JPH04268591A - Image forming device - Google Patents

Abstract

PURPOSE:To obtain an image forming device which forms a high-quality color image. CONSTITUTION:Three image forming devices 10, 11 and 12 are istalled, and yellow toner 13, magenta toner 14, cyan toner 15 are stored in toner cases 16, respectively. An aperture electrode body 1 which is formed of a control electrode 4, an insulating layer 2 and a reference electrode 3 and has an aperture 6 which penetrates three layers is disposed on the upper part of each image forming device. Then, a feeding roller 18 is disposed so that a supporting body is carried while facing to the aperture electrode body of the image forming device. The electrostatically charged toner of every color is held on the supporting body through the aperture so as to form the color image by impressing voltage on the control electrode of the image forming device for each color in accordance with the image signal of each color while the supporting body is carried.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is applicable to copying machines, printers,
The present invention relates to an image forming apparatus that can be used for plotters, facsimile machines, etc.

0002

2. Description of the Related Art Conventionally, image forming apparatuses control passage of toner particles through an aperture by applying an image signal to an electrode having an aperture, thereby obtaining a color image on a support.
This is proposed in Japanese Patent Application Laid-Open No. 62-248662. In this publication, a conductive toner flight control member having a plurality of minute apertures and a plurality of control electrodes for controlling passage of toner through each aperture is disposed between a toner carrier carrying conductive toner and a counter electrode. We have proposed an image forming apparatus that includes multiple pixel forming apparatuses.

This pixel forming device applies a voltage between a toner carrier and a control electrode in accordance with an image signal, induces and injects charges into the conductive toner on the toner carrier, and uses an electric field to apply a voltage to the conductive toner on the control electrode side. In this method, the conductive toner is caused to fly, and the flying conductive toner is passed through a minute aperture, transferred to the counter electrode side, and deposited on the support.

Conductive toners of different colors are stored in the toner cases of the plurality of recording devices, and an image signal for each color is applied to a control electrode to form an image for each color.

[0005]

[Problems to be Solved by the Invention] However, in the above method, since the toner particles are conductive, the toner flying onto the support may have an opposite charge on the toner particles due to the conductivity of the support. is injected. In particular, in the case of a hygroscopic support such as paper, the conductivity increases with humidity. When charges of opposite signs are injected into the toner particles, they receive a repulsive force from the support and cannot be stably held on the support, causing the toner particles to peel off or shift from the support. Therefore, the apparatus having the above-mentioned configuration has the disadvantage that it cannot form high-quality color images.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an image forming apparatus capable of forming high-quality color images.

[0007]

[Means for Solving the Problems] In order to achieve this object, the image forming apparatus of the present invention includes means for conveying a support;
It consists of a plurality of pixel forming devices storing toner of different colors arranged in the transport path of the support, and each of the plurality of pixel forming devices has a reference electrode on one side and a reference electrode on the other side with an insulator layer in between. an aperture electrode body consisting of one or more control electrodes insulated from each other in a plane, each insulated control electrode having one or more apertures extending through three layers; and a control electrode of the aperture electrode body. It is characterized by comprising means for selectively applying a potential between the reference electrode and the reference electrode, and means for supplying insulating charged toner to the vicinity of the aperture of the reference electrode.

[0008]

[Operation] According to the image forming apparatus of the present invention having the above configuration, when the support is conveyed, the charged toner is transferred to the reference of the aperture electrode body in the pixel forming apparatus having the toner of the first color. Supplied near the electrode aperture. At this time, when a voltage with a polarity opposite to the charged polarity of the toner is applied to the control electrode according to the image signal, the aperture of the applied control electrode applies a force to the charged toner in the direction from the reference electrode toward the control electrode. An electric field is formed. The toner is drawn from the reference electrode side of the aperture to the control electrode side,
It flies onto the support and is held to form an image area. By applying a voltage having the same polarity as the charged polarity of the toner to the control electrode of the aperture corresponding to the non-image area, an electric field formed within the aperture suppresses the toner from passing through the aperture.

Next, while forming an image of the first color as described above, a pixel forming device of a different color is formed using the same process as that of the pixel forming device having toner of the first color. Pixels of a color are formed overlying an image of a first color.

[0010] In this way, a color image can be obtained by overlappingly forming images of the necessary colors using pixel forming devices of the necessary number of colors.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment embodying the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of an embodiment embodying the present invention. In FIG. 1, a conveyance roller 18 is arranged to convey the support body 17 in the direction of the arrow. Support body 17
Three pixel forming devices 10, 11, and 12 are installed so as to face the lower surface of the support during the transport path, and yellow toner 13, magenta toner 14, and cyan toner 15 are stored in a toner case 16, respectively. has been done. Each pixel forming device has an aperture electrode body 1 disposed above it. A toner case 16 is provided on the lower surface side of the aperture electrode body 1 . A brush roller 20 and a supply roller 23 arranged parallel to the brush roller 20 are disposed inside the toner case 16 . The brush of the brush roller 20 and the supply roller 23 are in contact with each other. A brushing blade 24 is in contact with the brush roller 20 at a position before rotating to the aperture surface.

As shown in detail in FIG. 2, the aperture electrode body 1 has a continuous reference electrode 3 on one side of an insulating layer 2 and a divided control electrode 4 on the other side. A large number of apertures 6 penetrating the insulating layer 2 and the control electrode 4 are formed in a line corresponding to the width of the support 17.

The reference electrode 3 is grounded as shown in FIG. The control electrodes 4 of the pixel forming devices for each color are respectively connected to control voltage drive circuits 8 that generate voltages based on image signals of the respective colors.

Each pixel forming device 10 with the support 17 in between,
A back electrode 19 is provided on the opposite side of the electrodes 11 and 12. The back electrode 19 is connected to a positive DC power source 30 .

The operation of the above configuration will be explained in detail below.

The support body 17 is conveyed by a conveyance roller 18 in the direction of the arrow so as to face the aperture electrode body 1 of the three-color pixel forming device in sequence.

During this time, in the three-color pixel forming device,
The toner is carried on the brush of the brush roller 20 by rotating the brush roller 20 and the supply roller 23 in the direction of the arrow. At this time, the toners 13, 14, and 15 rub against the brush or supply roller 23 and become negatively charged. The charged toners 13, 14, and 15 are conveyed toward the vicinity of the brushing blade 24 by the rotation of the brush roller 20. When the brush near the brush scraping blade 24 is scratched by the brush scraping blade 24, it splashes up the charged toners 13, 14, and 15 with its elasticity, and the toner 1
3, 14, and 15 are supplied in the vicinity of the reference electrode aperture 6 of the aperture electrode body 1 in the form of a cloud.

At this time, each pixel forming device 10, 1
1 and 12, voltage is applied to the control electrode 4 by the control electrode drive circuit 8 in accordance with image signals of each color corresponding to the position of the supporting body 17 facing the aperture electrode body 1.

When a positive voltage is applied, lines of electric force are formed in the aperture 6 of the applied control electrode 4 from the control electrode 4 toward the reference electrode 3, and the negatively charged toner 13, 14, 15 is drawn out from the reference electrode 3 side of the aperture to the control electrode 4 side, and is further flown and held onto the support 17 by the flying electric field formed by the back electrode 19 to form an image portion.

By applying the same potential as the reference electrode 3 or a negative voltage to the control electrode 4 of the aperture 6 corresponding to the non-image area, the flying electric field due to the back electrode 19 can be shielded, or the electric field inside the aperture 6 can be shielded. By forming electric lines of force from the reference electrode 3 toward the control electrode 4, toner is prevented from passing through the aperture.

In this manner, while the support 17 passes over the three color pixel forming devices, three color images are superimposed and formed to obtain a color image.

[0023]

[Effects of the Invention] As is clear from the above explanation, according to the present invention, since the toner used is insulating,
Since the toner flying onto the support is not injected with charges of opposite polarity and therefore does not have a repulsive force with the support, the toner image is stably held on the support.

Therefore, according to the configuration of the present invention, it is possible to provide an image forming apparatus that can form high quality color images.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment embodying the present invention.

FIG. 2 is a perspective view showing details of an aperture electrode body.

[Explanation of symbols]

1 Aperture electrode body 2 Insulating layer 3 Reference electrode 4 Control electrode 6 Aperture 8 Control electrode drive circuit 10 Yellow color pixel forming device 11 Magenta color pixel forming device 12 Cyan color pixel forming device 18 Conveyance roller 20 Brush roller 23 Supply roller 24 Brush scraper blade

Claims (1)

[Claims] 1. A pixel forming device comprising means for transporting a support, and a plurality of pixel forming devices storing toners of different colors disposed in a transporting path of the support, each of the plurality of pixel forming devices comprising:
It consists of a reference electrode on one side with a layer of insulator in between, and one or more control electrodes insulated from each other on the other side, with one or more apertures passing through the three layers for each insulated control electrode. an aperture electrode body having an aperture electrode body, means for selectively applying a potential between a control electrode and a reference electrode of the aperture electrode body, and means for supplying insulating charged toner to the vicinity of the aperture of the reference electrode. An image forming apparatus characterized by: