JP2003295725A - Image forming device and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device allowed to be reduced in size and cost by loading a cleaning device having a photosensitive body of an extremely simple constitution and capable of realizing space saving. <P>SOLUTION: A vibration field for brush fibers is formed by using a recovery brush device in an image forming process. Voltage twice or more discharge starting voltage between the recovery brush device and the photosensitive body is impressed to the recovery brush device as a means for forming the vibration field. Consequently toner remaining on the surface of the photosensitive body can be recovered independently of positively/negatively charged electrodes. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method and an image forming apparatus applied to a copying machine, a facsimile, a printer and the like, and more particularly, to transferring a developer image formed on an image carrier onto an image receiving paper. The present invention relates to an image forming method and an image forming apparatus for forming an image.

[0002]

2. Description of the Related Art Conventionally, as a method for cleaning the surface of an image bearing member in an image forming apparatus using an electrophotographic method, Japanese Patent Application Laid-Open No. 9-90840 and Japanese Patent No. 313 have been proposed.
The brush method is proposed in Japanese Patent Publication No. 7962.

FIG. 3 shows a simplified block diagram of a conventional cleaning device using a brush method. In FIG. 3, 101 is a photoconductor, and 102 is a brush roller that contacts the photoconductor 101 and rotates. Further, 103 is an intermediate roller that is in contact with the brush roller 102, and 104 is a scraping member that scrapes off the toner on the intermediate roller. The toner remaining on the photoconductor 101 after the transfer is mechanically or electrostatically collected on the brush roller side. Further, the collected toner is electrostatically transferred to the intermediate roller, and then removed from the intermediate roller by the scraping member. The removed toner is conveyed and stored in a waste toner container by a toner conveying means (not shown).

Further, in Japanese Patent No. 3137962,
Peak voltage 400-700V, frequency 100-2,0
A method of applying a voltage of 00 Hz and a DC bias of 100 to 300 V to the brush roller is proposed.

[0005]

However, the above structure has the following problems.

First, the components of the cleaning device are
At least three brush rolls, an intermediate roll, and a scraping member are required, and a plurality of bias power supplies are required to move the toner to the intermediate roll by electrostatic force. Therefore, it is extremely difficult to reduce the size and cost of the cleaning device. For example, a method has been proposed in which the flicker directly blows out the toner attached to the brush fiber without using an intermediate roller, but if the flicker and the brush roller are left in contact with each other for a long time, the brush fiber may be deformed. However, there is a problem that the cleaning performance of the brush roller locally deteriorates.

Secondly, the charge distribution of the toner conveyed to the cleaning device changes broadly compared with that in the developing device, and toners of both positive and negative charging polarities are mixed. Therefore, even if you try to collect it on the brush roller side by electrostatic force,
There is a problem that only toner having a polarity opposite to the bias voltage can be collected. According to Japanese Patent No. 3137962, a method in which a direct current voltage is superimposed on an alternating current voltage is proposed, but toner of both positive and negative polarities vibrates between the brush roller and the photosensitive drum, but It is considered extremely difficult for the bipolar toner to be collected by the brush. This is because the alternating electric field strength between the brush roller and the photoconductor gradually weakens as the brush roller and the photoconductor are gradually separated, and as a result, the toner cannot reciprocate between the two. As a result, although the toner having the polarity opposite to the voltage applied to the brush roller is attracted to the brush roller side,
This is because it is considered that the toner of the same polarity repels and moves to the photoconductor side.

In view of the above-mentioned problems, the present invention provides an image forming apparatus equipped with a cleaning device which can be reduced in size and cost and which does not depend on the polarity of transfer residual toner.

[0009]

That is, an image forming apparatus of the present invention comprises an image carrier, a developing unit for forming a visible particle image with visible particles on the image carrier, and a member for receiving the visible particle image. Transfer means for transferring to, a brush-like collecting means for collecting the visible particle images remaining on the image carrier after the transfer, and a brush vibrating means for vibrating the brush fibers of the brush-like collecting means during the image forming operation, A voltage application unit that switches the DC voltage of both positive and negative polarities during the non-image forming operation to apply the brush-shaped collecting unit, and a second image collecting unit that collects the image particles discharged from the brush-shaped collecting unit during the non-image forming operation. And a collecting means.

The brush vibrating means is an AC voltage applying means for applying an AC voltage to the brush-like collecting means.

Further, it is preferable that the AC voltage applying means applies a voltage that is at least twice as high as the discharge starting voltage between the surface of the image bearing member and the brush-like collecting means.

The second collecting means is composed of an image carrier for carrying and conveying the discharged image particles, and a transfer means for collecting the image particles on the image carrier.

Further, the image forming apparatus is provided with a developing particle removing means for removing the developing particles adhering to the surface of the transferring means and a developing particle storing means for storing the removed developing particles.

Alternatively, the second collecting means is composed of an image carrier for carrying and conveying the discharged image particles, and a developing means for collecting the image particles on the image carrier.

Further, the image forming method of the present invention comprises a developing step of forming a visible particle image with visible particles on the image carrier.
A transfer step of transferring the visible particle image to the image receiving member and a first step of collecting the visible particle image remaining on the image carrier after the transfer to the brush collecting means by vibrating brush brush fibers during the image forming operation. In the collecting step, a DC voltage of both positive and negative polarities is sequentially applied to the brush-like collecting means during the non-image forming operation, and a discharging step for discharging the image-forming particles from the brush collecting means, and the image-developing particles discharged by the discharging step. A second collecting step of collecting by means other than the brush collecting means.

Further, in the first recovery step, an AC voltage is applied to the brush-shaped recovery means.

Further, the AC voltage applied to the brush-shaped collecting means in the first collecting step is more than twice the discharge starting voltage between the surface of the AC image carrier and the brush-shaped collecting means. Is preferred.

The second collecting step is composed of a carrying step of carrying the discharged visible image particles on an image carrier, and a transfer collecting step of collecting the visible particles on the image carrier by a transfer means. It will be.

The image forming apparatus further comprises a developing particle removing step of removing the developing particles adhering to the surface of the transfer means, and a developing particle storing step of storing the removed developing particles.

Alternatively, the second collecting step includes a carrying step for carrying and carrying the discharged visible image particles on the image carrier, and a developing and collecting step for collecting the visible particle on the image carrier by the developing means. It consists of

Further, it is preferable that the brush-shaped collecting means is made of a material that easily charges the image-forming particles to a predetermined charging polarity.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration and operation of the image forming apparatus of the present invention will be described below with reference to FIG.

