JPS58184984A - Toner recycling device of electrostatic recording device - Google Patents

Abstract

PURPOSE:To make the quality of reused developer and toner very high to form a high quality image, by carrying selectively only the developer and the toner suitable for reuse when recovered developer and toner are carried to a developing part. CONSTITUTION:A recovered toner D which is carried to the position corresponding to the first projecting part P of a fixed magnetic 5C and includes impurities is stored in this position, and succeeding toners reach this position successively, and they rise high gradually, and they are stopped until the pressure of succeeding toners is increased to exceed the limit of resistance, but at the next instance, they fly over the position corresponding to a recessed part of the magnet 5C and reaches the position corresponding to the second projecting part Q. At this time, a dust such as paper powder, a coagulated toner, a fatigued toner unsuitable for reuse, nonmagnetic impurities, etc. are separated from normal toners and are dropped downward and are accumulated in the bottom part of a vessel of a repeating part 1 and are not transferred to a part Q2''. Only toners which have removed impurities and are suitable for reuse are transferred and attracted selectively onto a sleeve 4 in the part Q2''.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an electrostatic recording device such as an electrophotographic copying machine, in which, for example, an image 1 support is charged, exposed to light to form a latent image, dry development, transfer, and cleaning are repeatedly performed. The cleaning section removes and collects the developing agent remaining on the surface of the front F image support, and transports it to the developing section for reuse.

In this type of toner recycling device, toner particles collected from the -9 support and paper dust generated from a part of the transfer material adhere to the support and are transported.
Contains dust such as paper powder, coagulated toner, and impurities from the pond, and these are returned to the developing section and reused as developing toner. Problems such as vertical stripes and other gaps may occur. Also, dust etc. got mixed into the toner! If this is the case, problems such as toner deterioration will occur.

These problems caused by the contamination of impurities are also noticeable when developing with powder developers or -component toners that have been used in recent years, in which insulating ball wet carriers and toners are mixed. That is, the one-component toner and the insulating spherical carrier tend to coagulate each other, and the distance between the developing roller and the spike control plate or the distance between the developing roller and the image support is extremely small.

As an example of solving all of the above problems, a toner reusing device is disclosed in Japanese Patent Laid-Open No. 56-140386, in which an electric field is formed between two adjacent rotating members provided on a toner conveying path.
It is disclosed in the publication No. However, the conventional apparatus described above has a complicated mechanism, is large in size, and has the disadvantage that the toner itself is easily affected by humidity and the like, and it is difficult to control the electric field.

The present invention has been made to improve the above-mentioned drawbacks.
It is an object of the present invention to provide a reliable, efficient, small and compact toner recycling device which removes impurities and coagulated toner from the toner collected from the surface of an image support and returns it to a developing section.

The toner recycling device according to the present invention has rotating 1ii
i The electrostatic latent image formed on the image support is made visible using a powder developer, and after the visible image is transferred, the powder developer remaining on the surface of the image support is removed by a cleaning means. Remove and! 141J) by said cleaning means.
An electrostatic recording device comprising a conveying means for conveying the developer recovered from the support to a developing section for reuse, comprising a fixed magnet having a concave shape and a fixed magnet for forming a repulsive magnetic field in the conveying means. A rotary conveying means for conveying the developer is provided on the outer periphery.

As a result, according to the present invention, impurities, etc. contained in the powder developing agent conveyed on the sleeve-shaped rotary conveyance means are removed by the action of the repelling magnetic field formed by the concave fixed magnet. Only the developer that has been completely released and removed is returned to the developing section.

The present invention will be explained below by showing specific examples thereof.

FIG. 1 is a schematic sectional view of an embodiment of the toner recycling device of the present invention.

A relay section 1 for removing impurities and coagulated toner from the collected toner is provided in the middle of a recovered toner transport path connecting a cleaning section (not shown) and a developing section (not shown). Conveyor pipes 2A and 2B are disposed on both sides of the relay section [, and conveyors 3 for conveying toner are rotating inside the conveyor pipes, respectively. A hollow non-magnetic sleeve 4 for conveying the toner D is rotating at a constant speed in the direction of the arrow, and attracts and conveys the collected toner D conveyed from the conveyor 3.

Furthermore, inside the sleeve 4 are several fixed magnets 5A.

5B, 5C, and 5D are arranged radially, and the magnetic poles iz facing the inner peripheral surface of the sleeve 4 have opposite polarity to the magnetic poles wa in contact with them.

Of the four magnets mentioned above, the one placed at the bottom in Figure 1 is
The magnets 5C and 5D have a concave shape in which the magnetic poles facing the inner peripheral surface of the sleeve 4 protrude on both sides and are flat in the center (P, Q). In FIG. 2, the width of the recess in the magnetic pole part is a and the depth is J.
- If a is constant, the deeper b is, and if b is constant, the wider a is, the deeper the dip in the center of the magnetic field strength distribution becomes, and the lower the peak height becomes. FIG. 3 shows the magnetic field strength distribution on the non-magnetic sleeve 4 generated by the concave-shaped magnet having the notch, and shows that the magnetic field strength distribution of a conventional magnet with a flat end face is uniform as shown by the broken line. In contrast, the magnetic field strength distribution of a concave magnet as shown in Figure 2 has two peaks P as shown by the solid line.
It has ',Q'.

Therefore, a non-magnetic sleeve 4 is disposed around the outer periphery of the magnet 5C having such protrusions on both sides, and the magnetic toner D is placed on the sleeve 4.
When sprayed, the toner separates into positions corresponding to both protrusions P and Q and forms a mountain, but a repelling magnetic field is formed at the intermediate position between both protrusions and there are almost no lines of magnetic force, so toner is present here. do not.

Next, FIG. 4 shows a first toner recycling device according to the present invention.
It is a partially enlarged explanatory diagram of the figure. 1 and 4, the non-magnetic sleeve 4 rotates in the direction of the arrow, and the collected toner D containing impurities is transported from the stone to a position corresponding to the first protrusion P of the fixed magnet 5C. It remains at position 11, and as subsequent toners arrive one after another, it gradually swells up into a mountain shape at this position, and it is stopped at this position until the pressure of the subsequent toner increases and it can no longer resist, but the next toner In an instant, the magnet 5C flies over the position corresponding to the concave part and immediately corresponds to the second protrusion Q - reaching the stone position - 1 stone.During this flight, dust such as paper powder, solidified toner, etc. During reuse, unsuitable fatigued toner, non-magnetic impurities, impurities with large pond specific gravity, etc. are separated from normal toner, fall to the bottom, and accumulate at the bottom of the container in the relay section. There is no migration, and only the Tonani that is suitable for reuse and has impurities removed by flying between the magnetic poles P and Q is 91
The dislocation is selectively suctioned onto one part of the sleeve 4.

Next, the reusable toner is adsorbed onto the i# distribution sleeve 4 and conveyed from the Q2'' section in the direction of the arrow, and is scraped from the surface of the sleeve 4 by a scraper 6 fixed in front of the magnet 5. Then, feed the toner into the conveying pipe 2B that is connected to the developing section.The toner fed into the pipe 2B is conveyed to the developing section by the rotating shaft 3, and the toner is transferred to the developing section.

4, Yo, Yo, Tech□65, 5...:... So, 11 (Yo, A1. A, I only needed one concave shaped magnet 5C to form,
If a plurality of concave magnets 5D and all other magnets are arranged adjacently as shown in FIG. 1, impurity selection will be more effective.

Moreover, the upper structure 5 according to the present invention! , the preferred arrangement of the concave magnets 5C and 5D that form the repulsive magnetic field is as follows:
It is preferable to arrange the magnets where the influence of gravity is most exerted, that is, so that the trajectory of the toner flight is perpendicular to the y direction with respect to the direction of gravity, but this is also possible in the case of an oil arrangement.

Furthermore, the impurity screening power is determined by the shape and dimensions (a,
b) Since it is related to the magnetic flux density, rotational speed of the sleeve, roughness of the sleeve surface, etc., selecting and combining these optimum values will be efficient.

In addition, in order to uniformly place the toner D containing impurities on the surface of the sleeve 4 from the two-person side of the conveyance pipe and convey it to the position corresponding to the magnetic pole P, as shown in the zt diagram, Placing the blade 7 in the relay part i and maintaining a constant gap between the tip of the blade 7 and the surface of the sleeve 40, or lightly pressing the blade 7 against the surface of the sleeve 40 using an elastic blade, etc. It is also effective when used in combination with the magnet 50.50 and the like.

Although the toner recycling apparatus of the present invention has been described with respect to -component magnetic toner, the present apparatus can also be sufficiently effective when applied to two-component developers.

As described above in detail with specific examples, the toner recycling device of the present invention selectively transports only the developer and toner suitable for reuse when transporting the collected developer and toner to the developing section. This makes it possible to make reusable developer and toner of extremely high quality, and it has a remarkable effect in forming high-quality images.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a specific lid making according to the present invention, Fig. 2 is a plan view of a fixed magnet according to the present invention, and Fig. 3 is a diagram showing the magnetic field strength distribution of the conventional example and the device of the present invention. , FIG. 4 is a partially enlarged explanatory view of the apparatus according to the present invention. [...Relay section 2A, 2B...
Conveying pipe 3... Conveyor 4...
Non-magnetic IJ 7'5C, 5D...Concave magnet 6...Scraper 7...Blade A...Impurity D...Contaminant Agent Yoshimi Kuwahara

Claims (1)

[Claims] 1. The latent image formed on the support is made into a visible image using a powder developer, and after the previous image is transferred, the latent image is visualized on the support. The powder developer remaining on the image support is removed by a cleaning means, and the developer recovered from the previous i-image support by the cleaning means is conveyed to the present section for reuse. gIiL(・) A toner recycling device comprising: a magnet having a slimy concave shape that forms a repulsive magnetic field in the conveying means; and a rotary conveying means.