JPS60146277A - Developing device by one component magnetic toner - Google Patents

Abstract

PURPOSE:To vary size and hardness of a wall of a magnetic toner, and to make a toner layer thin and uniform by using a magnetic pole opposed to an opposed magnetic pole of a trimming member, as magnetic poles opposite to each other. CONSTITUTION:A magnetic toner 2 is attracted to an opposed magnetic pole N of a trimming member 6 by its magnetic force and a toner wall 11 is fored. In this case, the toner wall 11 swells out toward a magnetic pole S1 of a magnet group 9, but since a sleeve 8 rotates, a small gap 12 is generated in the lower part of the toner wall 11. A force taken away by a rotation of the sleeve 8 is stronger than a force by the toner 2 of the lower part of the toner wall 11 adheres to the member 6, and a thin toner layer which is always constant and uniform can be obtained without receiving strongly an influence of an uneven rotation of the sleeve 8 or a machining accuracy of the tip of the member 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a -component magnetic toner developing device (1), more specifically (- having a rotatable sleeve and a fixed group of magnets therein). In a magnetic toner developing device consisting of a developing roll and a trimming member disposed opposite the developing roll and regulating the amount of toner conveyed on the developing roll, the toner layer is made thinner and more uniform. The present invention is characterized in that it is possible to improve the copy performance as well as to improve the copy performance.

[Prior art]

Generally, in the -component magnetic toner development method, in order to obtain high image quality, the thickness of the layer on the developing sleeve must be set to 0.05 to 0.
．． It is necessary to reduce the thickness to about 2 mm and improve uniformity. To counter this, high-precision technology is required, such as significantly improving the machining accuracy of the trimming member (1 = ('/100mm straightness)) and suppressing the rotational runout of the developing sleeve to less than 2iQQ+I1m. This is difficult in terms of processing technology, as vibrations from other components and external sources must also be taken into consideration during use.

Therefore, conventionally, in order to make the toner layer thinner (-1), as shown in Fig. A method in which the toner (d) is made into a thin layer by bringing the toner (d) into contact with the toner (d), and a method in which the trimming member disposed opposite the developing roll is made of a magnetic material have been adopted.

However, in the method of using the former, that is, the blade (c >'a), the contact pressure between the sleeve (bl and the plate r fc) is not constant, so it is difficult to achieve even more uniformity of the toner, and there are problems with durability. However, in the latter method, which uses a magnetic trimming member, the trimming member is strongly influenced by the opposing magnetic poles of the developing roll. There was a problem that it had to be done.

[Purpose of the invention]

The present invention has been made with the intention of solving the above problems, and its purpose is to form a wall of magnetic toner between the developing roll and the trimming member so that the magnetic toner on the developing sleeve is It is an object of the present invention to provide a component magnetic toner developing device characterized by making magnetic toner a thin and uniform layer and improving copying performance.

[Structure of the invention]

That is, the gist of the present invention is to provide a developing roll having a rotatable sleeve and a fixed group of magnets inside (1), and a developing roll disposed at a portion facing the developing roll to be transported by the developing roll. In a magnetic toner developing device comprising a trimming member that regulates the amount of toner, the trimming member is formed of a plate magnet, and the opposing magnetic poles of the trimming member and the opposing magnetic poles of the magnet group are opposite to each other. The size and hardness of the wall of the magnetic toner are changed by changing the gap between the trimming part and the developing roll, thereby making the toner layer thinner and more uniform, and improving the copying performance. The present invention relates to a component magnetic toner developing device characterized by being able to achieve high performance.

〔Example〕

Hereinafter, two embodiments of the present invention will be described in detail based on the accompanying drawings.

FIG. 1 is a schematic side sectional view showing how the magnetic toner developing device of the present invention is installed, and shows a position adjacent to the photosensitive drum (1) (
: A developing device (3) containing magnetic toner (2), and a developing device disposed in an opening (4) provided at the lower part of the developing device (3) on the side of the photoreceptor drum. Roll (5)
A developing device (7) is constituted by a trimming member (6) that is disposed on three sides of the developing roll (5) and controls the amount of toner conveyed on the developing roll (5). There is. In this case, the developing roll (5) includes a rotatable cylindrical sleeve (8) and a plurality of N poles ('N+=N3) and S poles (s+ to
Fixed magnet group (9) formed by alternately arranging S4)
During operation, the sleeve (8) rotates counterclockwise (twice) in the figure.

On the other hand, the trimming member (6) is formed of a plate magnet, and its opposing magnetic poles (N) are in a relationship in which they are tightly pulled together with the magnetic poles (S4) in the opposing magnet group (9). (See Figure 2). In this case, the upper part of the opening of the developing device (3) to which the trimming member (6) is attached is formed of a magnetically insulating material, and the toner (2) in the developing device (3) is inadvertently ( = It is designed not to be absorbed.

As described above, in the developing device of the present invention having two configurations,
The magnetic toner (2) is attracted to the opposing magnetic pole (N) of the trimming member (6) by its magnetic force, and as shown in FIG.
A toner wall (11) is formed so as to add two. In this case, the toner wall (ID is the magnetic pole (Sl) of the magnet group (9)
), but since the sleeve (8) rotates,
A slight gap (12) is created at the bottom of the toner wall (11). In this case, since the rotation of the sleeve (8) (and therefore the force with which it is carried away) is stronger than the force that causes the toner (2) at the bottom of the toner wall to adhere to the trimming member (6), uneven rotation of the sleeve (8) or trimming may occur. It is possible to always obtain a constant and uniform thin layer of toner without being strongly affected by the machining accuracy of the tip of the member (6).

Note that in reality, the opposing magnetic poles (
The magnetic force of N is less than % of the magnetic force of the magnetic pole (Sl) of the magnet group (9), and ideally it is desirably less than %.
+) is 800 Gauss, the opposing magnetic pole (N) is 150 ~
200 gax was optimal.

〔Effect of the invention〕

As explained above, the magnetic toner developing device (
According to No. 2, a trimming member facing a developing roll having a rotary sleeve and a fixed magnet group is formed of a plate magnet, and the opposing magnetic pole of this trimming member and the magnetic pole in the opposing magnet group are formed to be mutually opposite magnetic poles. As a result, a toner wall is formed on the opposing magnetic poles of the trimming member, and even if the gap changes due to rotational vibration of the developing roll, the size and hardness of the toner wall will follow according to the gap ratio. Therefore, it is possible to make the toner layer thinner and improve its uniformity. Therefore, according to the developing device of the present invention, the working precision of the trimming member can be made rough, and the setting precision between the developing roll and the trimming member can also be made rough, and the floating toner, which causes internal contamination, can be removed from the trimming member (two parts). Because it adsorbs on air, it has excellent effects such as preventing the harmful effects of contamination inside the aircraft, so its utility value is remarkable.

[Brief explanation of the drawing]

FIG. 1 is a schematic side sectional view showing the installed state of the developing device of the present invention, FIG. 2 is an enlarged sectional view showing the main parts of the developing device of the present invention, and FIG. 3 is a diagram showing the conventional components of the magnetic toner developing device. FIG. Explanation of symbols (1)...Photosensitive drum (2)...
-Component magnetic toner (3)...Developer (5).
...Development roll (6) ...Trimming member (8) ...Sleeve (9) ...Magnet group (10) ...Magnetic insulation Sex parts (11
)...Toner wall (12)...Gap (
N)... Opposing magnetic poles (S+ to S3)... Magnetic poles of magnet group (9) (Nl-N3)... Magnetic poles of magnet group (9) Patent applicant Fuji Zeronokunu Co., Ltd. Agent Tomohiro Donakamura Patent Attorney Katsuo Naruse

Claims (1)

[Claims] It consists of a developing roll having a rotatable sleeve and a fixed group of magnets inside (1), and a trimming member disposed at a portion facing the developing roll and controlling the amount of toner conveyed through the developing roll. In the magnetic toner developing device, the trimming member is formed of a plate magnet, and the opposing magnetic pole of the trimming member and the opposing magnetic pole of the magnet group are opposite magnetic poles. Magnetic toner developing device.