FIG. 1 is a sectional view of the construction of the image forming apparatus of the present invention.

In FIG. 1, reference numeral 1 denotes a photosensitive drum corresponding to an electrostatic latent image holding member in which a photosensitive layer is provided on a metal drum. An OPC layer, an a-SiH layer, a selenium layer, or the like is used as the photoreceptor layer. Further, a conductive undercoat layer may be provided between the aluminum tube and the CGL so that scratches or stains on the tube do not affect the charging characteristics of the photoconductor.

Reference numeral 6 denotes a charging device which is arranged with a predetermined gap from the surface of the photoconductor drum 1 to charge the photoconductor drum. Although a scorotron charging device is shown in FIG. 1, a non-contact charging device such as a corotron charging device or a solid charging element may be used in addition to the scorotron charging device. A contact charging device such as a brush may be used. In this embodiment, a scorotron charging device will be described.

An exposure source 7 forms a latent electrostatic image by irradiating the charged surface of the photosensitive drum 1 with light. Laser light, LED light, CRT light, EL light, or the like may be used as the exposure source as long as the photosensitive drum emits light having a high absorption spectrum. Reference numeral 8 denotes a developing device as a developing means for developing the electrostatic latent image on the photosensitive drum 1. The developing device 8 may be either a two-component developing device or a one-component developing device, but in the present embodiment, the two-component developing device is used.
In the case of a two-component developing device, a two-component developer in which carrier particles and toner particles are mixed is used. The carrier particles are composed of magnetic particles such as ferrite, magnetite and iron powder. Further, a coated carrier for coating the surface of the magnetic core particles with a coating material may be used. Examples of the coating material include amino resins such as urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, and epoxy resin, and further polyvinyl and polyvinylidene resins, acrylic resin, polymethylmethacrylate. Examples thereof include resins, polyacrylonitrile resins, polyvinyl acetate resins, polyvinyl acetate resins, polyvinyl alcohol resins, polyvinyl butyral resins, and cellulose resins such as ethyl cellulose resins. Further, the carrier particles are preferably spherical. In the case of flakes or flat plates, the ability to collect transfer residual toner in the developing device increases, but on the other hand, brush-like image noise is likely to occur. Also,
The average particle size of the carrier particles is preferably 30 μm to 70 μm, and more preferably 35 μm to 55 μm. If it is less than the above range, the coercive force of the magnetic brush becomes small and the magnetic brush is easily separated from the developing sleeve, so that the carrier adhesion to the photosensitive drum increases. On the other hand, when it exceeds the above range, the carrier surface area per unit weight becomes small, and the charging of the toner becomes unstable. Further, in the case of a so-called cleanerless system in which no waste toner is generated, the surface area of the magnetic brush that comes into contact with the transfer residual toner is reduced, so that the chances of contact between the transfer residual toner and the magnetic brush are reduced, and as a result, the photosensitive drum The ability to recover from the water will decrease.
Furthermore, since the toner is carried by carrier particles larger than the electrostatic latent image, it becomes impossible to develop a fine electrostatic latent image. The toner particles are composed of a binder resin in which a colorant is dispersed, regardless of whether it is a two-component developing device or a one-component developing device. Examples of the binder resin material include polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer. , Polyethylene, polypropylene and the like. In addition, polyester, polyurethane, epoxy resin, silicone resin, polyamide,
Modified rosin and paraffin wax are used. Further, as the colorant, carbon black, nigrosine,
Aniline blue, calcoil blue, chrome yellow,
Ultramarine Blue, DuPont Oil Red, Quinoline Yellow, Methylene Blue Chloride, Phthalocyanine Blue, Malachite Green Oxalate, Lamp Black, Rose Bengal, C.I. I. Pigment Red 4
8: 1, C.I. I. Pigment Red 122, C.I. I.
Pigment Red 57: 1, C.I. I. Pigment Yellow 97, C.I. I. Pigment Yellow 180 can be used. In addition to the above components, the toner of the present invention may contain a charge control agent, wax, etc., if necessary. Further, if necessary, an external additive such as an inorganic oxide such as silica, titanium oxide or zinc oxide, or organic fine particles may be added. The toner is preferably spherical,
Specifically, when the projected area S and the peripheral length L of the toner particles are used, it is preferable that the shape factor C represented by the following equation is 1.1 to 1.5.

When the C = L ² / 4πS shape coefficient is below the above range, not only the releasability of the toner is lowered and the transfer efficiency is lowered, but also the maximum transfer efficiency of the halftone image and the solid black image is the same. Is difficult to realize with the transfer voltage. Therefore, the transfer residual toner increases, which is not preferable. When the amount exceeds the above range, the releasability of the toner is too high and the toner easily separates from the image receiving paper or the photoconductor drum, and the toner scatters on the image receiving paper after transfer and the toner contamination of the charging device easily occurs. Further, in order to realize the above shape factor, it is preferable to use a toner produced by a suspension polymerization method or an emulsion polymerization method. Further, the toner base prepared by the mechanical pulverization method may be dropped into a hot air stream to be subjected to the spheroidizing treatment. The volume median diameter of the toner is preferably 5.0 to 7.5 μm. When it is within the above range, the mechanical adhesion between the toner particles and the photoconductor drum increases, and the transfer efficiency decreases. On the other hand, if it exceeds the above range, it becomes difficult to faithfully develop a fine electrostatic latent image. Further, since the concealment ratio for concealing the image receiving paper with the toner when a solid black image is printed is reduced, it is necessary to achieve a sufficient image density of 0.
It is necessary to develop with a toner amount of 55 mg / cm ² or more. However, when the amount of developing toner increases, it becomes difficult to transfer the toner lowermost layer on the photosensitive drum to the image receiving paper. Further, even if a high transfer bias is applied to transfer a solid black image on the photosensitive drum, an excessive voltage is supplied to the halftone image, and as a result, the polarity of the toner is reversed during the transfer process. However, the transfer efficiency of the halftone image is reduced. Therefore, in the present invention, it is preferable that the toner having the volume median diameter in the above range is used and the amount of the developing toner on the photosensitive drum is 0.55 mg / cm ² or less. A predetermined developing voltage is applied to the developing sleeve 8c by a power source (not shown). In the case of a two-component developing device,
The developing voltage is preferably a voltage obtained by superimposing an AC voltage on a DC voltage. As a result, the toner is easily separated from the carrier particles, so that development is possible even if the level of the DC voltage is low. Further, even in the one-component developing device, when the photosensitive member 1 and the developing sleeve 8c are not in contact with each other, a voltage obtained by superposing an AC voltage on a DC voltage is preferable. As a result, the toner particles are easily separated from the developing sleeve, so that development is possible even if the level of the DC voltage is low. The waveform of the AC voltage, a sine wave, a rectangular wave, a triangular wave, or a sawtooth wave may be used, or an AC wave whose duty ratio is modulated may be applied. The peak-to-peak voltage of the AC voltage is preferably 500V to 2000V. Below the above range, the toner is less likely to vibrate and the effect of the AC voltage is reduced. On the other hand, if it exceeds the above range, carrier adhesion to the photoconductor occurs.
Further, when the conductivity of the carrier particles is high, electric discharge occurs between the magnetic brush on the developing sleeve and the photoconductor, disturbing the toner on the photoconductor. When a higher peak-to-peak voltage is applied,
Due to the above discharge, discharge marks are formed on the photoconductor and the developing sleeve. The frequency of the alternating voltage is 1 kHz to 8 kHz.
Is desirable. If the amount is out of the above range, the amount of toner developed will decrease.
Although the detailed function and effect are unknown, it is considered that there is a natural frequency at which the toner easily separates from the magnetic brush. Further, when the toner discharged from the collecting brush device described later is collected in the developing device, the frequency is further set to 4
It is preferable to set it to kHz to 7 kHz. If the amount is out of the above range, the efficiency of collecting the toner on the photoconductor is lowered. Although the detailed function and effect are also unknown, it is considered that there is a natural frequency at which the toner is easily separated from the photoconductor and is easily taken into the magnetic brush of the developing device. When the toner discharged from the collecting brush device is not collected in the developing device, the frequency may be set outside the above range, or only the DC voltage may be applied.

Reference numeral 3 is a transfer device as a transfer means. As a transfer device, a transfer roller in which a sponge layer such as conductive urethane, EPDM, or silicon is wound around a core metal, a transfer brush made of conductive fibers such as nylon or rayon, a tip of a conductive rubber plate or a conductive film sheet Transfer blade, transfer film, PTFE, PFA, TE
A conductive belt in which a conductive material is dispersed in a resin material such as P, polyimide, or polycarbonate is used. As will be described later, in the case where the scraping member collects the toner discharged from the brush collecting member in the transfer device, it is preferable that the toner particles are mechanically easily separated from the transfer device. Therefore, among the above-mentioned transfer devices, it is preferable to use a transfer device such as a transfer roller or a transfer belt having a film layer such as PFA or PTFE on the surface.

A registration roller 2 conveys the image receiving paper at a predetermined speed. 5 is plain paper, postcard paper, OHP
An image receiving sheet such as a sheet. Further, 10 is an upstream guide means for guiding the conveying direction of the image receiving paper 5 from the registration roller 2 to the photosensitive drum 1. A fixing device 4 fixes the toner image transferred onto the image receiving paper 5. Again 11
Is a downstream guide unit that guides the conveyance direction of the image receiving paper from the transfer area to the fixing device 4. In a high humidity environment, the image receiving paper 5 has a low resistance, and a current leaks from the flexible member 3b to the guiding means 10 and 11 via the image receiving paper 5. For this reason, sufficient charges are not supplied to the back surface of the image receiving paper 5, and transfer defects occur. In order to solve this problem, it is preferable that the guide means 10 and 11 are made of an insulating member or a voltage having the same polarity as the transfer voltage is applied. Further, a self-bias element such as a resistance element or a Zener diode element may be connected between the guide means 10 and 11 and the ground.

A fixing device 4 is composed of a heating means 4a and a pressing means 4b. In FIG. 1, heating means 4a
Although the pressing means 4b and the pressing means 4b have a roller shape, the present invention is not limited to this, and a film-shaped or belt-shaped heating means, a pressing means, or the like may be used.

Reference numeral 12 is a collecting brush member as a brush-like collecting means which is arranged between the transfer device and the charging device in the direction of rotation of the photosensitive member. The brush member 12 is arranged such that the brush fibers are substantially perpendicular to the surface of the photoconductor and are in contact with the surface of the photoconductor. Although a fixed brush member is shown in FIG. 1, it may be a roll-shaped brush member. Further, the roll-shaped brush member may rotate, and its rotation direction may be either forward or reverse with respect to the surface of the photoconductor. For the brush member 12, a fiber (pile) in which a conductive material is dispersed in a yarn such as nylon, rayon, cellulose, or polyester is woven or flocked. It is preferable that the pile length is 0.5 to 7 mm, the pile thickness is 2 to 10 denier, and the pile density is 100 to 300 F / mm ² .

Reference numeral 17 denotes a recovery brush member power source connected to the recovery brush member. The power supply 17 is controlled so that it is applied to the recovery brush member 12 by switching between AC voltage, positive DC voltage, and negative DC voltage.

Reference numeral 13 denotes a toner removing device as a means for removing visible particles, which mechanically scrapes off the toner adhering to the surface of the transfer device by a scraping member. The toner removing device 13 may use a rubber blade, a brush, a web or the like other than that shown in FIG. In the present embodiment, it is premised that the toner once collected by the brush member 12 is discharged to the photoconductor, then collected again by the transfer device and then removed by the toner removing device. Alternatively, the developing device may collect the toner. When the toner is collected by the developing device, the toner removing device is not necessary, which is suitable for downsizing and cost reduction of the image forming apparatus. However, in the case of a color image forming apparatus, when toner is collected in the developing device, a toner of a color different from the original color is mixed and the hue of the printed image changes, so-called color mixing problem easily occurs.

Next, the operation of the image forming apparatus of the present invention will be described with reference to FIG. 1 and the timing chart of FIG.

First, the image forming apparatus receives an image signal transmitted from the outside such as a computer and starts a preparatory step before image formation. First, the fixing device is heated, and after reaching a predetermined temperature, the rotation driving of the fixing device is started.
Further, the rotational driving of the photosensitive drum is also started. At this time, a predetermined voltage is applied to the charging device, and the photosensitive drum is charged to a predetermined surface potential. Further, rotation driving of the developing device is also started. At this time, a voltage in which a DC voltage is superimposed on an AC voltage is applied to the developing sleeve. Further, an AC voltage is applied to the recovery brush member. Further, the image receiving paper stored in a paper feeding cassette (not shown in FIG. 1) is fed to the registration rollers and is maintained in a state of being sandwiched between the registration rollers.

