JPS58202474A - Magnetic brush cleaning method - Google Patents

Abstract

PURPOSE:To execute complete cleaning, irrespective of a kind of a magnetic toner, by removing a residual magnetic toner on the surface of a photoreceptor, by use of a magnetic brush formed by magnetic particles containing magnetic fine powder of a specified quantity of more. CONSTITUTION:A magnetic brush is formed by controlled an tuft by a blade 9 on a sleeve 5 of a magnetic roll 6 provided in a casing 4, by magnetic particles (CP) which disperse >=50wt% magnetic fine powder in resin, whose mean particle diameter is within a range of 10-60mu and is larger than a magnetic toner (MT), and whose resistance value is >=10<12>OMEGAcm. The roll 6 is rotated in the direction as indicated with an arrow (b), and a residual MT on a photosensitive drum 1 is reduced its electrostatic attracting force by an eraser lamp 3 and removed by the magnetic brush. The removed MT is scraped by a guide plate 10 by charging a collecting roll 7 to the opposite polarity to the MT, is led to a carrying spring 11 and is sent to a collecting vessel. The CP is charged to the opposite polarity to the MT, therefore, it is used repeatedly. In this way, a photoreceptor is cleaned completely.

Description

Detailed Description of the Invention Technical Field The present invention relates to a cleaning method for removing and recovering magnetic toner remaining on the surface of a toner image carrier.
The present invention relates to a magnetic brush cleaning method f in which a magnetic brush formed of magnetic particles rubs the entire surface of a toner image carrier.

Prior art In recent years, toner image transfer type electrophotographic copying machines have been put into practical use, in which a one-component magnetic developer consisting only of magnetic toner is shredded when forming a toner image by electrostatic latent development. I have reached the point where I can sleep. Therefore, as a cleaning method suitable for carrying out in this type of copying machine, the surface of the photoreceptor is rubbed with a magnetic brush formed by magnetic toner to remove any residue remaining on the surface. A magnetic brush cleaning method for completely removing and collecting magnetic toner has already been proposed.By the way, other cleaning methods, such as elastic brushes that are pressed against the surface of the photoreceptor, are better than this proposed method f. Compared to cleaning methods that use a blade to remove and collect magnetic toner, this method has far less negative effect on the surface of the photoreceptor. This has the advantage of extending its lifespan. Oh, and the configuration of the copying machine itself can also be simplified. However, in this case, the removal and recovery of the magnetic toner, in other words, the cleaning of the surface of the photoreceptor, becomes unstable due to the +M imager used in the copying machine, that is, the magnetic toner. This may occur. %f% copying speed] 1) How long does it take for a high-speed copying machine f to be used? 1 (occurrence?) 11″1 Author.

Therefore, despite the various advantages of this proposed method, depending on the type of developer used,
It is considered that this method cannot be implemented in the copying machine described above. Further, it is considered that this method is not suitable for implementation in a high-speed copying machine π.

OBJECTS OF THE INVENTION An object of the present invention is to remove and collect h from the surface of a toner image carrier.
It is an object of the present invention to provide a magnetic brush cleaning method that can effectively remove and collect magnetic toner regardless of the type of magnetic toner to be used. ')f'c Another object of the present invention is to provide a method for cleaning a magnetic sub-handle which does not cause cleaning defects even if it is implemented in a copying machine f whose copying speed is increased ζh.

SUMMARY OF THE INVENTION The gist of the present invention is that in the magnetic brush cleaning method according to the present invention, magnetic particles forming a magnetic brush are contained in a resin.
The reason is that the magnetic fine powder is contained in a proportion of 50 ωt% or more. As a result, the magnetic toner can be removed and recovered in a good manner.

Embodiment An embodiment π of the magnetic brush cleaning method according to the present invention will be described with reference to FIGS. 1 to 3.

Figure 1 σ is an example of a cleaning device suitable for carrying out the entire magnetic brush cleaning method according to the present invention, and is shown in the figure as a device installed in a so-called toner image transfer type electrophotographic copying machine. I'm here. In this copying machine, the copying speed has been increased, and the Shigeko photosensitive drum (1) moves at π260 in the direction of arrow (a) during copying.
It is designed to be rotated at a circumferential speed of mm 2 /see. Further, a Se-based photoreceptor is deposited on the peripheral surface f of the photoreceptor drum (1), and along with the rotational drive 1, the t-surface K
(A latent image of +1 polarity is formed, and its electrostatic charge 1
Decoration 1# is turned into a toner image by a developing device (not shown). Then, this toner angle is transferred onto the surface of the transfer paper by a transfer charger π (not shown). By the way, during this transfer, the V is used to clean the surface of the photoreceptor drum (1), which will be described later. Since the device (2) is provided, the pre-8C toner (MT) is removed and collected from the surface of the photoreceptor drum (1).

Here, the developing device includes a thermoplastic resin containing a small amount of coloring agent and a magnetic fine powder of 40 ωt%. This is a so-called magnetic brush that has a (+) polarity electrostatic image using a -component magnetic developer consisting only of magnetic toner (MT), and has a developing sleeve and a magnetic roller. This is a developing device. In addition, Mtl magnetic toner (
The average grain size of MT) is 15I7rn, and its resistance value is 1012 Qtm or more, specifically 1014 cm.

However, before the magnetic toner (MT) is fully developed with a (+) polarity electrostatic latent image, it is charged with a unipolarity due to frictional contact with a developing sleeve or the like. Therefore, the magnetic toner (MT) remains on the surface of the photoreceptor drum (1).
) holds a 1 charge with (@ polarity).

The cleaning device is disposed opposite to the surface of the photosensitive drum (1) which is rotated in the direction of arrow (a) in FIG. 1 while carrying the magnetic toner (MT). An eraser lamp (3) is provided near the opposite arrow (a1 direction side) with respect to the device (2) π. Before the magnetic toner (MT)'!r is removed and collected from the surface, the photoreceptor drum (1) is uniformly irradiated with light to erase the electric charge that is retained on the surface of the photoreceptor drum (1). 1) The electrostatic attraction of the magnetic toner (IVIT) to the surface is weakened to facilitate the removal and collection of the magnetic toner (MT).

In FIG. 1, the cleaning device (2) is equipped with a casing (4) having a cleaning opening on the surface (opposed to) of the photoreceptor drum (), and a cleaning sleeve (5) installed inside the casing (4). ), a magnetic roller (6), and a collecting roller (7).A cleaning sleeve 151r, made of a conductive non-magnetic phase, for example, non-magnetic stainless steel, It is rotatably installed with an m1 gap of 0.3 mm maintained, and is driven to rotate at a rotational speed of 200 rpm in the direction of arrow (b) i'i' during cleaning. The cleaning sleeve (5) is grounded and has an outer diameter of 31 mm.On the other hand, the magnetic roller (6) is
) is installed in a stationary state π h inside the cleaning sleeve (5), and magnetic particles <cp) + a = air adsorption [
-7 In order to form a magnetic brush for cleaning, a magnetic effect is exerted on magnetic particles (CP) VC.

In addition, the magnetic force of the magnetic opening (6) on the circumferential surface of the cleaning sleeve (5) is 1 t"11100 Gauss l.
/i' is set, and the magnetic pole position of the magnetic roller (6) is also set to face each of the photoreceptor drum (1), the collection roller (7) described later, and the height regulating plate (9). There is.

The magnetic particles (CP) u are made by dispersing magnetic fine powder with a particle size of 0.5 to 1.0 μm at a ratio of 60Ω in a styrene/acrylic resin, and are made of the cleaning sleeve (5). Along with the rotational drive, an arrow (b) is drawn along the circumferential surface f of the cleaning sleeve (5) with a magnetic brush formed.
It is transported in one direction. Note that the magnetic particles (CP')
The particle size σ is larger than the particle size of the magnetic toner (MT),
The average grain size σ20μm and the tongue-shaped 0-shape.
It is m.

In addition, when the magnetic toner (MT) is conveyed along the circumferential surface of the cleaning sleeve (5), it comes into frictional contact with the circumferential surface of the cleaning sleeve (5), thereby holding the magnetic toner (MT) to be removed and collected. opposite polarity to the charge, υI
A material having the characteristic of being charged to a (+) polarity cannot be used. This means that magnetic toner (MT
) is extremely effective in achieving complete removal and recovery.

The collecting roller (7) is made of a conductive non-magnetic material, such as a non-magnetic stainless steel material, and the cleaning sleeve (5)
The cleaning sleeve (9) is rotatably arranged with a gap of 0.3 mm relative to the circumference Uff1' of the cleaning sleeve (9), and is rotated in the direction of the arrow (c1) at a rotational speed of 5 Orpm in synchronization with the cleaning sleeve (9). The collection roller (7) is connected to the bias power supply (8), and the
Its outer diameter kr is 12 mm.

An electric field is applied to the bias power supply (8) between the cleaning sleeve (5) and the collection roller (7) in the direction in which the magnetic toner (MT) is quietly attracted to the collection roller (7). In the cleaning device (2), the (+) polarity bias'*total recovery roller ( 7) For this reason, h1 is removed from the surface of the photoreceptor drum (1).
A cleaning sleeve (5) is attached together with the magnetic particles (CP).
) is electrostatically attracted to the circumferential surface of the magnetic toner (MT) U collection roller (7) that moves in the direction of arrow (b). At this time, the peripheral surface of the collecting roller (7) is rubbed with a magnetic brush formed by a mixture of magnetic toner (M'r) and magnetic particles (CP).
P) is attracted to the circumferential surface of the cleaning sleeve (51) with a strong magnetic force, and the magnetic particles (
The magnetic particles (CP) are already charged to vc (+) polarity due to frictional contact with the cleaning sleeve (5) and are electrostatically repelled toward the cleaning sleeve (5). will not adhere to the circumferential surface of the collection roller (7). That is, at this time, only the magnetic toner (MT) is attracted to the circumferential surface of the selective r/recovery roller (7).

On the other hand, the female of the magnetic toner guide plate (10) is pressed against the circumferential surface of the collection roller (7). This guide &, (10) is electrostatically attracted to the river surface (&k +I toner ( MT) and guides it to the magnetic toner transport spring (11), and the other end extends to the top of the transport spring (11). Here, the transport spring (11)
) is removed from the surface of the photoreceptor drum (1) by rotationally driving the casing (4) in the direction of arrow (d).
The magnetic toner (MT) (i7) collected in the lower part of the inside is conveyed into a collection container (not shown). Opposed to the circumferential surface of the sleeve (5), 0.
A gap of 3 mm was maintained. In this state, the Hotakachi control board (9) is installed. This regulating plate (9) C, the cleaning section, that is, the photosensitive drum (1) and the cleaning sleeve (5)
The hot height is 0.35 at the part 1-- where the and are close to each other.
The circumferential surface V of the cleaning sleeve (5) is adjusted so that a magnetic brush of about mm in size is formed. This is to control the transport of cured magnetic particles (CP).

Namaru, β! l*r' In the cleaning device (2), magnetic toner (M
The air suction passage (1
2) A suction fan (13) is provided within. This suction fan (13) is rotated to
The airflow is created in one direction to completely reduce the pressure inside the casing (4), and as a result of this pressure reduction, the airflow generated near the recovery roller (7) effectively performs the adsorption. There is. The filter (14) contains magnetic toner (M
'll; The casing (
By the way, in the cleaning device (2), the magnetic brush cleaning method according to the present invention is carried out as follows. First, in the cleaning section, a cleaning agent is moved onto the surface of the photoreceptor drum (1) at a circumferential speed of 260 mm/see in the direction of arrow (a).At this time, the surface V (
U, Quadripolar city rAsk retaining magnetic toner (abrasive) remains. This magnetic toner (MT) is a material that does not easily transfer to the transcription schedule at the time of transfer. On the other hand, a magnetic brush with a brush height of about 0.35 mm is formed by the magnetic particles (CP) r on the circumferential surface π of the cleaning sleeve (5), and the cleaning sleeve (5) The rotating part! is being conveyed in the direction of arrow (b) along with the ribs. During this conveyance, the magnetic particles (CP) are exposed to friction with the circumferential surface of the IJ-ning sleeve (5). Here, the surface of the photoreceptor drum (1) in the cleaning section and the cleaning sleeve (
5) Since the gap with the circumferential surface is 0.3 mm, which is smaller than the height of the front 9-piece brush, the 4Fi K setting is made.
The surface of the photosensitive drum (1) is rubbed and fitted by a magnetic brush formed by magnetic +1 particles (CP).

Then, the remaining surface of the photoreceptor drum (1) is
r, fi(E'I'ltof-(?VIT)(
t'l iC (71i Seven wa wiped out by the air brush f, (I
B, Cleaning sleeve (5
) will be carried 1f in the direction of arrow (b) along the line 11r. At this time, the magnetic brush is shaped like 1 to 1.
Since the Kpi particles (CP) are dispersed in the resin at a ratio of 60ωt% or more (11°Q powder), when wiping with the magnetic brush, the surface of the π photoreceptor drum (1) is The magnetic toner (MT) remaining on the surface of the photoreceptor drum (1) due to its high speed movement is not so hard as to cause damage, and on the other hand, it is difficult to completely remove it from the surface.
It has sufficient strength. For this reason, the magnetic toner (
MT) is completely V (removed ζ
Sleep.

In addition, since the magnetic toner (MT) and the magnetic particles (CP) to be removed each hold charges of opposite polarity, the magnetic toner (IVIT) is different from the magnetic particle (CP) if?
: Since the magnetic toner (MT) tends to be electrostatically attracted to the magnetic toner (MT), the magnetic toner (MT) is completely removed.

It is carried out in a stable and stable state. For this reason, a good cleaning effect is constantly achieved at 21π.It should be noted that along the circumferential surface of the cleaning sleeve (5) along with the magnetic particles (CP) :Magnetic toner (MT) transported in direction b
u, f? to be separated from magnetic +/1 particle (CP)? However, this point V′r′l! The details of I and I have already been described in t2, so the details will be omitted.

On the other hand, regarding the magnetic brush cleaning method related to xylophone Akira,
When I put this book to practical use using the cleaning device, I found that the magnetic particles (0) were made by adding magnetic fine powder at a rate of 50 ωt% or more in the cylinder. It has been confirmed that it should be used. As for stiffness, as shown in Figure 2 1, the Ah ratio is 5.
This is because if it is less than 0 ωt%, a good leaning effect cannot be achieved. In addition, Figure 2 shows the change in the removal efficiency of magnetic toner (MT) when the needle containing magnetic fine powder changes in the previous cleaning device FfK (σ in magnetic particles (CP) at 21F). It is something. In Fig. 2, it is shown that 100% toner removal efficiency is not achieved even if the fore-fertilization content is less than 50ωt%;
Although the related toner removal efficiency is achieved, it is not consistent and there is a possibility that cleaning failures may occur.

The crushed magnetic toner (■
It is preferable to use grains with a diameter of 10 to 10 cm, and the average grain size f is 10 to 60.
It is also confirmed that the range of 11 μm can be used arbitrarily. Furthermore, magnetic toner (MT) is used.

When a magnetic particle (CP) having a resistance value of 1012 Qtm or more is used, a resistance ftK' of 1012 Ωcm or more is used to hold the magnetic toner (MT) to be removed. It has also been confirmed that charging to the opposite polarity to the charge is advantageous in achieving better removal and recovery of magnetic toner (MT).

Although an example of a cleaning device suitable for implementing the magnetic brush cleaning method according to the present invention is shown in FIG. 1, a cleaning device having a configuration different from the cleaning device (2) shown in FIG. 1 may also be used. The cleaning method described above can be carried out.

For example, the magnetic roller (G
A similar cleaning method can also be implemented using π made rotatable. Further, as shown in FIG. 3, the same can be said of a cleaning device that is separately provided with a charger (15) for charging the magnetic particles (CP). In addition, in the cleaning device shown in FIG. 3, since the magnetic particles (CP) are charged not by contact with the cleaning sleeve (5) but by the charger (15) f, the amount of charge is small. This is advantageous because it can be easily controlled.

Effects of the Invention In the magnetic brush cleaning method according to the present invention, since the magnetic particles forming the magnetic brush are made by dispersing magnetic fine powder in a resin at a ratio of 50 ωL% or more, they can be removed and collected from the surface of the toner image carrier. Regardless of the type of magnetic toner to be used, it is possible to consistently remove and recover the magnetic toner in a good manner. ′! ! In addition, even if the cleaning is carried out on the first 80-year-old machine whose copy speed has been increased, there will be no occurrence of cleaning defects.

In addition, the magnetic 41j child cleaning method according to the present invention includes:
The original advantages of the magnetic brush cleaning method, namely, in copying machine vr '4! It has the advantage of extending the life of the photoreceptor itself when applied, and produces the above-mentioned effects, and in that respect it is extremely useful.

[Brief explanation of the drawing]

Figure 1 shows an example of a cleaning device suitable for applying the magnetic brush cleaning method according to the present invention +/
Fig. 26 is a drawing showing the variation in magnetic toner removal efficiency when the content of magnetic fine powder in the magnetic particles is changed in the cleaning device #3, and Fig. 3 shows a modification of the cleaning device #1. O CP...Magnetic particles ■...Magnetic toner
・Electrophotographic photosensitive drum 2...Cleaning device 5...Cleaning sleeve 6...Magnetic roller 7
... Collection roller 15 ... Charger applicant Minolta Camera Co., Ltd. Figure 1? Figure 2 Figure B

Claims (1)

[Scope of Claims] 1. A magnetic brush cleaning method in which magnetic toner remaining on the surface of a toner image carrier is removed and recovered by rubbing the surface of a toner image carrier with a magnetic brush formed by magnetic particles f. A method for cleaning a magnetic brush, characterized in that the magnetic particles are made by dispersing magnetic fine powder at a ratio of 50 ωt% or more in the horizontal direction and the horizontal direction. 2. Claim 1, Nr', σ) characterized in that the particle size of the magnetic particles is smaller than the particle size of the magnetic toner.
Magnetic brush cleaning method. 3. The full air particle cleaning method according to claim 1 or 2.2, characterized in that the average particle diameter of the magnetic particles is within the range of 10 to 60 mm. 4 The resistance value between the magnetic particles and the N4'tlner is 1012K
A magnetic jaw brushing IJ-ning method according to Izuka K12 according to Claims 1 to 3, characterized in that the IJ-ning method is at least h. 5. The magnetic brush cleaning method according to claim 4, wherein the magnetic particles are charged with a polarity opposite to the charge held by the magnetic toner remaining on the surface of the toner image carrier.