JPS6016932Y2 - Electrophotographic copying machine photoreceptor cleaning device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a photoreceptor cleaning device for an electrophotographic copying machine, and particularly to a sealing device for this cleaning device.

In normal dry or wet electrophotographic copying machines,
After the electrostatic latent image formed on the photoreceptor is developed with toner and transferred to paper or the like, the photoreceptor surface is cleaned to remove residual toner in preparation for the next development step.

This cleaning method uses a fur brush, a cleaning web, a doctor blade, etc., and these cleaning devices are housed in a housing of an appropriate size to prevent the removed toner from scattering, and are used to clean the surface of the photoreceptor. is located very close to.

The present invention relates to a sealing device for preventing toner leakage from the housing.

The configuration will be explained below based on the embodiment shown in the drawings.

In FIG. 1, a part of the surface of a photosensitive drum 1 is covered with a cleaner housing 2.
A cleaning blade 3 is disposed within the housing 2 and on the downstream side of the photosensitive drum 1 in the rotational direction so as to wipe the surface of the drum 1.

A sealing material 4 is provided between this cleaning blade 3 and an end opening 2' of the cleaner housing 2 on the upstream side in the rotational direction of the photosensitive drum 1.

This sealing material 4 has a substantially triangular cross-sectional shape,
One side of the photosensitive drum 1 faces the surface of the photosensitive drum 1 with a gap of 1 to 2 ran, and the top thereof protrudes into the cleaner housing 2 .

Reference numeral 5 denotes a toner conveyor provided at the bottom of the cleaner housing 2.

In the above structure, first, the surface of the photosensitive drum 1, on which transfer has already been completed, passes through the opening 2' of the cleaner housing 2, past the sealing material 4, and the cleaning blade 3 scrapes off residual toner.

At this time, the surface of the photosensitive drum 1 enters the portion facing the sealing material 4 while drawing a boundary layer of air.

The facing gap with this sealing material 4 is 1 to 2rIr! Since the air flow is set to n, the air flow during this time is constricted and ejected from the downstream side of the sealing material 4 into the cleaner housing 2, and this ejected air flow is guided by the cleaning blade 3 and reversed, and then The toner is guided to the upstream side of the sealing material 4 along the peak of the sealing material 4, and most of the toner riding this flow falls onto the toner conveying device 5.

The air, which contains almost no toner, is drawn by the boundary layer on the drum surface and sucked into the gap between the sealing material 4 and the surface of the photosensitive drum 1 again.

Therefore, toner hardly leaks out of the cleaner housing 2 at least during operation of the copying machine.

Note that if the copying machine stops, the photosensitive drum 1 and cleaner
Depending on the positional relationship with the housing 2, toner adhering to the tip of the cleaning blade 3 or the sealing material 4 may spill out from the opening 2' of the cleaner housing 2.

Therefore, in order to prevent this, as shown in FIG.
A film seal 6 that tightly contacts the photosensitive drum 1 may be provided at '.

When the copying machine is stopped, this film seal 6 adheres tightly to the surface of the photosensitive drum 1 to prevent toner from spilling out from the opening 2', but when the copying machine starts operating, it is pulled against the drum surface. Due to the inflow of the boundary layer, it is stabilized by keeping a predetermined gap slightly apart from the drum surface.

However, if a peeling error occurs at this time, the paper 7 will enter the cleaner blade 2 through the opening 2', collide with the cleaning blade 3, and stop, but as shown in FIG. The film seal 6 is often folded several times, and if you try to pull it out in that state, the film seal 6 will be damaged.

However, according to the present invention, when the folded portion is pulled out, it is stretched by passing through the gap between the sealing material 4 and the drum surface, thereby preventing damage to the film seal 6. is possible.

FIG. 3 shows another embodiment in which a plurality of sealing materials 4 are provided inside the cleaning device 2 to enhance the sealing effect.
An example is shown in which rectifying plates 4', 4' are added to improve air circulation.

According to the present invention, the air inside the cleaner housing 2 is
As the photosensitive drum 1 rotates, the toner is circulated around the sealing material 4, and during this period, the toner riding on the circulating air flow is dropped onto the toner conveyor 5, thereby almost eliminating toner leakage from the cleaner housing 2. This makes it possible to minimize the amount of dirt inside the copying machine.

Particularly, according to the present invention, the airflow circulating around the sealing material 4 within the cleaner housing 2 is generated spontaneously as the photosensitive drum 1 rotates, thereby generating an airflow within the cleaner housing 2. There is no need for a special device for this purpose, and the air flow becomes a laminar flow at an extremely slow speed, so that the toner riding on this air flow can be efficiently dropped.

Further, according to the present invention, even if the paper 7 enters the cleaner housing 2 due to a peeling error, collides with the cleaning blade 3 and stops, and its tip is folded, the paper 7 can still be pulled out. At this time, since the paper 7 is stretched by passing through the gap between the sealing material 4 and the drum surface, the paper 7 that has entered the cleaner housing 2 due to a peeling error can be pulled out without being damaged.

The sealing material 4 according to the present invention is made of a conductive material, and by grounding it, toner is prevented from adhering to the sealing material 4, and the gap with the photosensitive drum 1 is always maintained. Needless to say, it is necessary to maintain the sealing effect normally for a long time.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a main part of an embodiment of the present invention, and FIGS. 2 and 3 are sectional views showing main parts of other embodiments. 1 is a photosensitive drum, 2 is a cleaner housing, 2' is an opening, 3 is a cleaning blade, and 4 is a sealing material.

Claims (1)

[Scope of utility model registration request] A cleaning blade 3 is provided on the downstream side in the rotational direction of the photosensitive drum 1 in a cleaner housing 2 that covers a part of the surface of the photosensitive drum 1 of the electrophotographic copying machine. The opening 2' at the upstream end of the photosensitive drum 1 in the rotational direction has a substantially triangular cross-sectional shape, one side of which is closely opposed to the surface of the photosensitive drum 1, and the top of the photosensitive drum 1 is connected to the cleaner housing. A photoreceptor cleaning device for an electrophotographic copying machine, characterized by a trowel having a sealing material 4 protruding into the trowel.