JP3337356B2 - One-component non-magnetic developing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device using a one-component developer which is used in a copying machine, a facsimile, a printer, and the like.

[0002]

2. Description of the Related Art FIG. 3 shows a laser printer having a developing device using a one-component non-magnetic developer. In this laser printer, a recording sheet 2 supplied from a sheet feeding device 1 in the direction of arrow a is conveyed to a latent image carrier composed of a photoreceptor 4 at a timing by a pair of registration rollers 3. Photoconductor 4
Is rotated clockwise. At this time, the surface is charged by the charging device 5, and is irradiated with laser light from the laser optical system 6 to form an electrostatic latent image on the photoconductor 4. This latent image is visualized by toner when passing through the developing device 7, and this visible image is transferred to the recording paper 2 conveyed to the photoreceptor 4 by the transfer device 8, and the visible image on the transferred recording paper is transferred. The image is fixed by the fixing device 9. Then, the recording paper 2 that has exited the fixing device 9 is discharged in the direction of arrow b. On the other hand, the cleaning device 10 removes residual toner from the photoconductor 4 after the transfer of the visible image.

FIG. 4 shows the structure of the developing device 7. The developing device 7 includes a toner transport member 11, a thin layer forming blade 12 that contacts the toner transport member 11 to form a thin toner layer, a supply roller 13 that supplies toner to the toner transport member 11, An agitator 14 for feeding the toner 13 and a casing 15 for supporting and storing the toner and storing the toner. In the figure, reference numeral 16 denotes a blade holder for holding the thin layer forming blade 12.

The toner is charged by frictional charging between the supply roller 13 and the toner conveying member 11, adheres to the toner conveying member 11 by an electric field, and forms a thin layer forming blade 12.
Regulates the layer thickness. At this time, the small charged toner that is not sufficiently charged has a weak holding force in the toner conveying member 11 and is scattered.

That is, in this type of developing device, it is necessary to prevent toner from scattering. For example, JP-A-63-1
According to the technique described in Japanese Patent No. 9856, the upper portion of the developing sleeve is covered with a downstream portion in the rotation direction, and a lid having a toner trap is provided below the developing sleeve to store scattered toner and to prevent toner scattering. Also, JP-A-4-36
In the technique described in Japanese Patent No. 8969, a suction collecting plate for collecting scattered toner is provided on the side of the developing device opposite to the developing sleeve after regulating the toner layer on the developing sleeve, and the scattered toner is adsorbed. Trying to prevent toner scattering. Further, in the technique described in Japanese Patent Application Laid-Open No. Sho 62-127871, a toner scattering preventing member is provided on the opening edge side of the casing along the width direction of the developing roller to prevent toner scattering.

[0006]

SUMMARY OF THE INVENTION However, Japanese Unexamined Patent Publication No.
The technique described in Japanese Patent Application Laid-Open No. 3-19856 has a problem that the space of the lid is large, and it is difficult to arrange the layout in color development or two-color development. Also, JP-A-4-36
The technique described in Japanese Patent No. 8969 has a problem that even if a non-magnetic toner is provided, even if a suction collecting plate is provided, the non-magnetic toner cannot be attracted by magnetic force and cannot be attracted. Further, Japanese Patent Application Laid-Open No. 62-1
According to the technique described in Japanese Patent No. 27871, scattered toner accumulates at a contact portion between a sheet of a toner scattering prevention member and a developing roller, and the toner leaks from the contact portion or disturbs a thin toner layer on the developing roller. There's a problem.

[0007] The present invention has been made in view of such conventional problems.
An object of the present invention is to provide a one-component non-magnetic developing device that prevents toner scattering and does not stain the inside of the apparatus with toner.

[Means for Solving the Problems]

According to a first aspect of the present invention, there is provided a one-component non-magnetic developing device according to claim 1, wherein the toner transport member is disposed in contact with a latent image carrier having an electrostatic latent image formed thereon in order to prevent toner scattering with a simple structure. A one-component non-magnetic developing device for visualizing the electrostatic latent image with toner conveyed by the toner conveying member, wherein the toner conveying member is formed before a thin toner layer is formed on the toner conveying member. And a member that abuts the member.

The one-component non-magnetic developing device according to claim 2 is
In order to prevent toner scattering with a simple structure, a voltage having the same polarity as that of the toner is applied to a member abutting on the toner conveying member.

BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of the present invention will be described below with reference to the drawings. In the following, portions common to the related art will be given the same reference numerals. FIG. 1 shows a developing device 20 according to a first embodiment of a one-component non-magnetic developing device of the present invention.
The developing device 20 has a scraping member 21 for scraping off the small charged toner on the toner conveying member 11 below the blade holder 3. The position of the scraping member 21 is on the toner conveying member 11 on the upstream side in the rotation direction from the portion where the thin layer of the toner 22 is formed by the thin layer forming blade 12.

The scraping member 21 scrapes off the small charged toner on the toner conveying member 11 which is easily scattered.
Although the scattering of the toner 22 can be prevented, the sufficiently charged toner is strongly pulled by the toner conveying member 11, so that the toner is not scraped off by the scraping member 21, and only the small charged toner is scraped off. It is.

FIG. 2 shows a developing device 20 according to a second embodiment of the one-component non-magnetic developing device of the present invention. The developing device 20 has substantially the same configuration as that of the first embodiment,
A bias power source 23 for applying a bias voltage having the same polarity as that of the toner is connected to the scraping member 21 for the small charged toner so that charges can be injected from the scraping member 21 into the toner.

The scraper 21 to which the voltage is applied from the bias power source 23 injects electric charge into the toner and charges the toner sufficiently. At the same time, the toner having a weak adhesive force is scraped off, thereby preventing toner scattering.

【The invention's effect】

In the one-component non-magnetic developing device according to the first aspect of the present invention, a member is provided which comes into contact with the toner conveying member before forming the thin toner layer on the toner conveying member. There is an effect that the small charged toner that is easily scattered is scraped off, thereby preventing the toner from being scattered.

In the one-component non-magnetic developing device according to the second aspect, a voltage having the same polarity as that of the toner is applied to the member abutting on the toner conveying member. There is an effect that the toner is sufficiently charged to easily adhere to the toner conveying member, and the toner having a weak adhesive force is scraped off to prevent the toner from scattering.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a developing device according to a first embodiment of a one-component non-magnetic developing device of the present invention.

FIG. 2 is a cross-sectional view illustrating a developing device according to a second embodiment.

FIG. 3 is a cross-sectional view showing a laser printer having a developing device using a one-component non-magnetic developer.

FIG. 4 is a sectional view showing a developing device of the laser printer of FIG. 3;

[Explanation of symbols]

 Reference Signs List 3 blade holder 11 toner transport member 12 thin layer forming blade 13 supply roller 20, 30 developing device 21 scraping member 22 toner 23 bias power supply

Claims (2)

(57) [Claims] An image forming apparatus comprising: a toner conveying member which is in contact with a latent image carrier on which an electrostatic latent image is formed and which is driven to rotate; A toner supply member that is driven to rotate, and a thin layer forming blade that contacts the toner transport member and forms a thin layer of the toner on the toner transport member. In the one-component non-magnetic developing device that visualizes the electrostatic latent image after the supplied toner is thinned by the thin layer forming blade, the one-component non-magnetic developing device includes: A one-component non-magnetic developing device, wherein a scraping member is provided between the thin layer forming blade and the toner conveying member. 2. The one-component non-magnetic developing device according to claim 1, wherein a voltage having the same polarity as that of the toner is applied to the scraping member.