JPH04369Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement of a developing device used for electrophotographic recording.

[Conventional technology]

A conventional developing device used for electrophotographic recording is disclosed in U.S. Pat.

Fig. 3 is a side sectional view of the main parts of the developing device according to Utility Model Application No. 59-049709, and Fig. 4 is a diagram showing the limiter and spring material of the device shown in Fig. 3. It is a diagram.

In Figures 3 and 4, 1 is in the direction of arrow B.
Magnet roll rotating at a rotational speed of V _M , 2
contains magnet roll 1 and moves V _S in the direction of arrow B.
The sleeve rotates at a rotational speed of , 3 is sleeve 2
4 is a limiter made of an insulating elastic body, 4a is a tip thereof, and 4b is a side surface thereof.

5 is a spring member that supports the limiter 4 at its tip;
5a indicates the side portion of the tip of the spring material 5.

Reference numeral 6 denotes a plate that fixes one side of the spring material 5 to the bottom of the frame 3, and the end surface 4a of the limiter 4 attached to the frame 3 is brought into close contact with the outer periphery of the sleeve 2 by the spring material 5 at an appropriate pressure. ing.

Reference numeral 7 indicates an opening formed between the frame 3 and the sleeve 2, and reference numeral 8 indicates toner for development contained in the frame 3.

Here, the spring material 5 forms part of a partition member that partitions the frame 3 from other parts, and at this time, the spring material 5 and the limiter 4 are formed to have the full width of a side wall (not shown) of the frame 3, and are in contact with the side wall. are doing.

The conventional developing device is constructed as described above, and its operation will be explained next.

As shown in FIG. 3, the magnet roll 1 is rotating in the direction of arrow B at a rotation speed of V _M , and the sleeve 2 is also rotating in the direction of arrow B at a rotation speed of V _S.

At this time, if the rotational speed of the magnet roll 1 and the sleeve 2 is set to V _M > V _S and the ratio of V _M /V _S is kept constant, the toner 8 will first flow from the opening 7 as the magnet roll 1 rotates. The toner 8 is conveyed in the direction of A by rotating in a chain, and the limiter 4 is installed in contact with the sleeve 2.
When the toner 8 reaches the tip end surface 4a of the toner 8, the toner 8 is no longer able to rotate on its own axis, sinks under the toner 8 that is being conveyed in the direction of the arrow A, and is moved in the rotational direction B of the sleeve 2 due to the frictional force with the sleeve 2. It is transported and housed in the frame 3 through the opening 7.

When a steady state is reached, the thickness of the toner 8 on the surface of the sleeve 2 depends only on the rotational speed of the magnet roll 1 and the sleeve 2, the magnetization pattern of the magnet roll 1, and the magnetic flux density, forming a uniform spike. That will happen.

As mentioned above, in order to change the conveying direction of the toner 8 from the direction of arrow A to the direction of arrow B, there is a simple and convenient method in which the limiter 4 made of an elastic body is uniformly brought into contact with the sleeve 2 by the appropriate pressure of the spring member 5. The structure is adopted.

Therefore, when the sleeve 2 is used as a developing electrode, especially in a system in which only the exposed portion of the photoreceptor used for electrophotographic recording is developed,
It is necessary to apply a developing voltage of about 200 to 1000 V to the sleeve 2.

In addition, toner 10 has high electrical resistance (10 ¹⁰ Ω-
In a developing device that uses a dry single-component toner (cm or more), when the toner 10 flows as it is consumed, static electricity is generated due to the friction of the toner particles and the toner 10 aggregates. The frame 3 and spring material 5 need to be grounded.

The following problems occur with the voltage application to the sleeve 2 and the grounding of the frame 3 and spring material 5 as described above.

[Problem that the invention attempts to solve]

The problem is that the side portion 5a of the spring member 5 supporting the limiter 4 is exposed at the side surface 4b of the limiter 4 and is close to the sleeve 2, so that the developing voltage applied to the sleeve 2 is applied to the spring member 5. An accident occurred where the material 5 leaked from the side 5a to the frame 6 of the developing device.
This may result in equipment malfunction.

The present invention improves the structure of the limiter and spring material in order to prevent voltage leakage from the sleeve 2 to the frame 3.

[Means for solving problems]

In order to solve the above problems, the present invention includes a sleeve that includes a magnet roll that rotates at a predetermined speed and that rotates in the same direction as the magnet roll at a slow predetermined speed, and a sleeve that contains toner for development. A spring material that forms part of a partition member that partitions the frame from other parts and is formed with the full width of the side wall of the frame, and an insulating and elastic material that is supported by the spring material so as to come into contact with the outer periphery of the sleeve. In the developing device, the developing device has a limiter having a width of the limiter, and in which the conveying direction of the toner conveyed from the frame onto the sleeve is reversed by the limiter, the spring member has a first width portion of the limiter and a limiter having opposite sides thereof. and a second part cut out to be narrower than the width of the first part, and the second part is covered on both sides with an insulating elastic body forming a part of the limiter. They are characterized by being formed to have the same width.

