JP3958769B2 - Toner storage container and image forming apparatus - Google Patents

Description

  The present invention relates to a toner container and an image forming apparatus, and more particularly to a toner container and an image forming apparatus used in an electrophotographic image forming apparatus.

  Conventionally, since a toner storage container storing toner toner is made of a hard bottle such as a cartridge or a bottle, there has been a big problem in disposal of used containers accompanying replacement of the toner storage container. In other words, the used toner storage container is collected from the user by the manufacturer, and is recycled, reused, and incinerated. However, the container has a large capacity and requires a high distribution cost until it is recovered. In the past, there has been a proposal that can reduce the volume of the toner container.

  However, when a toner storage container whose volume can be reduced is supplied from the container using a toner supply device, the supply performance cannot be stably maintained. It has also been proposed to use a container whose volume can be reduced only during transportation, but in this case as well, problems such as contamination caused by toner scattering are solved when transferring toner to a hard bottle or toner hopper. The current situation is that it has not been put into practical use.

  By the way, the applicant of the present application can stably maintain the replenishment performance even when using a toner storage container that is made of a flexible sheet of resin, paper or the like and is capable of reducing the volume. A toner replenishing device capable of replenishing toner has already been proposed. The toner container used in the toner replenishing device in this case is used with the toner discharge port facing downward.

  By the way, when the toner storage container of the image forming apparatus that replenishes toner to the developing unit during operation is detected as a toner near end, the toner in the container is not completely emptied and residual toner is generated. . This residual toner is also generated in the toner storage container of the toner replenishing device described above, and it is desired to reduce the remaining amount as much as possible.

  An object of the present invention is to provide a toner storage container and an image forming apparatus capable of greatly reducing the amount of residual toner at the time of toner near end.

In order to achieve the above object, according to the present invention, a toner discharge unit that discharges toner is set downward with respect to an image forming apparatus, and the stored toner is in response to a toner replenishment command issued according to an image density detection result. In the image forming apparatus provided with a toner storage container that is conveyed to the developing unit by a powder pump and replenished, the toner storage container is a toner formed on an inclined surface having at least one surface tapered toward the toner discharge port. A storage bag, the toner storage bag can be deformed according to external pressure, and depending on pressure urging by pressure urging means from the vicinity of the slope and a decrease in the amount of stored toner by replenishing the toner An image forming apparatus is proposed in which the angle of the inclined surface is gradually increased with respect to the toner storage bag.

The present invention is effective when the inclined surface is at an angle of 40 ° or more with respect to the horizontal line when it is detected that the toner near end .

  According to the first and second aspects of the invention, the amount of remaining toner can be reduced without reducing the volume of the toner storage bag of the toner storage container.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a configuration diagram showing an example of a toner supply device of an image forming apparatus using the toner storage container as a powder storage container according to the present invention, and FIG. 2 shows an example of a toner storage container. It is a perspective view.

  1 and 2, reference numeral 1 denotes a developing device, and 2 denotes a toner storage container for storing powder toner. The toner storage container 2 of the present embodiment includes a deformable toner storage bag 20 (hereinafter referred to as a toner bag) that stores toner, and an outer box that stores the toner bag 20 and has a rigidity higher than that of the toner bag 20. 50 and the back-in-box type.

  The toner container 2 is configured as a separate unit from the developing device 1 and is attached to a set unit provided in the main body of the image forming apparatus. The set portion of the toner storage container 2 may be a position inside the apparatus that appears when a door, a cover, or the like of the image forming apparatus main body is opened, or may be a position that appears outside the apparatus.

  The toner storage container 2 is set on the image forming apparatus main body from above, and a nozzle 30 to be inserted into the container is erected on the set portion of the image forming apparatus main body. The nozzle 30 is provided with a pointed member 31 formed in a conical shape in the upper part by integral molding or fixing, and an air supply path 32 and a toner discharge path 33 are provided following the pointed member 31. The inside of the nozzle 30 has a double-pipe structure, and the toner discharge path 33 is bent to the left in the figure at the lower end of the nozzle 30, and a toner connection port 35 is provided at the tip. The air supply path 32 is bent to the right in the figure above the toner discharge path 33 and reaches the air connection port 34.

  In the case of this embodiment, the air connection port 34 is connected to an air pump 40 as an air supply means via an air transfer pipe 41. When the air pump 40 is activated, air is ejected from the pump into the toner storage container 2 through the air transfer pipe 41 and the air supply path 32. Then, the air blown into the toner storage container 2 passes through the toner layer and fluidizes while diffusing the toner.

  The developing device 1 is provided with a uniaxial eccentric screw pump that is a suction type powder pump 3 in the vicinity or integrally therewith. The structure of the powder pump 3 includes a rotor 4 formed in a screw shape eccentrically made of a rigid material such as a metal, and a stator 5 formed in an elastic body such as rubber and formed in a double thread shape. And a holder 6 made of a resin material or the like that wraps them and forms a powder conveyance path. A toner suction portion 7 is provided at the tip of the holder 6, that is, the right end in FIG. 1, and the toner suction portion 7 is connected to the toner connection port 35 provided in the nozzle 30 by the toner transfer tube 15. As this 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. An effective and flexible tube can be easily piped up and down, left and right.

  In the toner replenishing device configured as described above, the single-shaft eccentric screw pump that is the powder pump 3 is capable of continuous quantitative transfer at a high solid-gas ratio, and is an accurate toner proportional to the rotational speed of the rotor 4. It is known that the transfer amount can be obtained. Therefore, when a toner replenishment command is issued by image density detection or the like, the powder pump 3 is operated to replenish the requested amount of toner to the developing device 1.

FIG. 2 is a perspective view of the toner bag 20 of the toner storage container 2 as viewed from below.
In FIG. 2, the toner bag 20 is made of a flexible sheet made of resin or paper such as polyethylene or nylon having a thickness of about 80 to 200 μm, for example, and the toner bag 20 is blow-molded. A base portion 21 made of a resin or the like formed by a method or the like and provided with a toner discharge portion is fixed. The toner bag 20 has a hermetically sealed structure, and a cap 21 at the bottom is provided with a seal valve 23 made of a self-closing elastic body, preferably a foamed sponge, as a toner discharge portion. In addition, it is effective as a countermeasure against static electricity or moisture prevention to perform aluminum vapor deposition on the front or back surface of the sheet of the toner bag 20.

  The toner bag 20 of the toner container 2 of the present example is substantially rectangular when inflated, and the surface on which the base part 21 is provided is a taper formed on four inclined surfaces 24 toward the central base part 21. It has a shape. The outer box 50 has an internal space in which the toner bag 20 can be accommodated with almost no gap, and the material thereof can be made of resin or paper having a certain degree of rigidity.

  By the way, the toner contained in the toner bag 20 is sucked and replenished by the powder pump 3, and is detected as a toner near end when it becomes empty and the toner supply is stopped. At this time, toner that does not fall in the vicinity of the nozzle 30 due to gravity remains in the toner bag 20, and when the toner bag 20 is examined, a large amount of toner remains at a position indicated by symbol B as shown in FIG. 3. . Even when air is sent to the toner bag 20 and agitated, the slope 24 is difficult to agitate because the air is difficult to reach.

  Therefore, as a result of various experiments, the inventor has found that the remaining amount of toner varies greatly depending on the angle of the inclined surface 24 toward the base portion 21. In the experiment, when the toner bag 20 having a different angle of the inclined surface 24, that is, the angle θ shown in FIG. 4, was used, the result shown in the graph of FIG. 5 was obtained. From this result, it was found that the inclined angle θ of the toner bag 20 needs to be 40 degrees or more. That is, it has been found that when the angle θ of the slope 24 is 40 degrees or more, the remaining amount of toner is 30 g or less, which is generally desirable. This is presumed that the toner falling to the vicinity of the nozzle 30 due to gravity is carried out up to a certain amount according to the slope angle, and if the slope angle increases, the air also easily reaches the above-described B portion. Further, in the experiment, as shown in FIG. 6, when the inclined surface 24 ′ is also used for one toner bag 20 ′, when the angle θ ′ of the inclined surface 24 ′ becomes larger than 40 degrees, the remaining amount of toner is 30 g or less. Became.

  Further, since the toner bag 20 is a deformable bag, it is considered that the slope angle of the toner bag 20 itself cannot be maintained by the weight of the toner. However, in this embodiment, as shown in FIG. 1, the toner bag 20 is housed in the outer box 50, and the inclined angle of the toner bag 20 is formed by forming the inclined angle of the outer box 50 at the same angle as the toner bag 20. Is maintained by the outer box 50.

  As described above, the angle θ of the inclined surface 24 of the toner bag 20 is preferably 40 degrees or more and closer to 90 degrees, so that the remaining toner is reduced. However, if the angle θ of the inclined surface 24 is increased, the toner storage amount is increased accordingly. Less. That is, increasing the angle θ of the inclined surface 24 and increasing the volume of the toner bag 20 are in a contradictory relationship.

  In the embodiment shown in FIG. 7, both the increase in the angle θ of the inclined surface 24 having the contradictory relationship and the increase in the volume of the toner bag 20 are satisfied.

  In FIG. 7, the toner bag 20 is provided with a pair of elastic members as pressure urging means for urging the pressure in the direction of increasing the angle of the inclined surface 24. The pair of elastic members is, for example, a spring or rubber, and a leaf spring 25 is used in the present embodiment. The leaf springs 25 are urged by the elastic force in the direction approaching each other up to the position indicated by the dotted line, but in the state where a large amount of toner is stored in the initial toner bag 20, the solid spring is indicated by the solid line. Is held in the open position shown. As the toner replenishment progresses and the amount of stored toner decreases, the toner bag 20 can be deformed, and the leaf spring 25 gradually approaches the position indicated by the dotted line with its elastic force overcoming the toner weight. When the toner in the toner bag 20 is almost empty, the leaf spring 25 reaches the position indicated by the dotted line. At this time, the angle of the inclined surface 24 approaches a right angle, and the remaining amount of toner can be greatly reduced.

  With this configuration, even if the slope angle of the toner bag 20 is reduced to secure the volume, the slope angle can be greatly changed by the leaf spring 25 when the toner in the toner bag 20 approaches the sky, and there is a reciprocal relationship. It is possible to satisfy both the increase in the angle θ of the inclined surface 24 and the increase in the volume of the toner bag 20.

  FIG. 8 is a modification of FIG. 7. In this example, for example, an elastic elastic member 26 such as a rubber band is wound around the side surface of the toner bag 20. At this time, the elastic expansion / contraction member 26 is urged in a contraction direction in a state where a large amount of toner is stored in the toner bag 20, and when the toner amount is reduced as in the above-described embodiment, the side portion of the toner container is narrowed. Thus, the angle of the slope 24 can be increased.

  By the way, the toner remaining in the B portion of the toner bag 20 can be sufficiently reduced by dropping a certain amount to the nozzle 30 if vibration is applied from the outside. Therefore, as shown in FIG. 1, an air pump 40 is brought into contact with the toner container 2, and vibration of the air pump 40 is transmitted to the toner container 2. In this case, the air pump 40 is provided with a vibrator 42 in terms of its function. Therefore, when the air pump 40 is activated, the toner container 2 can be vibrated. In the toner storage container 2 to which vibration is applied, the shaking of the outer case 50 is transmitted to the toner bag 20, so that it is difficult for the toner to stay in the B portion or the like in the container, and the remaining amount of toner can be reduced. The vibration to the toner storage container 2 can be performed by newly providing vibration generating means. However, if the vibration of the air pump 40 is used, the toner storage container 2 is vibrated without providing such vibration generating means. can do. Further, the vibration of the air pump 40 may be appropriately performed with a vibration transmission member interposed.

3 is a configuration diagram illustrating a toner supply mechanism of the image forming apparatus according to the present invention. FIG. FIG. 6 is a perspective view of the toner container as viewed from above. FIG. 6 is an explanatory diagram illustrating a portion where toner residue is likely to occur in a toner storage container. It is explanatory drawing which shows an example of the toner storage container of this invention. 6 is a graph showing a relationship between a slope angle and a toner remaining amount. It is explanatory drawing which shows the other example of the toner storage container of this invention. It is explanatory drawing which shows another embodiment of the toner storage container of this invention. It is explanatory drawing which shows the modification Example of FIG.

Explanation of symbols

1 Developing Device 2 Toner Storage Container 20 Toner Bag 24 Slope 40 Air Pump 50 Outer Box θ Slope Angle

Claims (2)

A toner discharge unit for discharging the toner is set downward with respect to the image forming apparatus, and the stored toner is conveyed to the developing unit by a powder pump according to a toner supply command issued based on the image density detection result and supplied. In the image forming apparatus provided with the toner storage container,
The toner storage container has a toner storage bag formed on an inclined surface having at least one surface tapered toward the toner discharge port;
The toner storage bag can be deformed according to external pressure,
From the vicinity of the inclined surface, the angle of the inclined surface with respect to the toner storage bag is gradually increased according to the pressure urging by the pressure urging means and the decrease in the stored toner amount due to the replenishment of the toner. An image forming apparatus. The image forming apparatus according to claim 1, wherein the slope has an angle of 40 ° or more with respect to a horizontal line when the toner near end is detected.

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