JPH0486774A - Toner replenishment device - Google Patents

Abstract

PURPOSE:To make a toner replenishment device comply with a high-speed image forming device by vibrating toner which is preliminarily charged, between a toner supply member and an electrode, mixing it with developer and replenishing it in a developing device. CONSTITUTION:By a regulation blade 24, the toner 1a which is carried is charged by friction with a toner carrying blade 23 and preliminarily charged. Besides, the electrode 25 is provided at a position on a downstream side in the rotating direction of the toner carrying member 23 through small gap with the surface of the carrying member 23. Then, a bias voltage is impressed on the carrying member 23 and the electrode 25 from a bias power source 16 and an alternating voltage is impressed on them from an alternating voltage power source 27. Besides, the toner, which is preliminarily charged, is vibrated and scattered. Moreover, it is carried to a toner supply port 26 side while it is charged and mixed with the developer 1 at a mixing part 28. Then, it is replenished to the developing device 10. Thus, the replenished toner is well brought into contact with carrier and the first transition of the electrostatic charge of the toner is accelerated. As the result, the toner replenishment device is made to comply with the high-speed image forming device.

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 apparatus 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 apparatus such as a copying machine or a printer. The present invention relates to a toner replenishing device that replenishes toner to a two-component developing type developing device using a carrier and a carrier.

[Prior art and its problems] Conventionally, in image forming devices such as copying machines and printers, in addition to developing devices using a one-component development method that uses only toner as a developer, there are also developing devices that use toner and a carrier as a developer. A developing device using a two-component developing method was used.

Even in a two-component development type developing device that uses toner and carrier, the toner is consumed during development and the amount of toner in the developing device decreases. I was trying to replenish the toner.

Conventionally, various types of toner replenishing devices have been used to replenish toner to the developing device.

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

If the toner aggregates and is supplied to the developing device in the form of a lump, the supplied toner will not be sufficiently mixed with the carrier in the developing device, and the toner will not be sufficiently charged by contact with the carrier. This practice was no longer carried out, resulting in problems such as a decrease in the amount of charge on the toner and toner scattering.

Therefore, in conventional toner replenishment devices, in order to prevent the toner from agglomerating and being replenished to the developing device in the form of lumps, a brush or the like is used to transport the toner through a large number of fine holes provided in a screen member to the developing device. It is also known that the fuel is dispersed and replenished.

However, when the toner is dispersed by such mechanical action and supplied to the developing device, mechanical stress is applied to the toner, causing problems such as deterioration of the toner.

On the other hand, if the agitation conditions are increased in order to sufficiently mix the toner supplied in the form of agglomerated lumps with the carrier in the developing device, the normally replenished toner may become excessively charged. There were problems such as the developer being deteriorated due to strong agitation.

In addition, in recent years, as the speed of the image forming apparatuses mentioned above has increased, consideration has been given to using toner with small particle diameters in order to form high-definition images. .

For this reason, it has become necessary to quickly charge the replenished toner in the above-mentioned developing device, but if the toner was replenished to the developing device with a conventional toner replenishing device, the replenished toner would be charged quickly. The toner is not mixed well with the carrier, and it is difficult to accelerate the charge build-up of the toner, resulting in problems such as the charge amount of the toner further decreasing and more toner scattering.

Furthermore, when toner with small particle size is used to form high-definition images, the smaller the toner particle size, the more easily the toner aggregates. When replenishing the developing device with toner of the diameter,
The toner often aggregates and is supplied to the developing device in the form of lumps, and the smaller the toner particle size, the less effective the contact with the carrier, which worsens the toner's charging properties, and the toner becomes insufficient. Problems such as not being charged occurred occurred.

[Problems to be Solved by the Invention] The present invention solves the various problems described above when replenishing toner from a toner replenishment device to a two-component development type developing device that uses toner and carrier as the developer. The problem is to solve the problem.