After the above preparation process is completed, the image forming process is started while continuing the operation of each member. At the beginning,
When the charged surface of the photosensitive drum is conveyed to a position facing the exposure source, the surface of the photosensitive drum is irradiated with light according to the received image signal. As a result, the charging potential of the surface of the photosensitive drum in the area irradiated with light is lowered. As a result, an electrostatic latent image is formed on the surface of the photosensitive drum. Next, when the electrostatic latent image on the surface of the photoconductor drum is conveyed to a position facing the developing device, the toner on the developing sleeve to which a predetermined voltage is applied becomes a potential difference between the electrostatic latent image and the developing sleeve. Accordingly, it moves onto the photosensitive drum. As a result, the toner adheres to the electrostatic latent image on the photosensitive drum and a toner image is formed on the photosensitive drum. The toner image formed on the surface of the photoconductor drum is conveyed to a transfer area where the transfer device and the photoconductor drum are in contact with each other. At this time, a voltage having a polarity opposite to that of the toner particles is applied to the transfer device. On the other hand, the rotational driving of the registration rollers is started, and in synchronism with the transfer of the toner image to the transfer area, the transfer of the image receiving paper nipped by the registration rollers is started. The image receiving paper 5 conveyed along the upstream guide means 10 projects into the transfer area. While passing through the transfer area, an electric field E is formed between the image receiving paper and the photoconductor drum by the charges accumulated on the back surface of the image receiving paper from the transfer device. As a result, the Coulomb force F =
The qE acts to transfer the toner on the photoconductor drum to the image receiving paper side. The toner that is not charged to the regular polarity or the toner that has an excessive mechanical adhesive force is not attracted to the image receiving paper side by the Coulomb force F and remains as transfer residual toner on the surface of the photosensitive drum.

The transfer residual toner is carried to the photosensitive drum and then to the collecting brush device to which an AC voltage is applied. When AC voltage is applied, the brush fiber vibrates,
The transferred transfer residual toner is sucked. As a result, the transfer residual toner is collected by the collecting brush device, and the surface of the photoconductor is cleaned.

On the other hand, the image receiving paper which has passed through the transfer area is conveyed to the fixing device along the downstream guide means 11. While passing through the fixing device, the toner image on the image receiving paper is heated and fixed. After passing through the fixing device, the image receiving paper is discharged out of the image forming apparatus, and the output of the fixed print image is completed.

Next, after the image forming process is completed, the first discharging process is started. In the first discharging step, a DC voltage having the same polarity as the charging polarity of the regular toner is applied to the recovery brush device. As a result, among the toners collected by the collection brush device, those having a regular charging polarity are discharged from the collection brush device onto the surface of the photoconductor. The voltage application to the charging device continues from the image forming process. Further, the voltage applied to the developing device is switched to only the DC voltage. Further, the voltage applied to the transfer device is switched to a DC voltage having a polarity opposite to the charging polarity of the regular toner. The toner discharged onto the surface of the photoconductor is carried and conveyed as the photoconductor rotates, and passes through the charging device. Ions having the same polarity as the regular toner are poured from the charging device to the surface of the photoconductor, so that the charge amount of the toner on the photoconductor increases. Next, the toner on the photoconductor passes through the developing device. At this time, since only the DC voltage is applied to the developing device, no alternating electric field is formed between the photoconductor and the developing device. Therefore, since the toner particles do not vibrate, the ability of collecting toner from the photoconductor to the developing device is extremely reduced. As a result, the toner on the photoconductor is carried and conveyed to the transfer device without being collected by the developing device. Since a voltage having a polarity opposite to the charging polarity of the regular toner is applied to the transfer device, the toner on the photoconductor is attracted to the transfer device by Coulomb force. The toner transferred to the transfer device side is removed from the transfer device surface by the scraping member of the toner removing device.

After the first toner discharging step is performed at least while the photosensitive member makes one round, the second discharging step is started. In the second discharging step, the polarity of the voltage applied to the recovery brush device is reversed. As a result, the regular toner remaining in the collecting brush device is discharged to the surface of the photoconductor, the toner being charged to the opposite polarity. Voltage application to other devices continues from the previous toner discharging step. The reverse polarity toner discharged onto the surface of the photoconductor is carried and conveyed as the photoconductor rotates, and passes through the charging device. Ions having the same polarity as the regular toner are poured from the charging device to the surface of the photoconductor, so that the toner on the photoconductor is reversed to the regular charge polarity. Next, the toner on the photoconductor passes through the developing device. At this time, since only the DC voltage is applied to the developing device, no alternating electric field is formed between the photoconductor and the developing device. Therefore, since the toner particles do not vibrate, the ability of collecting toner from the photoconductor to the developing device is extremely reduced. As a result, the toner on the photoconductor is carried and conveyed to the transfer device without being collected by the developing device. Since a voltage having a polarity opposite to the charging polarity of the regular toner is applied to the transfer device, the toner on the photoconductor is attracted to the transfer device by Coulomb force. The toner transferred to the transfer device side is removed from the transfer device surface by the scraping member of the toner removing device.

After the second toner discharging step is performed at least while the photosensitive member makes one revolution, the rotation of the photosensitive member is stopped. Further, the voltage application to each device is also stopped, and all the operations are completed.

In the above configuration, the scorotron charging device is used for description, but as described above, a contact type charging device such as a charging roller or a charging brush in which a photoconductor and a charging device are in contact may be used. However, in the case of the contact type charging device, in the first discharging process and the second discharging process,
It is desirable that the charging device and the recovery brush device have the same voltage polarity. If they are not the same, the toner discharged from the collecting brush adheres to the charging device, and a step or member for cleaning the charging device is required. Further, in the second discharging step, it is difficult to properly reverse the charge polarity of the toner discharged from the recovery brush device. For this reason, if the toner of the opposite polarity is to be collected by electrostatic force, the toner on the developing sleeve will move to the photoconductor, and it is extremely difficult to collect it in the developing device. Therefore,
When the contact type charging device is used, it is preferable to collect the toner in the developing device by a force other than the electrostatic force, or to provide a separate collecting means as described above.