[Effect]

According to the above-mentioned means, the portion of the spring material that is close to the sleeve, that is, both sides of the tip end of the spring material that supports the limiter, are not exposed to the outside and are covered with an insulating elastic material. Therefore, the developing voltage applied to the sleeve can be cut off.

〔Example〕

First and second embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a first embodiment of a limiter and a spring material used in the developing device of the present invention, and the same figure is a plan view and the same figure is a side view.

In FIG. 1, 9 is a limiter made of an elastic body;
10 is a spring material that supports the limiter 9, and 11 is a filler material that has both insulation and elasticity.

In this first embodiment, the spring member 10 is composed of a first part having the same width as the limiter 9, and a second part supporting the limiter 9, with both end parts of the second part extending by a width D. On the other hand, in the limiter 9, both ends thereof are cut out by a width D and a thickness d.

The limiter 9 is supported on the second part of the spring material 10, and a filler having insulation and elasticity is provided in the notch portions having a width D and a thickness d formed at both ends of the limiter 9. 11.

Here, the limiter 9 and the second portion of the spring material 10 are assumed to have a width equal to the entire side wall (not shown) of the frame 3 shown in FIG. are formed to have similar widths.

Therefore, if the limiter 9 and the spring material 10 are attached to the frame 3 instead of the conventional limiter 4 and spring material 5 shown in FIG. Since the ends are covered with the filler 11, electrical leakage from the sleeve 2 can be blocked.

FIG. 2 is a diagram showing a second embodiment of the limiter and spring material used in the developing device of the present invention, in which FIG. 2 is a plan view and FIG. 2 is a side view.

In Fig. 2, 9' is a limiter made of an elastic body;
10 is a spring material, and in this second embodiment, the spring material 10 has a first part having the same width as the limiter 9 and a second part that supports the limiter 9, as in the first embodiment.
The limiter 9' is formed integrally with the second part of the spring member 10 so as to enclose the entire second part of the spring member 10, although both ends of the second part are cut out by the width D.

Therefore, if the limiter 9' and the spring material 10 are supported by the second part and the limiter 9' and the spring material 10 are attached to the frame, both ends of the spring material 10 close to the sleeve 2 Since the sleeve 2 is covered with a limiter 9' having insulation and elasticity, leakage of current from the sleeve 2 can be interrupted in the same manner as in the first embodiment.

[Effect of idea]

As explained above, in the present invention, the spring material that supports the limiter is the first part of the width of the limiter,
and a second part cut out so that both sides are narrower than the width of the limiter, and the second part is covered with an insulating elastic body forming a part of the limiter on both sides, and the first part is Because it is formed to have the same width as the spring material, unlike conventional methods, both ends of the spring material close to the sleeve are not exposed, and even if a developing voltage is applied to the sleeve, current leakage occurs through the spring material to the frame of the developing device. This has the effect of preventing equipment malfunctions.

Furthermore, since the limiter formed of the elastic material is pressed against the sleeve by the spring material, uniform spikes of toner can be formed with a simple structure, and the first portion of the spring material and the second portion covered with the elastic material The portion is formed to have the limiter width, and each side portion is in contact with the side surface of the frame that accommodates the toner, so there is no gap between the side surface and the frame side.
Another effect is that toner leakage does not occur.

Furthermore, the present invention does not require the addition of other special parts or increase the size of the limiter, so it is an improvement that maintains the simple structure of the conventional device.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a first embodiment of a limiter and a spring material used in the developing device of the present invention, and the same figure is a plan view and the same figure is a side view. FIG. 2 is a diagram showing a second embodiment of the limiter and spring material used in the developing device of the present invention, and the same figure is a plan view and the same figure is a side view. FIG. 3 is a sectional side view of a main part of a conventional developing device, and FIG. 4 is a diagram showing a limiter and a spring member of the device shown in FIG. 3, which is a plan view and a side view. 1... Magnet roll, 2... Sleeve,
9,9'...limiter, 10...spring material, 11...
...Filling material.

Claims (1)

[Claims for Utility Model Registration] A sleeve containing a magnet roll that rotates at a predetermined speed, a sleeve that rotates in the same direction as the magnet roll and at a slower predetermined speed, a frame that accommodates toner for development, and others. a spring member forming part of a partition member that partitions the sleeve and having a width that is the full width of the side wall of the frame; and an insulating and elastic spring member supported by the spring member so as to come into contact with the outer periphery of the sleeve. and a developing device in which the conveyance direction of toner conveyed from the frame onto the sleeve is reversed by the limiter, the spring member having a first portion of the width of the limiter and a width of the limiter on both sides thereof. and a second part cut out to be narrow, and the second part is covered on both sides with an insulating elastic body forming a part of the limiter, and has the same width as the first part. A developing device characterized in that: