JP2001038958A - Imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent adhesion of developer to an exposing plane and generation of spark discharge by providing an insulating member at least on the side facing a body to be charged of a conductive member provided substantially in parallel with the exposing plane. SOLUTION: On the downstream side in the rotational direction of a photosensitive drum 1 positioned contiguously to the exposing plane 21 of an aligner, a conductive member 22 is provided along the exposing plane 21 in parallel therewith and applied with a bias. A bias applied to a magnetic brush charger can be utilized as the bias being applied to the conductive member 22. The applying bias may be a DC voltage superposed or not superposed with an AC voltage. A conductive member 23 is also provided on the upstream side of the exposing plane 21 of the aligner along the exposing plane 21 and the conductive member 23 is grounded. Furthermore, the surface of the conductive member 22 being applied with a bias is coated with insulating paint (e.g. epoxy resin).

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 using an image forming method for developing an electrostatic latent image formed on an image carrier corresponding to an image to be recorded with a developer and recording the image on paper or the like. About.

[0002]

2. Description of the Related Art Hitherto, many image forming apparatuses using an electrophotographic system or an electrostatic recording system have been devised, but the schematic configuration and operation will be briefly described with reference to FIG.

In the image forming apparatus shown in FIG. 3, when a copy start signal is input, the photosensitive drum 1 is charged by a charger 3 to a predetermined potential. On the other hand, an original irradiating lamp La for the original G placed on the original platen 10,
When the short focus lens array Le and the CCD sensor C form an integrated reader unit 9 and scan while irradiating the original G, the reflected light of the illumination scan light on the original surface is imaged by the short focus lens array Le. The light is incident on the CCD sensor C. The CCD sensor C is a light receiving section, a transfer section,
It consists of an output unit. The light signal is converted into a charge signal in the CCD light receiving unit, and the transfer unit sequentially transfers the light signal to the output unit in synchronization with the clock pulse. The output unit converts the charge signal into a voltage signal, amplifies the signal, reduces the impedance, and outputs the voltage signal. The obtained analog signal is subjected to well-known image processing, converted into a digital signal, and sent to the printer unit 11. In the printer unit 11, an original image is formed on the surface of the photosensitive drum 1 by a laser exposure hand-throw 2 in which the light of a solid-state laser element which is turned on and off in response to the image signal is scanned by a rotating polygon mirror rotating at high speed. To form an electrostatic latent image corresponding to. Laser exposure means 2
As shown in Fig. 4, instead of laser, LED
Some use an array head.

Next, the electrostatic latent image is developed by a developing device 4 containing a so-called two-component developer having toner particles and carrier particles.
And a toner image is obtained on the photosensitive drum 1.

[0005] The toner image formed on the photosensitive drum 1 in this manner is electrostatically transferred onto a transfer material by the transfer device 7. Thereafter, the transfer material is electrostatically separated, conveyed to the fixing device 6, and thermally fixed to output an image.

In recent years, because of the advantages such as low ozone and low power, a contact charging device, that is, a charging member which applies a voltage to a member to be charged, is brought into contact with the above-described photosensitive drum 1 as a charging member of the photosensitive drum 1. A device of a system for charging a member to be charged has been put to practical use.

As a charging member of this type, a magnetic brush type device is preferably used in terms of stability of charging contact.

In a magnetic brush type contact charging device, conductive magnetic particles are magnetically constrained directly on a magnet or a sleeve containing a magnet, and are stopped or rotated to contact a member to be charged. By applying a voltage thereto, charging is started.

A brush formed of conductive fibers on a brush (hereinafter referred to as a fur brush) or a conductive rubber roller in which conductive rubber is rolled is also preferably used as a contact charging member.

In particular, when such a contact charging member is used, a member having a surface layer in which conductive fine particles are dispersed on a normal organic photoreceptor, or an amorphous silicon photoreceptor is used as a member to be charged. It is possible to obtain, on the surface of the member to be charged, a charging potential substantially equal to the DC component of the applied bias. Such a charging method is called injection charging. The use of the injection charging does not use a discharge phenomenon in which a charged object is charged using a corona charger, so that a completely ozone-free and low-power-consumption charging is possible, which has attracted attention.