In the present embodiment, a color image forming apparatus using a plurality of color toners may be used. The form of the color image forming apparatus will be described below.

FIG. 2 is a sectional view showing the configuration of the color image forming apparatus according to the embodiment of the present invention. In FIG. 2, 1K, 1
C, 1M, and 1Y are photosensitive drums corresponding to the toners of the respective colors. 6K, 6C, 6M, and 6Y are charging devices that charge the surface of each photoconductor drum. Although a roller-shaped charging device is shown in FIG. 2, a non-contact charging device such as a corotron charging device or a solid charging element may be used instead.
Further, a contact charging device such as a charging brush that contacts the surface of the photosensitive drum may be used.

Reference numerals 7K, 7C, 7M, and 7Y are exposure sources for forming an electrostatic latent image by irradiating the charged photosensitive drum surface of each color with light. Laser light, LED light, C
RT light, EL light or the like may be used as the exposure source.

Denoted at 8K, 8C, 8M and 8Y are developing devices for developing the electrostatic latent images on the photosensitive drums of the respective colors with the toners of the respective colors. The developing device may be either a two-component developing device or a one-component developing device, but as in the above, the two-component developing device is used in this embodiment.

12K, 12C, 12M and 12Y are recovery brush members as brush-like recovery means. The brush member 12 is arranged such that the brush fibers are substantially perpendicular to the surface of the photoconductor and are in contact with the surface of the photoconductor. Although the fixed brush member is shown in FIG. 2, it may be a roll-shaped brush member. Further, the roll-shaped brush member may rotate, and its rotation direction may be either forward or reverse with respect to the surface of the photoconductor. For the brush member 12, a fiber (pile) in which a conductive material is dispersed in a yarn such as nylon, rayon, cellulose, or polyester is woven or flocked. The pile length is 0.5 to 7 mm, the pile thickness is 2 to 10 denier, and the pile density is 100 to 300 F /
It is preferably mm ² . A power source (not shown) for the recovery brush members as shown in FIG. 1 is connected to each of the recovery brush members. A transfer belt 15 carries and conveys the image receiving paper. The transfer belt uses a resin material such as PTFE, PFA, TEP, polyimide, or polycarbonate as a base material. Further, a conductive material may be dispersed in order to adjust the electric resistance of the transfer belt. Also, 18K,
18C, 18M, and 18Y are bias supply means that come into contact with the respective photosensitive drums via the transfer belt. As the bias supply means, a brush shape, a roller shape, a blade shape, a film shape or the like may be used as long as it can supply a predetermined charge to the back surface of the transfer belt. Further, a non-contact corona discharger or a solid charging element may be used on the back surface of the transfer belt. Reference numeral 14 is a belt support roller that stretches the transfer belt 15. Further, reference numeral 16 is a paper suction roller for applying a bias voltage to the image receiving paper conveyed on the transfer belt to attract and fix the image receiving paper to the transfer belt by Coulomb force. Reference numeral 17 denotes a charge eliminating needle for removing charge from the image receiving paper to separate the image receiving paper from the transfer belt 15.

Reference numeral 13 is a toner removing device for removing the toner adhering to the transfer belt, and an intermediate roller for electrostatically collecting the toner adhering to the brush roller and the brush roller 13a and the brush roller which comes into contact with and rotates with the transfer belt. 13b and a scraping member that mechanically scrapes the toner attached to the intermediate roller. Other than this, the toner removing device 13 may use a rubber blade, a metal scraper, a web, or the like.

Next, the operation of the color image forming apparatus of the present invention will be described with reference to the timing charts of FIGS.

First, the color image forming apparatus receives an image signal transmitted from the outside such as a computer and starts a preparatory step before image formation. First, the fixing device (not shown) is heated and, after reaching a predetermined temperature, the rotational driving of the fixing device is started. Further, the rotational driving of the transfer belt and the photosensitive drum is also started. At this time, a predetermined voltage is applied to the charging device for each color, and the photosensitive drum is charged to a predetermined surface potential. Further, the rotational driving of the developing devices for the respective colors is also started.
At this time, a voltage in which a DC voltage is superimposed on an AC voltage is applied to the developing sleeve. Further, an AC voltage is applied to the recovery brush member. In addition, the image receiving paper stored in the paper feeding cassette (not shown) in FIG. 2 is fed to a registration roller (not shown), and is kept sandwiched between the registration rollers.

After the above preparation process is completed, the image forming process is started while continuing the operation of each member. At the beginning,
When the charged surface of the photosensitive drum is conveyed to a position facing the exposure source, the surface of the photosensitive drum is irradiated with light according to the received image signal. As a result, the charging potential of the surface of the photosensitive drum in the area irradiated with light is lowered. As a result, an electrostatic latent image is formed on the surface of the photosensitive drum. Next, when the electrostatic latent image on the surface of the photoconductor drum is conveyed to a position facing the developing device, the toner on the developing sleeve to which a predetermined voltage is applied becomes a potential difference between the electrostatic latent image and the developing sleeve. Accordingly, it moves onto the photosensitive drum. As a result, the toner adheres to the electrostatic latent image on the photosensitive drum and a toner image is formed on the photosensitive drum. The toner image formed on the surface of the photoconductor drum is conveyed to a transfer area where the transfer belt and the photoconductor drum are in contact with each other. At this time, a voltage having a polarity opposite to that of the toner particles is applied to the bias supply means. On the other hand, the rotational driving of the registration rollers is started, and the image receiving paper nipped by the registration rollers is started to be conveyed to the transfer belt. By passing between the transfer belt and the paper suction roller, the image receiving paper is attracted to the transfer belt by Coulomb force, is carried and carried by the transfer belt, and enters the transfer area of each color.
While passing through the transfer area, an electric field E is generated between the image receiving paper and the photoconductor drum by the electric charge accumulated on the back surface of the image receiving paper from the transfer device.
Is formed. As a result, the Coulomb force F = qE due to the electric charge q of the toner and the electric field E acts, and the toner on the photosensitive drum is transferred to the image receiving paper side. The toner that is not charged to the regular polarity or the toner that has an excessive mechanical adhesive force is not attracted to the image receiving paper side by the Coulomb force F and remains as transfer residual toner on the surface of the photosensitive drum.

The transfer residual toner is conveyed to the photosensitive drum and then to the collecting brush device to which an AC voltage is applied. When AC voltage is applied, the brush fiber vibrates,
The transferred transfer residual toner is sucked. As a result, the transfer residual toner is collected by the collecting brush device, and the surface of the photoconductor is cleaned.

On the other hand, the image receiving paper that has successively passed through the transfer areas of the respective colors is conveyed to the vicinity of the charge elimination needle in the state where the color toner images of a plurality of colors are formed. In the vicinity of the charge removal needle, the transfer belt and the image reception paper are separated by the curvature of the support roller and the charge removal on the back surface of the image reception paper by the charge removal needle. The image receiving paper separated from the transfer belt is conveyed to the fixing device. While passing through the fixing device, the toner image on the image receiving paper is heated and fixed. After passing through the fixing device, the image receiving paper is discharged out of the image forming apparatus, and the output of the fixed print image is completed. On the other hand, the transfer belt from which the image receiving paper has been separated passes through the toner removing device to remove the toner and paper dust adhering to the transfer belt.

Next, after the image forming process is completed, the first discharging process is started. In the first discharging step, a DC voltage having the same polarity as the charging polarity of the regular toner is applied to the recovery brush device. As a result, among the toners collected by the collection brush device, those having a regular charging polarity are discharged from the collection brush device onto the surface of the photoconductor. Further, the voltage applied to the charging device is the same as that of the recovery brush. Further, the voltage applied to the developing device is switched to only the DC voltage. Further, the voltage applied to the bias supply means is switched to a DC voltage having a polarity opposite to the charging polarity of the regular toner. The toner discharged onto the surface of the photoconductor is carried and conveyed as the photoconductor rotates, and passes through the charging device. Since a voltage having the same polarity as the charging polarity of the toner is applied to the charging device, the toner on the photoconductor passes without adhering to the charging device. Next, the toner on the photoconductor passes through the developing device. At this time, since only DC voltage is applied to the developing device,
No alternating electric field is formed between the photoconductor and the developing device. Therefore, since the toner particles do not vibrate, the ability of collecting toner from the photoconductor to the developing device is extremely reduced. As a result, the toner on the photoconductor is carried to the transfer area without being collected by the developing device. Since a voltage having a polarity opposite to the charging polarity of the regular toner is applied to the bias supply means, the toner on the photoconductor is attracted to the transfer belt side by Coulomb force. The toner transferred to the transfer belt side is conveyed to the toner removing device after passing through the transfer area of each color. In the toner removing device, the toner is mechanically peeled off from the transfer belt by the rotation of the brush roller. The toner attached to the brush roller is transferred to the intermediate roller by the Coulomb force and is removed by the scraping member.

The first toner discharging step is performed and then the second discharging step is started while at least one rotation of the photosensitive member is made and toner is conveyed from the most upstream transfer area to the most downstream transfer area. . In the second discharging step, the polarity of the voltage applied to the recovery brush device is reversed. As a result, the regular toner remaining in the collecting brush device is discharged to the surface of the photoconductor, the toner being charged to the opposite polarity. Further, a voltage equivalent to that of the recovery brush device is applied to the charging device. Further, a voltage having the same polarity as the regular toner charging polarity is applied to the bias supply means. The reverse polarity toner discharged onto the surface of the photoconductor is carried and conveyed as the photoconductor rotates, and passes through the charging device. Since a voltage having the same polarity as the charging polarity of the discharged toner is applied to the charging device, the toner passes through without being attached to the charging device. Next, the toner on the photoconductor passes through the developing device. At this time, since only the DC voltage is applied to the developing device, no alternating electric field is formed between the photoconductor and the developing device. Therefore, since the toner particles do not vibrate, the ability of collecting toner from the photoconductor to the developing device is extremely reduced. As a result, the toner on the photoconductor is carried and conveyed to the transfer area without being collected by the developing device. Since a voltage having a polarity opposite to the charging polarity of the toner discharged from the collecting brush device is applied to the bias supply means, the toner on the photoconductor is attracted to the transfer belt side by Coulomb force. The toner that has sequentially passed through the transfer regions of the respective colors and transferred to the transfer belt side is removed from the transfer belt surface by the toner removing device as in the first discharging step.

After the second toner discharging step is performed while the photosensitive member makes at least one round and the toner is conveyed from the most upstream transfer region to the most downstream transfer region, the transfer belt and the photosensitive member are rotated. Stop. Further, the voltage application to each device is also stopped, and all the operations are completed.

In the above description, the transfer belt is shown as a component for carrying the image receiving paper, but a drum shape or a roller shape may be used instead of the belt. Alternatively, an intermediate transfer belt may be used in which toner images of four colors are formed on the belt without directly carrying the paper and then secondary transfer is performed to the image receiving paper.

Further, in the above embodiment, the contact type charging system such as the charging roller is used, and the toner discharged from the collecting brush device is not collected in the developing device. In the case of the contact charging method, it is desirable that the charging device and the recovery brush device have the same voltage polarity in the first discharging process and the second discharging process. If they are not the same, the toner discharged from the collecting brush adheres to the charging device, and a step or member for cleaning the charging device is required. Also,
In the second discharging step, it is difficult to properly reverse the charge polarity of the toner discharged from the collecting brush device. For this reason, if the toner of the opposite polarity is to be collected by electrostatic force, the toner on the developing sleeve will move to the photoconductor, and it is extremely difficult to collect it in the developing device. Therefore, when the contact type charging device is used, it is preferable to collect the toner in the developing device by a force other than the electrostatic force or to provide a separate collecting means as described above. Further, in the case of the color image forming apparatus, the upstream side toner is mixed in the recovery brush device that comes into contact with the downstream side photosensitive drum. Therefore, when the toner accumulated in the collecting brush device is collected by the developing device, a different color toner is mixed in the developing device, which causes a problem of so-called color mixing in which the color reproduction range is narrowed. Therefore, in order to avoid the problem of color mixing, it is preferable to collect and remove the toner discharged onto the photoconductor by a device other than the developing device.

Next, a specific embodiment of the recovery brush device according to the present invention will be described.

(Example 1) A woven square brush having the following specifications was attached to the above-mentioned image forming apparatus as a recovery brush device, and the transfer residual toner recovery capability was evaluated.

Brush fiber material: Nylon-based conductive thread Brush thickness: 6 denier Brush density: 100 kF / inch ² Pile length: 5 mm Width: 4 mm Biting into the photoconductor: Approximately 0.5 mm The photoconductor is aluminum. An OPC drum having a film thickness of about 20 μm and φ16, in which CGL and CTL were sequentially laminated on a raw tube, was used. The toner has a volume of 50% and a diameter of about 6.5μ.
m, the coefficient of variation was about 25%, and the shape factor was about 1.25. The amount of developing toner on the surface of the photoconductor was set to about 0.5 mg / cm ² . At this time, the amount of charge of the toner developed on the surface of the photoconductor was about -25 μC / g. Further, as a transfer device, an electric resistance of about 10 ⁶ to 10 ⁷ Ω, φ1
2 transfer rollers were used. The transfer roller has a sponge layer in which carbon black is dispersed in EPDM and has a thickness of about 70 μm.
A roller provided with m conductive PFA layer was used. Further, the transfer roller was brought into contact so that the contact width (transfer area) with the photoreceptor was about 2 mm. The photosensitive drum was rotated at a speed of about 75 mm / s, and a voltage of about 800 V was applied to the transfer roller.

As a result of applying a DC voltage to the recovery brush device and measuring the surface potential of the photoconductor, the discharge start voltage between the recovery brush device and the surface of the photoconductor is about 520V.
Met.

Under the above conditions, the peak-to-peak voltage Vpp of the sinusoidal AC voltage applied to the recovery brush device and the frequency f are changed to visually observe the amount of toner adhered to the surface of the photosensitive member before and after passing through the recovery brush device. Observed at. The results are shown in (Table 1).

[0064]

[Table 1]

In the above table, x indicates the level at which the toner can be visually confirmed on the photoconductor even after passing through the collecting brush device. Further, ◯ indicates a level at which the toner cannot be visually confirmed on the photoconductor after passing through the collecting brush device. Furthermore E
Indicates a case where abnormal discharge occurs between the recovery brush and the photoconductor.

The DC voltage superimposed on the AC voltage is -6
No significant difference was observed in the recovery capacity even when the voltage was varied from 00 to + 600V.

At a frequency of about 100 Hz, 1000
It was confirmed that when a peak-to-peak voltage of V or more was applied, the brush fibers vibrated and toner mist was generated from the contact area between the brush and the photoconductor. When the frequency was further increased, the vibration of the brush fibers was not visible, but the amount of toner mist increased. Since the frequency is high, it is considered that the brush fibers vibrate slightly at a level that cannot be visually confirmed.

From the above results, it has been found that the transfer residual toner can be recovered by the recovery brush device by setting it in a specific AC voltage setting range.

(Embodiment 2) Next, an uncharged toner before being supplied to the developing device was made to adhere to the photosensitive member, and the same experiment as above was conducted. The results are shown in (Table 2).

[0070]

[Table 2]

The DC voltage superimposed on the AC voltage is -6
No significant difference was observed in the recovery capacity even when the voltage was varied from 00 to + 600V.

From the above results, the recoverable area is narrower than that in (Table 1), but even if the uncharged toner is supplied to the recovery brush, the recovery brush device can be set by setting a specific AC voltage setting range. It turned out that it can be recovered.

(Embodiment 3) Next, with the toner being accumulated in the fixed brush device, the frequency was fixed at 6 kHz,
By changing the peak-to-peak voltage and the superimposed DC voltage, the effect of discharging the toner from the recovery brush device was evaluated. The results are shown in (Table 3).

[0074]

[Table 3]

In the above table, x indicates a case where the toner adhesion to the rotating photosensitive drum is not visually recognized when the above voltage is applied to the collecting brush device, that is, the toner is discharged from the collecting brush. No case shown. In addition, △ is, when the above voltage is applied to the recovery brush device,
A case is shown in which toner adheres to the rotating photoconductor drum and toner remains on the recovery brush device.

From the above results, when the peak-to-peak voltage is low, or when only the DC voltage is used, the toner ejection performance is recognized although the toner is not sufficient.

(Example 4) Next, the test of Example 3 was carried out until the photosensitive drum rotated twice, and then the polarity of the DC voltage applied to the recovery brush device was reversed, and the same procedure as in (Table 3) was conducted. An evaluation was made. The results are shown in (Table 4).

[0078]

[Table 4]

In the above table, ◯ indicates a case where toner adhesion to the rotating photosensitive drum is visually recognized when the polarity of the DC voltage applied to the recovery brush device is reversed.

From the above results, when the peak-to-peak voltage is low, or when only the DC voltage is used, the polarity of the DC voltage is reversed to further improve the toner discharging performance.

From the above results, the action and effect of the present invention will be considered as follows.

As can be seen from the second embodiment, when the peak-to-peak voltage of the AC voltage is set to be twice the discharge start voltage or more and the predetermined frequency is set, the toner is collected by the collecting brush device regardless of the charging polarity. Therefore, the force of directly attracting the toner to the recovery brush is considered to be a force other than the electrostatic force. In addition, since it is considered that the brush fiber is mechanically vibrating in Example 1, it is considered that the mechanical force of the brush fiber is acting.

That is, by vibrating the brush fibers,
Mechanical adhesion occurs between the toner and the brush fibers. When the vibration is further continued, the toner sunk into the brush, and the toner is held in the brush fiber. As a result, it is considered that the toner is collected on the collecting brush side regardless of the charging polarity of the toner.

Further, it is considered that the peak-to-peak voltage which is more than twice the discharge starting voltage has an effect of vibrating the brush fiber. That is, at the time of the negative voltage peak, negative charges are discharged from the tip of the brush fiber to the surface of the photoconductor.
As a result, a negatively charged region A is formed on the surface of the photoconductor in the vicinity of the tips of the brush fibers. When the tip of the brush is charged with a negative electric charge after discharging, the brush fibers and the surface of the photoconductor electrostatically repel because of the same polarity as the photoconductor charging polarity. If there is an uncharged or positively charged area B around the tip of the brush on the surface of the photoconductor, the tip of the brush is attracted to the area B. As a result, a force that moves from the area A to the area B on the surface of the photoconductor acts on the tip of the brush. next,
At the time of the negative voltage peak, a force opposite to the above acts. As a result, it is considered that the brush fibers vibrate. The distance between the area A and the area B is determined by the frequency of the AC voltage, the relative speed between the recovery brush device and the photoconductor, and the brush fiber density. It is considered that the frequency dependence as in Examples 1 and 2 was observed because there is a space between the regions AB where the brush fibers are easily vibrated.

