JPH0519624A - Developing device - Google Patents

Abstract

PURPOSE:To prevent the softening of toner and to stabilize an image by forming a duct for making air circulate and forcing the air to circulate. CONSTITUTION:The duct 15 for making the air to circulate is formed around a toner replenishing housing (including a tube part 12A) including a toner replenishing housing part (including a sealing member 2) to which a toner replenishing container 3 is connected so that the side of the connecting part may be the upstream side of the flow of the air. In such a case, a duct armoring member 16 surrounds the periphery of the toner replenishing housing 1, and the duct 15 is formed between the housing 1 and the member 16. Furthermore, a suction fan 17 is provided at the lower end of the member 16 and actuated to be rotated by the driving force of a motor. When the fan 17 is rotated, the air flows in from an aperture 19 at the upper end of the member 16 and passes through the duct 15, and gets out of a filter 18 to the outside of the member 16. Namely, the air is forcedly circulated in the duct 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device having a toner replenishing device.

[0002]

2. Description of the Related Art In image forming apparatuses such as copying machines and printers,
There is one that visualizes an electrostatic latent image formed on a latent image carrier such as a photoconductor as a toner image. The developing device that achieves such a function is a developing device having a toner replenishing device, and a toner replenishing container such as a toner cartridge is connected to the toner replenishing device to replenish toner to the toner storage portion. In the configuration described above, when the amount of toner remaining in the toner storage unit becomes low or runs out, this is replaced with a new toner supply container.

One of the chronic problems of this type of image forming apparatus is that, when the toner supply container is replaced, the toner is scattered around and the surroundings are contaminated with the toner. is there. In this case, of course, the person who replaces the toner supply container is also soiled with the toner.

On the other hand, since a light source of the exposure optical system and a heat source such as a fixing device are provided in the image forming apparatus of this type, the temperature inside the apparatus greatly rises when continuous copying is performed. Then, the replenishment toner in the toner replenishing device is likely to be softened. If such softening occurs, the replenishment amount of the toner is reduced, the image density is lowered, or a toner end detection error occurs. .

Further, when the toner is softened, the toner particles are fused with each other to form a toner core, and when this adheres to the photoconductor, poor adhesion between the transfer paper and the photoconductor causes a transfer defect. , The image quality tends to deteriorate.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to prevent toner from scattering during replacement of a toner replenishing container and to prevent softening of the toner due to temperature rise in the machine to stabilize a high quality image. To get it.

[0007]

In order to achieve the above-mentioned object, the present invention provides a toner storage unit connected to a toner supply container and storing toner to be replenished from the toner supply container, and a toner in the toner storage unit. A toner replenishing housing internally provided with a toner supply / conveying unit that conveys toner toward the developing container main body while supplying the toner is provided. At least one of the developing container main body and the toner replenishing housing is supplied with toner. To circulate the air around the toner replenishment case including a part or the whole area of the toner replenishment case to which the container is connected, so that the connection side with the toner replenishment case is the upstream side of the air flow. In addition to forming the duct of the above, a configuration is proposed in which a means for forcibly circulating the air is provided.

It is effective to use a toner replenishing case made of a material having a high thermal conductivity.

Further, it is effective to use a duct for sucking outside air.

Further, the means for forcibly circulating the air is a suction fan attached to the duct, and the suction fan is used after the toner end of the toner storage section is detected.
It is effective to use a suction fan that can increase the air suction force until the toner end state is resolved.

Further, means for forcedly circulating air are provided,
A suction fan attached to the duct is used, and the suction fan is rotated only when the temperature reaches or exceeds a predetermined temperature and until the toner end state is cleared after the toner end in the toner storage section is detected. It is effective to use a suction fan that operates.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, a cartridge-shaped toner supply container 3 is connected and set to the upper end portion of a toner supply housing 1. The toner replenishing container 3 is integrally formed of, for example, a synthetic resin, and the case is filled with the toner T (FIG. 3).

As shown in FIG. 3, the opening of the lower end of the toner replenishing container 3 is closed by a sealing tape 4, and the sealing tape is set in a state where the toner replenishing container 3 is set on the upper end of the toner replenishing case 1. 4 is pulled in the direction of arrow a, that is, in FIG. 1, for example, in the front side direction, the tape is peeled off from the toner supply container 3. At this time, the toner in the toner supply container 3 drops and is stored in the toner storage portion 5 of the toner supply housing 1. That is,
The toner replenished from the toner replenishing container 3 is stored in the toner storage section 5.

The toner replenishing container 3 also serves as the upper lid of the toner replenishing housing 1, and the connecting portion between the two is closed by the sealing member 2 made of foamed polyurethane or the like, whereby the connection after the toner replenishing container is set. It is possible to prevent the toner from being scattered from the outside. The toner storage section 5 is provided with an agitator 7, which is rotationally driven in the direction of the arrow to prevent blocking of toner in the toner storage section 5.

Below the agitator 7, a toner replenishing roller 9 sandwiched between a pair of seal members 8 is provided. Further, a toner agitating / conveying member 13 is provided in the lower portion of the toner replenishing housing 1 and inside the cylindrical portion 12A via the seal member 11. As shown in FIG. 2, the toner stirring / conveying member 13 extends toward the inside of the developing container body 12, and the cylindrical portion 12A is integrally formed with the developing container body 12 and forms a part thereof. ing.

The developer container main body 12 contains a two-component developer, and the toner replenishing roller 9 starts to rotate when the toner concentration in the developer decreases. Then, the toner in the toner storage portion 5 is supplied into the cylindrical portion 12A by the toner replenishing roller 9 and is conveyed in the axial direction while being agitated by the toner agitating and conveying member 13 therein, and the developing container main body 12 (see FIG. 2) Can be placed inside.

The cylindrical portion 12A may have a structure separate from the toner replenishing case 1 or may have an integrated structure, and in any case, it is connected to the toner replenishing case 1.
It can be regarded as a part of the toner supply case 1. The toner supply / conveyance unit 6 has a toner replenishment roller 9 and a toner agitating / conveyance member 13, and the toner supply / conveyance unit 6 is provided inside the toner replenishment housing 1 and a cylindrical portion 12A forming a part thereof. -ing

The toner sent by the toner agitating and conveying member 13 of FIG. 2 is mixed with the developer in the developing container main body 12 and is agitated and supplied to the peripheral surface of the developing roller 14. In this way, the developing roller 1 receives the toner supply.
The developer supplied onto the developing roller 14 is carried while being carried on the developing roller 14, and is used for visualizing the electrostatic latent image formed on the surface of the photoconductor 10 shown in FIG. The agitator 7, toner replenishing roller 9, toner agitating and conveying member 13
Etc. are driven by the rotation of the motor through a rotation transmitting member such as a gear. However, such driving means is omitted in the drawings. It is also possible to provide a spiral on the surface of the toner stirring / transporting member 13 so that the toner and the carrier are transported while stirring.
Further, the developing container body 12 may contain a one-component developer containing no carrier to perform the developing operation.

The developing device having such a toner replenishing device has two major problems in the past.

One is that the toner easily scatters when the toner supply container 3 is replaced, and the area around the toner supply device and the person who replaces the toner supply container are stained with the toner.

Another is the environmental temperature outside the image forming apparatus,
When the temperature inside the image forming apparatus rises, the toner is apt to be softened, and as described above, the transfer failure occurs and the image quality deteriorates. Particularly in a high-speed machine, the amount of heat generated is large, and the toner is more likely to be softened.

The present invention solves these two problems at the same time.

That is, around the toner supply housing (including the cylindrical portion 12A) 1 including the toner supply housing portion (portion of the seal member 2) to which the toner supply container 3 is connected, the side of the connected portion is air. The duct 15 for circulating the air is formed so as to be located on the upstream side of the flow.

The duct exterior member 16 is the toner replenishing case 1.
Is formed into a tubular shape having a rectangular cross section, and the duct 15 as described above is formed between this and the toner supply case 1.

A suction fan 17 is provided at the lower end of the duct exterior member 16 and is integrally provided with a fan motor, which is rotationally operated by the driving force of the motor. When the suction fan 17 rotates, air flows in through the opening 19 at the upper end of the duct exterior member 16, passes through the duct 15, and passes from the filter 18 to the duct exterior member 1.
6 Go out. That is, the air is forced to flow in the duct 15 from top to bottom. The suction fan 17 is one example of means for achieving such a function. In addition, in FIG. 1, the arrow shown in the duct 15 shows the direction of the air flow.

Due to the flow of air in the duct 15 as described above, the toner replenishing housing 1 including the cylindrical portion 12A is air-cooled,
The toner inside is cooled. Even if the temperature inside the apparatus rises, the toner is cooled, so that the softening is prevented.

The empty toner supply container 3 is replaced with the toner supply housing 1
When it is removed from the printer or a new toner supply container is connected to the container and the sealing tape 4 (FIG. 3) is peeled off, the toner is apt to be scattered. At this time, if the suction fan 17 is operated, the connection set portion is covered with the duct exterior member 16 itself,
Moreover, since the air is forced to flow into the opening 19, the scattered toner is drawn into the flow and the duct 1
Since it enters inside 5, there is no possibility that the periphery of the connection set portion will be soiled with toner. The toner carried on the air flow is caught by the lower filter 18 and adheres and accumulates there. With such a function, the toner is not discharged to the outside of the duct exterior member 16, and the surroundings are not contaminated with the toner.

Incidentally, as an apparatus having an exhaust section for removing dust and smoke in the toner supply container and a purifying section, one disclosed in Japanese Utility Model Laid-Open No. 63-124260 has been proposed.

By the way, in this embodiment, the duct exterior member 16 covers the toner replenishing housing 1 including the cylindrical portion 12A. In addition to this, the developing container shown in FIGS. You may cover even the main body 12. With this structure, a duct is formed even in the portion of the developing container main body 12, the developer in the developing container main body is cooled, and softening of the toner inside is prevented. Further, in this example, the toner replenishing housing 1
Although the whole is covered with the duct exterior member 16, depending on the configuration of the supply casing 1, only a part thereof may be covered with the duct exterior member 16. Similarly, in this example, the duct exterior member 16 covers the entire area of the toner replenishing housing portion to which the toner replenishing container is connected, but only a part thereof may be covered.

The toner replenishing case 1 including the cylindrical portion 12A
If it is made of a material with high thermal conductivity such as metal,
Even if it is partial, the cooling effect of the toner supply case can be enhanced, and the toner inside can be cooled efficiently.

In FIG. 1, the air entering through the opening 19 is the air in the image forming apparatus. On the other hand, if the air (outside air) outside the image forming apparatus is allowed to flow into the duct 15, the cooling effect as described above can be further enhanced.

For example, the opening 19 is closed and the duct exterior member 16 is integrally formed with a duct extension portion as indicated by reference numeral 16A. A filter 22 is provided between the duct extension portion and the exterior plate 21 of the image forming apparatus. Set up. In this case, of course,
The portion A of the duct exterior member 16 is opened.

With this structure, the outside air flows in the direction of the arrow b from the opening 21a of the exterior plate 21, and the duct 15
It is sucked in. In this way, by introducing the outside air into the duct, the toner cooling effect can be further enhanced.

It should be noted that if the suction fan 17 is kept operating, noise will be generated without difficulty, but a temperature sensor is provided in the image forming apparatus to detect a temperature at which the toner softens. Suction fan 1 only when
When 7 is activated, the noise generation time can be limited.

As described above, when the outside air is taken into the duct, a suitable cooling effect can be obtained even in a breeze, so the voltage applied to the suction fan may be lowered.
The noise level can be reduced by this amount.

Only when the suction fan 17 detects a predetermined temperature at which the toner softens, and from when the toner end of the toner storage portion 5 is detected until the toner end state is eliminated. When it is operated, it is possible to prevent the toner from being softened and the toner from scattering when the toner replenishing container is replaced. At the same time, it is not necessary to turn the suction fan 17 without sticking, and the noise generation time is reduced. It can be limited, and also saves power.

Regarding the method of detecting the toner end, for example, it is sufficient to provide the toner storage portion 5 with a piezoelectric sensor capable of detecting the presence or absence of toner. Also, the developing container body 1
2 (FIG. 4) may be provided with a magnetic sensor,
In this case, such a sensor detects the concentration of the toner in the developer, and if the concentration does not rise for a long time, it is considered that the supply toner has been exhausted. Further, as the toner end detecting means, a pattern image is formed by toner on the photoconductor 10 (FIG. 4),
A means for detecting the toner end when the density of the image does not increase may be used.

When such toner end is detected,
This is displayed on the panel operation unit of the image forming apparatus (not shown), and when this display is seen, the front cover (not shown) is opened, and the old and new toner supply containers are replaced. When this replacement is completed and toner is replenished, the toner end state as described above is resolved.

Since the scattered toner must be strongly sucked when the toner supply container is replaced, a corresponding amount of air is required. If the air suction force of the suction fan 17 is increased from the time when the toner end of the toner storage unit 5 is detected until the state of the toner end is eliminated, as compared with the other cases, the scattered toner is removed. It can be sufficiently sucked into the duct 15.

For example, the voltage applied to the suction fan is set to 12V within the time period during which the toner is prevented from softening, and is doubled to 24V when the toner supply container is replaced. In this way, the voltage applied to the suction fan (actually, the fan motor) may be switched.

When the above-mentioned front cover is opened to replace the toner supply container, an appropriate switch is turned off. After the replacement is completed and the cover is closed, the switch is turned on. With this configuration, the applied voltage can be raised from 12V to 24V when the switch is off, and can be lowered from 24V to the original 12V when the switch is on.

When the output of the fan motor has a margin,
Air may be sucked from the developing container body 12 to cool it. Further, by providing the fan motor with a corresponding output, in the case of a developing device having a plurality of developing devices such as a color developing device, air is supplied to ducts of all toner replenishing devices attached to this developing device. Can be forced to distribute. In addition, in this example, a cartridge-shaped container is used as the toner replenishing container, but the present invention is not limited to this, and a bottle type toner replenishing container or the like can be used, and is not necessarily limited to such a container. Absent.

[0043]

According to the developing device of the first aspect of the present invention, it is possible to prevent the toner from scattering during the replacement of the toner replenishing container. It does not get soiled with toner. Further, even if the temperature of the toner replenishing section rises, the softening of the toner is prevented, so that it is possible to prevent the toner replenishment amount from decreasing and the toner particles from melting each other, and it becomes difficult for transfer defects to occur, so that the temperature becomes high or low. Regardless of this, it is possible to stably obtain a high-quality image at any time.

According to the developing device of the second aspect, the cooling effect of the toner replenishing case can be enhanced, and the toner inside can be cooled efficiently.

According to the developing device of the third aspect, the effect of cooling the toner in the toner replenishing housing can be greatly enhanced, and the suction fan can be of a small capacity.

According to the developing device of the fourth aspect, it is possible to greatly enhance the toner scattering preventing effect when the toner supply container is replaced.

According to the developing device of the fifth aspect, the noise generation time of the suction fan can be limited and the power consumption can be further saved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of components such as a toner replenishing housing and a duct exterior member provided in a developing device according to an embodiment of the present invention.

FIG. 2 is a side view of the above component.

FIG. 3 is a cross-sectional view of a toner replenishing container connected and set to a toner replenishing case.

FIG. 4 is a front view showing a mutual positional relationship among a duct exterior member, a developing container body, and a photoconductor.

[Explanation of symbols]

1 Toner supply case 3 Toner supply container 5 Toner storage section 6 Toner supply and transport section 12 Development container body 15 ducts 17 Suction fan

Continued front page    (72) Inventor Takuro Kamiya             1-3-3 Nakamagome, Ota-ku, Tokyo Stocks             Company Ricoh (72) Inventor Naoki Sato             1-3-3 Nakamagome, Ota-ku, Tokyo Stocks             Company Ricoh

Claims (5)

[Claims] 1. A toner replenishing container is connected to the toner replenishing container, and a toner reserving unit for replenishing the toner replenished from the toner replenishing container, and a toner for feeding the toner in the toner reserving unit to the developing container body. A toner replenishing housing having a supply / conveyance unit inside is provided, and at least a part or the whole of the toner replenishing housing portion to which the toner replenishing container is connected, of the developing container body and the toner replenishing housing. Around the toner replenishing case including the toner supply container, a duct for circulating the air is formed so that the connection side with the toner replenishing container is on the upstream side of the air flow, and a means for forcedly circulating the air is provided. A developing device provided. 2. The developing device according to claim 1, wherein the toner supply case is a toner supply case made of a material having a high thermal conductivity. 3. The developing device according to claim 1, wherein the duct is a duct through which outside air is sucked. 4. A suction fan attached to a duct is used as a means for forcedly circulating air, and the suction fan is
4. The developing device according to claim 1, wherein the developing device is a suction fan capable of increasing an air suction force from when the toner end of the toner storage portion is detected to when the toner end state is resolved. 5. A suction fan attached to a duct is used as a means for forcedly circulating air, and the suction fan is
5. The suction fan which is rotationally operated only when the temperature reaches a predetermined temperature or higher and after the toner end of the toner storage section is detected until the state of the toner end is eliminated. The developing device according to 1.