JPH01204082A - Image forming device - Google Patents

Abstract

PURPOSE:To locally and continuously form powder cloud and to form an image which is in high image quality and is excellent in continuous gradation property by setting an oscillating body in the back surface of a toner supplying belt. CONSTITUTION:Electrified toner 2 is supplied from a toner hopper 1 onto the toner supplying belt 3. The belt 3 is moved in B direction by a belt driving roller 4. The toner 2 which is conveyed from the belt 3 is parted from the surface of the belt 3 by means of impact force due to the oscillating body 5 which is set in the back surface of the belt 3 and is formed into the powder cloud 6. A direct current bias is applied between the belt 3 and an image forming body 7 in direction which the toner 2 is attached to the image forming body 7. Toner which performs image forming in the cloud 6 leaps to an electrostatic latent image on the surface of the image forming body 7 and the development is performed.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an image forming apparatus using electrophotography.

[Conventional technology]

In an image forming apparatus that forms an electrostatic latent image on the surface of an image forming body and develops the electrostatic latent image with a developer to form an image, various methods have been used to develop the electrostatic latent image. Methods have been proposed, such as 'electrophotography', R,
M, 5CHAFFERT, Kyoritsu Shuppan, pages 16-2
6, etc.

[Problem to be solved by the invention]

Toner, which is fine particles containing a pigment, is used as the developer, and a magnetic brush development method is widely used because the fine particles can be easily handled.

However, in order to reproduce high-quality continuous tone,
Magnetic brush development has its limitations, and powder cloud development is desired in order to achieve continuous gradation with higher image quality.

In the powder cloud development method, a powder cloud is formed by spraying toner between an image forming body on which an electrostatic latent image is formed and a developing electrode installed in close proximity to the image forming body. Toner corresponding to the charge density of the electrostatic latent image on the body surface adheres to the surface of the image forming body, and development is performed.

However, in the powder cloud development method in which development is performed using such a mechanism, maintenance is essential due to problems such as clogging of the toner spray nozzle and scattering of toner inside the image forming apparatus due to toner spray. Currently, this method has not been put into practical use due to problems such as the need for an air pump and other equipment, making it impossible to miniaturize the device.

SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus that solves these problems.

[Means to solve the problem]

The image forming apparatus according to the present invention is characterized in that a vibrating body is installed on the back surface of the toner supply heald.

[For production]

In the image forming apparatus of the present invention, by installing a vibrating body on the back surface of the toner supply belt, a mechanical impact force is applied to the toner conveyed on the toner supply belt, thereby causing the toner to float on the toner supply belt -F. Powder clouds can be formed locally and continuously.

〔Example〕

FIG. 1 shows a schematic diagram of an image forming apparatus' of the present invention.

From a toner hopper 1, toner 2 that is electrically charged due to friction between toner particles is supplied onto a toner supply belt 3.

The toner supply belt 3 is moved in the direction B in the figure by a belt drive roller 4 rotating in the direction A in the figure.

The toner 2 conveyed by the toner supply belt 3 is separated from the surface of the toner supply belt 3 by the impact force generated by the vibrating body 5 installed on the back surface of the toner supply belt 3, and forms a powder cloud 6.

The image forming body 7 including a photoconductor is uniformly charged to the same polarity by a corona charger 8 .

The image forming body 7 is rotating in the direction C in the figure, and after being uniformly charged by the corona charger 8, the charge on the light irradiated part of the image forming body 7 is erased by the image exposure 9, and the electrostatic latent image is It is formed.

A direct current bias is applied between the toner supply belt 3 and the image forming body 7 in the direction of attaching toner of a desired charge polarity to the image forming body 7 for image formation, and image formation is performed in the powder cloud 6. The charged polarity toner flies to the electrostatic latent image on the surface of the image forming body 7, and development is performed.

Note that due to this DC bias, toner of opposite polarity to the desired one, which does not contribute to image formation, remains on the toner supply belt 3 even when an impact force is applied by the vibrating body 5 on the back surface of the toner supply belt 3.
It is difficult to separate from the surface, and even if it does, it is quickly attracted to the toner supply belt 3, so it does not cause image deterioration.

The toner 2 that did not adhere to the image forming body 7 during development is
It returns to the toner supply belt 3, is removed from the toner supply belt 31 by the collection blade IO, and is collected and reused.

The toner 2 that has developed the electrostatic latent image on the surface of the image forming body 7 is transferred onto the surface of the recording medium 11 by the electrostatic force generated by the transfer corona charger 12 from the back side of the recording medium 11 that is conveyed in the direction shown in the figure.