In the cleanerless image forming apparatus having the above-described magnetic brush charger for simultaneous cleaning with development, when an LED array head is used as the exposure means, the drum and the exposure surface are close to each other. The transfer residual toner, which is collected once by the charger, and then discharged after its polarity has been adjusted, flies from the drum to the exposure surface along with the change in the potential distribution on the drum caused by image exposure in the next process. A defect occurs that the image is defective due to the adhesion to the surface (FIG. 5). Therefore, as shown in FIG. 6, a conductive member is provided adjacent to and parallel to the exposure device, and the conductive member has the same polarity as the surface potential of the image carrier after the charging process and the absolute value is equal to or more than the same value. It has also been proposed to apply a bias to prevent scattering of the discharged toner from the surface of the image carrier due to exposure.

[0012]

However, in a cleaner-less image forming apparatus having a magnetic brush charger as described above, which performs simultaneous development and cleaning, the magnetic brush charger collects the toner once, and then discharges the toner after making the polarity uniform. The remaining transfer toner flies from the drum to the exposed surface with the change in the potential distribution on the drum caused by the image exposure in the next process, and adheres to the exposure device, exposing the image to prevent image defects. A conductive member is provided adjacent to and parallel to the apparatus, and a bias having the same polarity as the surface potential of the image carrier after the charging process and the absolute value of which is equal to or greater than that of the image carrier after the charging process is applied to the conductive member, so that the image carrier is exposed to light. When trying to prevent scattering of the discharged toner from the body surface, since the conductive member and the drum are close to each other, paper dust, toner, etc. Spark discharge occurs between the drum and the conductive member by the accumulation, there is a problem that damage the drum.

The present invention has been made to solve the problems of the prior art, and an object of the present invention is to provide a stable image for a long period by preventing the developer from adhering to an exposed surface, Another object of the present invention is to provide an image forming apparatus capable of preventing occurrence of spark discharge between a conductive member to which a predetermined voltage is applied and a member to be charged.

[0014]

In order to achieve the above-mentioned object, the present invention provides a charging member which contacts a member to be charged and charges the member with a bias voltage applied thereto; Image developing means for forming a latent image by performing image exposure on the developing means, and a developing means having a developer carrying member for carrying a developer, and developing the latent image with the developer to form a developer image And a transfer means for transferring the developer image to a transfer material, wherein the developing means recovers the developer remaining on the charged body after being transferred to the transfer material by the developing means. A conductive member that is provided adjacent to and substantially parallel to the exposure surface of the image exposure unit that faces the charged body and that is applied with a predetermined voltage, and that faces at least the charged member of the conductive member; Insulation on the side to be Characterized in that a wood.

According to this structure, in the cleaner-less apparatus for performing simultaneous development and cleaning, the conductive member provided adjacent to and substantially parallel to the exposure surface of the image exposure means facing the member to be charged is provided. By applying a predetermined voltage, the developer remaining on the member to be charged is prevented from adhering to the exposed surface, and a stable image can be provided for a long period of time. In addition, the occurrence of spark discharge between the conductive member and the member to be charged can be prevented by the insulating member provided at least on the side of the conductive member facing the member to be charged.

Here, the insulating member may be provided so as to cover the surface of the conductive member, or another insulating member may be provided. The method of forming the insulating member is not limited to these. Further, the insulating member needs to be interposed at least between the conductive member and the member to be charged, but may be formed so as to cover the front surface of the conductive member.

Further, the insulating member may be formed by a coating process on a surface of the conductive member.

The object to be charged is provided rotatably with respect to the image exposure means, and the conductive member is provided downstream of the image exposure means in the rotation direction of the object to be charged. It may be.

Also, a conductive member is provided adjacent to the exposure surface of the image exposure means and substantially in parallel with the exposure surface on the upstream side in the rotation direction of the charged member with respect to the exposure means. It may be.

The potential of the conductive member to which the predetermined voltage is applied may have the same polarity as the charged surface potential of the member to be charged.

Further, it is preferable that the absolute value of the potential of the conductive member to which the predetermined voltage is applied is not less than the absolute value of the surface potential of the charged member after charging.

Further, a power supply for applying a bias voltage to the charging member may be used as a power supply for applying a voltage to the conductive member.

Further, an electric field generated by a predetermined voltage applied to the conductive member is formed by removing the residual developer discharged to the member to be charged after being collected by the charging unit and causing the image exposure unit to remove the residual developer from the member to be charged. It is preferable that it is formed in a direction that suppresses the flight to

Further, as the bias voltage applied to the charging member, a bias voltage in which an alternating voltage is superimposed on a DC voltage may be used.

The object to be charged may have a photosensitive layer and a surface layer, and the surface layer may have a resin and conductive fine particles.

[0026] The charging member may include magnetic particles and a magnetic particle carrier for supporting the magnetic particles, and the magnetic particles may be in contact with the member to be charged.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The image forming apparatus used in the embodiment shown in FIG. 1 will be briefly described.

Here, since the leader unit 9 is the same as that of the conventional example, the description is omitted.

The exposure means 2 as a latent image forming means uses an LED array writer head here.

The charging means used in this embodiment is a magnetic brush charger 3 using a magnetic carrier. The charging magnetic carrier has an average particle diameter of 10 to 100 μm and a saturation magnetization of 20 to 250 emu / cm ^3. And the resistance is 1 × 10 ² to 1 × 1
0 ¹⁰ Ω · cm is preferable, and considering that there is an insulation defect such as a pinhole on the photosensitive drum, 1 × 1
0 it is preferable to use a ⁶ Omega · cm or more. In order to improve the charging performance, it is better to use one having as small a resistance as possible.
m, saturation magnetization 200 emu / cm ³ , resistance 5 × 10 ⁶ Ω · cm
Was used. Further, the magnetic carrier for charging used in the present embodiment is obtained by adjusting the resistance by oxidizing and reducing the surface of ferrite.

Here, as the photosensitive drum 1 used in the present invention, a commonly used organic photoreceptor or the like can be used.
When a material having a surface layer having a material of 0 ² to 10 ¹⁴ Ω · cm or an amorphous silicon photoreceptor is used, charge injection charging can be realized, which is effective in preventing ozone generation and reducing power consumption. . Further, the chargeability can be improved. Therefore, in this embodiment, the photosensitive drum 1 is used, which is a negatively charged organic photosensitive member and has the following first to fifth five layers provided in order from the bottom on an aluminum drum base having a diameter of 30 mm.

The first layer is an undercoat layer, and is a conductive layer having a thickness of 20 / μm provided to smooth defects and the like of an aluminum substrate (hereinafter referred to as an aluminum substrate).

The second layer is a positive charge injection preventing layer, which serves to prevent positive charges injected from the aluminum substrate from canceling out negative charges charged on the surface of the photoreceptor, and comprises an amylan resin and methoxymethylated nylon. 1 × 10 ⁶ Ω · c
This is a medium resistance layer having a thickness of 1 μm and a resistance adjusted to about m.

The third layer is a charge generating layer, and is a layer having a thickness of about 0.3 / μm in which a disazo pigment is dispersed in a resin.
Exposure generates positive and negative charge pairs.

The fourth layer is a charge transport layer, in which hydrazone is dispersed in a polycarbonate resin, and is a P-type semiconductor. Therefore, the negative charges charged on the photoreceptor surface cannot move through this layer, and only the positive charges generated in the charge generation layer can be transported to the photoreceptor surface.

The fifth layer is a charge injection layer, and is a coating layer of a material in which ultrafine SnO ₂ particles are dispersed in a binder of an insulating resin. Specifically, a material in which 70% by weight of SnO ₂ particles having a particle size of about 0.03 μm obtained by doping an insulating resin with antimony which is a light-transmitting insulating filler to reduce the resistance (conducting conductivity) is dispersed in the resin. It is a coating layer.

The coating solution thus prepared was applied to a thickness of about 3 μm by a suitable coating method such as dipping coating method, spray coating method, roll coating method, beam coating method, etc. to form a charge injection layer. The surface resistance is 10 ¹³ Ω · cm. By controlling the surface resistance in this way, the direct chargeability is improved and a high quality image can be obtained. Photoconductor is OPC
Not only that, but also an a-Si drum can be realized, and further high durability can be realized. Here, the volume resistance of the surface layer is a value measured by arranging metal electrodes at an interval of 200 μm, flowing a preparation liquid for the surface layer into the film between the electrodes, and applying a voltage of 100 V between the electrodes. The measurement is a value measured under the conditions of a temperature of 23 ° C. and a humidity of 50% RH.

Next, the developing step will be described. In general, the developing method is a method of coating non-magnetic toner on a sleeve with a blade or the like, coating magnetic toner by magnetic force, transporting the toner, and developing the photosensitive drum in a non-contact state (one-component non-contact development) ) And a method of developing the toner coated in the manner described above in contact with the photosensitive drum (one-component contact development), and using a mixture of toner particles and a magnetic carrier as a developer by magnetic force A method of transporting and developing the photosensitive drum in a contact state (two-component contact development) and a method of developing the two-component developer in a non-contact state (two-component non-contact development)
Are roughly divided into four types. The two-component contact development method is often used from the viewpoints of high image quality and high stability.