That is, the present invention provides a method for replenishing toner from a toner replenishing device to a two-component developing type developing device that uses toner and carrier as the developer, even if the toner has a small particle size. The toner is not supplied to the developing device in agglomerated and lumped state, and the toner is not deteriorated due to mechanical stress applied to the toner, and the toner is supplied to the developing device in a well-dispersed state. The objective is to make it possible for the toner to be replenished, to make good contact with the replenished toner and the carrier, to speed up the toner's charge build-up, and to make it compatible with high-speed image forming apparatuses. be.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a toner replenishing device that replenishes toner to a developing device containing a developer consisting of toner and carrier. A toner conveying member that conveys the toner to the side, a precharging means that precharges the toner supplied to the toner conveying member, and the precharged toner is vibrated and dispersed between the toner conveying member and the toner conveying member by the action of an alternating electric field. An electrode for mixing the dispersed toner with the developer is provided.

[Function] In the toner replenishing device according to the present invention, after the toner supplied to the toner conveying member is precharged by the precharging means as described above, the precharged toner is subjected to an alternating electric field. As a result, the toner is vibrated between the toner conveying member and the electrode, and the toner is dispersed.

Then, the toner thus dispersed is mixed with the developer in the mixing section, and in this state, the toner is supplied into the developing device.

When toner is replenished into the developing device in this way, the toner is supplied in a dispersed state and mixed with the developer, and even if the toner has a small particle size, it is supplied in the form of agglomerated lumps. disappears.

In addition, since the toner is dispersed and mixed with the carrier in the developer as described above, it is replenished into the developing device.
The replenished toner is brought into good contact with the carrier, and the replenished toner is sufficiently charged by the contact with the carrier at a quick stage.

[Embodiment] Hereinafter, a toner replenishing device according to an embodiment of the present invention will be specifically described based on the accompanying drawings.

(Example 1) In this example, as shown in FIG. 1, a two-component developing type developing device (10) using a developer (1) in which a toner (1a) and a carrier are mixed is used. In,
A toner replenishing device (
20).

Then, using this developing device (10), the image carrier (2
), when the toner (1a) in the developing device (10) is consumed and reduced, the toner (1a) is replenished into the developing device (10) by this toner replenishing device (20). I decided to do so.

Here, in the above-mentioned developing device (10), as shown in the figure, the toner (1a) and the carrier are mixed together by the stirring member (11) provided in the developing device (10). After stirring the developer (1),
) is sent to the conveying member (12), and this conveying member (12) transports the developer (1) inside the magnetic roller (13).
) is supplied to the surface of the developing roller (14).

As the developing roller (14) to which the developer (1) is supplied in this manner rotates, the developer (1) supplied to the developing roller (14) is transferred to a roller provided inside the developing roller (14). By the magnetic force of the magnet roller (12), a magnetic brush was formed and then conveyed to the image carrier (2).

Also, while forming the magnetic brush in this way, the developer (1
) is conveyed to the image carrier (2) side, the height of the magnetic brush caused by the developer (1) is controlled by a height regulating plate (15) provided at a required distance from the developing roller (14). The developer (
The amount of 1) was adjusted.

The height of the magnetic brush is thus adjusted by the height regulating plate (15), and the developer (1) conveyed to the image carrier (2) is transferred to the developing roller (14) or the image carrier. (
2), a magnetic brush is brought into contact with the surface of the image carrier (2), and a bias voltage Vb is applied from the bias power supply (16) to the developing roller (14) to develop the image carrier. The toner (1a) was supplied to the electrostatic latent image formed on the surface of the body (2).

On the other hand, in the toner replenishing device (20) of this embodiment that replenishes the toner (la) to such a developing device (10), the toner (1a) is stored in the toner storage section (21), and this toner is A feeding member (
22).

Then, the feeding member (22) is rotated to supply the toner (la) stored in the toner storage section (21) onto the surface of the roller-shaped toner transporting member (23). The member (23) is rotated to transport the toner (la) supplied to the surface of this toner transport member (2 phantom) to the developing device (10) side.

In addition, in this embodiment, when the toner (1a) transported to the developing device (10) side by the toner transport member (23) is precharged by the precharging means (24), the toner transport member (23) is A regulating blade (24) is brought into pressure contact with the surface of the member (23).

The regulating blade (24) regulates the amount of toner (1a) carried by the toner conveying member (23), and also frictionally charges this toner (1a) with the toner carrying member (23). Make sure to pre-charge it.

Further, the toner conveying member (
At a position on the downstream side in the rotational direction of the toner conveying member (23), the electrode (25) is moved along the outer periphery of the toner conveying member (23) with a slight distance from the surface of the toner conveying member (23). 1a> toner supply port (26
) side.

Then, the bias voltage Vb is applied from the bias power supply (16) to the toner transport member (23) and this electrode (25), and the alternating voltage VAC is applied from the alternating voltage power supply (27) to the toner transport member (23). (23) and this electric current 1 (25>), the toner (1a) pre-charged as described above is transferred to the toner conveying member (2).
3) and the electrode (25), the toner (1a) is vibrated and dispersed, and while being charged, the toner (1a) is conveyed to the toner supply port (26) side as the toner conveying member (23) rotates. I did it like that.

Here, the distance between the toner conveying member (23) and the electrode (25) is usually 0.3 to 2 mm, preferably 0.3 to 1 mm.
mm, and from the bias power supply (16), a DC bias voltage Vb of usually +150 to 350V is applied.
At the same time, the alternating voltage power supply (27)
From then on, an alternating voltage VAC having a normal frequency of 500 to 5000)-IZ and a vehicle peak voltage Vp- of 100 to 30 oOV is applied.

Note that in this embodiment, the toner conveying member (
23) and the electrode <25) is approximately 1 mm, and the bias power supply (16) supplies a DC bias voltage Vb of 150V, and the alternating current voltage supply (27) supplies a voltage vehicle with a frequency of 1 kHz. Beak value V-2 is 20
An alternating voltage VAC of 00V was applied.

Then, the toner supply port (
The toner (1a) that has been conveyed to the toner supply port (26) is mixed with the developer (1
).

Here, in order to mix the toner (1a) that has been dispersed and transported as described above with the developer (1), in this example, the height regulation provided in the above-mentioned developing device <10) The toner conveying member (
23) A guide plate (17) extending downward is provided, and the developer (1) removed from the surface of the developing roller (14) by the height regulating plate (15) as described above is transferred to the guide plate. (17
) to guide the toner to the toner conveying member (23) side.

Further, as described above, the electrode (25) is provided along the outer periphery of the toner conveying member (23) up to the toner supply port (26) side.
) to the top of this guide plate (17), and connect the guide plate (17) to the electrode (25) that extends above the guide plate (17) in this way.
A passage port (29) is opened through which the developer (1) guided by the developer (1) passes through, and the developer (1) is transferred to the mixing section (28) near the toner supply port (26) through this passage port (29).
I tried to lead to.

The developer (1) that has not been introduced through the passage port (29) in this manner and the toner (1a) that has been dispersed and conveyed as described above are mixed in this mixing section (28) and dispersed. The toner (1a) mixed with the carrier in the developer (<1) is supplied to the developing device (10).

When the toner (1a) is replenished into the developing device (1o) in this way, the toner (1a) is taken into the developer (1) in a dispersed state as described above, and in this state, the developing device ( Since the toner (la) is replenished within 1o>, the toner (la) is no longer replenished into the developing device (10) in an aggregated state as in the past.

Further, as described above, the toner (1a) is transferred to the regulating blade (2).
4) and the action of an alternating electric field, and the toner (1a) is dispersed in the developer layer 1.
) and is supplied to the developing device (10) in a state where it is thoroughly mixed with the carrier.
Due to the stirring by the stirring member (11) provided inside, the replenished toner (1a) quickly reaches an appropriate charge amount.

Note that in the toner replenishing device (20) of this embodiment,
When stopping the supply of toner (1a) to the developing device (10), the rotation of the toner conveying member (23) is stopped.

<Example 2> As shown in FIG. 4, the toner replenishing device (20) of this example is also housed in the toner storage section (21), similar to the toner replenishing device (20) of Example 1 above. Toner (1a
) is supplied to the surface of the roller-shaped toner conveying member (23) by the feeding member (22), and the amount of toner (1a) thus supplied to the surface of the toner conveying member (23) is The toner (1a) is regulated by a regulating blade (24) pressed against the surface of the conveying member (23), and the toner (1a) is precharged by frictional charging between the toner conveying member (23) and the toner conveying member (23).

Then, the toner (1a) pre-charged in this way is
As in the case of Example 1 above, the toner conveying member (23)
As the toner rotates, the toner is conveyed to the toner supply port (26) side.

Here, in order to convey the pre-charged toner (1a) as described above to the toner supply port (26) side, the toner conveying member (23) is moved from the regulating blade (24) as in the case of the first embodiment. At the downstream position in the rotational direction of
The electrode (25) is connected to the surface of the toner transport member (23) with a slight gap between the electrodes (25) and the surface of the toner transport member (23).
3) up to the toner supply port (26), while later in this embodiment, the toner supply port (26) is provided along the outer periphery of the
6) was provided with a mesh electrode (25a).

In this way, the mesh electrode (25) is connected to the toner supply port (26).
When providing a), the distance between the toner conveying member (23) and this mesh electrode (25a) is usually set to 0.2 to
1 mm, preferably 0.5±0.1 mm, and the mesh electrode (25a) used has a mesh diameter of 100 μm to 1 mm.

Note that in this embodiment, the toner conveying member (
23) and the mesh electric fi (25a) is Q, 5m.
In addition, a mesh electrode (25a) with a mesh diameter of 200 μm was used.

Then, the toner conveying member (23) and the electrode (25)
A bias voltage V is applied to the mesh electrode (25a) from the bias power supply (16) in the same manner as in Example 1 above.
b is applied, and at the same time, an alternating voltage VAC is applied from an alternating voltage power source (27) to apply an alternating electric field between the toner conveying member (23), the electrode (25), and the mesh electrode (25a). Pre-charged toner (
1a) is vibrated and dispersed between the toner transport member (23) and the electrode (25), and while being charged, the toner supply port (26) is opened as the toner transport member (23) rotates.
).

Further, in the toner replenishing device (20) of this embodiment, the mesh electrode (25a) provided at the toner supply port (26) as described above, and the brush height regulating plate (1) as described above.
A wire electrode (30) is provided between the guide plate (17) that guides the developer (1) removed from the surface of the developing roller (14) by step 5) to the mixing section (28).

Here, in providing the wire electrode (30),
This wire electrode (30) and the mesh electrode (25a)
) so that the distance between them is usually about 1 to 3 mm.

In this example, the distance between the wire electrode (30) and the mesh electrode (25a) is 2 mm, and the wire electrode (30) is provided with a guide plate (17).
) was brought into contact with the developer (1).

A changeover switch (32) which is switched by the output from the developer concentration control means (31) is connected to this wire electrode (30), and this changeover switch (32) causes the wire electrode (30) to The bias voltage V outputted from the bias power supply (16) may be applied, or other power supply (
Voltage V of opposite polarity to the toner (1a) output from 33)
Dc was applied.

Here, depending on the output from the developer concentration control means (31), as shown in FIG. 5(A), the above changeover switch (
32) is turned on to the bias power supply (16) side and the bias voltage Vb from the bias power supply (16) is applied to the wire electrode (30), the toner ( 1a) is a toner conveying member (2).
3) and the mesh electrode (25a), the toner transport member (23) and the mesh electrode (25a)
25a) and stays there while vibrating, and the mesh 1iE
[Toner (1a) is no longer supplied through f (25a).

On the other hand, as shown in FIG. 5(B), the changeover switch (32) is turned on to the other power source (33) side by the output from the developer concentration control means (31), and the wire electrode (
30), when a voltage VDC of opposite polarity to that of the toner (1a) is applied, a wire voltage is applied from the mesh electrode (25a) to the toner (1a). An electric field is generated toward (30), and this causes the toner (1a) to be transported to the toner supply port (26).
is now introduced to the wire electrode (30) in a dispersed state through the mesh electrode (25a).

In addition, in this example, the above wire electric & (3
0) is supplied with a DC voltage V of 3 kV from another power source (33) of opposite polarity to that of the toner (1a). C was applied.

Then, in this dispersed state, wire electricity 1 (3
The toner (la) guided by the guide plate (17)
) is mixed with the developer (1) guided by the developer (1) in the mixing section (28), and the dispersed toner (1a) is mixed with the developer (1).
) is supplied to the developing device (10) in a state where it is mixed with the carrier in the container.

As a result, in the toner replenishing device (20) of this embodiment, as in the case of the toner replenishing device (20) of the first embodiment, the developer (1
) is taken into the developing unit in this state! (10), and the toner (1a) is no longer replenished into the developing device (10) in an agglomerated state as in the past, and the supplied toner (1a) is the developing unit! (10) The stirring member (11) provided within
By stirring with , an appropriate amount of charge was quickly reached.

