JPH05134581A - Image forming device - Google Patents

Abstract

PURPOSE:To provide an image forming device capable of forming an excellent image on the full surface of a recording form. CONSTITUTION:A signal electrode 33 and a common electrode are provided interposing a toner passing hole 31a, on an insulation substrate 31 having the toner passing hole 31a. An electric field is formed between both electrodes 33 and 35, so that toner passes the toner passing hole 31a. A base roller 60 whose periphery is meshed, is provided in a toner passing direction side on the insulation substrate 31, and pressure in the base roller 60 is reduced by a pump. The recording paper 70 is sucked on the meshed periphery, by reducing the pressure in the base roller 60, and integrally carried with the base roller 60, by the rotation of the base roller 60.

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 powder toner.

[0002]

2. Description of the Related Art An image forming apparatus using a powder toner as an image recording medium is disclosed in, for example, Japanese Patent Application Laid-Open No. 3-57658. An example of an image forming apparatus using such powder toner is shown in FIG. This image forming apparatus has a toner container 100 that contains powder toner. The toner storage container 100 is provided with a supply roller 110 for supplying toner, and the powder toner stored in the toner storage container 100 is supplied to the side by the rotation of the supply roller 110. Toner control means 130 is provided on the side of the supply roller 110. An electric signal corresponding to the image information is transmitted to the toner control unit 130, and the powder toner supplied from the supply roller 110 is controlled by the toner control unit 130 according to the electric signal and is recorded on the recording paper 70. A predetermined toner image is formed.

Toner control means 130 for controlling the powder toner
Is an insulating substrate 133 having a large number of pinhole-shaped toner passage holes 134, and a pair of electrodes sandwiching the insulating substrate 133 so as to form an electric field in each toner passage hole 134. 131 and 132. Each of the electrodes 131 and 132 forming a pair is provided with a pinhole-shaped through hole of the same size as that of the toner passage hole 13 and
Each through hole is attached to each surface of the insulating substrate 133 so as to be aligned with each toner passage hole 134. Then, by applying a predetermined voltage between the electrodes 131 and 132, an electric field is formed in the toner passage hole 134 so that the charged toner passes through the toner passage hole 133, and the toner particles are generated in the toner passage hole 134. Is passed through. When the toner particles are prevented from passing through the toner passage hole 134, an electric field is formed in the toner passage hole 134 between the electrodes 131 and 132 so as to form an electric field in the opposite direction to that when the toner is passed. A predetermined voltage is applied.

A base roller 140 is provided on the side of the toner control means 130 so as to be rotationally driven. The recording paper 70 is wound around the base roller 140 so as to be positioned between the recording paper 70 and the toner control means 130 and is conveyed. Above the base roller 140, a conveying roller 150 made of an elastic material such as rubber is rotatably provided, and the recording paper 70 is nipped by the conveying roller 150 and the base roller 140. The roller 140 is conveyed in close contact with it. The base roller 140 has electrodes 131 and 13
Toner that has passed through the toner passage hole 134 between
The voltage is applied so that an electric field is created which can be transported towards 70.

In such an image forming apparatus, the recording paper 70 is nipped by the base roller 140 and the conveying roller 150 and is conveyed while being in close contact with the base roller 140. The electrodes 132 of the sheet 130 do not come into contact with each other, and the image formed on the sheet 70 is not disturbed.

In order to bring the recording paper 70 into close contact with the base roller 140 and to convey the recording paper 70, at each end of the conveying roller 150, as shown in FIG.
As shown in (a) and (b), the engaging protrusion 16 is provided on the outer peripheral edge portion.
A method has also been proposed in which a thin disc-shaped transport member 160 made of synthetic resin on which 1 is formed is attached, and the recording paper 70 is locked to each transport member 160 and transported.

[0007]

In such an image forming apparatus, the recording paper 70 can be conveyed while being in close contact with the base roller 140, but the conveying roller 150 is provided on the surface of the recording paper 70 on which the toner image is formed. Therefore, the toner image in the unfixed state may be damaged by the transport roller 150. For this reason, an image cannot be formed on the portion where the transport roller 150 contacts. By arranging the conveyance roller 150 having a short axial length at both ends in the width direction of the recording paper 70, the image forming area of the recording paper 70 can be increased, but the conveyance force of the recording paper 70 may be reduced. Therefore, the recording paper 70 may not be conveyed reliably.

Further, when the conveying member 160 shown in FIG. 5 is used, the area where the conveying member 160 contacts the recording paper 70 is greatly reduced, but at the portion where the conveying member 160 contacts,
Again, the toner image on the recording paper 70 is damaged, and an image cannot be formed on the entire surface of the recording paper 70. Moreover, recording paper
Since the recording sheet 70 is conveyed while being locked to the outer peripheral edge of the conveying member 160, the recording paper 70 is likely to float from the base roller 140. When the recording paper 70 floats from the base roller 140 and comes into contact with the electrode 132 of the toner control unit 130, the quality of the image formed on the recording paper 70 deteriorates.

The present invention solves such a problem, and an object thereof is to make it possible to form an image on the entire surface of the recording paper and to improve the adhesion between the recording paper and the base roller. Another object of the present invention is to provide an image forming apparatus capable of stably forming a high quality image.

[0010]

An image forming apparatus of the present invention is provided with a toner passage hole through which toner passes, and a substrate to which the toner is supplied and a toner passage hole. A pair of electrodes arranged to sandwich the substrate so as to form an electric field, and between the electrodes so as to form an electric field in each toner passage hole in at least a direction in which toner passes according to image information. The image information generating means having a predetermined potential, and the rotation of the image information generating means are arranged rotatably on the toner passage direction side of the substrate so that the recording paper to which the toner is attached is conveyed. A configured base roller, and means for depressurizing the inside of the base roller so that the recording paper is attracted to the mesh on the peripheral surface,
The above object is achieved thereby.

[0011]

In the image forming apparatus of the present invention, an electric field is formed in the toner passage hole provided on the substrate by the pair of electrodes,
The toner supplied to the substrate passes through the toner passage hole due to the electric field. A base roller having a meshed peripheral surface is provided on the toner passage side of the substrate. The inside of this base roller is decompressed by decompression means,
The recording paper is brought into close contact with the mesh on the peripheral surface. Then, the recording paper is conveyed as the base roller rotates. The toner that has passed through the toner passage holes adheres to the recording paper conveyed in this way, and an image is formed.

[0012]

EXAMPLES Examples of the present invention will be described below. As shown in FIG. 1, the image forming apparatus of the present invention has a toner container 10 that contains powder toner. The toner container 10 is formed with an opening 11 that is open to the side, and the toner supply roller 20 is provided in the opening 11.
Are arranged. The toner supply roller 20 has a side portion extending outward from the opening 11, and is indicated by an arrow B.
Is rotated in the direction indicated by.

An opening is provided on the side of the toner supply roller 20.
A toner control member 30 is provided opposite to 11. As shown in FIG. 2, the toner control member 30 has a vertical insulating substrate 31 whose lower end is connected to the toner container 10.
On the insulating substrate 31, a large number of toner passage holes 31a penetrating in the horizontal direction are arranged in parallel along the axial direction of the supply roller 20. Each toner passage hole 31a has a constant inner diameter. Further, the ultrasonic vibration generator 40 is provided on the insulating substrate 31.
(See FIG. 1) is provided, and the ultrasonic vibration generator 40
Thereby, ultrasonic vibration is applied to the insulating substrate 31.

A common electrode 35 is provided on a surface of the insulating substrate 31 facing the toner supply roller 20, and the common electrode 35 has a through hole 35a having a diameter similar to that of each toner passage hole 31a.
Are formed. The common electrode 35 has an insulating substrate 31 so that each through hole 35a is aligned with each toner passage hole 31a.
Is attached to.

Signal electrodes 33 are provided on the opposite surface of the insulating substrate 31 so as to correspond to the toner passage holes 31a. Each signal electrode 33 is provided with a through hole 33a having a size similar to that of each toner passage hole 31a of the insulating substrate 31, and each through hole 33a corresponds to each toner passage hole 31a of the insulating substrate 31.
The respective signal electrodes 33 are attached to the insulating substrate 31 so as to be aligned with.

An image information generator 50 is connected between the common electrode 35 and the signal electrode 33 of the insulating substrate 31, and the image information generator 50 outputs an image signal as a voltage signal to each signal electrode 33. (Control signal) is input. Predetermined positive and negative potentials are applied to each signal electrode 33 according to image information. For example, in the case of information for forming an image, +100 is applied.
A voltage of V is applied, and in the case of non-image information that does not require image formation, a voltage of -100V is applied. The image information generator 50 operates in response to a signal from a device body such as a word processor, a facsimile, a computer or the like, and generates an electric signal corresponding to the image information.

A base roller 60 is provided on the side of the toner control member 30 so as to face the toner control member 30.
As shown in FIG. 3, the base roller 60 has a peripheral surface made of a metal mesh except for each end. A recording paper 70 on which a toner image is formed is wound around a side portion of the base roller 60 on the toner control member 30 side. A pump 65 for reducing the pressure inside the base roller 60 is connected to the base roller 60.

Inside the base roller 60, a semi-cylindrical guard plate 61 is provided so as to cover a side portion opposite to the side where the toner control member 30 is disposed. The guard plate 61 is in a fixed state. Therefore, when the inside of the base roller 60 is depressurized by the pump, the recording paper 70 is sucked by the metal mesh through the peripheral surface made of the metal mesh facing the toner control member 30, and The recording paper 70 is conveyed along with the rotation. Then, when the recording paper 70 reaches the side portion of the base roller 60 provided with the guard plate 61, the peripheral surface of the metal mesh is covered with the guard plate 61.
70 is not adsorbed on the peripheral surface of the base roller 60 and is easily peeled off from the base roller 60.

The base roller 60 includes a toner control member 30.
Common electrode 35 on the toner supply side and the base roller
A predetermined voltage is applied by 60 to form an electric field in which the toner passing through the toner passage hole 31a moves toward the base roller 60. Then, the toner that has passed through the toner passage hole 31a adheres to the recording paper conveyed by the base roller 60, and a predetermined image is formed. The size of the metal mesh on the peripheral surface of the base roller 60 is set to about 1 mm, and a uniform electric field is formed on the entire surface of the recording paper 70 to form a good image. When a predetermined toner image is formed on the recording paper 70, the recording paper 70 is conveyed to a fixing device (not shown), and the toner image is fixed on the recording paper 70 by the fixing device.

An image forming process by the image forming apparatus having such a configuration will be described. Toner supply roller 20
When is rotated, the powder toner in the toner container 10 is supplied to the common electrode 35 of the toner control member 30. Common electrode 35
Since ultrasonic vibration is applied through the insulating substrate 31 by the ultrasonic vibration generator 40 provided on the insulating substrate 31, the toner supplied on the common electrode 35 is From the through hole 35a of the electrode 35 to the toner passage hole 31a of the insulating substrate 31
Flows in.

The toner particles flowing into the toner passage hole 31a of the insulating substrate 31 are controlled according to the image signal given to the signal electrode 33 and adhere to the recording paper 70 or the common electrode 35.
Returned to.

For example, when a positive voltage is applied to the signal electrode 33 by the image signal generating means 50, an electric field from the signal electrode 33 to the common electrode 35 is generated in the toner passage hole 31a. This electric field is formed along the inner peripheral surface of the toner passage hole 31a. By forming such an electric field, the toner particles that are negatively charged in advance are attracted to the signal electrode 33 and flow along the inner peripheral surface of the toner passage hole 31a,
The toner passes through the toner passage hole 31a and the through hole 33a. At this time, the recording paper 70 is attracted to the mesh of the peripheral surface by the pressure reduction in the base roller 60,
The toner is supplied on the recording paper 70 as the toner is rotated. Since a positive bias voltage is applied to the base electrode 60 with respect to the common electrode 35, an electric field is formed between the base roller 60 and the common electrode 35. The toner particles that have passed through the holes 31a are reliably supplied onto the recording paper 70. As a result, a toner image is formed on the recording paper 70.

The recording paper 70 is attracted to the peripheral surface of the mesh at the half-circumferential portion of the base roller 60 facing the toner control member 30, and is conveyed as the base roller 60 rotates.
Then, when it reaches the half circumference where the guard plate 61 is provided,
Since the peripheral surface of the mesh is covered with the guard plate 61, the recording paper 70 is not adsorbed on the peripheral surface of the base roller 60 and is peeled off from the base roller 60. Therefore, the surface of the recording paper 70 on which the toner image is formed is not brought into contact with a member for conveying the recording paper 70, and the recording paper 70 is conveyed in a state of being in close contact with the base roller 60. As a result, recording paper
70 is lifted from the peripheral surface of the base roller 60 to be a signal electrode.
33, there is no risk of contact with 33, there is no fear of disturbing the electric field formed in each toner passage hole 31a and the electric field formed between each electrode and the base roller, a clear image is formed by a stable electric field .. Further, even when a toner image is formed on the entire surface of the recording paper 70, the recording paper 70 can be conveyed along the base roller 60 without damaging the toner image. Since the bias voltage applied to the base roller 60 is transmitted along the metal mesh, it is almost evenly transmitted to the surface of the recording paper 70 which is not a high resistance material, and is uniform over the entire surface of the recording paper 70. An electric field is created. As a result, the toner image formed on the recording paper 70 is free from the possibility that the density of the mesh on the peripheral surface of the base roller 60 is generated, and a good image can be obtained. According to the experiments conducted by the inventors of the present application, it has been confirmed that when the mesh size of the mesh roller 60 is about 1 mm or less, a good image is formed without causing shading of the image due to the mesh.

When the recording paper 70 is conveyed and the peripheral surface of the base roller 60 is exposed, the pressure inside the base roller 60 is reduced, so that the air around the base roller 60 passes through the mesh on the peripheral surface of the base roller 60. It is sucked into 60. As a result, the air in each toner passage hole 31a is also sucked into the base roller 60, and the toner that has accumulated in each toner passage hole 31a due to the air flow flowing in the toner passage hole 31a. The toner is discharged to the outside of 31a, and each toner passage hole 31a is cleaned. Due to such a cleaning effect of each toner passage hole 31a, each toner passage hole 31a
Are prevented from being blocked by the toner staying inside.

[0025]

According to the image forming apparatus of the present invention,
The recording paper, to which the toner that has passed through the toner passage hole adheres, is conveyed by the rotation of the base roller while being adsorbed to the peripheral surface of the base roller whose peripheral surface is a mesh by depressurizing the inside. Because it is
It is possible to convey the recording paper without bringing the member into contact with the surface of the recording paper on which the toner adheres. as a result,
It becomes possible to form an image on the entire surface of the recording paper. Further, since the recording paper does not come into contact with the electrodes of the toner control member, a high quality image can be formed.

When the toner image is not formed on the recording paper, the pressure inside the base roller is reduced so that the toner in the toner passage hole is removed and the inside of the toner passage hole can be cleaned.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing an example of an image forming apparatus of the present invention.

FIG. 2 is a vertical sectional view showing a main part of the image forming apparatus shown in FIG.

FIG. 3 is a perspective view showing a base roller used in the image forming apparatus shown in FIG.

FIG. 4 is a vertical sectional view showing an example of a conventional image forming apparatus.

FIG. 5A is a front view showing an example of a recording paper conveying member used in a conventional image forming apparatus, and FIG. 5B is a sectional view thereof.

[Explanation of symbols]

 10 toner container 20 toner supply roller 30 toner control member 31 insulating substrate 31a toner passage hole 33 signal electrode 35 common electrode 50 image information generator 60 base roller 61 guard plate 65 pump 70 recording paper

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masaaki Yukawa 1-2-2 Tamatsukuri, Chuo-ku, Osaka Mita Engineering Co., Ltd.

Claims (1)

[Claims] 1. A toner passage hole through which a toner passes is provided, and a substrate to which the toner is supplied is arranged to sandwich the substrate so as to form an electric field in the toner passage hole. A pair of electrodes, and image information generating means for setting a predetermined potential between the electrodes so that an electric field is formed in each toner passage hole in at least a direction in which the toner passes according to the image information. It is arranged rotatably on the toner passage direction side of the substrate so that the recording paper to which the toner is attached is conveyed by rotation, and the peripheral surface is composed of a mesh of the base roller and the mesh of the peripheral surface. An image forming apparatus comprising: a means for depressurizing the inside of the base roller so that the recording paper is adsorbed.