The toner 2 transferred to the surface of the recording medium 11 is fixed by a heat roller 13 rotating in the direction of the arrow in the figure.

The toner 2 remaining on the surface of the image forming body 7 without being transferred to the recording medium 11 is removed by the cleaning blade 14 .

After the residual toner has been removed, the entire surface of the image forming body 7 is irradiated with erasing light to erase all charges on the surface of the image forming body 7 and initialize it.

In the image forming apparatus of the present invention, an image is formed through the above process.

The toner supply belt 3 used in the image forming apparatus of the present invention is a conductive belt or a conductive belt whose surface is coated with an insulating material. In the latter case, the insulating material coating the surface is a toner supply belt. Regarding No. 2, it is desirable that the charging sequence generates toner with a desired charging polarity that contributes to image formation.

[Example 1] An image is formed using the image forming apparatus shown in FIG.

The configuration of the image forming apparatus in this embodiment is shown below.

Toner 2: Polystyrene fine particles containing pigment as the main additive Toner supply belt 3: Resin film with AP deposited on its surface Vibrating body 5: Piezoelectric ceramic vibrating element composed of PbTi0s-PbZrOs Recording medium 11: Plain paper This example In this embodiment, development is performed by attaching the toner 2 to the light irradiated portion of the image forming body 7 by the image exposure 9. Therefore, in this embodiment, the desired charge polarity of the toner 2 is set to negative and corona charge. The charge polarity of the image forming body 7 by the device 8 was also set to be negative.

When an image was formed using the image forming apparatus having the above configuration shown in FIG. 1, a high quality image with no fogging or blurring and excellent continuous gradation was obtained.

Images equivalent to 100 A4 size sheets were continuously output, but no deterioration was observed in the resulting images. Furthermore, almost no toner scattering inside the image forming apparatus was observed.

[Example 2] This example differs from Example 1 in the following points among the components of the image forming apparatus shown in FIG. I did it.

Vibrating body 5: piezoelectric vibrating element made of polyvinylidene fluoride In this example, as in Example 1, high-quality images with no fogging or blurring and excellent continuous gradation were obtained.

Images equivalent to 10,000 sheets of A4 size paper were continuously output, but no deterioration was observed in the resulting images. Furthermore, almost no toner scattering inside the image forming apparatus was observed.

[Example 3] This example differs from Example 1 in the following points among the components of the image forming apparatus shown in FIG. I did it.

Toner supply belt 3: Affi vapor-deposited resin film side coated with nylon on the surface As in Example 2, high-quality images with excellent continuous gradation were obtained.

Images equivalent to 10,000 sheets of A4 size paper were continuously output, but no deterioration was observed in the resulting images. Furthermore, almost no toner scattering inside the image forming apparatus was observed.

(Example 4) This example differs from Example 3 in the following points among the components of the image forming apparatus shown in FIG. I did it.

Vibrating body 5: Vibrating element using a moving coil using electric F61 induction In this example, as in Example 1, high-quality images with excellent continuous gradation were obtained.

Images equivalent to 10,000 sheets of A4 size paper were continuously output, but no deterioration was observed in the resulting images. Furthermore, almost no toner scattering inside the image forming apparatus was observed.

[Example 5] This example differs from Example 3 in the following points among the components of the image forming apparatus shown in FIG. I did it.

Vibrating body 5: vibrating element by rotation of a cam In this example, as in Example 1, high-quality images with excellent continuous gradation were obtained.

Images equivalent to 10,000 sheets of A4 size paper were continuously output, but no deterioration was observed in the resulting images. Furthermore, almost no toner scattering inside the image forming apparatus was observed.

〔Effect of the invention〕

As is clear from the above embodiments, according to the image forming apparatus of the present invention, by installing a vibrating body on the back surface of the toner supply belt, an impact force is applied to the toner on the toner supply belt to form a powder cloud. By performing development using the powder cloud, it has become possible to form high-quality images with excellent continuous gradation.

Furthermore, according to the present invention, the image quality of output images has been dramatically improved compared to image forming apparatuses using electrophotography that have been put into practical use up to now. In comparison, there are advantages such as no need for a toner spray pump or nozzle, and a reduction in toner scattering, making it possible to reduce the cost and size of the device, making maintenance easier, and making it possible to put an image forming device using the powder cloud development method into practical use. It becomes possible.

[Brief explanation of the drawing]

FIG. 1 is a diagram schematically showing an image forming apparatus according to the present invention. Applicant: Seiko Epson Co., Ltd. Agent Patent Attorney Mogami fM (' and 1 other person) Figure 1

Claims (1)

[Claims] An image forming apparatus using electrophotography, characterized in that a vibrating body is installed on the back side of a toner supply belt.