JPS63137253A - Spray type developing device - Google Patents

Abstract

PURPOSE:To eliminate the unevenness of density of a developed image by rubbing a powdery toner over a fur brush roll and blowing off the stuck powdery toner by spray air to fill up a developing chamber with the powdery toner and uniformly filling up the developing chamber with the powdery toner without clogging. CONSTITUTION:A recording member 2 on which an electrostatic latent image is formed is arranged in the aperture part of a developing chamber 1 formed into a box shape, and the electrostatic latent image is developed with a misty powdery toner. The chamber 1 is formed into a box shape, and plural nozzles 3 and 4 from which air is blown are provided on both inside faces. The nozzle 3A in the center has plural air jet orifices to blow air with the same width as a fur brush roll 11. Nozzles 4 and 3A are not arranged on a straight line, and air supply pipes 5 and 6 are coupled to nozzles 3, 3A, and 4. The roll 11 is provided in the center in the breadthwise direction of the chamber 1, and the powdery toner stuck to meshes 14 of the roll 11 is blown off by air and is filled up in the chamber 1.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an electrophotographic apparatus, and in particular, a method for developing a recording member after forming an electrostatic latent image by uniformly spraying toner powder into a developing chamber. The present invention relates to a spray type developing device for an electrophotographic device, which can thereby achieve uniform density.

[Prior Art] Electrophotography equipment, particularly X-ray electrophotography equipment, is capable of replacing the conventional In recent years, X-rays have attracted wide attention in the medical field because they have the advantage of being able to obtain clearer images than radiographs and reducing the amount of X-rays the human body is exposed to.

The principle of the X-ray electrophotographic apparatus is as shown in FIG.
A photoconductor layer (Se+
Se) e) 140 and a surface transparent insulating layer (for example, polyester) 15 provided on the photoconductor layer 140
0.

At the same time as the transparent IJ4150 surface of the recording member 100 is irradiated with light, a corona discharger is used to uniformly apply a (+) charge at a voltage of about 6700 V corona discharge. is excited and charges move within the leading ml and are trapped in a trap near the interface with the insulating layer 130 in the photoconductive layer. Next, Figure 4 (8)
As shown in the figure, a subject 200 is placed on or above the substrate 110.
The subject 200 is exposed to X-rays from above, and at the same time a corona discharger is used to apply a voltage of approximately -7300V.
A (-) charge is discharged to the surface transparent insulation W4150 at a corona discharge ml pressure of . The photoconductive layer is excited by irradiation of the recording member 100 with X-rays, and the photoconductive layer becomes electrically conductive to a degree corresponding to the X-ray transmittance of the subject, thereby promoting (-) charging. this(
-) charges vary in density depending on the amount of X-rays transmitted through the subject. Then, as shown in FIG. 174 (C), the trapped charges are released by exposing the entire surface to light, creating a difference in bright and dark potential on the recording member. Fine toner powder is supplied to the recording member 100 on which the electrostatic latent image has been formed in this way, and the toner powder is adsorbed onto the surface of the surface transparent insulation FM 150, and then the entire surface of the recording member is covered with a pre-transfer corona discharger. (
-), the transfer film is placed on the surface of the insulating layer 150, and a (+) charge is applied from the back side of the transfer film to transfer the toner powder image onto the transfer film. The transferred film is passed through a heat roller to fix the toner image.

Spraying of toner powder onto the surface of the recording member 100 during development has conventionally been carried out by a method as shown in FIG. That is, the upper end of the box-shaped main body 410 of the spray developing device 400 for an electrophotographic apparatus is connected to the recording member 420.
It is configured so that it can be placed. An opening 411 is provided on the side surface of the main body 410.
11, an air spray nozzle 412 protrudes from the side surface, and a toner powder nozzle 413 protrudes from the bottom surface. The tip of the air spray nozzle 412 and the tip of the toner powder nozzle 413 are provided close to each other.
The toner powder is sprayed into the main body 410 from the nozzle opening 414 at the tip of the toner powder nozzle 413 by air jetted from the tip of the toner powder nozzle 413 on the principle of atomization. The lower end of the toner powder nozzle 413 is placed inside the toner powder container 430! It is worn.

[Problems to be Solved by the Invention] Such a spray developing device for an electrophotographic device uniformly disperses toner powder into the main body in the form of a mist. This is useful for devices that require clear images with high gradation. However, in conventional developing devices, toner powder is transported from a toner powder container to a nozzle opening through a toner powder nozzle, and compressed air is injected into the nozzle opening from the side. Fills the developing box (main body) in a mist form to develop the electrostatic latent image on the recording member placed facing inside the developing box.
The nozzle opening must be formed with a relatively small diameter because it is necessary to be filled with toner powder in the form of a mist, and this has the problem that the nozzle may become clogged with toner powder, making it impossible to perform proper spraying. ing.

[Means for Solving the Problems] The present invention does not cause inconveniences such as clogging or non-uniform toner powder mist, and does not cause density unevenness. In a spray type developing device, a recording member on which an electrostatic latent image is formed is positioned in an opening of a chamber to be formed, and the electrostatic latent image is developed with atomized toner powder. A nozzle that injects compressed air in the - direction, a bristle brush roller whose surface is covered with a large number of short hairs in front of the nozzle and rotates during development, and a toner supply that supplies toner powder to the surface of the bristle brush roller. and developing the electrostatic latent image by atomizing the toner powder supplied to the surface of the bristle brush roller by the toner supply device into the chamber with compressed air from the nozzle. Examples] Examples of the present invention will be described below.

First Embodiment (Figures 1 and 2) In Figure 1, a developing chamber 1 is made of a grounded conductive material, and a recording member 2 is insulated from the chamber by a suitable insulating backing in its upper opening. It is configured so that it can be placed on the table. The recording surface 21 of this recording member 2 is exposed in the developing chamber 1 during the above-mentioned placement. The developing chamber 1 is formed into a box shape, and a plurality of nozzles 3.4 for blowing out compressed air (hereinafter referred to as air) are provided on the inner side surface of the developing chamber 1.

Among the plurality of nozzles 3, the nozzle 3A located at the center has a plurality of air injection ports so as to be able to blow air over approximately the same width as the bristle brush roller 11 described later. A vibrator 5 for air feeding is connected to the nozzle 3, and a vibro is connected to the nozzle 4, and the vibrators 5 and 6 are connected to an air tank 8 via a solenoid valve 7, respectively. There is. The nozzle 4 is provided at a position that does not coincide with the nozzle 3A on a straight line. The air tank 8 is configured to be operated by a compressor 9. Further, a step is provided on the side of the developing chamber 1 where the nozzle 3 is attached, and a toner reservoir 10 is removably provided in close contact with the side wall surface of the nozzle 4 of this step.

Further, in front of the nozzle 3A, a bristle brush row 511 whose roll surface is made of a material with short bristles, such as velvet, and has a predetermined width is installed at approximately the center in the width direction of the developing chamber 1, as shown in FIG. It is provided. The bristles of the material such as velvet that forms the surface of this bristle brush roller 11 are
Approximately 1.5 to 2M is optimal. The optimal rotational speed of this bristle brush roller 11 is 2 Or, p, m, around 200 m, and it is configured to rotate in the direction shown by arrow A (clockwise). Below this bristle brush roller 11, a leveling roller 12 is provided which rotates in contact with the bristle brush roller 11 and has a roller shape having approximately the same width as the bristle brush roller 11. This smoothing row 512 is similar to the hair brush row 511.
Its surface is constructed in the same manner as in the above, and is configured to rotate in the direction shown by arrow B (clockwise).

Further, at the lower end of the developing chamber 1, a toner hopper 13 is provided, the wall surface of which is partially formed in the shape of a drum, and having a toner population 22 into which toner powder is introduced from above.

A mesh 14 capable of supplying toner powder to the outside is provided at a part of the drum-shaped wall surface portion of the toner hopper 13 at approximately the center in the width direction and has approximately the same width as the leveling roller 12. The leveling roller 12 is provided so as to rotate while rubbing the mesh 14 with an appropriate relatively weak pressure. As the mesh 14, for example, a 100-line SUS mesh having a thickness of 0.1 seconds is used. Further, in the toner hopper 13, a plurality of rotary blades 15 (four in this embodiment) are provided which rotate while their tips are in contact with the drum-shaped inner wall of the toner hopper 13. At the tip of the rotary blade 15, the toner powder introduced into the toner hopper 13 is placed in the mesh 1.
4 and suitably feed through the mesh 14 are provided. The hair length of this hair 16 is approximately 3 meters
Around s+ is optimal. This rotary blade 15 is configured to rotate in the direction shown by arrow C (clockwise). The rotary blade 15 rotates faster than the leveling roller 12.

Further, a stirring blade is provided coaxially with the rotary blade 15.

On the other hand, on the inner bottom surface of the developing chamber 1, a spatula-shaped cleaner 17 that slides on the bottom surface is provided. Further, a groove 18 is formed on the bottom surface on the side of the nozzle 4, and a duct 19 is connected to this groove 18. This duct 19
A filter box 20 is attached to the.

Next, the operation of the apparatus of Example 1 will be explained.

First, the recording member 2 on which the electrostatic latent image has been formed is placed in the opening of the development chamber with the image recording surface facing downward. Next, the rotary blade 15 in the toner hopper 13 containing the toner powder is rotated to convey the toner powder to the mesh 14 via the bristles 16 at the tip of the rotary blade 15. The toner powder conveyed to this mesh is leveled by a leveling roller 1.2' rotating at an excessive speed.
1 and is then scraped off through the mesh and transferred to the bristle brush roller 11. The compressor 9 is operated at the same time as (or before and after) the rotation of the bristle brush roller 11, compressed air is sent to the pipe 5.6 via the air tank 8 and the solenoid valve 7, and the compressed air is injected from the nozzle 3.4. In this example, the electromagnetic valve 7 is repeatedly opened and closed an appropriate number of times during development of one recording member, and compressed air is intermittently injected accordingly.

The toner powder adhering to the bristle brush roller 11 is blown away by the air jetted from the air nozzle 3A.
The developing chamber 1 is filled with a mist. Preferably, the nozzle 3A is provided on an extension of a tangent passing through the upper end of the bristle brush roller 11. At this time, the nozzles 3 located parallel to and on both sides of the nozzle 3A develop the toner powder blown up by the nozzle 3A without wasting it. This is to uniformly diffuse and move the particles to the center of the chamber 1. Further, the air jetted from the nozzle 4 provided on the side opposite to the nozzle 3 has the function of uniformly filling the developing chamber 1 with the toner powder carried by the air jetted from the nozzle 3.3A. ing. When the henna powder is uniformly filled with the air jetted from the nozzle 3A by the bristle brush roller 11, the toner powder is deposited on the recording surface 21 of the recording member 2, which increases the surface potential of the electrostatic latent image. It adheres depending on the height and development is completed. When this development is completed, nozzle 3A
Stop the air injection from the bristle brush roller and leveling O.
- Stop the camera 12.

By applying a (+) back bias to the recording member during development, a positive image is formed, and a (-)
A negative image is formed by applying a back bias of .

Next, the toner powder floating in the developing chamber is collected into the filter box 20 through the duct 19 by forced suction. At the same time or around this time, Cleaner 1
7 in the direction shown by the arrow to drop the toner into the toner reservoir 10 and the groove 18 to remove the toner powder accumulated on the bottom surface of the developing chamber 1.

The key to repeating these series of actions! Accordingly, recording members can be continuously developed one after another. It is also possible to improve the adhesion of toner powder by using a metal roller as the base of the bristle brush rollers 11 and/or 12, or using a conductive bristle brush and applying an appropriate bias.

Second Embodiment (FIG. 3) FIG. 3 shows a second embodiment of the present invention. This embodiment differs from the embodiment shown in FIGS. 1 and 2 in that the leveling roller 12 is omitted and the toner powder is directly attached to the bristle brush roller 11 from the mesh 14 of the toner hopper 13. This is the point. The rest is the same as the first embodiment shown in FIG.

The operation of this embodiment is the same as that of the first embodiment. By configuring as in this embodiment, it is possible to make the configuration as compact as one leveling roller.

Although this embodiment has been described as a developing device for XSA electrophotography, it goes without saying that it can also be applied to a dry copying machine or the like that forms an image by electrostatically depositing toner powder.

[Effects of the Invention] As is clear from the above description, according to the present invention, the toner powder is filled in the developing chamber by injecting air from the nozzle opening through the air injection nozzle as in the conventional method. Instead of rubbing the toner powder on the bristle brush roller through the mesh, the toner powder is applied to the bristle brush roller from the bristle brush roller, and the toner powder adhering to the bristle brush roller is jetted. Since the developing chamber is filled with air, no clogging occurs and the toner powder can be uniformly filled in the developing chamber. Therefore, according to the invention:
No density unevenness occurs in the developed image.

[Brief explanation of the drawing]

FIG. 1 is an overall schematic diagram showing the first embodiment of the present invention, FIG. 2 is a plan view of the developing chamber shown in FIG. 1, FIG. 3 is an overall schematic diagram showing the second embodiment, and FIG. 4 is an X FIG. 5, which is a diagram for explaining the principle of line electrophotography, is a diagram showing a toner spraying section of a conventional developing device. 1...Development chamber, 2...Recording member, 3.3
A14... Nozzle, 11... Bristle brush roller, 13... Toner hopper, 14... Net mesh, 15... Rotating blade, 16
···hair. Lock 1 Figure Broom 2 Figure

Claims (2)

[Claims] (1) A spray type developing device in which a recording member on which an electrostatic latent image is formed is positioned in the opening of a chamber formed in a box shape, and the electrostatic latent image is developed with atomized toner powder. A nozzle that injects compressed air in the longitudinal direction of the chamber, a bristle brush roller whose surface is covered with a large number of short hairs in front of the nozzle and rotates during development, and toner powder on the surface of the bristle brush roller. the electrostatic latent image is developed by spraying the toner powder supplied to the surface of the bristle brush roller by the toner supply device into the chamber with compressed air from the nozzle. A spray developing device. (2) A spray type developing device according to claim 1, wherein a leveling roller is interposed between the brush roller and the toner supply device.