JPS6217226B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developer scattering prevention device in a copying machine or the like, and more particularly to a toner scattering prevention device in transfer to a transfer member and separation area of the transfer member.

2. Description of the Related Art In a copying apparatus, a developer of colored particles, generally called a toner, is used to visualize an electrostatic latent image formed on an image bearing member such as a photosensitive drum. Since toner particles are usually fine powders with a particle size of several μm to several tens of μm, they tend to scatter or float inside the device, and the scattered toner causes various problems.
In other words, the optical system (mirror/lens), charger wire,
Contamination due to toner adhesion to the magnetic head etc. makes it difficult to form and supply a stable latent image, and contamination of the drive system, especially the bearings, causes an increase in torque and damage to gears, etc. Also, if the high voltage connectors or electrical circuits are dirty, there is a risk of high voltage leaks or control malfunctions.

Therefore, various anti-scattering devices have been used in the developing area and the cleaning area, which have traditionally been the main sources of toner scattering. However, when a transfer member such as paper comes into close contact with an image carrier and is separated after transfer, an air current is generated in the width direction of the image carrier by the edge of the transfer member, causing toner to scatter and float inside the machine, causing the above-mentioned problem. wake up A portion of the scattered toner adheres to the end of the image carrier and becomes a stain. When the image bearing member is cleaned by a cleaning device installed downstream of the transfer/separation area, this dirt causes toner to leak from the edge, contaminating the charger wire in the subsequent process, thereby impairing the safety of electrostatic latent image formation. There was a problem that caused harm.

The object of the present invention is to prevent toner scattering in such transfer/separation areas.

That is, according to the present invention, by covering at least one side of the area of the image carrier outside the maximum permissible width of the transfer member in the transfer/separation area with a cover member, toner scattering and image carrying due to the scattering are prevented. This provides a mechanism to prevent the body end from becoming dirty.

FIGS. 1 and 2 show a part of a copying apparatus equipped with a toner scattering prevention mechanism according to the present invention, using a photosensitive drum as an example of an image carrier. That is, around the photosensitive drum 1 rotating in the direction of the arrow, a guide 4 for supplying a transfer member 5 such as paper, and a photosensitive drum 1 are arranged.
A corona charger 2 for transferring the above developed image onto the transfer member 5 and a corona charger 3 for removing the charge on the transfer member are provided. Covers 6 according to the present invention are provided on both sides of the photosensitive drum 1 on the outsides 1a and 1b of the maximum transfer member width. As can be seen from FIG. 2, this cover 6 separates the area from the area near the exit of the transfer member supply guide 4 of the photosensitive drum 1 to a little downstream of the corona charger 3 for separating the transfer member, that is, the transfer area. covers the area.

As a result of providing such a cover 6, the transfer member 5
The action of bringing the toner into close contact with and separating from the photosensitive drum 1 makes it difficult to generate airflow in the width direction of the image carrier, thereby preventing toner from scattering. Even if some of the toner scatters and adheres to the cover 6, this prevents the toner from staining the end of the photoconductor and prevents the toner from leaking from the end of the downstream cleaning mechanism (not shown). This prevents the wires of the charger from becoming contaminated.

FIG. 3 shows another example of the toner scattering prevention mechanism according to the present invention applied to a copying apparatus that mechanically separates the transfer member. That is, in this example, the separation charger 3 is not provided, and a separation belt 7 and a separation roller 8 are provided on one side of the photosensitive drum 1 in the transfer/separation area.
9 is provided, and a cover 6 is provided on the end region 1b of the photosensitive drum 1 on the opposite side.

In this case, the transfer member (not shown) such as paper is not neutralized after the transfer, and the belt 7 and separation rollers 8 and 9
Since it is mechanically separated from one side by the transfer member, a relatively large airflow is caused by the transfer member on the side opposite to the separation mechanism during separation, but by providing the cover 6 on the side opposite to the separation mechanism, the same effect as in the previous example is achieved. By reducing the airflow, it was possible to prevent toner scattering or staining of the end portion 1b of the photosensitive drum 1 with toner.

FIG. 4 shows a cover 6 having a shape that further enhances the scattering prevention effect. That is, the edge 6a of the cover 6 on the side closer to the center of the photosensitive drum 1 is formed in a vertical plane, thereby suppressing the influence of turbulence caused by the transfer member.

As described above, the present invention suppresses toner scattering and floating, prevents toner from adhering to the edge of the photosensitive drum, thereby preventing leakage of toner from the edge of the cleaning device, and charging It was possible to eliminate any negative effects on the device and obtain high-quality copied images.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a portion of a copying machine equipped with the mechanism of the present invention, FIG. 2 is a side view of the portion shown in FIG. FIG. 4 is a perspective view of a portion of the copying apparatus, and FIG. 4 is a perspective view showing a modification of the cover. 1 is a photosensitive drum, 2 is a corona charger for transfer, 3
5 is a transfer member, 6 is a cover, 7 is a separation belt, and 8 and 9 are separation rollers.

Claims (1)

[Claims] 1. In a copying apparatus having a visible image transfer step to a transfer member and a separation step of the transfer member from the image carrier,
A developer scattering prevention device characterized in that a fixing member covers at least one of an outer region of a maximum transfer member width in a transfer/separation region of a rotating image carrier.