JPS6088975A - Image forming device - Google Patents

Abstract

PURPOSE:To eliminate a defect in cleaning securely and obtain a sharp toner image by neutralizing the charge of residual toner by an electrode positioned at the movement upstream side of an image carrying conductor. CONSTITUTION:Toner 40 on a developing sleeve 32 is carried as shown by an arrow 40' by a magnet 33 which is rotated as shown by an arrow 33'. The conductive substrate 2 of the image carrier 44 is grounded and the 1st electrode 34 held at the same potential with the conductive substrate is provided at the upstream side of the image carrier 44 in a relative movement direction 37, so the conductive magnetic toner 40 passing over the electrode is held at the same potential. The electrode 34 is held almost in the grounding state, so the residual charge is neutralized nearly completely, thereby separating the residual toner which is neutralized electrically almost perfectly near the electrode 34 with the magnetic force of the magnet 33. The 2nd electrode 35 performs development and a developing process is a substantial developing process right after the surface of the image carrier is cleaned and prevented from being charged electrostatically nearly completely, so an extremely sharp image is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides visual recognition of electrical image information output from, for example, an electronic computer or an image reading device, or image information stored on a magnetic tape or microfilm. The present invention relates to an image forming apparatus used in an apparatus for reproducing an image, or a copying machine for further obtaining a hard copy, and particularly relates to an apparatus for forming a toner image on the surface of an image carrier.

Conventionally, the following method is known as a simple method for forming a toner image on the surface of an image carrier.

In one method, as shown in FIG. 1, a photosensitive layer 1 is provided on a transparent conductive substrate on which a bright conductive layer 2 and a transparent supporting body 3 are laminated to form a photoreceptor. Then, a direct current bias is applied to the substrate between the toner carrier 5, on which the conductive magnetic developer (hereinafter referred to as toner) 6 is uniformly adhered by the magnetic field generating means 5a, and the substrate of the photoreceptor. Apply at 4. This creates a uniform potential difference between the developer and the surface of the photoreceptor.

Then, at a position where the conductive toner 6 on the toner carrier is guided to the surface of the photoreceptor, 0! ii) By carrying out image exposure P, a toner image in the form of an image pattern is formed on the surface of the photoreceptor. For example, if we consider the process of depositing toner on the surface of an i-i'N type photoreceptor, as shown in FIG. With a direct current/Ias applied from the power supply 4,
The magnetic toner 6 is guided onto the surface of the photoreceptor. Then, a uniform potential difference is formed between the toner and the surface of the photoreceptor,
At the same time, image light is irradiated from the transparent conductive substrate side. As a result, positive charges 7 are induced in the conductive toner 6 held by the toner carrier according to the photocarriers 8 generated and moved in the image/four turn shape in the photosensitive layer 1, and due to the Coulomb force. As shown in FIG. 3, toner 6 is deposited on the surface of the photoreceptor.

Although the above explanation uses the Nu photoreceptor as an example, similar results can be obtained even if other photoreceptors are used by selecting the polarity of the direct current applied between the toner carrier and the transparent sea turtle substrate. In addition, a method has been proposed in the past in which a high resistance layer having an appropriate time constant is provided on the conductive layer to further sharpen the formed toner image. - Figure 4 shows a format in which the image light in the above example is given to a signal-modulated laser beam, and 5 in the figure
a is a magnetic field generating means, 14 is a terribon mirror, 15 is f-
The θ lens 16 indicates a mirror for turning back the optical path.

The following method is also known as another simple method for forming an image as a toner image. That is, a toner having conductivity and magnetism, a toner carrier having a conductive or non-conductive surface and having a magnetic field generating means disposed therein, and a toner carrier which is electrically insulated from the toner carrier and which contains the toner. a plurality of recording electrodes arranged in parallel on the toner carrier, an image carrier having a charge retention ability, and an image carrier having the recording electrode arrangement position; and opposing electrodes placed at opposing positions. Then, the toner is conveyed onto the recording electrode by the magnetic force of the magnetic field generating means, and a bias is selectively applied between the opposing electrode and the recording electrode according to a recording signal to transfer the toner into an image. This type of toner is attached to the surface of a carrier to form an image using toner.

As another form similar to this method, a toner carrier having a conductive, magnetic, and magnetic toner and a conductive or non-conductive surface having a magnetic field generating means therein,
a counter electrode having a function of supplying charge to the toner and disposed on the toner carrier, an image carrier having a charge retention ability, and a counter position sandwiching the image carrier at the counter electrode position. A plurality of recording electrodes arranged in parallel are used. Then, the toner is conveyed onto the recording electrode by the magnetic force of the magnetic field generating means, and a bias is applied to the opposing electrode and the recording electrode according to the recording signal to cause the toner to adhere to the surface of the image carrier. There is also a method for forming 0. Fig. 5 shows a schematic configuration of an example of an apparatus according to these methods for forming.
6,840 is a schematic diagram of an example described in No. 6,840. In the figure, 20 is a thin-layer insulating image carrier, 21 is a conductive toner carrier, and a magnet 22, which is an internal magnetic field generating means, rotates in the direction of the arrow and rotates in the direction of the arrow. Magnetic toner 24 is being conveyed in the direction of arrow 25. 23
is a recording electrode that is installed on the opposite side of the image carrier, facing the position where the toner contacts the image carrier, and has a large number of independent electrodes arranged in the width direction of the image carrier. A power source E is placed so that a voltage can be selectively applied between the plurality of recording electrodes and a predetermined electrode of the conductive sleeve 21.

iit! FIG. 6 briefly shows the process of forming a toner image on an image carrier by the method described above.

When the switch 26 is connected to the contact point on the side of the power source E, a voltage is generated between the conductive toner carrier 21 which becomes the direction electrode and the recording electrode 23 corresponding to the predetermined switch. applied. As a result, a closed circuit consisting of the conductive toner 24→toner carrier 21→ground→power supply E→switch 26→recording electrode 23→support carrier 20 is formed. In this circuit, due to the capacitance of the image carrier 20, charges are almost instantaneously accumulated at the tip of the conductive toner 24 which is closest to the recording electrode 23 and at the tip of the recording electrode 23. Coulomb force acts on the charge. Then, at the time when the image carrier 20 is separated from the brush formed by the toner, the toner carrier 21
By applying a strong Coulomb force to the magnetic force exerted on the magnetic toner in which the charge is accumulated by the internal magnet, the switch 26 is turned on and off on the image carrier 20.
As shown in FIG. 7, the recording electrodes 23 are arranged in a plurality of insulating layers in a direction substantially perpendicular to the moving direction of the image carrier 20. A shear array is constructed by arranging them in parallel. And each driver (drive circuit) 27 [
[Circuit details are not shown] By selectively applying a voltage between the recording electrode and the image carrier 20 and depositing toner on the image carrier 20, an arbitrary toner image can be formed. It is now possible to do so.

FIG. 8 is a schematic diagram of an image forming method described in US Pat. No. 3,879,737. In this example as well, as in the explanation in FIG. Configure a closed circuit consisting of. In this circuit, due to the capacitance in the image carrier 20, the tip of the conductive toner 24 on the recording electrode 30 that is closest to the counter electrode 31 and the tip of the counter electrode 31 are almost instantaneously Charge is accumulated. Then, a Coulomb force acts between these charges, and when the image carrier 20 is separated from the brush formed by the toner, the conductive magnetic toner in which the charges have been accumulated is removed by the magnet inside the toner carrier 21a. By applying the Coulomb force strongly to the magnetic force that is applied to the image carrier 20, the switch 26 is turned
A toner shell according to F can be formed. In the same way as explained in FIG. 7 above, a plurality of electrically independent recording electrodes 30 are arranged in parallel in the width direction of the image carrier in a direction approximately perpendicular to the moving direction of the image carrier 20. to configure the array. Then, by selectively applying a signal voltage to the signal electrode by a driver (drive circuit), a voltage is applied between the counter electrode 31 and the toner is selectively deposited on the image carrier 20. It is possible to form a toner image of .

The image forming method described above applies a voltage between a pair of electrodes that are placed opposite each other so as to sandwich the conductive toner and the image carrier (including the photoreceptor described in FIGS. 1 to 4) in between. By doing so, it can be said that the image carrier is formed with toner on the image carrier.
Wear. The "pair of electrodes" referred to here refers to the conductive surface of the current sleeve and its opposing electrode (this opposing electrode is
(including both the transparent electrode shown in FIG. 4 and the case of recording electrodes arranged in parallel as shown in FIGS. 5 to 7), or the toner is supported as part of a toner carrier. This refers to a plurality of recording electrodes arranged in parallel on the body and their opposing electrodes (as shown in FIG. 8).

By the way, the above-described image forming method can be said to have the characteristic that it does not require a cleaning process to remove toner from the surface of the image carrier when the image carrier is repeatedly used. , When image formation is performed repeatedly, the toner adhered to the surface of the supine carrier, which is not in the image area when the next image is formed, is easily removed from the image carrier by magnetic force. This is because it can be considered. However, if the magnetic force applied to the toner on the image bearing member is weak, a so-called cleaning failure may occur in which the previously stuck toner cannot be removed. However, there was a problem in that the requirements regarding design and manufacturing accuracy had to become stricter (8).

To explain this in more detail, the strength of the magnetic force near the contact area between the image carrier and toner depends on the distance between the image carrier and the magnet on the toner carrier side, the strength of the magnetic force of the magnet itself, and the strength of the magnetic force of the magnet itself. Determined by the number of poles etc. Therefore, as mentioned above, in order to ensure that the shell agent on the surface of the image carrier can be removed reliably and easily by magnetic force, it is necessary to adjust the distance between the magnet and the image carrier. Setting range 1 conditions are strictly enforced, and the smoothness of the bare surface of the image carrier used must be extremely high.

In view of these points, an object of the present invention is to obtain a clear toner image in which cleaning defects are reliably removed in the above-mentioned image forming apparatus, and furthermore, to ease the design and manufacturing requirements of the apparatus. The present invention provides an image forming apparatus as described above.

Therefore, the gist of the present invention for achieving such an object is to provide a movable image carrier, a surface of which conductive magnetic toner is supported by magnetic force, and a surface adjacent to the image carrier. a first electrode located on the upstream side of movement of the image bearing member and a second electrode located on the downstream side at or near the surface of the toner bearing member facing the image bearing member; and an electrode opposed to the first and second electrodes on the back side of the image carrier, the first electrode and the opposing electrode being held at approximately the same potential, and the first electrode An image forming apparatus characterized in that it is configured to generate a potential difference between the second electrode and the opposing electrode. The present invention will be described below based on the embodiments shown in the drawings from FIG. 9 onwards. In FIG. 9, 32 is a developing sleeve which is a toner carrier, and in this example, it is made of conductive non-magnetic stainless steel (SUS).
It is made of a magnetic material (or a material that exhibits some magnetism) and is further provided to be electrically grounded.

Reference numeral 33 denotes a magnet built into the developing sleeve f32, which is rotated by means not shown in the direction of arrow 33' in the figure υ to convey the toner on the surface of the developing sleeve 232 in the opposite direction to the direction 33'. .

Reference numeral 44 denotes an image carrier), which is provided so as to be moved in the direction of arrow 37 in the figure to a position that maintains a predetermined gap with respect to the current tilting sleeve 32. The path of the image carrier 44 is the same as that of the photoreceptor explained in FIG.
O, ), ITO (In2O, containing 5%-SnO) 4! a transparent Ei11 conductive layer 2 as an electrode of
The same reference numerals as in FIG. 1 are given to the transparent support 3.

The characteristics of this example are that the developing sleeve 32 and the image carrier 44
The first electrode 34 is provided on the developing sleeve on the upstream side of the movement of the image bearing member, that is, the position where toner is supplied and conveyed to the surface of the image bearing member, and the electrode 34 is provided on the developing sleeve on the downstream side of the movement of the image bearing member. This is because the second electrode 35 is provided on top.

The first electrode 34 is for erasing the charge of the conductive magnetic toner on the surface of the image carrier, and in this example, the transparent conductive layer 2 of the image carrier 44 is grounded as shown in 1. Corresponding to this, the first electrode 34 is electrically connected to the developing sleeve 32 and grounded.

Note that the first electrode 34 may be directly grounded, and in this case, the developing sleeve 32 may be made non-conductive. On the other hand, the second electrode 35 charges the toner and transfers the toner necessary for image formation to the image carrier 44 using Coulomb force.
It is provided to be electrically connected to a power source E so that a DC bias is applied thereto. In this example, since the developing sleeve 32 is constructed of a conductive member, the developing sleeve 32 and the second electrode 350 are completely isolated by the insulating layer 36.

Next, the operation in the developing section will be explained with reference to FIG.

The toner 40 on the developing sleeve 32 is conveyed in the direction of arrow 40' by the rotation of magnet 33 in the direction of arrow 33'. As described above, the conductive substrate 2 in the image carrier 44 is grounded, while the relative movement direction 37 of the image carrier 44 is grounded.
Since the first electrode 34 kept at the same potential (or almost the same potential) as the conductive substrate is provided on the upstream side of the conductive substrate, the conductive magnetic toner 40 passing over the electrode is kept at the same potential. It will be.

By the way, if the image carrier 44 is to be used repeatedly, the conductive magnetic material 3 that was previously deposited on the image carrier 44 may be
8 remains, and this residual developer 38 may have some residual charge injected during the previous development, and it has already been mentioned that this causes poor cleaning.

However, according to the configuration of the embodiment described above, the electrode 3 of the helmet l
4 is kept almost grounded, so the residual charge is reduced to t.
The hills have a completely neutralizing effect, and as a result, the electrically neutralized residual toner is almost completely peeled off from the image carrier surface near the first electrode 34 by the magnetic force of the magnet 33.

In the process of neutralizing the charge of the residual toner on the image carrier 44 brought about by the presence of the electrode 34 of the turtle 1, the rotation direction of the magnet 33 is set in the direction of arrow 33', and the toner 4
Setting the movement direction of 0 in the direction of arrow 40' is a particularly effective choice. Because in this state, the first
A toner reservoir is formed near the electrode 34, that is, on the upstream side in the moving direction of the image carrier 44, and the toner density here is high.
This is because the peeling effect of the residual toner becomes even stronger.

In addition to the cleaning effect, the presence of the electrode 34 described in 1 above also has the advantage of preventing unnecessary frictional electrification on the surface of the image carrier 44.

Next, the action of the second electrode 35 will be described. This is a component for performing development similar to the cases shown in FIGS. 1 to 4, and in this example, the development step is The first electrode is characterized by being able to form extremely clear images because it is a concentrated development step immediately after the surface of the image carrier has been completely cleaned and antistatic.

The best position for the second electrode 35 is to provide it at a position facing the image exposure P, and further on the line connecting the image carrier 44 and the closest part of the current support sleeve f32 (indicated by 41 in the figure). The best image quality can be obtained by providing the image carrier 44 on the above-mentioned line 41 to the upstream or downstream side of the movement of the image carrier 44. It is also possible to give a deviation of .

Next, the first electrode 34 and the electrode 35 of the fabric 2 are brought into instantaneous contact.
Regarding the fi 41R between the two electrodes, the separation distance, that is, the gap X (see FIG. 11) must ensure the electrode insulation between the two electrodes. A problem with this insulation is leakage through conductive magnetic toner, but as is well known, magnetic toner 40
forms spikes on the developing sleeve 32 as shown in FIG. 12 due to the action of the magnet 33, and the electrical resistance is low in the direction in which the spikes stand, but in the direction almost perpendicular to this. In this case, the resistance is at least two orders of magnitude higher. Therefore, by appropriately selecting the gap between the first electrode and the silk electrode 2, the influence of leakage via toner between these two electrodes can be almost ignored.

Generally, with an insulator (or one with sufficiently high resistance) interposed between the two electrodes, the gap X is at least 0.
．． It is desirable that it be 5 or more.

Note that providing the gap X in the current shell part does not impose any particular restrictions on the electrode arrangement. In other words, the contact width between the image carrier 44 and the toner 40 is approximately 105 m on the upstream side and 105 m on the downstream side from the nearest point shown in FIG. In contrast, the gap between the first electrode and the second electrode is so small that its effect on the development process can be ignored. It is from.

As described above, the first electrode 34 and the second electrode 35 are
A clear image (formed with the toner 39) without any image capri is obtained on the surface of the image carrier 44 that has passed through the 0 portion.

Although the present invention is concretely realized by the embodiments shown in FIGS. 9 to 12 described above, the present invention is not limited thereto, and various other modified embodiments may be used. can be considered.

The embodiment shown in FIG. 13 (at e Cb)
This type is a modified version of the one shown in FIGS. By forming the conductive toner 40 on the magnetic material, stable spikes of the conductive toner 40 can be formed on the magnetic material.
．． 43, the above-mentioned cleaning effect on the first electrode 34 or the antistatic effect on the surface of the image carrier 44 becomes more reliable. That is, the 13th
As shown in Figure (a), the isoelectric magnetic toner 40 is conveyed along the conveyance path (in the direction of arrow 40') on the developing sleeve.
Among them, the magnetic material 42 portion of the first electrode 34 receives a strong magnetic force and forms a tall spike. For this reason, the electrical paths in the direction of the spikes with low electrical resistance become dense between the surface of the image carrier 44 and the first electrode 34 (including the magnetic material 42), as described above. The effect of neutralizing the residual charge and preventing the surface of the image bearing member from being charged is greatly obtained, and furthermore, since the toner density is high, the effect of removing the residual toner is even greater. Furthermore, the magnetic material 43 in the second electrode 35
Since the image exposure P can be applied by applying a voltage at the contact portion between the stable spike and the image carrier 44, a good image with sufficient sharpness without unevenness can be obtained.

Furthermore, the effect of providing the magnetic bodies 42 and 43 is to further ensure the prevention of leakage in the gap between the first electrode 34 and the second electrode 35 described above. In other words, magnetic flux is concentrated at the magnetic bodies 42 and 43. This is because the density of the electromagnetic developer in the gap can be made sufficiently small.

Note that the magnetic bodies 42 and 43 described above each independently produce the effects described above, so depending on the case, they may be provided only at the first t@34, or may be provided at the second t@34.
It may be provided only in the electrode 35.

In the former case, it is desirable to arrange the electrodes for image exposure P and 8h 2 near the point of closest contact between the image carrier 44 and the developing sleeve 32.

In the latter case, it is effective to apply the image exposure P at the contact portion of the toner that stands up in spikes with the image carrier due to the magnetic material.

In the embodiments of the present invention described above, the image carrier 44 is, for example, a CdS sensitized material in which a transparent conductive layer is provided on a transparent Mylar film (for example, Daicel Kagaku (a) CELEK ■ transparent conductive film).

A photoreceptor with a photosensitive layer formed by coating ZnO etc. dispersed in a binder can be used, or a photoreceptor with TiO2 etc. dispersed in a binder coated on the photosensitive layer can be used. It may also be coated to provide a surface layer on the photoreceptor.

In each of the embodiments shown in Figures 9 to 12 and 13 above, the image exposure P may be provided by scanning a gas laser with a variable signal or a semiconductor laser with a polygon scanner. LED array,
Modulated light by a liquid crystal shutter array may also be used. Alternatively, the document illumination light may be applied through a slit like in a normal copying machine. The developing sleeve 32 is SU as described above.
A non-magnetic S material is advantageous for smooth developer transport on the surface. The insulator 36 may be made of mylar or the like.

It is preferable that the magnetic material 42 or 43 described above has a width of about 0.5 U to 5 mm and forms a strip in the longitudinal direction of the developing strip f32.

As the conductive magnetic toner, one having a volume resistivity of 10<13 >[Omega].sigma or less, preferably 1O3 to 10<10 >[Omega].Nishiki, can be used. The second electrode 35 is heated once in the morning.
It is optimal to apply a direct current voltage of 50V to 500V to the transfer goods 2 made exclusively for Qi.

Further, in the above embodiment, the toner is conveyed in the same direction as the moving direction of the image carrier (-6), but the toner may be conveyed in the opposite direction.

FIG. 14 shows another embodiment of the present invention, in which a conductive developing strip 132' is connected to the second electrode 35'.
A voltage is applied through the first electrode 34', while the first electrode 34' is formed using a conductive thin string such as corona wire.

In the case of this example, it is possible to bring the first electrode 34' closer to the surface of the image carrier, and the above-mentioned IJ =ing effect or antistatic effect can be performed more efficiently. Also in this example, it is possible to use a magnetic material for the electrode 34' of the electrode 1 or to provide a magnetic material for the second electrode 35 as well, and this is highly effective.

The embodiment shown in FIG.
The figure shows a configuration in which the electrodes 35 are separated from a simulated sleeve and held separately.

In such an example, the developing sleeve itself can be a conductive electrode, and by doing so, the first electrode can be transferred between the pole 34 and the second electrode 351 through the conductive toner. leakage can be reliably prevented. Of course, in this example as well, when a magnetic body is placed at the electrode position facing the image carrier 44, the effect is similar to that described above.

The embodiment shown in FIGS. 16 and 17 corresponds to an improved version of the image forming apparatus shown in FIG. An image carrier provided with an insulating layer 46 is generally used, such as electrostatic recording paper. 47 is a first electrode for toner cleaning), and 48 is a second electrode consisting of a plurality of signal electrodes to which voltages related to development are applied. Also 5o
is the second electrode, that is, the plurality of signal electrodes 48a t 48
This is an insulator for connecting b+ to the driver 49 circuit independently and for electrically isolating the first electrode 47. In this example, the second electrode 48m
, 48b, . . . are normally arranged in parallel to the insulator 50 on the current sleeve 32'' at a density of about 0V nm or more, and a voltage of about 10 to 100V is selectively applied to each. Based on this, a toner image is formed on the image carrier 51. In this case, the action of the first electrode 47 is the same as that described above as a cleaning action or an antistatic action. When used repeatedly, since the surface of the image carrier is coated with a highly insulating layer 46, there are many cases in which charge remains in the toner remaining from the previous use. Neutralization of residual charges has a great effect on forming clear images.One of the characteristics of this example is that the first electrode is provided with a magnetic material part, or the first electrode itself is By composing the electrode with a magnetic material, leakage can be effectively prevented not only between the second electrode but also between each of the first electrodes formed as multiple signal electrodes arranged in parallel. can be mentioned.

FIG. 18 is an improved version of the one shown in FIG. 5. 5
Reference numeral 2' denotes a first electrode that substantially promotes cleaning and is kept at the same potential as the toner carrier 21.

Reference numeral 52 denotes a second electrode consisting of a plurality of signal electrodes to which voltages related to development are applied. Both of these electrodes are arranged to face the contact position between the image carrier 20 and the toner.

As described above, according to the present invention, cleaning defects can be reliably prevented with a simple configuration.
It is possible to provide a stable image forming apparatus by significantly relaxing the apparatus setting conditions for forming clear images, and its usefulness is extremely great.

[Brief explanation of drawings]

The drawings are only for explaining the present invention, and FIGS. 1 to 8 show the configuration of a conventional image forming apparatus, and FIG. 1 shows the image 4!
Figures 2 and 3 are diagrams illustrating the structure of the main part in the fA exposure format, Figures 2 and 3 are diagrams explaining the image formation process, and Figure 4 shows the configuration of the main part in the format in which the image light is provided by a laser beam. diagram showing,
5, 6, and 8 are diagrams showing the configuration of the main parts of an image forming apparatus that changes the applied voltage, and FIG.
The figure is a partial perspective view of the one shown in FIG. 6. 9 to 18 are for the sake of clarity. FIG. 9 is a diagram illustrating a part of the present invention, an outline of the configuration of an image forming apparatus according to an embodiment, and FIG. FIG. 11 is a partially enlarged view, FIG. 11 is a partial perspective view of the electrode portion, and FIG. 12 is a diagram illustrating the state of toner spikes. FIGS. 13(a) and 13(b) are diagrams showing modifications of the embodiment shown in FIGS. 9 to 12. FIG. 14 and FIG. 15 are a schematic diagram of an image forming apparatus according to another embodiment of the present invention, and FIG. 16 is a diagram showing a dry image forming apparatus. FIG. 17 and FIG. 18 are diagrams showing still other embodiments. 1... Photosensitive layer 2... Transparent conductive foot 13... Transparent support 4... Power source 5... Toner carrier 6... Toner 5a... Magnetic field generating means 7.9.10 ...Winner load 8...Photo carrier 14...Polycon mirror 15...f-
θ lens 16...Mirror 20...Image carrier 21
, 21m...toner carrier 22...magnet) 2
3.30... Recording electrode 24... Conductive magnetic toner 26... Switch, switch 27... Driver 31...
・Counter electrode 32132' 132N...Developing sleeve (toner carrier) 33...Magnet 34, 34', 34''...First electrode 35.3
FI, 35#...Second electrode 36...Insulator 38
, 39.40... Toner 42.43... Magnetic material 4
4... Low carrier 45... Conductive base 46... Insulating layer 47... First electrode 48... Second electrode 49.
...Driver circuit 50...Insulator 51...Gallery carrier 52...Second electrode 52'...First electrode Fig. 3 Fig. 4 Fig. 13<a) Fig. 13 (b)

Claims (1)

[Claims] An image carrier to be moved, a toner carrier that carries conductive magnetic toner on its surface by magnetic force and conveys it to a surface adjacent to the image carrier, and the toner carrier faces the image carrier. A first electrode located on the upstream side of the movement of the image carrier and a second electrode located on the downstream side of the image carrier.
and the first electrode on the back side of the image carrier. an electrode opposite to the second electrode, the first electrode and the opposite electrode are maintained at substantially the same potential, and the second electrode is maintained at substantially the same potential.
An image forming apparatus characterized in that the image forming apparatus is configured to generate a potential difference between the electrode and the electrode facing the electrode.