JP3042914B2 - Developing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device to which a toner supply container is connected and which has a toner storage section for storing toner supplied from the toner supply container.

[0002]

2. Description of the Related Art Image forming apparatuses such as copiers and printers
In a developing device of the above-described type in which an electrostatic latent image formed on a latent image carrier such as a photoconductor is visualized as a toner image,
When the remaining amount of toner in the toner storing unit is reduced or exhausted, the toner is replaced with a new toner supply container. When such a toner supply container is replaced, the toner may scatter around and may be contaminated with toner. At that time, the person who has replaced the toner supply container may be contaminated with toner.

On the other hand, since a light source of an exposure optical system and a heat source such as a fixing device are provided in this type of image forming apparatus, the temperature inside the apparatus increases when continuous copying is performed. Then, the toner in the toner storing section is easily softened, and when such softening occurs, the amount of replenished toner is reduced, and the image density is reduced or a toner end detection error is caused. Further, when the toner is softened, the toner particles are welded to each other to form a toner nucleus, and when this adheres to the photoreceptor, poor adhesion between the transfer paper and the photoreceptor occurs, resulting in poor transfer and poor image quality. It is easy to get worse.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to prevent toner from scattering when replacing a toner supply container, and to prevent toner from softening due to a rise in temperature inside the apparatus, thereby stabilizing a high-quality image. It is another object of the present invention to provide a developing device which can be obtained by the following method.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a developing device of the type described at the beginning.
In a developing device to which a toner replenishing container is connected and which includes a toner storing portion for storing toner replenished from the toner replenishing container, a connecting portion between the toner storing portion and the toner replenishing container is on the upstream side of the air flow. A duct for circulating air is formed as described above, the duct is formed including around the toner storing section, and a suction fan for forcibly circulating air is provided in the duct, and the temperature of the toner is set to a predetermined temperature. The suction fan is operated only at the time when it is detected that the above situation is detected, and only at two timings from when the toner end of the toner storing section is detected to when the toner end is eliminated. A developing device characterized by the above is proposed (claim 1).

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A developing device shown in FIG.
A cartridge-shaped toner supply container 3 is connected and set to the upper end of the toner supply housing 1. The toner supply container 3 is integrally formed of, for example, a synthetic resin. The case is filled with the toner T (FIG. 3), and the lower end opening of the toner supply container 3 is closed by a sealing tape 4 as shown in FIG. When the sealing tape 4 is pulled in the direction of arrow a while the toner supply container 3 is closed and the toner supply container 3 is set on the upper end of the toner supply case 1, the tape is peeled from the toner supply container 3. At this time, the toner in the toner supply container 3 falls and is stored in the toner storage unit 5 of the toner supply housing 1. In this manner, the illustrated developing device is connected to the toner replenishing container 3 and has the toner storing part 5 for storing the toner replenished from the toner replenishing container 3.

The toner replenishing container 3 also serves as an upper lid of the toner replenishing housing 1, and a connection portion between the two is closed by a sealing member 2 made of polyurethane foam or the like. The toner is prevented from being scattered from the unit to the outside. The toner storage unit 5 is provided with an agitator 7, which is driven to rotate in the direction of the arrow, thereby preventing the toner in the toner storage unit 5 from blocking.

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

A two-component developer is accommodated in the developing container body 12, and when the concentration of the toner in the developer decreases, the toner supply roller 9 starts rotating. Then, the toner in the toner storage section 5 is supplied into the cylindrical portion 12A by the toner replenishing roller 9, and is conveyed in the axial direction while being stirred by the toner stirring and conveying member 13 therein, so that the developing container main body 12 (FIG. It is replenished in 2).

The cylindrical portion 12A may have a separate structure from the toner supply housing 1 or may have an integrated structure. In any case, the cylindrical portion 12A is connected to the toner supply housing 1.
The toner supply / conveyance unit 6 includes a toner supply roller 9 and a toner stirring / conveyance member 13 and the like.
Are provided inside the cylindrical portion 12A and the toner supply housing 1. As described above, the developing device of the present embodiment includes the above-described toner storage unit 5 and the toner supply / transport unit 6 that supplies the toner in the toner storage unit 5 and conveys the toner toward the developing container main body 12. Is provided.