On the contrary, in the third embodiment, the toner is not discharged from the recovery brush unless the peak-to-peak voltage is lower than the discharge start voltage. This is considered to be because the toner moves inside the brush when the brush fiber vibrates. Therefore, it is considered preferable that the brush fibers do not vibrate when the toner is discharged. Example 3 corresponds to the case where the peak-to-peak voltage is 500 V or less. At this time, it is considered that the toner having the same polarity as the superimposed DC voltage has separated from the brush and moved to the photoconductor. In Example 4,
It is considered that, by reversing the polarity of the DC voltage, the toner charged to the opposite polarity to that in Example 3 was discharged from the brush.

Although the polarity of the DC voltage component is reversed when the toner is discharged from the collecting brush device, uncharged toner is accumulated in the collecting brush device in this method. Therefore, as the material of the collected brush fiber, a material that easily charges the toner to either positive or negative polarity is preferable. In this test, nylon fibers, which tend to be positively charged by themselves in the charging series, were used. By using such a material, when the brush fiber vibrates, the toner taken into the brush is gradually charged to a specific polarity, so that the toner can be discharged electrostatically.

[0087]

As described above, according to the present invention, a recovery brush device is used to form an oscillating field of brush fibers, thereby recovering the toner remaining on the photoconductor regardless of the positive and negative charging polarities. You can Further, by switching the positive and negative polarity DC voltage to the collecting brush and applying it, it becomes possible to discharge the toner from the collecting brush to the surface of the photoconductor and convey it to the second collecting means. As a result, the configuration of the cleaning device for the photoconductor is extremely simple and space is saved, and it is possible to reduce the size and cost of the image forming apparatus.

[Brief description of drawings]

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

FIG. 2 is a sectional view showing the configuration of a color image forming apparatus according to the present invention.

FIG. 3 is a simplified configuration diagram of a conventional brush-type cleaning device.

FIG. 4 is a voltage application timing chart according to the image forming apparatus of the present invention.

FIG. 5 is a voltage application timing chart according to the color image forming apparatus of the present invention.

[Explanation of symbols]

1 photoconductor drum 2 Registration roller 3 Transfer device 4 fixing device 5 Image receiving paper 6 charging device 7 Exposure source 8 developing device 10 Upstream guide means 11 Downstream guide means 12 Collection brush device 13 Toner remover 14 Belt support roller 15 Paper transport belt 16 Paper suction device 17 Power supply for recovery brush member 101 photoconductor drum 102 brush roller 103 Intermediate roller 104 scraping member

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2H077 AA37 AC16 AD06 AD35 AD36                       AE06 EA03 EA16 GA13                 2H134 GA01 GA05 GB02 HB01 HB03                       HB16 HB17 HB18 HB19 HF13                       JA05 JA11 KB04 KD04 KD12                       KG08 KH03 KH09 KH17 MA02                       MA07 MA09 MA11 MA16 MA17                 2H200 GA16 GA18 GA23 GA34 GA45                       GA47 GA57 GB13 GB25 GB26                       GB37 HA02 HB12 JA02 JA25                       JA26 JA27 JB10 JB12 JB17                       JB18 JB20 JB41 LB09 LB13                       LB17 LB18 MA03 MA08 MA20                       MB01 MC01

Claims (14)

[Claims] 1. An image carrier, a developing means for forming a visible particle image on the image carrier by the visible particles, a transfer means for transferring the visible particle image to an image receiving member, and an image carrier after the transfer. Brush-shaped collecting means for collecting the visible image particles remaining on the top, brush vibrating means for vibrating the brush fibers of the brush-shaped collecting means during the image forming operation, and DC voltage of both positive and negative polarities during the non-image forming operation. An image characterized by comprising a voltage applying means for switching and applying to the brush-like collecting means, and a second collecting means for collecting the visible image particles discharged from the brush-like collecting means during the non-image forming operation. Forming equipment. 2. The image forming apparatus according to claim 1, wherein the brush vibrating unit is an AC voltage applying unit that applies an AC voltage to the brush-like collecting unit. 3. The image forming apparatus according to claim 2, wherein the AC voltage applying unit applies a voltage that is at least twice as high as a discharge starting voltage between the surface of the image carrier and the brush-like collecting unit. . 4. The second collecting means is composed of an image carrier that carries and conveys the discharged image particles, and a transfer means that collects the image particles on the image carrier. The image forming apparatus according to item 1. 5. The image forming apparatus according to claim 4, further comprising image developing particle removing means for removing the developing particles adhering to the surface of the transfer means, and image developing particle storing means for storing the removed developing particles. The image forming apparatus described. 6. The second collecting means is composed of an image carrier that carries and conveys the discharged image particles, and a developing means that collects the image particles on the image carrier. The image forming apparatus according to item 1. 7. The image forming apparatus according to claim 7, wherein the brush-shaped collecting unit is made of a material that easily charges the image-forming particles to a predetermined charging polarity. 8. A developing step for forming a visible particle image with visible particles on an image carrier, a transfer step for transferring the visible particle image to an image receiving member, and a residual toner on the image carrier after transfer. The image particle image is first collected in the brush collecting means by the vibrating brush brush fibers during the image forming operation, and the positive and negative polarity DC voltage is sequentially applied to the brush collecting means during the non-image forming operation. And a second collecting step for collecting the visible image particles discharged by the discharging step to a means other than the brush collecting means. Forming method. 9. The image forming method according to claim 8, wherein an AC voltage is applied to the brush-shaped collecting means in the first collecting step. 10. The AC voltage applied to the brush-like collecting means in the first collecting step is at least twice as high as the discharge starting voltage between the surface of the AC image carrier and the brush-like collecting means. The image forming method according to claim 9, wherein 11. The second collecting step comprises a carrying step for carrying and carrying the discharged visible image particles on an image carrier, and a transfer collecting step for collecting the visible particle on the image carrier by a transfer means. 9. The image forming method according to claim 8, wherein: 12. The method according to claim 11, further comprising a visible particle removing step of removing visible particles adhering to the surface of the transfer means and a visible particle storing step of storing the removed visible particles. Image forming method. 13. The second collecting step includes a carrying step for carrying and carrying the discharged visible image particles by an image carrier, and a developing and collecting step for collecting the visible particles on the image carrier by a developing means. 9. The image forming method according to claim 8, comprising: 14. The image forming method according to claim 1, wherein the brush-shaped collecting means is made of a material that easily charges the image-forming particles to a predetermined charging polarity.