coulter Counter TA-II or Coulter Multisizer (both manufactured by Coulter Co.).

The method for producing the toner of the present invention is not particularly limited, but it is preferable to use a so-called polymerization method in which toner particles are produced during a polymerization reaction without performing kneading and pulverization classification as in a so-called pulverization method. This is because a product having a small particle size, a narrow particle size distribution, and a uniform particle shape can be easily produced.

4. Developer and Developing Conditions Next, the developer and developing conditions used in the present invention will be described.

The toner used in the present invention may be used as a one-component developer or a two-component developer, but is preferably a two-component developer.

When the toner is used as a one-component developer, there is a method of using the toner as it is as a non-magnetic one-component developer, but usually, the toner particles contain magnetic particles of about 0.1 to 5 .mu.m. Used as a developer.

Further, it can be used as a two-component developer by mixing with a carrier. In this case, conventionally known materials such as metals such as iron, ferrite and magnetite, alloys of these metals with metals such as aluminum and lead are used as the magnetic particles of the carrier. Ferrite particles are particularly preferable. The volume average particle diameter of the magnetic particles is 15
˜100 μm, more preferably 25 to 60 μm.

The volume average particle diameter of the carrier is typically measured by a laser diffraction type particle size distribution measuring apparatus "HELOS" equipped with a wet disperser (SYMPATIC (SYMP).
(Made by ATEC)).

The carrier is preferably one in which magnetic particles are further coated with a resin, or a so-called resin dispersion type carrier in which magnetic particles are dispersed in a resin. The resin composition for coating is not particularly limited, but, for example, an olefin resin, a styrene resin, a styrene-acrylic resin, a silicone resin, an ester resin, a fluorine-containing polymer resin, or the like is used. The resin for forming the resin-dispersed carrier is not particularly limited and known ones can be used, for example, styrene-acrylic resin, polyester resin, fluorine resin, phenol resin, etc. You can

The developing method can be used either in contact or in non-contact. The direct current developing electric field at that time is 1 × 10 ³ to 1 × 10 ⁵ V / cm in absolute value, preferably 5 × 10 ³
Is a ^{~1 × 10 4 V / cm,} 10 3 and development is less than V / cm is insufficient, no sufficient image density is obtained, 10 ⁵ V / c
If it exceeds m, the image quality is poor and fogging occurs.

AC bias is 0.5 to 4 kV (p-
p), preferably 1 to 3 kV (pp), and the frequency is 0.1 to 10 kHz, preferably 2 to 8 kHz. When the AC bias is less than 0.5 kV (pp), the toner adhering to the carrier does not separate, the non-contact development becomes insufficient, and the image density becomes insufficient. When the AC bias exceeds 4 kV (pp), the carrier in the developer flies and carrier adheres to the photoconductor. Further, if the frequency of the AC bias is less than 0.1 kHz and the frequency from the carrier exceeds 10 kHz, the toner cannot follow the fluctuation of the electric field, resulting in poor development and a decrease in image density.

5. Other Configurations A so-called contact heating method can be cited as a suitable fixing method used in the present invention. In particular, as the contact heating method, a heat pressure fixing method, a heat roller fixing method, and a pressure contact heating fixing method in which fixing is performed by a rotating pressure member containing a fixedly arranged heating body can be mentioned.

The image forming apparatus of the present invention can be applied to general electrophotographic apparatuses such as copying machines, laser printers, LED printers, liquid crystal shutter printers, and the like. It can be widely applied to devices such as light printing, plate making, and facsimile.

[0077]

According to the present invention, in the first invention, a toner having a small particle diameter or a toner having a high sphericity is used, and even if the transfer member is electrostatically cleaned, the toner can be reliably cleaned. It is possible to provide an image forming apparatus that does not cause a problem such as a memory.

Further, according to the second aspect of the present invention, the problem of image deterioration due to toner filming or stain on the back side of the paper is not caused, and the timing at which the transfer member needs to be cleaned is accurately determined to produce the image. It is possible to provide an image forming apparatus in which the deterioration of the property is suppressed as much as possible.

[Brief description of drawings]

FIG. 1 is a configuration cross-sectional view for explaining an embodiment of the present invention.

FIG. 2 is a time chart diagram in which a ± alternating electric field is applied to a transfer member and an electrode member.

FIG. 3 is a configuration cross-sectional view for explaining an embodiment of the present invention.

FIG. 4 is a configuration cross-sectional view for explaining an embodiment of the present invention.

FIG. 5 is a diagram for explaining a method of installing a sensor.

FIG. 6 is a structural cross-sectional view when a high voltage power source for bias application is attached.

[Explanation of symbols]

1 photoconductor (electrophotographic photoconductor) 2 Transfer member 3, 13 Electrode member 4,14 Mechanically cleaning member 6 Image support 11 Intermediate transfer body 12 Secondary transfer member 15 Backup member 17 High-voltage power supply for bias application

Continued front page    (72) Inventor Hiroshi Morimoto             2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica stock             In the company (72) Inventor Masashi Saito             2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica stock             In the company F-term (reference) 2H035 AA15 AB02 AC01 AC06 AC07                 2H134 GA01 GA05 GA06 GB02 GB08                       HD00 HF14 HF16 JA04 JA05                       KA33 KA40 KB04 KB20 KF02                       KG04 KG08 KH01                 2H200 GA23 GA44 GA62 GA63 GB12                       HA02 HB12 HB22 JA02 JB10                       JC03 JC11 LA12 LB02 LB03                       LB13 LB39 LB40 PA02 PB11                       PB17 PB25

Claims (14)

[Claims] 1. A toner on a formed photoconductor, comprising: a latent image forming unit for forming an electrostatic latent image on an electrophotographic photoconductor; and a developing unit for developing the electrostatic latent image to form a toner image. In an image forming apparatus having a transfer member for transferring an image and a cleaning member for cleaning the toner on the photoconductor, the residual toner adhering to the transfer member is electrostatically returned to the photoconductor to mechanically remove the toner from the transfer means. An electrode member is provided in the path to the member to be cleaned, a bias applying unit capable of applying ± bipolar outputs to the electrode member and applying a bias of any polarity, and a control unit for controlling the bias application. An image forming apparatus comprising: 2. The bias control of the electrode member is performed together with the bias control of the transfer member.
The image forming apparatus described. 3. The transfer member during cleaning is
Control is performed so that the electrode member outputs + polarity to the photoconductor region to which the bias of polarity is applied, and the -polarity is output to the photoconductor region to which the bias of + polarity is applied to the transfer member. The image forming apparatus according to claim 1, wherein: 4. The method of controlling an image forming apparatus according to claim 1, wherein the electrode member outputs + polarity to the transfer member in a photosensitive member region where a −polarity bias is applied to the transfer member during cleaning. Control is performed so that a negative polarity is output to the photoconductor region to which a positive polarity bias is applied,
In addition, the bias of the electrode member and the transfer member at the time of performing electrostatic cleaning are both controlled by a constant current, and the absolute value of the current value applied to the electrode member is 2 times the absolute value of the current value applied to the transfer member. A control method characterized by being controlled to be less than or equal to twice. 5. A toner on the formed photoconductor, which has a latent image forming means for forming an electrostatic latent image on the electrophotographic photoreceptor and a developing means for developing the electrostatic latent image to form a toner image. In an image forming apparatus having a first transfer member that transfers an image onto an intermediate transfer member and a second transfer member that transfers a toner image on the intermediate transfer member onto an image support, the residual toner on the second transfer member is removed. An electrode member is provided electrically between the second transfer member and the cleaning member for mechanically cleaning the toner, and an electrode member is provided between the second transfer member and the cleaning member for mechanically cleaning the toner. An image forming apparatus, comprising: a bias applying unit capable of applying the bias and a control unit controlling the bias applying. 6. The image forming apparatus according to claim 5, wherein the bias control of the electrode member is performed together with the bias control of the second transfer member. 7. At the time of cleaning, the electrode member outputs + polarity, and the bias of + polarity is applied to the second transfer member, in the intermediate transfer member region where the −polarity bias is applied to the second transfer member. The image forming apparatus according to claim 5, wherein the intermediate transfer member area is controlled so as to output a negative polarity. 8. The method of controlling an image forming apparatus according to claim 5, wherein the electrode member outputs + polarity to the intermediate transfer body region in which a −polarity bias is applied to the second transfer member during cleaning. The bias of the second transfer member at the time of performing electrostatic cleaning with the electrode member is controlled so that the negative polarity is output to the intermediate transfer body region to which the positive polarity bias is applied to the second transfer member. Are controlled by a constant current, and the absolute value of the current value applied to the electrode member is controlled to be equal to or less than twice the absolute value of the current value applied to the second transfer member. 9. The image forming apparatus according to claim 1, wherein a polymerization method toner is used. 10. A toner on a formed photoconductor, comprising latent image forming means for forming an electrostatic latent image on an electrophotographic photosensitive member, and developing means for developing the electrostatic latent image to form a toner image. In an image forming apparatus having a transfer unit that first-transfers an image to an intermediate transfer member and then second-transfers the image to an image support, a backup member for suspending a belt-shaped intermediate transfer member from the back side and a backup member opposed thereto In an image forming apparatus including a secondary transfer member arranged and a bias applying unit for generating an electric field between the two members, residual toner adhering to the secondary transfer member is electrostatically transferred to an intermediate transfer member. An electrode member is provided between the transfer member and a member for mechanically cleaning the toner, and the electrode member is located outside the sheet passing width of the image support in the width direction of the secondary transfer member and inside the developing sleeve width of the developing means. With toner on the secondary transfer member An image forming apparatus comprising a detection unit for detecting the amount of landing. 11. In order to generate an electric field between the backup member and the secondary transfer member arranged opposite to the backup member,
Bias applying means is connected to the backup member, and 2
The image forming apparatus according to claim 10, wherein the next transfer member side is grounded. 12. The image forming apparatus according to claim 10, wherein the secondary transfer member is a roller having at least a semiconductive layer. 13. The image forming apparatus according to claim 10, wherein the cleaning operation of the secondary transfer member is controlled based on the information on the toner adhesion amount of the secondary transfer member and the sheet passing width of the image support. . 14. The method for controlling an image forming apparatus according to claim 10, wherein the width of the image support passed through during the image forming operation is switched from the width of the image support previously passed through. , If the width of the image support after switching is narrower than the width of the image support previously fed,
The image forming operation is continued without performing the cleaning operation of the secondary transfer member, and the paper passing width after switching is wider than the paper passing width up to then, and the toner adhesion amount detection means of the secondary transfer member adheres more toner than specified. When the image is detected, the image forming operation is interrupted, and after cleaning the secondary transfer member,
A control method characterized in that the image forming operation is restarted, and if the specified value is not reached, the image forming operation is continued without cleaning the secondary transfer member.