The toner sent by the toner stirring and conveying member 13 shown in FIG. 2 is mixed with the developer in the developing container main body 12 and supplied to the peripheral surface of the developing roller 14 while being stirred. The developer supplied on the developing roller 14 in response to the supply of the toner in this manner is supplied to the developing roller 14.
It is conveyed while being carried on the upper side, and is used for visualizing an electrostatic latent image formed on the surface of the photoconductor 10 shown in FIG. In addition,
The agitator 7, the toner replenishing roller 9, the toner stirring and conveying member 13 and the like are driven by a rotation of a motor via a rotation transmitting member such as a gear.
Such a driving means is not shown in the drawings. Further, for example, a spiral may be provided on the surface of the toner stirring and conveying member 13 so as to convey the toner and the carrier while stirring. Further, the developing operation may be performed by containing a one-component developer containing no carrier in the developing container main body 12.

Here, the conventional developing device of the above type has two major problems. One is that the toner is easily scattered when the toner supply container 3 is replaced, and there is a possibility that the surrounding area and the person who replaces the toner supply container 3 may be stained with the toner. Another problem is that if the temperature of the environment outside the image forming apparatus or the temperature inside the image forming apparatus rises, the toner tends to soften, and as described earlier, poor transfer may occur and the image quality may deteriorate. It is. In particular, in the case of a high-speed machine, the amount of heat generated is large, and the toner is more easily softened. The developing device of this embodiment solves these two problems at the same time.

First, the toner storage unit 5 and the toner supply container 3
A duct 15 for circulating the air is formed such that the connection portion side with the air flow is on the upstream side of the air flow. With this configuration, it is possible to prevent the toner from scattering when the toner supply container 3 is replaced. Moreover, the above-mentioned duct 15
Is formed so as to include the periphery of the toner storing section 5, whereby the softening of the toner in the toner storing section 5 can be prevented. In the illustrated example, around the toner replenishing housing (including the cylindrical portion 12A) 1 including the toner replenishing housing portion (the portion of the seal member 2) to which the toner replenishing container 3 is connected, the side of the connection portion has air. A duct 15 for flowing air is formed so as to be on the upstream side of the flow, and the duct exterior member 16 has a rectangular cross section surrounding the toner supply housing 1 and having a rectangular cross section. , This and toner supply housing 1
And the above-described duct 15 is formed between them.

A suction fan 17 is provided at a lower end of the duct exterior member 16 and is integrally provided with a fan motor, and is rotated by a 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 outside. That is, the air is forcibly circulated in the duct 15 from top to bottom. In FIG. 1, the arrow shown in the duct 15 indicates the direction of the air flow. As described above, the developing device of this embodiment includes the duct 15
Is provided with a suction fan 17 for forcibly circulating air.

The air flow in the duct 15 cools the cylindrical portion 12A and the toner replenishing housing 1 by air, thereby cooling the toner in the inside. Even if the internal temperature 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 the toner cartridge is removed from the container or a new toner supply container is connected to the container and set, and the sealing tape 4 (FIG. 3) is peeled off, the toner is easily scattered. In such a case, if the suction fan 17 is operated, the connection set portion is covered by the duct exterior member 16 itself,
Moreover, since air is forcibly flowing into the opening 19, the scattered toner is drawn into the flow, and
5, so that there is no risk of soiling the periphery of the connection set portion with toner. The toner riding on the flow of air is captured by the lower filter 18 and adheres and accumulates thereon. With such a function, the toner is not released to the outside of the duct exterior member 16 and the surroundings are not stained with the toner.

Further, in the developing device of this embodiment, when it is detected that the temperature of the toner has exceeded a predetermined temperature,
The suction fan 17 is operated only at two timings from when the toner end of the toner storage section 5 is detected to when the toner end is eliminated. If the suction fan 17 is kept operating, noise is generated without any noise. However, a temperature sensor is provided in the image forming apparatus, and when the sensor detects a temperature at which the toner softens, the suction is performed. By operating the fan 17, the noise generation time can be limited. Further, if the suction fan 17 is operated from the time when the toner end of the toner storing section 5 is detected to the time when the toner end state is eliminated, the toner is softened and the toner is discharged when the toner supply container is replaced. It is possible to prevent both scattering and the like, and at the same time, it is not necessary to turn the suction fan 17 all over,
Noise generation time can be limited and power can be saved.

As for the method of detecting the toner end, for example, it is sufficient to provide the toner storing section 5 with a piezoelectric sensor capable of detecting the presence or absence of toner. Further, a magnetic sensor may be provided in the developing container main body 12 (FIG. 4). In this case, the sensor detects the concentration of the toner in the developer, and the concentration does not increase forever. In such a case, the toner is regarded as being out of supply toner. Further, as the toner end detecting means,
A means for forming a pattern image with toner on the photoreceptor 10 (FIG. 4), and detecting that the toner is out 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). When the display is displayed, the front cover (not shown) is opened, and the old and new toner supply containers are replaced. When the replacement is completed and the toner is replenished, the toner end condition as described above is eliminated.

It is to be noted that Japanese Utility Model Laid-Open No. 63-124260 and the like have conventionally been proposed as those having an exhaust portion for removing powder dust in the toner supply container and a purifying portion.

By the way, in this embodiment, the cylindrical portion 12A and the toner replenishing housing 1 are covered by the duct exterior member 16, but in addition to this, FIGS.
May be covered. With this configuration, a duct is formed even to the portion of the developing container main body 12, so that the developer in the developing container main body is cooled, and the softening of the toner in the inside is prevented. Further, in the present embodiment, the whole of the toner supply case 1 is covered by the duct exterior member 16, but depending on the configuration of the supply case 1, only a part thereof may be covered by the duct exterior member 16. Similarly, in this embodiment, the entire area of the toner supply housing portion to which the toner supply container is connected is covered by the duct exterior member 16, but only a part thereof may be covered.

Further, when the toner replenishing housing 1 itself is made of a material having a high thermal conductivity such as metal, the cooling effect of the toner replenishing housing can be enhanced even if it is partial. The toner inside can be cooled efficiently.

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

For example, the opening 19 is closed, a duct extension 16A is integrally formed on the duct exterior member 16, and a filter 22 is provided between the duct extension and the exterior plate 21 of the image forming apparatus. In this case, of course, the portion A of the duct exterior member 16 is opened.

With this configuration, the outside air flows in the direction of arrow b from the opening 21a of the exterior plate 21, and the duct 15
It is sucked in. By introducing the outside air into the duct in this way, the cooling effect of the toner in the toner supply housing 1 can be further enhanced, and the suction fan 17 can have a small capacity. In this case, a suitable cooling effect can be obtained, so that the voltage applied to the suction fan may be reduced, and the noise level can be reduced accordingly.

If there is room in the output of the fan motor,
The air may be sucked from the developing container body 12 to cool it. In addition, by using a fan motor having an appropriate output, in the case of a color 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 the developing device. Can be forcibly distributed. In addition, in this example, a cartridge-shaped toner supply container is used as the toner supply container, but the present invention is not limited to this, and a bottle-type toner supply container or the like can be used, and is not necessarily limited to such. Absent.

[0027]

According to the present invention, it is possible to prevent the toner from being scattered when the toner supply container is replaced, and to prevent the toner from softening even if the temperature around the toner reservoir rises. Therefore, it is possible to prevent the toner supply amount from lowering and to prevent the toner particles from melting with each other, so that poor transfer is unlikely to occur, and a high-quality image can be stably obtained at any time regardless of the temperature. In addition, the noise generation time of the suction fan that circulates the air can be limited, and further power saving can be achieved.

[Brief description of the drawings]

FIG. 1 is a sectional view of components such as a toner supply 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 component.

FIG. 3 is a sectional view of a toner supply container connected and set to a toner supply housing.

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

[Explanation of symbols]

 3 Toner supply container 5 Toner storage unit 15 Duct

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takuro Kamiya 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company, Ltd. (72) Inventor Naoki Sato 1-3-6 Nakamagome, Ota-ku, Tokyo No. Ricoh Co., Ltd. (56) References Japanese Utility Model Sho 58-182947 (JP, U) Japanese Utility Model Sho 59-17447 (JP, U) Japanese Utility Model Sho 63-199262 (JP, U) (58) (Int.Cl. ⁷ , DB name) G03G 15/08

Claims (1)

(57) [Claims] In a developing device connected to a toner replenishing container and having a toner storing portion for storing toner replenished from the toner replenishing container, a flow of air flows between a connecting portion side of the toner storing portion and the toner replenishing container. ducts for circulating air to the upstream side of the is formed, the duct
Is formed so as to include around the toner storing section.
A suction fan for forcibly flowing air through the duct.
When the temperature of the toner has exceeded the specified temperature,
Time and whether the toner end of the toner storage section is detected.
Two times until the toner end is resolved
Only the suction fan is operated .