JPH0486686A - Toner replenishing device - Google Patents

Abstract

PURPOSE:To mix replenished toner well with developer in a developing device and to speedily electrify it to a specified electrification quantity by contact with carrier, etc., by constituting a surface of a brush from a material of a reverse polarity as the polarity to which toner is to be electrified against the toner. CONSTITUTION:The brush member 15 with brush 15a whose surface is constituted from the material of the reverse polarity as the polarity which the toner is electrified to is utilized against the toner, and the toner is replenished to the developing device 20 through fine holes of a screen member 14 provided in a toner replenishing opening 13 by the brush member 15. Because of this, the toner preliminarily charged to the polarity which the toner is to be electrified is replenished through the fine holes of the screen member 14 to the developing device 20 in a dispersed state. Thus, the replenished toner is sufficiently mixed with the developer in the developing device 20 and is speedily electrified to the specified electrification quantity by coming into contact with the carrier.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a toner replenishing device that replenishes toner to a developing device used in an image forming device such as a copying machine or a printer, and particularly relates to a toner replenishing device that replenishes toner to a developing device used in an image forming device such as a copying machine or a printer. The present invention relates to a toner replenishing device in which a screen member having a large number of fine holes is provided at a toner replenishing port for replenishing toner, and toner is supplied to a developing device through the fine holes of the screen member using a brush member.

[Prior art and its problems] Conventionally, in image forming apparatuses such as copying machines and printers, the amount of toner in the developing device decreases as images are formed, so toner is supplied to the developing device from a toner supply device. Various types of toner replenishment devices have been used in the past.

Here, when toner is replenished to the developing device as described above, since the toner tends to aggregate, the toner is sometimes supplied from the toner replenishing device to the developing device in the form of agglomerated lumps.

If the toner is supplied to the developing device in the form of agglomerated lumps, the toner supplied in this way may be used for development in the form of lumps, or the toner may be mixed into the developer in the developing device. If the toner is not mixed sufficiently with the carrier, the toner is not sufficiently charged by contact with the carrier, and the amount of charge on the toner is insufficient, resulting in toner scattering, fogging, etc. on the formed image, and resulting in poor image quality. Problems such as a decrease in

Therefore, conventionally, in order to ensure that the toner is sufficiently charged even when the toner is supplied in the form of agglomerated lumps as described above, stirring conditions within the developing device have been strengthened.

However, when the agitation conditions in the developing device are strengthened in this way, problems such as the normally replenished toner being excessively charged and the developer being deteriorated due to strong agitation arise.

Therefore, conventionally, when replenishing toner from the toner replenishing device to the developing device, in order to prevent the toner from being supplied to the developing device in the form of agglomerated lumps,
A screen member having a large number of fine holes is provided at a toner supply port for supplying toner into the developing device, and while this screen member is rubbed with a brush member, the toner is dispersed into the developing device through the fine holes of the screen member. It is also known to replenish in the state.

In recent years, systems in image forming apparatuses such as those described above have become faster, and as a result, it has become necessary to charge the replenished toner more quickly in developing devices such as those described above. .

However, if the toner replenishing device described above simply supplies the toner in a dispersed state to the developing device,
The charge rising speed of the replenished toner is still not sufficient, and in high-speed image forming apparatuses such as those mentioned above,
The supplied toner is not sufficiently charged before it is used for development, causing problems such as toner scattering and fogging on the formed image, resulting in poor image quality, as described above. .

[Problems to be Solved by the Invention] It is an object of the present invention to solve the various problems described above when replenishing toner to a developing device using a toner replenishing device.

That is, in the present invention, as described above, a screen member having a large number of fine holes is provided at the toner replenishing port for replenishing toner to the developing device, and toner is replenished to the developing device through the fine holes of this screen member using a brush member. In today's toner replenishment device, the toner supplied from the toner replenishment device to the developing device can be quickly charged to a predetermined amount of charge, making it compatible with high-speed image forming devices. This is an issue to be addressed.

[Means for Solving the Problems] In order to solve the above-mentioned problems, in the present invention, a screen member having a large number of fine holes is provided in the toner replenishment port for replenishing toner to the developing device, and a brush member is used to remove toner from the toner supply port. In the toner replenishing device that supplies toner to the developing device through the micropores of the screen member, at least the surface of the brush in the brush member is made of a material with a polarity opposite to the polarity that charges the toner. That's what I did.

Therefore, when positively charging the toner, the brush in the brush member is generally made of polytetrafluoroethylene, polypropylene, polyethylene, polystyrene, etc. whose charging series is on the negative polarity side compared to the toner;
Use a brush whose surface is coated with these materials.

On the other hand, when toner is to be negatively charged, the brush in the brush member is generally made of nylon or the like whose charging series is more positive than the toner, or the surface of the brush is coated with these materials. do it like this.

[Function] As described above, the toner replenishing device according to the present invention uses a brush member in which at least the surface of the brush is made of a material with a polarity opposite to the polarity that charges the toner. The member supplies toner to the developing device through the fine holes of the screen member provided at the toner supply port.

Therefore, the toner supplied to the developing device is pre-charged to a polarity that charges the toner by contact with the brush in the brush member, and the pre-charged toner passes through the fine holes of the screen member to the developing device. Replenishment will now be distributed.

When the pre-charged toner is supplied to the developing device in a dispersed state, the supplied toner is sufficiently mixed with the developer in the developing device, and the toner is prevented from coming into contact with the carrier. The battery is quickly charged to a predetermined amount of charge.

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

In this embodiment, as shown in FIG. 1, the toner replenishing device (10) is placed above the developing device (20) on the opposite side of the image carrier (2) where the developing device (20) performs development. I tried to position it.

Here, in the toner replenishing device (10) of this embodiment, toner (10) made of styrene-acrylic resin is used.
1a), and put this toner (1a) into the toner storage section (
11) and this toner storage section (11).
) first and second conveying members (12a) rotating within the
(12b) is provided.

And each of these conveying members (12a), (12b)
is rotated to convey the above-mentioned toner (1a) contained in the toner storage portion (11) to the toner replenishment port (13) side.

Further, the toner supply port (13) through which the toner (5) is conveyed in this manner is provided with a screen member (14) having a large number of fine holes, and a brush member (15) is provided.
A rotating brush roller (15) is used, and the brush (15a) of this brush roller (15) is in contact with the screen member (14).
5) is provided above the toner supply port (13).

Then, by rotating this brush roller (15), the screen member (1) provided at the toner supply port (13) is rotated.
4) on the brush (15) of this brush roller (15).
5a), the toner (1a) that has been transported to the toner supply port (13) side as described above is transferred into the developing device (20) through a large number of fine holes provided in the screen member (14). It was decided to supply it to

Here, in this example, the above-mentioned developing device (20
), in order to positively charge the toner (1a) made of styrene-acrylic resin, in the brush roller (15), the brush (15a)
A polypropylene resin having a more negative charge series than the styrene-acrylic resin constituting the toner (1a), which is hard and has excellent heat resistance and durability, was used.

Then, while rubbing the top surface of the screen member (14) with the brush (15a) of this brush roller (15) as described above, the toner (1a) is applied to the screen member (14).
) through a number of fine holes provided in the developing device (20).
If the brush (15a) is made of a resin whose charging series is more negative than the toner (1a), electrons will be transferred from the toner (1) to the brush (15a) upon contact. As shown in FIG. 2, the brush (15a) is negatively charged while the toner (1a) is positively charged.

Therefore, the toner supply device (10) of this embodiment supplies the toner (1a) to the developing bag! If you replenish within <20),
The toner (la> pre-charged to a positive polarity as described above is supplied in a dispersed state into the developing bag W (20) through a large number of fine holes provided in the screen member (14).

On the other hand, toner (1a
) is supplied in a dispersed state, as shown in FIG.
21), the developer (1) thus supplied is supplied to the surface of the developing port roller (23) in which a fixed magnetic roller (22) is provided, and the developer (1) thus supplied is applied as the developing roller (23) rotates. Due to the magnetic force of the fixed magnet roller (22), a magnetic brush is formed and the image carrier (22)
) side.

Then, while forming a magnetic brush like this, the developer (
1) to the image carrier (2), the developer is transported to the image carrier (2) by the height regulating plate (24) provided at a required distance from the developing roller (23). After adjusting the amount of (1), the developer (1) that is sent to the developing area facing the image carrier (2) as the developing roller (23) rotates is transferred to the image carrier (2). At the same time, a bias power source (2) is applied to this developing roller (23).
5) to apply the bias voltage ①8 to the image carrier (2).
) The toner (1a) was supplied to the electrostatic latent image formed on the surface of the toner (1a).

On the other hand, the developing roller (
The developer (1) removed from the transport member (23) is transferred to the transport member (
The developer (1) is collected in a collection section (26) provided above the developer (21), and is collected by the first and second stirring blades (27a) and (27b) provided in this collection section (26).
At the same time, the toner replenishing device (1
The toner (1a) supplied in a dispersed state and pre-charged to positive polarity from 0) is mixed and stirred with this developer (1), and then the developer to which the toner (1a) is replenished in this way is (1) was returned to the conveying member (21).

In this way, from the toner replenishing device (10) to the developing device (2).
When the toner (la) supplied to the toner (la) is mixed and stirred with the developer (1), the toner (la) is pre-charged to a positive polarity and is supplied in a dispersed state.
) is well mixed with the developer (1), and the developer (
1) It became quickly charged to a predetermined amount of charge by contact with the carrier inside.

As a result, when an image is formed using this developing device (20), blurring in the formed image is extremely reduced, the edges of the image are sharp, and even halftone images are free from unevenness. No good images can now be obtained over a long period of time.

In the toner replenishing device (1O) of this embodiment, the toner (1a) made of styrene-acrylic resin as described above is stored in the developing bag! (20), the brush roller (15) is made of a resin whose charging series is more negative than the resin constituting the toner (1a). However, the toner'(la> was transferred to the developing device F (20)
When the brush (15a) of the brush roller (15) is negatively charged in the toner (1a).
For example, use a resin that has a more positive charging series than the resin that makes up the brush roller (1).
The brush (15a) in step 5) is made of nylon, which has excellent flexibility, heat resistance, and durability.

In this way, the brush (15) on the brush roller (15)
If you use a nylon brush for a), this brush (1
Since the brush (15a) is composed of a resin whose charging series is more negative than the toner (1a), it plays the role of a donor, and while this brush (15a) is positively charged, the toner (
1a) became negatively charged.

Then, the toner (1
a) as in the above embodiment, the screen member (14
) is dispersed through the micropores of the developing device (20).
When the toner (1a) is supplied into the developer (1a), the toner (1a) comes into contact with the carrier in the developer (1) and is quickly charged to a predetermined amount of charge as described above.

As a result, the brush (15) on the brush roller (15)
a) Toner supply device (10) using a nylon device
), even when image formation is performed by replenishing the toner (1a) to the developing device (2o), the blur in the formed image is extremely small and the edges of the image are sharp, as in the case above. , and even halftone images can now be obtained over a long period of time.

Also, as mentioned above, toner (1a) and brush roller (1a)
When the brush (15a) in 5) is charged to the opposite polarity, the toner (1a) is electrostatically attracted to the brush (15a), and the toner (1a) is not released from the brush (15a). Since the toner (1a) may not be sufficiently supplied to the developing device (20) through the fine holes of the screen member (14), as shown in FIG. 3, the brush (15a) of the rotating brush roller (15) A flicker member (16) is provided so that the brush roller (15) collides with the flicker member (16).
It was preferable that the toner (1a) adhering to the brush (15a) be repelled from the brush (15a).

[Effects of the Invention] As described in detail above, in the toner replenishment device according to the present invention, at least the brush member replenishes toner to the developing device through the fine holes of the screen member provided at the toner replenishment port. The surface of the member is
By using a brush member made of a material with a polarity opposite to the polarity that charges the toner,
The toner is precharged to a polarity by contact with the brush member, and the thus precharged toner is supplied in a dispersed state to the developing device through the fine holes of the screen member.

Therefore, when the toner replenishing device according to the present invention is used, the pre-charged toner as described above is supplied to the developing device in a dispersed state, and the replenished toner is inside the developing device. In addition to being able to mix well with the developer, it also came to be quickly charged to a predetermined amount of charge by contact with the carrier.

As a result, when the toner replenishing device according to the present invention is used to replenish toner to the developing device, the replenished toner is quickly charged to a predetermined amount of charge as described above. Even in high-speed image forming devices,
This eliminates the problem of toner scattering, fogging, etc. in the formed image, and deterioration in image quality.

Further, in the toner replenishing device according to the present invention, it is not necessary to strengthen the stirring conditions in the developing device as in the conventional case, and the replenished toner is quickly charged to a predetermined amount of charge in the developing device as described above. Therefore, the developer no longer deteriorates due to strong agitation in the developing device.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view showing the usage state of a toner replenishing device according to an embodiment of the present invention, and FIG. 2 is a partially enlarged explanatory diagram showing the charged state of toner and a brush member in the toner replenishing device of the same embodiment. FIG. 3 is a sectional view showing a state in which a flicker member is provided in contact with a brush member in the toner replenishing device of the same embodiment. (1a)...Toner (2)...Image carrier (10)...Toner supply device (13)...Toner supply port (14)...Screen member (15)...Brush member (Brush roller) (15a)
... Brush (20) ... Developing device

Claims (1)

[Claims] 1. A toner replenishing device in which a screen member having a large number of fine holes is provided at the toner replenishing port for replenishing toner to the developing device, and toner is supplied to the developing device through the fine holes of the screen member using a brush member, A toner replenishing device characterized in that at least the surface of the brush in the brush member is made of a material having a polarity opposite to the polarity that charges the toner.