(Embodiment 3) The toner replenishing device (2o) of this embodiment is also almost the same as the toner replenishing device (20) of the above-mentioned embodiment 2, as shown in FIG. In (20), the part where the developer (1) is accommodated in the vicinity of the wire electrode (30>) is not provided with the guide plate (17) that guides the developer (1) to the mixing section (28). A magnetic roller (34) is provided at the top.

Then, rotate this magnet roller (34),
Move the magnetic brush of the developer (1) to this magnetic roller (3).
4) above, and this magnetic brush was brought into contact with the above wire electrode (30).

Here, as described above, the changeover switch (32) is switched to the other power source (3) by the output from the developer concentration control means (31).
3> side, and the toner (
When a voltage VDC having a polarity opposite to that of 1a) is applied, the toner (1a) conveyed to the toner supply port (26) is transferred to the mesh electrode! (25a) in a dispersed state to be guided to this wire electrode (30).

In this embodiment, the toner (
1a) in the mixing part (28) near the wire electrode (30)
, the toner (1a) is mixed with the magnetic brush of the developer (1) formed on the magnetic roller (34) as described above, and the toner (1a) is taken into the magnetic brush of the developer (1). Toner (
1a) was replenished.

As a result, in the toner replenishing device (20) of this embodiment, as in the toner replenishing device (20) of each of the above-described embodiments, the toner (Ia) is taken into the developer (1) in a dispersed state. The toner (1a) is now replenished into the developing device (10) in this state, and the toner (1a) is no longer replenished into the developing device (10) in an aggregated state as in the past. The replenished toner (1a) is stirred by the stirring member (11) provided in the developing device (10), so that it quickly reaches an appropriate charge amount.

[Effects of the Invention] As detailed above, in the toner replenishing device according to the present invention, after the toner supplied to the toner conveying member is precharged by the precharging means, the precharged toner is subjected to an alternating electric field. The toner is vibrated between the toner supply member and the electrode to disperse it, and the thus dispersed toner is mixed with the developer in the mixing section, and in this state the toner is replenished into the developing device. Even if the toner supplied to the device is of small particle size, as in the past, the toner may be supplied to the developing device in the form of agglomerated clumps, or mechanical stress may be applied to the toner, causing the toner to deteriorate. There is no deterioration, and the toner is supplied to the developing device in a well-dispersed state.

Furthermore, in the toner replenishing device according to the present invention, since the toner is dispersed and mixed with the carrier in the developer and replenished into the developing device as described above, the replenished toner is mixed with the carrier. Upon contact, the charge buildup became faster, and the replenished toner became sufficiently charged at a faster time.

As a result, when the toner replenishing device according to the present invention is used, even if the toner to be replenished to the developing device has a small particle size, the toner can be replenished to the developing device in a well-dispersed state. The supplied toner is mixed well with the carrier, and the charging of the toner becomes faster, making it compatible with high-speed image forming apparatuses.

[Brief explanation of the drawing]

1 to 3 show a toner replenishing device according to a first embodiment of the present invention, FIG. 1 is a schematic sectional view showing the toner replenishing device according to the first embodiment in use, and FIG. 2 is the same. 3 is a partially cutaway partial perspective view of the embodiment; FIG. 4 is a partial sectional view of a toner replenishing device according to Embodiment 2 of the present invention; FIG. 5(A) , (B) is a partial sectional view showing a state in which toner is not replenished and a state in which toner is replenished by the toner replenishing device of the same embodiment, and FIG. 6 is a partial sectional view of the toner replenishing device according to Embodiment 3 of the present invention. It is. (1)...Developer (1a)...Toner (1
0)...Developing device (20)...Toner supply device 23)...Toner conveying member (24)...Preliminary charging means (regulating blade) (25)
... Electrode (27) ... Alternating voltage power supply (2
8)...Mixing section Figure 2

Claims (1)

[Claims] 1. In a toner replenishing device that replenishes toner to a developing device containing a developer consisting of toner and carrier, a toner conveying member that conveys the toner to the developing device side and the toner supplied to this toner conveying member are precharged. A pre-charging means, an electrode for vibrating and dispersing the pre-charged toner between the toner conveying member by the action of an alternating electric field, and a mixing section for mixing the dispersed toner with a developer are provided. A toner replenishing device characterized by: