Toner replenishing device and image forming device

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to a toner replenishing device that replenishes a developing device with toner stored in a toner storage container, and an image forming apparatus such as an electrophotographic printer, a facsimile, or a copying machine.

【0002】

[Conventional technology]

Conventionally, since the toner storage container is made of hard bottles such as cartridges and bottles, there has been a big problem in disposing of the used container when the toner storage container is replaced. That is, the used toner storage container is picked up by the manufacturer from the user, recycled, reused, and incinerated, but the capacity of the container is large and the distribution cost until recovery is high.

【0003】

Further, conventionally, it has been proposed that the volume of the toner storage container can be reduced, but when replenishing the toner from the container using the toner replenishment device, the replenishment performance cannot be stably maintained. Further, even when a container whose volume can be reduced only during transportation is used, problems such as toner contamination occur when transferring toner, and it has not been put into practical use.

【0004】

Further, since the conventional toner transfer technique is based on the mechanical auger means, the toner replenishing device and the toner storage container have to be installed integrally with the developing device or in a very close position. For this reason, the configuration of the toner replenishment device becomes complicated, which hinders high cost, low productivity, and machine maintainability, and it is difficult to secure protection and maintenance of toner quality characteristics. There was also a difficulty.

【0005】

The applicant of the present application has proposed a toner replenishing device that ejects air into the toner storage container, fluidizes the toner, discharges the toner from the container, and replenishes the discharged toner to the developing device using an air flow or a powder pump. ing.

【0006】

This proposed toner replenishment device has various advantages such as the installation position of the toner storage container can be set regardless of the position of the developing device, a soft case can be used for the container, and unnecessary stress is not applied to the toner. It is equipped. However, this does not mean that there is no problem with such a toner replenishing device. For example, the toner storage container is provided with a self-closing valve made of a sponge or the like into which a nozzle as an engaging element is inserted / removed, but if the nozzle is not closed immediately when the nozzle is removed, toner contamination will occur. The smaller the nozzle diameter, the more advantageous it is to maintain good rapid closure due to the elasticity of the self-closing valve.

【0007】

[Problems to be Solved by the Invention]

However, as shown in FIG. 13, the proposed nozzle 151 has a double-tube structure in which the toner passage 152 and the air passage 153 are provided, and therefore, the toner passage 152 is not clogged to some extent. When the cross-sectional area of the size was secured, it was inevitable that the nozzle diameter became large. As shown in FIG. 13, the nozzle 151 has an air passage 153 on the center side and a toner passage 152 on the outer periphery thereof, and a nozzle 151 has a toner passage 152 on the center side and an air passage on the outer peripheral side as shown in FIG. However, there is no change in the nozzle diameter becoming larger in both cases. Further, when the nozzle of the double tube is made of a resin molded product, there is a problem that the cost of the mold becomes very high.

【0008】

In view of the above problems, it is an object of the present invention to provide a toner replenishing device and an image forming device that can obtain a toner passage having an appropriate size without increasing the engagement element diameter.

【0009】

[Means for solving problems]

In order to achieve the above object, the present invention inserts and removes a toner storage container having an opening at a lower end and the toner storage container from the opening to the toner storage container by attaching and detaching the toner storage container to the image forming apparatus main body. In a toner replenishing device having a shaft-shaped engaging element to be replenished and the toner stored in the toner storage container is replenished to the developing device via the engaging element, the engaging element is replenished to the developing device. A toner passage through which the toner is passed is provided, and an air passage leading to the air supply means is merged in the middle of the toner passage.

【0010】

In the present invention, assuming that the angle formed by the toner passage and the air passage at the confluence of the air passage with respect to the toner passage is θ, the angle θ is 90 degrees when viewed from the side engaged with the toner storage container. It is effective when θ 180 degrees.

【0011】

Further, the present invention is effective when the toner stored in the toner storage container is provided with a suction means for urging the suction force for transferring the toner to the developing apparatus. Furthermore, the present invention is effective when the toner storage container is provided with at least a part of which is flexible and the toner is stored in the flexible container.

【0012】

Furthermore, the present invention is effective in that the flexible container is provided with a breathable filter. Furthermore, the present invention is effective when both axes of the air passage and the upstream side of the air passage confluence in the toner passage of the engager are substantially in a straight line.

【0013】

Furthermore, the present invention is a toner replenishing device characterized in that a valve for opening and closing the air passage is provided. Furthermore, the present invention is effective when the air supply means is located above the confluence in the height direction.

【0014】

Further, in order to achieve the above object, the present invention develops a latent image formed on the image carrier by using the toner replenishing device according to any one of claims 1 to 8. It is characterized by supplying toner to the developing device.

【0015】

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a configuration diagram showing a toner replenishment mechanism used in the image forming apparatus according to the present invention, and FIG. 2 is a cross-sectional view showing a part of a developing apparatus on which the toner is replenished.

【0016】

In FIG. 1, in the image forming apparatus by the electrophotographic method, the electrostatic latent image formed on the image carrier 1 by the developing apparatus 10 is developed as a toner image. Toner is supplied to the developing apparatus 10 from a toner storage container 20 containing toner, which will be described in detail later, via a powder pump 40 and a transfer tube 15 as suction means.

【0017】

The developing apparatus 10 includes a developing sleeve 11 arranged so as to face the image carrier 1, a first stirring screw 12, and a second stirring screw 13. The toner in the developing apparatus 10 is circulated so as to be conveyed by the first stirring screw 12. During this circulation, the electrostatic latent image formed on the image carrier 1 is developed by the toner transferred to the developing sleeve 11 in the middle of the transport path. Reference numeral 18 is a toner concentration sensor.

【0018】

The powder pump 40 is provided in the toner conduction path from the toner storage container 20 to the developing device 10, and is arranged adjacent to the developing device 10 in this example as shown in FIGS. 2 and 3. This powder pump 40 is a suction type uniaxial eccentric screw pump, which is composed of a rotor 42 made of a rigid material such as metal and eccentric in a screw shape, and an elastic body such as rubber inside. It has a stator 43 that is made into a double-threaded screw shape and is fixedly installed, and a holder 44 that is made of a resin material or the like that wraps them and forms a powder transport path. Then, in the present embodiment, the gear 16 integrally connected to the first stirring screw 12 and drive-connected to a drive device (not shown), and the gear integrally connected to the rotor 42 and the drive shaft 43a connected by the pin joint. The gear 45 is engaged with the gear 45, and an electromagnetic clutch 46 is interposed in the gear 45 as an intermittent means for interrupting the rotational drive by the gear 16. The electromagnetic clutch 46 switches the powder pump 40 on and off, and can be applied to a developing device of a type that controls the toner concentration in the developing device 10 to be kept constant.

【0019】

Further, the tip of the holder 44 is connected to a toner connection port 35 provided in a nozzle 51, which will be described later, by a toner transfer tube 15. As the toner transfer tube 15, for example, a flexible tube having a diameter of 4 to 10 mm and made of a rubber material having excellent toner resistance (for example, polyurethane, nitrile, EPDM, silicon, etc.) is extremely used. The effective and flexible tube can be easily piped in any direction up, down, left and right. The powder pump 40 generates a strong self-priming force due to the rotation of the rotor 42, and can suck toner from the toner storage container 20. The sucked toner is transferred into the developing apparatus 10 by a supply hole 17 formed between the powder pump 40 and the first stirring screw 12, and this transfer step when the two-component developing method is used. The toner replenished inside is agitated and mixed with the toner in the developing apparatus 10 to obtain a uniform agent concentration and an appropriate charge amount. The developing device is provided with a degassing hole 14a and a filter 14 covering the degassing hole 14a, and only air is degassed from the developing device 10 to suppress boosting in the device, stabilize toner supply, and from the developing device 10. It is configured to prevent the toner from scattering.

【0020】

In FIG. 3, reference numeral 50 is a set portion in which the toner storage container 20 provided in the image forming apparatus main body is set. The set portion 50 is provided with a nozzle 51 as an engaging element that can enter into the toner storage container 20 extending substantially upward, which is integrally or detachable, but is fixed in position. The nozzle 51 is formed in a straight line and a cylindrical shape, and a toner discharge path 33 is provided in the shaft core portion following the tip portion 52 provided in the upper portion. The inside of the nozzle 51 has a single tube structure, and the toner transfer tube 15 is connected to the toner discharge path 33 at the lower end of the nozzle 51.

【0021】

The toner storage container 20 is configured as a back-in box type having an outer box 21 as a protective case and a toner bag 22 as a flexible and deformable bag-like body detachably housed in the outer box 21. ing. The outer box 21 is made of a material such as rigid paper, corrugated cardboard, and resin, and has an internal space such that the toner bag 22 can be accommodated with almost no gap. Even if the toner bag 22 containing the toner is flexible, the toner storage container 20 is not only protected by being stored in the outer box 21, but also has improved handleability and is easy to handle and is stored. The advantage is that it is easy to organize the time.

【0022】

Further, the bag portion of the toner bag 22 has a bag-like container shape in which a flexible sheet material (thickness of about 80 to 125 μm) such as a polyester film or a polyethylene film is formed into a single layer or a multi-layer structure. The toner bag 22 is configured by providing a toner discharge hole 24 in the center of the lower portion thereof and fixing a base member 23 made of resin to polyethylene, nylon or the like. A single-layer or multi-layer seal 25 having a function of a self-closing valve is provided in the toner discharge hole 24 of the base member 23, and the seal 25 is made of an elastic body made of a non-breathable foam sponge or the like. Further, the toner bag 22 is formed in a shape that tapers toward the toner discharge hole 24 so that the toner does not easily remain.

【0023】

In the toner replenishing device having such a configuration, the air pump 30 joins the toner passage of the nozzle 51 through the air supply tube 31 and the air passage 32, and air is ejected into the toner storage container 20. The ejected air passes through while diffusing the toner layer, and then fills the inside of the toner storage container 20. The filled air passes through the inside of the nozzle 51 through the opening provided on the tip side of the nozzle 51 together with the toner, and is supplied to the developing device 10 by the self-priming force of the powder pump 40 via the toner transfer tube 15. The air ejected into the toner storage container 20 passes through the toner layer while diffusing to fluidize the toner. The toner bag 22 is provided with a breathable filter 27 above the toner bag 22 for reducing the internal pressure due to the supply of air.

【0024】

The toner in the toner storage container 20 is transferred to the outside of the container by using gravity and the suction force of the powder pump 40 as described above, but the toner in the electrophotographic photograph has poor fluidity, so the powder pump 40 is used. After sucking the toner near the nozzle 51, a cross-linking phenomenon may occur in the container. For this reason, the amount of toner replenished may become unstable or the remaining amount of toner in the toner storage container 20 may become extremely large. However, by supplying air into the toner storage container 20, the toner is agitated. Since it can be fluidized to prevent the toner cross-linking phenomenon or to be broken by the air supplied with the cross-linked toner, it is possible to stabilize the toner supply amount and reduce the remaining amount of toner in the container.

【0025】

The nozzle 51 is configured as a single-tube nozzle as described above, and the air passage 32 merges at the confluence point 34 of the toner passage 33. Therefore, the nozzle diameter can be reduced without reducing the cross-sectional area of the toner passage 33 as compared with the conventional nozzle having a double tube structure. Moreover, even if the toner passage and the air passage are used in combination, it is not necessary to perform the toner transfer and the air supply at the same time, so that there is no problem in that respect.

【0026】

However, as shown in FIG. 4, when the air passage 32 is merged at a right angle to the axis of the toner passage 33 on a straight line as shown in FIG. 4, the single pipe nozzle 51 having such a configuration is supplied. The air easily flows from the toner passage 33 in the direction of arrow A in the figure not only to the upstream side in the toner discharge direction but also to the downstream side in the direction of arrow B. In particular, the load on the toner suction port 53 side is large, for example, when the weight of the toner is large as immediately after loading a new toner container, or when the toner is left for a long time with the container set, the toner aggregates. When there is such a case, the supplied air tends to flow to the downstream side (direction of arrow B) where the load is lighter. Since the transfer tube 15 is located on the downstream side and is usually filled with the residual toner, the toner may be pressed by the pressure of the air flowing to the downstream side, and the toner may aggregate. Since the transfer tube 15 does not have a stirring means like the inside of the container, the aggregated toner does not move again when it does not move due to the suction force of the pump, and the toner is replenished by so-called "toner clogging in the tube". Will not be performed.

【0027】

Therefore, in the present invention, as shown in FIGS. 3 and 5, assuming that the angle formed by the toner passage 33 and the air passage 32 at the confluence 34 of the air passage 32 with respect to the toner passage 33 is θ, the toner storage container 20 of the nozzle 51 The angle θ is 90 degrees <θ 180 degrees when viewed from the side that engages with.

【0028】

With this configuration, the air supplied from the air passage 32 can easily flow to the toner storage container 20 due to the angle θ, and it is difficult for the air to flow back to the downstream side, so that the above-mentioned problem can be solved.

【0029】

The nozzles 51 shown in FIGS. 6 (a) and 6 (b) have almost the same size of the angle θ as the nozzle 51 in FIG. 5, except that the toner passage 33 is tilted downstream from the confluence 34. There is. This nozzle 51 also has the same effect as the nozzle 51 of FIG.

【0030】

Further, the nozzle 51 shown in FIGS. 7 (a) and 7 (b) is configured so that the maximum angle θ is 180 degrees and the air passage 32 and the toner passage 33 on the upstream side from the confluence 34 are in a straight line. doing.

【0031】

With this configuration, the air supplied from the air passage 32 is less likely to flow back to the downstream side, so that the above-mentioned problem can be further solved. The nozzles 51 shown in FIGS. 8 (a) and 8 (b) also have the same angle θ as the nozzle 51 in FIG. 7 at 180 degrees, and the toner passage 33 is bent at a substantially right angle from the confluence 34. The point is different. This nozzle 51 also has the same effect as the nozzle 51 of FIG.

【0032】

By the way, in the toner replenishment device using the nozzle 51 in which the angle θ is 90 degrees <θ 180 degrees, the toner fluidized by air should originally flow to the transfer tube 15 as shown by the solid arrow in FIG. However, immediately after the air supply operation by the air pump 30 is stopped, the load from the air passage 32 in the direction of the air pump disappears, and the air passage 32 points downward. Therefore, the dotted arrow in FIG. Toner easily flows into the air supply port. Then, the inflowing toner may invade the air pump 30 through the air supply tube 31 and cause a failure of the air pump 30 due to clogging of the air valve or the like inside or a problem of deterioration of durability.

【0033】

Therefore, in the embodiment shown in FIG. 10, the air pump 30 is arranged at a position higher than the toner receiving port 53 of the nozzle 51. With this configuration, even if toner flows in from the air passage 32, the toner reaches the air supply tube 31 and hardly penetrates into the air pump 30, so that the above-mentioned problem of the air pump 30 can be solved.

【0034】

Further, in another embodiment of the present invention shown in FIG. 11, a solenoid valve 35 is provided between the air pump 30 and the air passage 32, in this example, the air supply tube 31 as a valve for opening and closing the passage. The solenoid valve 35 is a valve that opens by passing an electric current and closes when no electric current flows, and is controlled in synchronization with the operation of the air pump 30. Therefore, the solenoid valve 35 is opened only while the air pump 30 is operating, the air supply path is opened, and while the air pump 30 is stopped, the toner is shut back from the air supply path to prevent the toner from flowing back to the air pump 30. It can be completely prevented. Therefore, it is possible to solve the problems of failure due to clogging of the air valve inside the pump and deterioration of durability.

【0035】

FIG. 12 is a cross-sectional explanatory view showing the overall configuration of the toner replenishment device according to another embodiment of the present invention, and since there are many similarities with the embodiment of FIG. 3, only the different parts will be described. The common members are given the same number.

【0036】

The most different point between this toner replenishing device and the device of FIG. 3 is that this toner replenishing device replenishes toner by air pressure, and therefore the powder pump 40 is not used in this device. Further, since the toner bag 22 of the toner storage container 20 is also a completely sealed container, it is not provided with the breathable filter 27.

【0037】

In such a toner replenishing device, the toner in the toner bag 22 of the toner storage container 20 is agitated and fluidized by the air supplied from the air pump 30, and at the same time, the pressure inside the toner bag 22 is increased. The toner fluidized by the increased internal pressure of the toner bag 22 tends to be easily discharged to the outside, and is replenished to the developing device 10 through the nozzle 51 and the transfer tube 15. The pressure inside the toner bag 22 is reduced again by discharging the toner and returns to a state close to the atmospheric pressure, and this is repeated to replenish the toner.

【0038】

Even in the toner replenishment device configured in this way, the nozzle 51 of FIGS. 5 to 8 and the air pump 30 are arranged at a position higher than the toner receiving port 53 of the nozzle 51 as shown in FIG. Needless to say, it is effective to provide a valve between the air pump 30 and the air passage 32 as shown in 11.

【0039】

The toner replenishment device is driven and controlled by a power outlet (not shown), a power supply and a switch (not shown), and a control circuit to drive and control the drive motor. For these, conventionally well-known techniques may be used.

【0040】

For the control of toner replenishment, a conventionally known toner concentration detection / control method is used. This detects a change in the mixing ratio of toner and carriers in the developing device 10 based on the magnetic coefficient detector 18 provided in a part of the developing device, and when it is detected that the amount of toner is small, the powder pump means 40 is used. Operate. When the amount of toner transferred into the developing apparatus 10 by the powder pump means 40 exceeds a certain amount, the electromagnetic clutch 46 shuts off the drive by the signal of the magnetic permeability detector 18 and stops the operation of the powder pump means 40. To do. As another method for controlling the toner replenishment amount, it is also possible to use a conventionally known technique such as a method for detecting the reflection density of the toner image on the photoconductor and controlling the same toner replenishment amount.

【0041】

According to the configuration of the present invention, the toner storage container 20 can be replaced by pushing or pulling out the toner storage container 20 into the nozzle 51, so that the operability at the time of replacement is good. At the same time, when these are replaced, toner scattering and contamination can be prevented by the sealing effect. Further, since the toner storage container 20 has a good sealing property, the toner in the toner storage container is not affected by the outside air, particularly humidity, and the toner quality characteristics can be protected and maintained. Further, since this sealing method has a simple structure, it contributes not only to simplification and cost reduction of the toner storage container but also to simplification and cost reduction of the toner replenishing device and improvement of machine maintainability.

【0042】

Further, since the outer box 21 of the toner storage container 20 has rigidity, operability at the time of loading / unloading the toner storage container 20 into the toner replenishment device is facilitated. It is also effective in protecting and maintaining the quality characteristics of the toner in the toner storage container 20. Further, as the toner storage container, it is also possible to use a flexible container having no outer box and having a base member 23 formed by a blow molding method or the like and a toner bag 22 having an integral structure.

【0043】

In addition, the used toner storage container 20 can be easily disassembled into the outer box 21 and the toner bag 22, the outer box 21 is foldable, and the toner bag 22 is flexible. Since the container is not bulky, it is easy to handle during transportation and storage, and since it does not take up storage space, it is possible to significantly reduce the collection and distribution cost from the user to the manufacturer.

【0044】

This toner replenishment device only needs to connect a flexible toner transfer pipe to the developing device of the image forming apparatus, and there are no restrictions on the installation position / location of the toner replenishing device with respect to the developing device. It is possible to provide the toner replenishment device in a place where the operability at the time of replacing the container is most convenient.

【0045】

[Effect of the invention]

According to the configuration of claim 1, since the engaging element has a single tube structure, the diameter does not become large and it can be provided at low cost.

【0046】

According to the configuration of claim 2, the air supplied through the air passage is unlikely to flow back to the downstream side in the toner discharge direction, and the occurrence of toner clogging in the transfer tube can be suppressed. According to the configuration of claim 3, since the toner is sucked and replenished by the suction pressure, stable toner replenishment can be obtained.

【0047】

According to the configuration of claim 4, cross-linking or the like without the toner storage container is unlikely to occur, the volume can be reduced, and the recovery cost can be significantly reduced. According to the configuration of claim 5, the pressure of the toner storage container can be adjusted to an appropriate pressure.

【0048】

According to the configuration of claim 6, the backflow of air can be prevented more reliably. According to the configurations of claims 7 and 8, it is possible to reliably prevent toner from entering the air pump.

【0049】

According to the configuration of claim 9, it is possible to provide an image forming apparatus of a type that stably replenishes toner and replenishes toner from a toner storage container having a small amount of residual toner to a developing apparatus.

[Simple explanation of drawings]

[Figure 1]

It is a block diagram of the toner replenishing apparatus which concerns on this invention.

[Figure 2]

It is a partial cross-sectional view of the end portion of the developing apparatus shown in FIG.

[Fig. 3]

It is sectional drawing which shows one Embodiment of the toner replenishing apparatus of this invention.

[Fig. 4]

(a) is a front view of the nozzle, and (b) is a cross-sectional view thereof.

[Fig. 5]

(a) is a front view of the nozzle which is an improvement of FIG. 4, and (b) is a cross-sectional view thereof.

[Fig. 6]

(a) is a front view of the nozzle which is an improvement of FIG. 4, and (b) is a cross-sectional view thereof.

[Fig. 7]

(a) is a front view of the nozzle which is an improvement of FIG. 4, and (b) is a cross-sectional view thereof.

[Fig. 8]

(a) is a front view of the nozzle which is an improvement of FIG. 4, and (b) is a cross-sectional view thereof.

[Fig. 9]

It is sectional drawing explaining the problem of the said toner replenishing apparatus.

[Fig. 10]

It is sectional drawing of the toner replenishing apparatus which solved the problem of FIG.

[Fig. 11]

It is sectional drawing of the toner replenishing apparatus which solved the problem of FIG.

[Fig. 12]

It is sectional drawing which shows the other embodiment of the toner replenishing apparatus of this invention.

[Fig. 13]

(a) is a front view of a conventional nozzle, and (b) is a cross-sectional view thereof.

[Fig. 14]

(a) is a front view of a conventional nozzle, and (b) is a cross-sectional view thereof.

[Explanation of symbols]

10 developing equipment 20 Toner storage container 22 Toner bag 27 Breathable filter 30 air pump 32 Air passage 33 Toner passage 34 Confluence 35 valve 51 nozzle