At least at the time of development, the developing sleeve 41 has a region closest to the photosensitive drum 1 by about 500 μm.
m so that the developer can be developed while being in contact with the photosensitive drum 1. In the two-component developer used in the present embodiment, the toner particles have an average particle diameter of 20 nm for a negatively charged toner having an average particle diameter of 6 μm.
A magnetic carrier having a saturation magnetization of 205 emu / cm ^{3 and} an average particle diameter of 35 μm was used as a magnetic carrier for development. A mixture of this toner and a magnetic carrier for development in a weight ratio of 6:94 was used as a developer. At this time, the toner in the developer had a triboelectric charge of about 25 × 10 ⁻³ c / kg.

A DC voltage and an AC voltage are applied to the developing sleeve 41 from a power supply (not shown). In this embodiment, the DC voltage is -480 V and the AC voltage is Vpp = 15.
00V and Vf = 3000 Hz are applied. In general, in the two-component developing method, when an AC voltage is applied, the developing efficiency is increased, and the quality of an image is high. On the contrary, there is a risk that fogging is likely to occur. For this reason, fog is generally prevented by providing a potential difference between the DC voltage applied to the developing device 4 and the surface potential of the photosensitive drum 1. The potential difference for preventing fog is called a fog removal potential (Vback), and the potential difference prevents toner from adhering to a non-image area during development.

This toner image is then transferred to a recording material by the transfer device 7. The transfer device 7 is an endless belt 71
Is suspended between the driving roller 72 and the driven roller 73,
It is rotated in the direction of the arrow in FIG. Further, a transfer charging blade 74 is provided in the transfer device 7. The transfer charging blade generates a pressing force from the inside of the belt 71 toward the photosensitive drum 1 and is supplied with power from a high-voltage power supply so that toner is applied from the back side of the recording material. Then, the toner images on the photosensitive drum 1 are sequentially transferred to the upper surface of the recording material.

Here, the recording material is conveyed from the paper feeding and conveying device to a transfer section formed by the photosensitive drum 1 and the belt 71 at an appropriate timing in synchronization with the rotation of the photosensitive drum 1.
In the present embodiment, the belt 71 has a thickness of 7 mm.
A polyimide resin having a thickness of 5 μm was used. The material of the belt 71 is not limited to a polyimide resin, but may be a polycarbonate resin, a polyethylene terephthalate resin, a polyvinylidene fluoride resin, a polyethylene naphthalate resin, a polyetheretherketone resin, a polyethersulfone resin, a polyurethane resin, or the like. Plastic, fluorine-based, or silicon-based rubber can be suitably used. The thickness is not limited to 75 μm, but a thickness of 25 to 2000 μm, preferably 50 to 150 μm can be suitably used.

Further, a transfer charging blade 74 having a resistance of 1 × 10 ⁵ to 1 × 10 ⁷ Ω was used. Transfer was performed by applying a bias of +15 μA to the transfer charging plate 74 under constant current control.

Thus, the toner image formed on the photosensitive drum 1 is electrostatically transferred onto the recording material by the transfer charging blade 74. Thereafter, the transfer material is conveyed to the fixing device 6 and thermally fixed to output an image.

On the other hand, the transfer residual toner is left on the photosensitive drum 1 after the transfer process. Here, the transfer residual toner on the photosensitive drum 1 often has both positive and negative polarities due to peeling discharge at the time of transfer. The transfer residual toner having the mixed polarity is conveyed to the magnetic brush charger 3 and mixed with the magnetic particles in the charger, and all the charges are negatively charged and discharged onto the photosensitive drum. At this time, the toner is not sufficiently taken into the charger only by applying the DC voltage to the charged magnetic brush, but when the AC voltage is applied to the magnetic brush charger 3, the vibration due to the electric field between the photosensitive drum and the charger is generated. By the effect, the toner is easily taken into the charger. The transfer residual toner discharged on the photosensitive drum after the polarity is adjusted by the charging device is collected in the developing device by a fog removing electric field at the time of development. Here, these simultaneous development and recovery are performed when the image area in the rotation direction is longer than the circumferential length of the photosensitive drum 1, and other charging, exposure,
It is performed simultaneously with the image forming process such as development and transfer. As a result, the transfer residual toner is collected and used after the next process, so that waste toner can be eliminated. In addition, there is a great advantage in terms of space, and it is possible to greatly reduce the size.

However, as shown in FIG. 5, in a cleanerless apparatus for performing simultaneous development and cleaning using such a magnetic brush charger, the magnetic brush charger 3 is used.
After the recovery, the transfer residual toner discharged onto the photosensitive drum 1 is attracted from the drum surface toward the exposure surface with the change in the photosensitive drum surface potential when exposed by the exposure device 2 in the next step. A phenomenon that the electric field flies and adheres to the exposure surface 21 (hereinafter referred to as exposure scattering) has occurred. Exposure scattering is considered to occur when the surface potential distribution of the drum changes due to exposure. Therefore, the present inventor conducted an experiment in which 4% of the toner was forcibly mixed into the magnetic brush charger 3 in the configuration used in the present embodiment, and forced ejection was performed while performing solid exposure on the entire surface. In this experiment, the developer was not put into the developing device 4, and the driving of the developing device 4 and the application of the bias were not performed. Then, the photosensitive drum surface potential after charging (hereinafter referred to as V
The experiment was conducted by changing d) the latent image contrast, which is the difference between Vd and Vl, by keeping d) constant at -800 V and changing the photosensitive drum surface potential (Vl) after exposure. As a result of this experiment, it was clear that the smaller the latent image contrast, the more the discharged toner on the photosensitive drum 1 flies perpendicular to the direction of the exposure surface 21. As a result, under the actual use condition, when the latent image contrast is small, that is, when the halftone exposure is performed, the exposure scattering is remarkably generated. When the exposure scattering occurs, the exposed surface 21 is shielded from light by the adhered toner, so that an appropriate amount of exposure cannot be given to the photosensitive drum at the portion of the exposed surface 21 where the toner adheres, resulting in an image defect that an image is missing. Will occur.

According to the present invention, in order to prevent the above-mentioned exposure scattering, as shown in FIG. 6, the exposure device 21 is arranged along the exposure surface 21 on the downstream side in the rotation direction of the photosensitive drum adjacent to the exposure surface 21 of the exposure apparatus 2. And a bias is applied to the conductive member 22. With this configuration, the electric field from the direction of the photosensitive drum to the direction of the exposure surface 21 is relaxed, and the electric field in the direction of pressing the discharged toner on the photosensitive drum 1 toward the photosensitive drum 1 acts, thereby preventing the occurrence of exposure scattering. . According to the experiment, the bias applied to the conductive member 22 provided adjacent to and parallel to the exposure surface 21 of the exposure apparatus 2 has the same polarity and the absolute value as Vd charged by the magnetic brush charger 3. By doing as described above, exposure scattering was completely prevented.

In the present embodiment, the bias applied to the magnetic brush charger 3 can be used as the bias applied to the conductive member 22 provided adjacent to and parallel to the exposure surface 21. Therefore, there is an advantage that the exposure scattering can be prevented without newly increasing the power supply device. Here, the bias applied to the conductive member 22 provided adjacent to and parallel to the exposure surface 21 of the exposure apparatus 2 is obtained by superimposing an AC voltage on a DC voltage applied to the magnetic brush charger 3. The effect on the exposure scattering can be similarly exerted by applying only the DC component or applying the DC component.

In the present invention, the exposure surface 21 of the exposure apparatus 2
A conductive member 23 is also provided on the upstream side along the exposure surface 21, and the conductive member 23 is grounded. Exposure device 2
When the conductive member 23 on the upstream side of the exposure surface 21 is grounded, an electric field in the direction of pressing the discharged toner on the photosensitive drum 1 toward the photosensitive drum 1 when a bias is applied to the conductive member 22 on the downstream side is generated. Further, exposure scattering can be prevented. Further, the conductive member 23 can have a heat radiation effect of heat generated in the exposure apparatus 2.

However, since the conductive member 22 to which a bias is applied and the photosensitive drum 1 are very close to each other, spark discharge may occur. For this reason, in the present invention, the surface of the conductive member 22 to which a bias is applied is coated with an insulating paint (for example, an ethoxy resin) to prevent the occurrence of spark discharge between the conductive member 22 and the photosensitive drum. Out. Even when the coating process is performed, the electric field from the photosensitive drum surface toward the exposure surface 21 is weakened, and the electric field in the direction of pressing the discharged toner on the photosensitive drum 1 toward the photosensitive drum 1 acts to prevent the occurrence of exposure scattering. Is similarly obtained.

According to the present embodiment, the transfer residual toner discharged from the magnetic brush charger flies from the photoconductor surface due to the fluctuation of the photoconductor surface potential distribution due to the image exposure, and causes an image defect by adhering to the exposure device. Thus, it is possible to provide a stable image for a long period of time, and at the same time, it is possible to prevent the occurrence of spark discharge in the conductive member and the photosensitive drum.

[0052]

As described above, according to the present invention, in a cleaner-less apparatus for simultaneous cleaning with development, the developer remaining on the member to be charged is prevented from adhering to the exposed surface, and stable for a long time. It is possible to provide an image, and further by providing an insulating member on at least the surface side of the conductive member facing the member to be charged,
While maintaining the effect of preventing the remaining developer from adhering to the exposed surface, it is possible to prevent the occurrence of spark discharge between the conductive member to which a predetermined voltage is applied and the photosensitive drum.

[Brief description of the drawings]

FIG. 1 is a sectional view of an image forming apparatus used in an embodiment of the present invention.

FIG. 2A is a sectional view of an exposure unit used in an embodiment of the present invention, and FIG. 2B is an enlarged view of FIG. 2A.

FIG. 3 is a cross-sectional view of an image forming apparatus using a conventional laser exposure unit.

FIG. 4 is a cross-sectional view of an image forming apparatus using a conventional LED exposure unit.

FIG. 5 is a schematic diagram of a phenomenon that the present invention seeks to improve.

FIG. 6 is a sectional view of a conventional phenomenon improvement plan.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photosensitive drum 2 Exposure device 3 Magnetic brush charger 4 Developing device 6 Fixing device 7 Transfer device 9 Leader unit 10 Document table 11 Printer unit 21 Exposure surface 22 Conductive member 23 Conductive member 24 Insulating paint 41 Developing sleeve C CCD sensor G Document La Document irradiation lamp Le Short focus lens array

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Mitsuo Shiraishi 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2C162 AE01 AE09 AE21 AE28 AE47 FA04 FA17 FA70 2H076 AB42 AB82

Claims (11)

[Claims] 1. A charging member that contacts a member to be charged and charges the member with a bias voltage applied thereto, and an image exposure unit that forms a latent image by performing image exposure on the member to be charged. A developing unit that has a developer carrying member that carries a developer, and that develops the latent image with the developer to form a developer image; a transfer unit that transfers the developer image to a transfer material; An image forming apparatus that recovers the developer remaining on the member to be charged after being transferred to the transfer material by the developing unit, wherein the image forming apparatus is adjacent to an exposure surface of the image exposure unit facing the member to be charged. An image, comprising: a conductive member provided substantially parallel to the exposure surface and to which a predetermined voltage is applied; and an insulating member provided on at least a surface of the conductive member facing the member to be charged. Forming equipment. 2. The image forming apparatus according to claim 1, wherein the insulating member is formed by coating a surface of the conductive member. 3. The object to be charged is provided rotatably with respect to the image exposure means, and the conductive member is provided downstream of the image exposure means in the rotation direction of the object to be charged. The image forming apparatus according to claim 1, wherein: 4. A grounded conductive member provided adjacent to an exposure surface of said image exposure means and substantially in parallel with said exposure surface with respect to said exposure means in a rotational direction of said member to be charged. 4. The image forming apparatus according to claim 3, wherein: 5. The image according to claim 1, wherein the potential of the conductive member to which the predetermined voltage is applied has the same polarity as the surface potential of the charged member after charging. Forming equipment. 6. The method according to claim 1, wherein an absolute value of a potential of the conductive member to which the predetermined voltage is applied is equal to or more than an absolute value of a surface potential of the charged member after charging. An image forming apparatus according to any one of the above. 7. The image forming apparatus according to claim 1, wherein a power supply for applying a bias voltage to said charging member is used as a power supply for applying a voltage to said conductive member. 8. An electric field generated by a predetermined voltage applied to the conductive member, wherein the residual developer discharged to the member to be charged after being collected by the charging unit is transferred from the member to be charged to the image exposing unit. The image forming apparatus according to any one of claims 1 to 7, wherein the image forming apparatus is formed in such a direction as to suppress the flight to the surface. 9. The image forming apparatus according to claim 1, wherein a bias voltage in which an alternating voltage is superimposed on a DC voltage is used as the bias voltage applied to the charging member. 10. The image forming apparatus according to claim 1, wherein the member to be charged has a photosensitive layer and a surface layer, and the surface layer has a resin and conductive fine particles. 11. The charging member according to claim 1, wherein the charging member includes magnetic particles and a magnetic particle carrier for supporting the magnetic particles, and the magnetic particles are in contact with a member to be charged.
The image forming apparatus according to any one of the above.