JPH01128075A - Conductive brush electrifier - Google Patents

Abstract

PURPOSE:To prevent the degradation of electrifying capability by using a band- shaped conductive brush and moving the brush at the time of detecting that it is dirty to bring an unused or cleaned part into contact with a recording body. CONSTITUTION:The conductive brush is formed into a band, and this band- shaped conductive brush 1a is supported by a supporting rod 2 or a supporting roll so that it is brought into contact with a recording body 4. That is, though the band-shaped conductive brush 1a is fixed at the time of normal use, the band-shaped conductive brush 1a is moved in the direction of an arrow to bring an undirtied part into contact with the recording body 4 when the conductive brush 1a is dirtied by toner A or the like remaining on the recording body 4 to degrade the electrifying capability. Since the undirtied part is brought into contact with the recording body 4, the electrifying capability is restored to uniformly electrify the recording body 4.

Description

[Detailed Description of the Invention] [Summary] Related to charging devices, particularly recording bodies (photoreceptors, dielectrics) in electrophotographic copiers, electrophotographic printers, electrostatic printers, etc.
The purpose of the present invention is to provide a conductive brush charging device that does not reduce the charging ability of the brush charging device used for charging the recording material. The conductive brush is formed into a strip, and includes a support rod that supports the strip-shaped conductive brush so as to be in contact with the recording medium, and a moving means that moves the conductive brush.

[Industrial application field]

The present invention relates to a charging device, and particularly to a recording body (photoreceptor,
The present invention relates to a brush charging device used for charging dielectric materials.

2. Description of the Related Art With the demand for smaller, simpler, and lower cost copying machines and printers, there has been a need for a charging device that can uniformly and stably charge a photoreceptor with a small and simple configuration.

[Conventional technology]

Conventionally, in electrophotographic recording devices such as electrophotographic copying machines and printers, corona charging devices have been widely used as charging means for recording bodies.

FIG. 14 is a block diagram of a conventional electrophotographic recording apparatus. The electrophotographic recording apparatus rotates the recording medium 4, charges it with a charger 22, exposes it to laser light 23 to form an electrostatic latent image, visualizes it with a developer 24, and then converts the visible image into The image is transferred onto a paper 26 by a transfer device 25, and the transferred image is fixed and outputted by a fixing device (not shown). Further, the residual charge on the recording medium 4 is eliminated by the static eliminator 28, the residual toner on the recording medium 4 is cleaned by the cleaner 27, and the initial state is returned.
repeated again.

The charger 22 is a corona charger, and the corona charger requires a high voltage of several KV to generate corona discharge, which increases the cost of the device. Furthermore, there is a problem in that ozone generated due to corona discharge not only has an adverse effect on device components, but is also harmful to the human body.

In order to solve these problems, a brush charging method has been attempted in which a voltage 5 is applied to a conductive brush 1 and the conductive brush 1 is brought into contact with the surface of a recording medium 4 to perform charging, as shown in FIG. According to this method, charging is possible with a voltage of 500 V to 1.0 KV, and there is no influence of ozone.

[Problem that the invention seeks to solve]

In the conventional brush charging method, the charging brush I charges the recording medium 4.
Contact and slide on the surface. Therefore, there is a problem in that the residual toner on the recording medium 4 gets mixed in and adheres to the conductive fibers constituting the brush, reducing the charging ability.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a conductive brush charging device that does not reduce its charging ability.

[Means for solving problems]

As shown in FIG. 1, in a conductive brush charging device that performs charging by bringing a conductive brush into contact with the surface of a recording medium 4, the conductive brush is formed into a band shape, and the conductive brush 1a is
is supported by a support rod 2 or a support roller so as to be in contact with the recording medium 4, and when the brush becomes dirty, the strip-shaped conductive brush 1a is moved so that the clean part of the brush comes into contact with the surface of the recording medium 4. This problem is solved by the four-electric brush charging device of the present invention configured to do so. Note that 5 is a voltage source for applying voltage to the conductive brush.

[Effect]

That is, the strip-shaped conductive brush 1a is fixed during normal use, but when the conductive brush 1a is contaminated by toner A etc. remaining on the recording medium 4 and the charging ability is deteriorated, The strip-shaped conductive brush 1a is moved in the direction of the arrow (in the direction opposite to the rotational direction of the recording medium 4) to bring the clean portion into contact with the recording medium 4. Since the uncontaminated portion comes into contact with the recording medium 4, the charging ability is restored and the recording medium 4 is uniformly charged.

〔Example〕

A first embodiment of the invention is shown in Figure 2a. In the figure,
1a is a band-shaped conductive brush made of conductive rayon or other fibers woven into pile fabric. Reference numeral 2 denotes a support rod that allows the strip-shaped conductive brush 1 to come into contact with the recording medium 4. This rod 2 may be fixed, or the strip-shaped conductive brush 1
It may be arranged to rotate so that a can be fed smoothly. 6 is a supply roller for the strip-shaped conductive brush 1a, and the strip-shaped conductive brush 1a is wound around the shaft. Reference numeral 7 denotes a winding roller for collecting the strip-shaped conductive brush 1a, which winds up and collects the dirty strip-shaped conductive brush 1a. Conductive brush 1
It is preferable that a is attached to the winding roller luff or that a holding mechanism (not shown) is provided on the winding roller luff.

The strip-shaped conductive brush 1a is wound up by detecting the deterioration of the output image or the decrease in the charged potential of the recording medium 4, and manually or by an automatic winding mechanism to wind up the clean part of the strip-shaped conductive brush 1a on the recording medium 4. Wind it up so that they touch each other. In addition, the number of output sheets is counted, and when the number of output sheets reaches a preset value, the brush winding time notification means notifies the operator of the brush winding time, and the operator can wind the brush manually or automatically. You can.

If the conductive brush 1a becomes dirty in this way, the charging ability can be restored by moving the brush and using a clean part.

Furthermore, when the above-mentioned Fig. 2a is applied to the apparatus, the result becomes as shown in Fig. 2b. The explanation of the configuration etc. will be omitted since it will be redundant.

Further, a second embodiment of the present invention is shown in FIG.

In the figure, lb is an endless strip-shaped conductive brush, 2 is a support rod, 8 is a roller for moving the endless strip-shaped conductive brush, and 9 is a tension buffer roller for preventing the strip-shaped conductive brush 1b from slackening. . 1st
This embodiment differs from the embodiment in that the strip-shaped conductive brush 1a is endless.

A third embodiment of the invention is shown in FIG. In the figure, 1
0 is means for detecting the amount of movement of the strip-shaped conductive brush 1b. The simplest example of this is to use a marker 10a on the back side of an endless strip-shaped conductive brush 1b as shown in FIG.
There is a method in which a marker detector 10b is provided and the marker detector 10b detects that the brush has made one revolution. By detecting when the brush has made one revolution, notifying the operator, and replacing the brush, there will be no need to use the used part again.

A fourth embodiment of the invention is shown in FIG. In the figure, the first
The difference from the embodiment described above is that the cover 11 is constructed as a unit except for the part where the strip-shaped conductive brush 1a contacts the recording medium 4. Thereby, the conductive brush charger can be replaced without touching the dirty part of the conductive brush 1a.

A fifth embodiment of the invention is shown in FIG. The difference from the fourth embodiment is that a cover 11' is provided only on the used charging brush take-up roller, and a cassette is formed. This allows the used charging brush to be removed without touching the used charging brush.

A sixth embodiment of the invention is shown in FIG. The difference from Embodiment 2.3 is that an endless strip-shaped conductive brush 1b is provided over the entire conductive brush charger, except for the portion that contacts the recording medium, and a cover 11 is provided in the form of a cassette. This makes it possible to remove a used conductive brush charger without getting your hands dirty.

A seventh embodiment of the invention is shown in FIG. The difference from the above embodiment is that means 12 for cleaning the strip-shaped conductive brush 1a is provided. The cleaning means 12 can be used to clean the conductive brush 1 by pressing a mesh, wire, ttIiB, etc. against the strip-shaped conductive brush 1a with appropriate pressure.
It is automatically cleaned when moving a. By providing the cleaning means 12, the strip-shaped conductive brush 1a can be used repeatedly.

An eighth embodiment of the invention is shown in FIG. The difference from Embodiment I shown in FIG. 7 is that means 13 for detecting the end of the strip-shaped conductive brush 1a is provided. The simplest example is
A league is provided at the end of the strip-shaped conductive brush 1a, and a reflective optical sensor is used as the end detection means 13.
There is a method of detecting the boundary between a and the reader 14. The conductive brush 1a is black in color because carbon is mixed therein. Therefore, it is preferable to select a league having a reflectance different from that of the conductive brush 1a, such as a metal film or a white film. Alternatively, a reflective marker may be provided on the back surface of the conductive brush 1a without providing the leader 14. It is possible to detect from the front side or use a transmission type sensor, but since the front side may be contaminated with toner, it is better to provide it on the back side. .

A ninth embodiment of the invention is shown in FIG. The difference from the seventh embodiment is that the conductive brush 1b is endless. By making it endless, the amount of movement of the brush is only in one direction, so it is only necessary to provide one cleaning means 12. Further, in the winding method, the position of the brush is moved by winding the brush around the shaft, and it is necessary to make the cleaning means (for example, a mesh) follow the brush, but this method does not require it.

A tenth embodiment of the present invention is shown in FIG. 5th, 8th
This embodiment differs from the embodiment in that a cover 11 is provided on the strip-shaped conductive brush 1a, and a cleaning means 12 is further provided.

An eleventh embodiment of the present invention is shown in FIG. The difference from the tenth embodiment is that the cover 11 of the strip-shaped conductive brush 1a
and the cleaning means 12 are integrated. Thereby, the used strip-shaped conductive brush 1a and the cleaning means 12 can be replaced at the same time.

In addition, an example applied to the endless conductive brush 1b is shown in the first example.
Shown in Figure 3. By making it endless, the brush can only move in one direction, so the cleaning means 12
It is sufficient to provide only one.

As in the above embodiments, the conductive brush is fixed during normal use, but if the conductive brush gets dirty with toner etc. and the charging ability deteriorates, the strip-shaped conductive brush is moved and the unstained part is placed on the recording medium. The charging ability is restored by touching it. Also, by making it into a cassette, it is possible to remove the used charging brush without getting your hands dirty.

〔Effect of the invention〕

As explained above, according to the present invention, a strip-shaped conductive brush is used, and when the brush becomes dirty, the brush is moved so that the unused or cleaned portion comes into contact with the recording medium, thereby preventing a decrease in charging ability. , and the time required to replace the conductive brush can be extended.

[Brief explanation of the drawing]

FIG. 1 is a diagram explaining the present invention in detail, FIGS. 2 to 13 are diagrams explaining the first to twelfth embodiments of the present invention, and FIG. 14 is a configuration diagram of a conventional electrophotographic recording apparatus. , FIG. 15 is a diagram illustrating a conventional conductive brush charging device. In the figure, 1a is a strip-shaped conductive brush, 1b is an endless conductive brush, 2 is a support rod or a support roller, 4 is a recording medium, 5 is a voltage source, 6 is a supply roller, 7 is a take-up roller, 8 is a winding roller roller, 9 is a tensile lamp buffer roller, 1O is a movement amount detection means, 11.11' is a cover, 12 is a cleaning means, 1st rho in Figure 77

Claims (5)

[Claims] (1) Bringing the conductive brush into contact with the surface of the recording medium (4),
In a conductive brush charging device that performs charging, the conductive brush is in the form of a band, and a support rod (2) that supports the band-shaped conductive brush (1a) so as to be in contact with the recording medium (4); and the band-shaped conductive brush (1a) A conductive brush charging device comprising a moving means for moving the conductive brush. (2) The moving means includes the strip-shaped conductive brush (1a)
and a winding means (7) for winding the strip-shaped conductive brush (1a) wound around the roller (6).
2. A conductive brush charging device according to claim 1, comprising: (3) The conductive brush charging device according to claim 1, wherein the strip-shaped conductive brush (1a) has an endless shape. (4) The moving means includes a means (10) for detecting the amount of movement of the strip-shaped conductive brush, and a means for controlling the movement of the strip-shaped conductive brush (1a) according to the output of the means (10). Claim 2, characterized in that it has:
3. The conductive brush charging device according to item 3. (5) The conductive brush (1a) is
2. The conductive brush charging device according to claim 1, wherein the conductive brush charging device has a cover (11) that covers the conductive brush.