JPH06110313A - Image forming device - Google Patents

Abstract

PURPOSE:To provide a small-sized image forming device having a simple structure and capable of obtaining image of high image quality. CONSTITUTION:The device is provided with a latent image holding body 1 which is moved with the electrostatic latent image held on its surface, a developer supplying means 2 for directly supplying the developer 10 to the whole surface of the electrostatic latent image formed on the surface of the latent image holding body l and an electrostatically charging member 5 facing the surface of the latent image holding body 1 at a prescribed space, and an alternating field is formed between the electrostatically charging member 5 and the latent image holding body 1. The device is provided with an electric field power supply 6 for vibrating the developer 10 which is supplied on the surface of the latent image holding body 1 and carried in between the electrostatically charging member 5 and the latent image holding body 1 accompanying the surface of the latent image holding body 1 by the alternating field to electrostatically charge the developer 10, and recovering means 7, 8 and 9 for recovering the developer 10 sticking to the non-image part of the electrostatic latent image on the surface of the latent image holding body 1.

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 applicable to printers, copying machines, facsimiles and the like.

[0002]

2. Description of the Related Art Conventionally, as image forming methods, there are a cascade developing method, a touchdown developing method, a jumping developing method and the like.

Various improvements have been added to all of these for the purpose of improving the reproducibility and sharpness of images.

A developer supplying member (hereinafter, referred to as a developer carrying member) for carrying and supplying a developer has been arranged facing the latent image holding body at a constant interval. Development is carried out by applying an appropriate developing bias voltage between the carrier and the latent image carrier.
As shown in Japanese Patent Publication No. 63-42256, an AC jumping developing method in which an AC bias is superimposed on a DC bias has been put into practical use.

In this conventional AC jumping developing method, due to the alternating current component of the developing bias applied between the developer carrying member and the latent image holding member, the developer carrying member and the latent image holding member are opposed to each other in the developing section. An AC electric field is formed, and by this AC electric field, the developer carried on the developer carrying body reciprocates between the developer carrying body and the latent image holding body, and by this reciprocating movement, the electrostatic latent image The image portion of the electrostatic latent image is attempted to be precisely developed by sequentially adhering to the image portion.

[0006]

However, the conventional AC
In the jumping developing method, a developer carrier is used, a developer layer is formed on the developer carrier, the developer is charged on the developer carrier, and the developer is charged from this charged developer layer by AC jumping. Since it is moved to the latent image carrier, it is necessary that the thickness of the developer layer is uniform in order to perform uniform charging, and the potential corresponding to the light and darkness of the image portion on the surface of the latent image carrier. The thickness of the developer layer is required to be uniform in order to move the developer accurately in accordance with the change. Therefore, in order to perform faithful development, an extremely uniform developer layer on the developer carrier. However, there is a problem in that it is indispensable to form the structure, and a process and a precise control mechanism are necessary to achieve this.

Further, in the conventional AC jumping developing method using the developer carrying member, as shown in FIG.
For example, with respect to a solid image, the hole portion 1 of the developer layer 103 generated by moving from the developer layer 103 to the latent image holding member 102 side.
06 is a mechanism for, when re-attaching the developer on the developer layer 103, this re-attachment causes the developer 100 to be attached in a layered manner by the blade 107, so that only the hole portion 106 is completely filled with the hole portion 106. A large amount of the developer cannot be reattached, and even after the developer layer 103 is reattached, it remains as a hysteresis hole 104, and the developer layer thickness becomes thin at the hysteresis hole 104 portion. There is a problem of a sleeve ghost phenomenon in which the amount of the developer in the image portion that has undergone the movement becomes insufficient, the insufficient portion 105 occurs, and the insufficient portion 105 appears as an afterimage of the previous image in the current image.

Further, since the developer carrying member is electrically conductive, the charged electric charge of the developer carried on the developer carrying member and conveyed easily leaks through the developer carrying member during the carrying process by the developer carrying member. .

The developer loses its charge due to such a leak, and the charge of the developer becomes insufficient at the stage of being used for development, or the charge becomes nonuniform. It is not achieved as set and the developing performance is reduced.

The leakage of the charged electric charges becomes more remarkable as the environmental humidity becomes higher, and the charging performance on the developer carrying member is greatly affected by the environment and the stability is lacking.

Further, the supply of the developer to the latent image carrier and the developing action by the developer carrier are limited to a very short time when the developer carrier faces the latent image carrier, so that the developing efficiency is improved. It is bad, and it is difficult to cope with the recent speedup.

An object of the present invention is to provide an image forming apparatus which solves the above-mentioned problems, has a simple structure, is small in size, and is capable of obtaining an accurate high-quality image.

[0013]

In order to solve the above-mentioned problems, an image forming apparatus of the present invention includes a latent image carrier that holds and moves an electrostatic latent image on the surface, and the surface of the latent image carrier. Developer supplying means for directly supplying the developer to the entire electrostatic latent image of
A charging member facing the surface of the latent image carrier with a predetermined gap, and an alternating electric field is formed between the charging member and the latent image carrier, and the alternating electric field supplies the latent image carrier surface with a latent image. A non-image of the electrostatic latent image on the surface of the latent image carrier, and an electric field power source for vibrating and charging the developer conveyed between the charging member and the latent image carrier along with the surface of the image carrier. And a developer collecting means for collecting the developer attached to the portion.

Further, in order to solve the above-mentioned problems, the image forming apparatus of the present invention discharges the developer with respect to the gap on the side where the developer is fed into the predetermined gap between the charging member and the latent image holding member. A wide side gap is preferred.

[0015]

The image forming apparatus of the present invention supplies a developer to the entire surface of the electrostatic latent image on the surface of the latent image carrier, charges the developer on the surface of the latent image carrier, and finally, the electrostatic latent image. It is characterized in that the developer attached to the non-image portion is recovered from the developer supplied to the entire surface of the image, and has the following action.

The developer supplying means supplies the developer directly from the developer reservoir to the entire surface of the electrostatic latent image on the surface of the latent image holding member. Since this supply supplies a large amount of developer to the entire surface of the electrostatic latent image, even if the supply amount is not particularly controlled, a sufficient amount of developer can be retained to eliminate uneven developer supply or insufficient supply. It has the effect of supplying and placing the entire electrostatic latent image on the body surface.

In this manner, after the sufficient amount of the developer has been placed on the latent image carrier, the charging member and the electric field power source that forms an alternating electric field between the charging member and the latent image carrier are on the latent image carrier. The developer is charged on the latent image carrier, and finally, the developer attached to the non-image portion of the electrostatic latent image on the surface of the latent image carrier is collected. The developer is brought into contact with the electrostatic latent image for a long time after the developer is attached to the non-image portion of the electrostatic latent image on the surface of the latent image carrier, so that the electrostatic latent image is formed. The electrostatic latent image is faithfully developed by the effect of charging with a developer even for a solid image with a large area or a fine fine line image where the developer is hard to adhere due to the wraparound of the electric field, and the non-image portion is faithfully developed. Only the developer can be collected.

The charging member and the electric field power source for forming an alternating electric field between the charging member and the latent image holding member are a predetermined amount of uncharged or slightly charged developer on the surface of the latent image holding member having a high insulating property. Charging, the charge of the developer does not easily leak and the charging efficiency is good, and the charged developer immediately acts on the development of the electrostatic latent image on the surface of the latent image carrier to charge it. Due to the good charge development efficiency, even in an environment where the charge of the developer is likely to leak at high temperature and high humidity, the effect of the leak is extremely small, and the effect of the specified amount of charged charge reliably acts on the development. High-resolution development and transfer stabilization are possible.

When the toner is charged by vibration, the developer can be charged without disturbing the electrostatic latent image on the surface of the latent image carrier, and the vibration disperses aggregates of the developer. Not only that, the developer moves on the surface of the latent image carrier, the amount thereof is uniformly distributed on the surface of the latent image carrier, and the charged developer is used for a long time. Since it contacts the electrostatic latent image on the surface of, the excellent image faithful to the electrostatic latent image can be obtained.

Further, vibration is applied to the developer supplied to the surface of the latent image carrier and conveyed along with the movement of the surface of the latent image carrier, so that the developer is diffused by the vibration. Then, the electrostatic latent image is stably conveyed, the amount of the developer for developing the electrostatic latent image is stabilized, and the electrostatic latent image can be faithfully developed.

The developer collecting means collects the developer adhering to the non-image portion of the electrostatic latent image on the surface of the latent image holding member.

Further, in the image forming apparatus of the present invention, the gap on the developer carrying-out side is wider than the gap on the developer carrying-in side to the predetermined space between the charging member and the latent image carrier. With this configuration, when vibration is applied to the developer conveyed through the predetermined gap on the latent image holder along with the movement of the surface of the latent image holder, the developer is diffused by the vibration and the gap is wide. Since it proceeds in the direction, the developer can be stably conveyed.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the basic structure of the image forming apparatus of the present invention will be described with reference to FIG.

In FIG. 2, the electrostatic latent image is held on the magnetic developer 10 in the developer reservoir 10 'by the attraction force of the magnetic field formed by the first magnetic field forming means 2 in the developer supplying step of this apparatus. It is directly supplied to the entire surface of the electrostatic latent image on the surface of the latent image holder 1 that is moving. The supplied magnetic developer 10 is the first
Due to the attraction force of the magnetic field formed by the magnetic field forming means 2, the latent image holder 1 moves in a state of being attracted and restrained on the entire surface of the electrostatic latent image. According to this supply method, the amount of developer required for development can be reliably supplied to the entire surface of the electrostatic latent image, and the defective development caused by the shortage of the developer supply amount in the conventional technique can be eliminated.

In the charging step, there is a charging member 5 arranged on the latent image holding member 1 with a predetermined gap, and the second electric field power source 6 generates a DC electric field between the charging member 5 and the latent image holding member 1. An AC electric field is formed, and the magnetic developer 10 is supplied to the entire surface of the electrostatic latent image on the surface of the latent image holder 1 and is attracted and held by the attraction force of the magnetic field formed by the first magnetic field forming means 2. ,
The electrostatic latent image is carried into the predetermined gap, vibrated by an AC electric field and charged, and is held by the DC electric field on the entire surface of the electrostatic latent image on the surface of the latent image holder 1. In this charging step, since the surface of the latent image carrier 1 having a high insulating property is charged, the leakage of the charged electric charge is small, and the electric charge of the charged magnetic developer 10 causes the electrostatic latent image on the surface of the latent image carrier 1. By acting on the image immediately, the development efficiency of the charged electric charge is good, and the vibration of the magnetic developer during charging makes the distribution of the magnetic developer on the electrostatic latent image uniform, and Charged magnetic developer 10
Is continuously in contact with the electrostatic latent image on the surface of the latent image holding member 1 until the developer is collected, so that even a fine line image of extremely fine line can be faithfully developed without fog or insufficient development.

In the developer collecting step, there is a developer collecting member 7 which is arranged on the latent image carrier 1 with a predetermined gap, and a third electric field is provided between the developer collecting member 7 and the latent image carrier 1. The power supply 8 forms a DC recovery bias and an AC recovery bias,
The second magnetic field forming unit 9 forms a magnetic field, and the attracting force of these collecting bias and magnetic field collects the developer adhering to the non-image portion of the electrostatic latent image on the surface of the latent image carrier 1. .

Next, the structure of one embodiment of the image forming apparatus of the present invention, which is a more specific form of the basic structure shown in FIG. 2, will be described with reference to FIG. In FIG. 1, the same components as those in FIG. 2 are given the same numbers.

Referring to FIG. 1, in the image forming apparatus of this embodiment, the latent image holder 1 contains the first magnetic field forming means 2 composed of a fixed magnet and is formed by the electrostatic latent image forming optical system 19. It moves while holding the electrostatic latent image. The developer collecting member 7 facing the latent image carrier 1 with a facing gap of about 350 μm formed of a fixed magnet and including the second magnetic field forming means 9 facing the first magnetic field forming means 2 includes the latent image holding means 9. It rotates in the same direction as the image carrier 1. A third electric field power source 8 that forms a direct current recovery bias and an alternating current recovery bias between the developer recovery member 7 and the latent image holding member 1 is connected to the developer recovery member 7. It is composed of a combination of an AC power supply and a DC power supply. In order to directly supply the developer 10 to the surface of the latent image holding member 1 on the upstream side as viewed from the latent image holding member 1 side in the vicinity of the latent image holding member 1 and the developer collecting member 7, The developer pot 10 ′ is attached so that the developer 10 inside forms a developer reservoir 11 in the vicinity, and the developer pot 10 ′ and the developer collecting member 7 are provided with the developer pot 10 ′. Developer 10 on collecting member 7
A scraper 13 for scraping off the developer is provided, and a seal 12 for preventing the developer 10 from leaking is provided between the developer pot 10 ′ and the latent image carrier 1.

In the developer reservoir 11, a charging member 5 is provided on the surface of the latent image carrier 1 near the proximity portion, with a minimum gap of 100 μm to 2 mm, and a predetermined gap. A second electric field power source 6 that forms a DC electric field and an alternating electric field between the latent image carrier 1 and the charging member 5 is connected to the charging member 5, and the second electric field power source 6 is an AC power source and a DC power source. Composed of and. As shown in FIG. 5, the clearance on the unloading side of the developer 10 is wider than the clearance on the loading side of the developer 10 to the predetermined clearance between the charging member 5 and the latent image carrier 1.

Further, in the developer reservoir 11, a developer supplying electrode roller 3 is provided so as to face the latent image holding member 1, and the developer supplying electrode roller 3 has a third electric field. The power supply 4 is connected.

On the paper 14, the developer developed on the latent image carrier 1 is transferred by the transfer charger 15 and fixed on the paper 14 by a fixing means (not shown). After the transfer, the latent image holding member 1 is cleaned by the cleaner 16 to remove the developer remaining on the latent image holding member 1, and the eraser 17 removes the potential remaining on the latent image holding member 1. The electrostatic latent image is formed by the electrostatic latent image forming optical system 19.

Next, the operation of this embodiment will be described with reference to FIGS.
It will be described based on.

In FIG. 1, first, an electrostatic latent image is formed on the surface of the latent image carrier 1 by the electrostatic latent image forming optical system 19. In this case, the image portion potential and the non-image portion potential are as shown in FIG.
As shown in, the image portion potential is -100V and the non-image portion potential is -500V.

The surface of the latent image holding member 1 upstream of the developer 10 in the developer pot 10 'when viewed from the latent image holding member 1 side in the vicinity of the latent image holding member 1 and the developer collecting member 7. To form a developer reservoir 11 in the vicinity. in this case,
The magnetic developer 10 is connected to the magnetic field of the first magnetic field forming means 2 contained in the latent image carrier 1 and to the developer supplying electrode roller 3 rotating facing the latent image carrier 1. One electric field is applied to the latent image carrier 1 by the electric field of the electric power source 4 to form the developer reservoir 11.

On the surface of the latent image carrier 1 in the developer reservoir 11, an alternating electric field is formed between the latent image carrier 1 and the charging member 5 by the second electric field power source 6 to vibrate the magnetic developer, The magnetic developer 10 may collide with the surfaces of the charging member 5 and the latent image carrier 1 or the magnetic developers 10 may collide with each other.
Charge to μC to −10 μC / g. The charge amount of the developer includes the AC recovery bias and the reciprocating flight force due to the charge amount.
There is a range of −0.5 μC / g to −40 μC / g as a range in which the developer can reciprocate beyond the adhesion of the developer to the latent image carrier due to the image force of the charged electric charge and the intermolecular force. In this embodiment, it is charged to −5 μC to −10 μC / g. In this embodiment, as described above, the gap on the unloading side of the developer 10 is wider than the gap on the loading side of the developer 10 to the predetermined gap between the charging member 5 and the latent image carrier 1. Therefore, the developer is vibrated by the alternating electric field, charged and diffused, and stably passes through this gap. In addition, a DC electric field may be superimposed on this alternating electric field.

When the developer 10 is magnetic, the magnetic flux formed between the latent image carrier 1 and the developer collecting member 7 by the first magnetic field forming means 2 and the second magnetic field forming means 9 is shown in FIG. In this way, the magnetic developer 10 is sucked into the facing gap between the latent image holding member 1 and the developer collecting member 7 as magnetic developer spikes 10 ″ to be restrained and held, and in this facing gap, the latent image holding member 1 is held.
Since the surface of the magnetic developer 10 and the surface of the developer recovery member 7 are moving in the opposite directions, the accompanying flow 21 of the magnetic developer 10 is formed. Since the amount of the developer in the magnetic developer chain 10 ″ is maintained at an amount determined by the magnetic flux density, the accompanying flow 21 causes the portion of the magnetic developer chain 10 ″ on the latent image carrier 1 side to be retained. Even if it is carried away, the same amount of developer 10 as that carried away is replenished, and the magnetic developer chain 10 ″ always has an integrated amount of developer 10, and the magnetic developer chain 10 ″ is used for development. The amount of developer supplied from is stabilized at a predetermined amount. Then, as shown in FIG. 4, a DC potential of −350 V
By the AC recovery bias in which the alternating rectangular potential of the peak-to-peak voltage of 1500 V is superposed on the magnetic developer 10, the magnetic developer 10 is discharged in the facing gap between the latent image carrier 1 and the developer recovery member 7 as shown in FIG. Reciprocate 22. As the waveform of this AC recovery bias, a sine wave, a triangular wave, a rectangular wave, or the like can be used, but a rectangular wave is preferable because a rectangular wave is efficient. Further, as the peak-to-peak voltage, it is possible to use a range of 500V to 2000V where a good image is obtained and no discharge occurs. Moreover, the frequency is 100 Hz to 10 kHz.
The z range can be used, but the required number of round trips is obtained 5
It is desirable that the frequency is from 00 Hz to 3 kHz where the developer 10 can sufficiently follow the reciprocating motion 22. Then, the accompanying flow 21
By the synergistic effect of the reciprocating motion 22 and the reciprocating motion 22, a circulating flow 23 of the magnetic developer 10 is formed, and a staying portion for circulating the magnetic developer 10 in the facing gap is formed. The AC recovery bias causes the magnetic developer in the staying portion that circulates and stays in the facing gap to reciprocate 22, so that the magnetic developer 10 repeatedly performs reciprocating motion 22, and the uncharged magnetic developer 10 Uncharged magnetic developer 10 even in the presence of
Reciprocally move 22 with the reciprocating motion 22 of the charged magnetic developer 10 to cause mutual friction and the developer collecting member 7.
It can be sufficiently charged by contact with.

Further, the reciprocating motion 22 of the magnetic developer 10 is performed.
By repeating the above, the magnetic developer 10 is dispersed in particles one by one and actively moves, and even if the magnetic developer 1 is not charged and adheres to the non-image portion of the electrostatic latent image, the electric recovery force does not work.
Even if there is 0, flip it to eliminate fog.

Further, the magnetic developer 1 by the AC recovery bias
As shown in FIG. 4, the reciprocating motion 22 of 0 is −1100 V, which is the negative peak of the alternating rectangular potential of the peak-to-peak voltage 1500 V in the image portion, and the forward path to the image portion of the magnetic developer 10 is 0. It flies with a potential difference of 1000 V, and at 400 V, which is the peak on the positive side of the alternating rectangular potential, the return path from the image portion of the magnetic developer 10 flies with a potential difference of 500 V, so only one difference between these potential differences in one round trip.
The magnetic developer 10 moves to the image portion and the image formation proceeds, and the peak-to-peak voltage 1500 V is generated in the non-image portion.
At −1100 V, which is the negative peak of the alternating rectangular potential, the outward path of the magnetic developer 10 to the non-image portion flies with a potential difference of 600 V, and the positive peak of the alternating rectangular potential is 400.
At V, the return path from the non-image portion of the magnetic developer 10 is 900
Since the magnetic developer 10 flies with a potential difference of V, the magnetic developer 10 is recovered from the non-image portion by the difference between these potential differences in one reciprocation. However, due to the synergistic action with the above-described repelling action, even a delicate image is accurate without fog. It can be developed.

When the gap between the electrostatic latent image on the surface of the latent image holding member 1 and the developer collecting member 7 becomes large due to the rotation of the latent image holding member 1, the electric field strength is gradually attenuated, which is accompanied by this. As a result, the movement of the magnetic developer 10 is attenuated, and the development is completed.

The surface of the developer collecting member 7 is the latent image holding member 1.
And a magnetic flux extending between the latent image carrier 1 and the developer collecting member 7 facing each other in a direction opposite to the surface of the latent image holding member 1 and the developer collecting member 7. The magnetic developer 10 floating between the latent image carrier 1 and the developer collecting member 7 is easily collected by the developer collecting member 7 and returns to the developer reservoir 11 by the rotation of the developer collecting member 7, The loss of the magnetic developer 10 is small, and the magnetic developer 10 can be prevented from scattering outside.

Further, as shown in FIG. 3, the developer collecting member 7
And the accompanying flow 21 generated by the rotation of the developer recovery member 7
Then, a part of the developer 10 that has returned to the magnetic developer spike 10 ″ part is the magnetic developer spike 10 ″ part and the magnetic developer spike 10 ″.
Of the latent image carrier 1 again, and becomes the accompanying flow 21 of the latent image carrier 1 and is supplied to the circulation flow 23.

The image forming method of the present invention is not limited to the above embodiment, but various modes are possible. For example, in the example,
The charging is carried out by the second electric field forming means 7 by vibrating the developer 10 by forming an alternating electric field between the latent image carrier 1 and the charging member 5. The developer may be rubbed between the image carrier 1 and the charging member 5 to be charged.
Although charging may be performed using a corona discharger, it is difficult to charge only the developer without disturbing the electrostatic latent image, which is not so preferable.

In the embodiment, the AC recovery bias of the third electric field power source 8 is used to recover the developer 10 attached to the non-image portion of the electrostatic latent image on the surface of the latent image carrier 1. However, in addition to this, the DC recovery bias of the third electric field power source 8 or the magnetic field of the second magnetic field forming means 4 can be used.

When the third electric field power source 8 which forms a DC recovery bias for this recovery is used as a part of the developer recovery means, the developer 10 supplied to the surface of the latent image holding member 1 is used.
However, the force received between the latent image carrier 1 and the developer collecting means 7 is
The intermolecular force, the mirror image force, and the electric field force, that is, the Coulomb force between the latent image potential, the recovery bias potential, and the charged charge of the developer. Among them, the intermolecular force and the mirror image force are the latent image. Since the image field and the non-image area are substantially constant, the electric field force that changes due to the DC recovery bias is such that the developer is recovered in the non-image area, and the latent image is the developer in the image area. By applying a DC recovery bias that has a magnitude that remains above, the developer in the non-image portion is recovered.

When the second magnetic field forming means 9 for forming a magnetic field for recovering the magnetic developer 10 is used as a part of the developer recovering means, the developer supplied to the surface of the latent image holding member 1 is used. The forces that 10 receives between the latent image carrier 1 and the developer collecting means 7 are intermolecular force, image force, and electric field force, that is, Coulomb between the latent image potential, the collecting bias potential, and the charge of the developer. Force and magnetic force, that is, magnetic attraction force between the second magnetic field forming means 9 and the magnetic developer, among which the intermolecular force and the image force are the image portion and the non-image portion of the latent image. Since the electric field force and the magnetic force are substantially constant regardless of the magnetic field, the magnetic field is such that the developer is collected in the non-image portion and the developer remains on the latent image in the image portion. By forming the, the developer in the non-image portion is collected.

In any case of recovery, the latent image carrier 1
And the direction of rotation of the developer collecting member 7 may be the same or opposite.

[0047]

The image forming apparatus of the present invention supplies a developer to the entire surface of the electrostatic latent image on the surface of the latent image carrier, charges the developer on the surface of the latent image carrier, and finally, It is characterized in that the developer adhering to the non-image portion is recovered from the developer supplied to the entire surface of the latent image, and the following effects are obtained.

Since the developer supplying means supplies a sufficient amount of developer to the entire surface of the electrostatic latent image on the surface of the latent image holding member, the sleeve ghost phenomenon can be eliminated. Further, since the conventional developer carrier is not used, the process and the precision control mechanism for forming a very uniform developer layer on the developer carrier are not required, the image forming apparatus is downsized, and the cost is reduced. become.

Since the charging member and the electric field power source for forming an alternating electric field between the charging member and the latent image holding member charge the developer on the surface of the latent image holding member having a high insulating property, development is carried out at high temperature and high humidity. Even in an atmosphere in which the charge of the agent is likely to leak, the influence of the leak is extremely small, and the effect of the specified amount of the charged charge reliably acts on the development, and high-resolution development and transfer stabilization can be achieved.

When the toner is charged by vibration, the developer can be charged without disturbing the electrostatic latent image on the surface of the latent image carrier, and the vibration disperses aggregates of the developer. Not only that, the developer moves on the surface of the latent image carrier, the amount thereof is uniformly distributed on the surface of the latent image carrier, and the charged developer is used for a long time. Since it contacts the electrostatic latent image on the surface of, the excellent image faithful to the electrostatic latent image can be obtained.

Further, the developer supplied to the surface of the latent image carrier and conveyed along the surface of the latent image carrier is vibrated, and the developer is diffused by the vibration. Then, the electrostatic latent image is stably conveyed, the amount of the developer for developing the electrostatic latent image is stabilized, and the electrostatic latent image can be faithfully developed.

Further, in the image forming apparatus of the present invention, the gap on the developer carrying-out side is wider than the gap on the developer carrying-in side to the predetermined gap between the charging member and the latent image carrier. With this configuration, when vibration is applied to the developer conveyed through the predetermined gap on the latent image holder along with the movement of the surface of the latent image holder, the developer is diffused by the vibration and the gap is wide. Since it advances in the direction, it is possible to stabilize the conveyance of the developer and perform the development faithful to the electrostatic latent image.

[Brief description of drawings]

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

FIG. 2 is a basic configuration diagram of an image forming apparatus of the present invention.

FIG. 3 is a partially enlarged view showing the operation of FIG.

FIG. 4 is an operation diagram showing an example of the operation of FIG.

FIG. 5 is a partially enlarged view of FIG.

FIG. 6 is a diagram illustrating the principle of sleeve ghost generation.

[Explanation of symbols]

 1 Latent Image Holder 2 First Magnetic Field Forming Means 3 Developer Supply Electrode Roller 4 First Electric Field Power Supply 5 Charging Member 6 Second Electric Field Power Supply (Electric Field Power Supply) 7 Developer Collection Member 8 Third Electric Field Power Supply 9 Second Magnetic Field Formation Means 10 Developer 10 ′ Developer pot 10 ″ Magnetic developer ear 11 Developer reservoir 21 Accompanying flow 22 Reciprocating motion 23 Circulating flow

Claims (2)

[Claims] 1. A latent image carrier that holds and moves an electrostatic latent image on the surface, a developer supply unit that directly supplies a developer to the entire surface of the electrostatic latent image on the surface of the latent image carrier, and the latent image carrier. A charging member facing the surface of the image carrier with a predetermined gap, and an alternating electric field is formed between the charging member and the latent image carrier, and the alternating electric field supplies the latent image carrier to the surface of the latent image carrier. An electric field power source that vibrates and charges the developer that is conveyed between the charging member and the latent image carrier along with the body surface, and a non-image portion of the electrostatic latent image on the surface of the latent image carrier. An image forming apparatus comprising: a developer collecting unit that collects the attached developer. 2. The image forming apparatus according to claim 1, wherein the developer carrying-out side gap is wider than the developer carrying-in side gap to the predetermined gap between the charging member and the latent image carrier.