JP2004264878A - Toner replenishment device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner replenishment device capable of obtaining a toner path of an appropriate size without making the diameter of an inserting/edjecting member into a large diameter, and to provide an image forming device. <P>SOLUTION: The toner replenishment device comprises: a tube-shaped nozzle 40 to be inserted/ejected to/from a toner storage 20; and an air pump 30 for feeding air into the toner storage 20 via the nozzle 40. The nozzle 40 is provided with a passage 41 used for an air passage through which the air to be fed into the toner storage 20 passes and also served for a toner passage through which the toner to be discharged from the toner storage . <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to a toner supply device and an electrophotographic image forming apparatus.

  Conventionally, since the toner container is made of a hard bottle such as a cartridge or a bottle, there has been a great problem in disposing of the used container when the toner container is replaced. That is, the used toner storage container is collected by the manufacturer from the user, and is recycled, reused, and incinerated. However, the container has a large capacity and requires a high distribution cost until it is collected.

  In addition, conventionally, there has been proposed a toner storage container in which the volume of the container can be reduced, but when replenishing the container using the toner replenishing device, the replenishment performance cannot be stably maintained. Further, even when a container whose volume can be reduced only during transportation is used, a problem such as toner contamination occurs at the time of transferring the toner, and it has not been put to practical use.

  Further, in the conventional toner transfer technique, since the toner supply technique is based on mechanical auger means, the toner supply device and the toner storage container have to be installed integrally with the developing device or at a position very close to the developing device. This complicates the structure of the toner replenishing device, hinders high cost, low productivity, and mechanical maintenance.It is also difficult to secure and maintain the toner quality characteristics. There was also difficulty.

  Note that a toner replenishing device that ejects air into a toner container, fluidizes the toner, discharges the toner from the container, and replenishes the discharged toner to a developing device by using an air flow or a powder pump is known in the art. Not suggested.

  This toner replenishing device has various advantages such as the setting position of the toner storage container irrespective of the position of the developing device, the use of a soft case for the container, and the prevention of unnecessary stress on the toner. Things.

  However, the above-described toner supply device has some problems. For example, since the insertion / removal member which is inserted / removed into / from the container has a passage for toner and a passage for air supply, the passage for toner becomes too narrow unless it has a certain diameter. For this reason, if the diameter of the insertion / removal member is increased, toner leaks from the seal valve when the insertion / removal member is removed.

  SUMMARY OF THE INVENTION In view of the above-described problems, an object of the present invention is to provide a toner replenishing apparatus and an image forming apparatus that can provide a toner passage having an appropriate size without increasing the diameter of the insertion / removal member.

  In order to achieve the above object, the present invention relates to a toner replenishing device for replenishing toner stored in a toner storage container to a developing device, wherein a tubular insertion / removal member which is inserted / removed into / from the toner storage container; Air supply means for supplying air into the toner storage container via a member; an air passage through which air supplied into the toner storage container passes through the insertion / removal member; A passage that also serves as a toner passage through which the toner passes.

  The present invention is effective when an opening / closing means for opening and closing the toner supply path is provided in the toner supply path from the air supply unit of the air supply means to the entrance of the developing device.

  Further, in order to achieve the above object, the present invention provides a toner supply device for replenishing toner stored in a toner storage container to a developing device, wherein a tubular insertion / removal member inserted / removed into / from the toner storage container, An air supply unit configured to supply air into the toner storage container via the insertion / removal member; and a suction-type powder pump configured to supply toner stored in the toner storage container to a developing device. Is characterized in that an air passage through which air supplied into the toner storage container passes and a passage through which toner discharged from the toner storage container passes also are provided.

  The present invention is effective when the powder pump also serves as an opening / closing unit that opens and closes a path provided in a toner supply path from the air supply unit of the air supply unit to the entrance of the developing device. .

  Further, the present invention is effective when the toner supply path is closed by stopping the opening / closing means or the powder pump when the air supply means is operated.

  Furthermore, the present invention is effective when the operation of the air supply unit is stopped when the toner supply path is opened by the operation of the opening / closing unit or the powder pump.

  Still further, the present invention is effective when the air supply from the air supply means to the toner storage container is performed when the accumulated time of the toner supply time by the operation of the powder pump is equal to or longer than a predetermined time. is there.

  Furthermore, the present invention is effective when the air supply unit and the toner supply unit are provided in the insertion / removal member, and the air supply unit is located at a position higher than the toner supply unit.

  Furthermore, the present invention is effective when the air supply unit and the toner supply unit are provided in the insertion / removal member, and the toner supply unit is located above the air supply unit.

Furthermore, the present invention is effective when the diameter of the air supply unit from the air supply unit is smaller than the diameter of the toner supply unit.
Furthermore, the present invention is effective when the air supply from the air supply unit to the toner container is supplied from the lowest position of the toner supply path.

Furthermore, the present invention is effective when the air supply from the air supply means to the toner container is opened and closed by an air valve.
In order to achieve the above object, the present invention is characterized by including a toner supply device according to any one of claims 1 to 12.

Note that the present invention is effective if it includes a plurality of toner storage containers, a toner replenishing device, and a developing device.
Furthermore, the present invention is effective when air is supplied to each toner storage container by a single air supply unit.

  Furthermore, the present invention is effective when air is supplied to each toner storage container from the single air supply means by means of an air valve provided for each toner storage container.

  Furthermore, the present invention is effective when the supply of air from the single air supply unit is controlled so as not to be simultaneously supplied to the toner container two or more times.

According to the configuration of the first and third aspects, the insertion / extraction member can have a single pipe structure, and the production cost of the member can be greatly reduced.
According to the configuration of the second aspect, it is possible to replenish the toner by air pressure even if a single-tube insertion / removal member is provided.

According to the configuration of (4), it is possible to prevent the air from the air pump from being sent into the developing device by the powder pump that urges the suction force to supply the toner to the developing device.
According to the configuration of the fifth, sixth and seventh aspects, the toner can be reliably transferred by the powder pump.

According to the configuration of the eighth aspect, leakage of the toner to the air supply path can be reduced.
According to the ninth aspect, it is possible to prevent the toner from being clogged in the insertion / removal member.

According to the configuration of (10), leakage of the toner to the air supply path can be reduced.
According to the configuration of the eleventh aspect, it is possible to prevent toner clogging in the toner transfer path.

According to the twelfth aspect, it is possible to prevent the air from being sucked through the air pump when the powder pump is operated.
According to the configuration of the thirteenth aspect, it is possible to provide an image forming apparatus capable of supplying toner stably at low cost.

According to the fourteenth to sixteenth aspects, it is possible to provide a color image forming apparatus that can supply toner stably at low cost.
According to the configuration of claim 17, even when the supply destination is a plurality of places, the required amount of air can be reliably supplied by one air pump.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a schematic diagram showing a color laser printer as an example of an image forming apparatus according to the present invention. This color laser printer has a configuration in which a paper feed unit 2 is disposed at a lower portion of an apparatus main body 1 and an image forming unit 3 is disposed above the paper feed unit 2. The image forming unit 3 is provided with a transfer belt device that is arranged so as to be inclined such that the paper supply side is downward and the paper discharge side is upward. The transfer belt device 8 has an endless transfer belt 8a wound around a plurality of belt wheels, in this example, four belt wheels, and the upper running side of the transfer belt 8a has magenta (M) in order from the bottom. , Cyan (C), yellow (Y), and black (Bk) are arranged in parallel.

  FIG. 2 is an explanatory diagram showing an enlarged portion of the image forming unit 4. As shown in FIGS. 1 and 2, each of the image forming units 4M, 4C, 4Y, and 4Bk is a photosensitive member as an image carrier. A body drum 5 is provided, and the photosensitive drum 5 is driven to rotate clockwise by driving means (not shown). Around the photoreceptor drum 5, there are provided a charging roll 6 as a charging unit, an optical writing unit in which writing by laser light is performed by an optical writing unit 7, a developing unit 10 as a developing unit, and a cleaning unit 9 as a cleaning unit. I have. The developing device 10 is a two-component developing device including a toner and a carrier, and toner corresponding to the consumed toner amount is replenished from the toner storage container 20 by the toner replenishing device. The toner replenishing device replenishes the image forming units 4M, 4C, 4Y, and 4Bk with the toner stored in the same number of toner storage containers 20.

  As shown in FIG. 3, the developing device 10 is provided with a uniaxial eccentric screw pump which is a suction type powder pump 11 in the vicinity or integrally therewith. As shown in FIG. 4, the configuration of the powder pump 11 is such that a rotor 12 made of an eccentric screw made of a rigid material such as a metal and an elastic body made of rubber or the like have a two-screw shape. And a holder 14 made of a resin material or the like which wraps the stator 13 and forms a powder conveyance path. The rotor 12 is driven to rotate via a gear 16 integrally connected to a drive shaft 15 connected by a pin joint. Reference numeral 17 denotes an electromagnetic clutch, and the operation of the powder pump 11 is controlled by the clutch.

  Further, a toner suction portion 18 is provided at the tip of the holder 14, that is, at the right end in FIG. 3, and a toner connection port 45 and a toner transfer tube provided in the toner suction portion 18 and a nozzle 40 serving as an insertion / removal member described later. 19. As the toner transfer tube 19, a flexible tube having a diameter of, for example, 4 to 10 mm and made of a rubber material having excellent toner resistance (for example, polyurethane, nitrile, EPDM, or silicon) is extremely used. Effective and flexible tubes can be easily piped in any direction, up, down, left and right. In the toner replenishing apparatus thus configured, the single-axis eccentric screw pump, which is the powder pump 11, is capable of performing a constant quantitative transfer at a high solid-gas ratio, and has an accurate toner proportional to the rotation speed of the rotor 12. Is known to be obtained. Therefore, when a toner replenishment command is issued due to image density detection or the like, the powder pump 11 operates to replenish the required amount of toner to the developing device 10.

  On the other hand, the setting unit 50 provided in the image forming apparatus main body 1 in which the toner container 20 is set is configured as a unit separate from the developing device 10. A nozzle 40 having a circular cross section which is inserted into and removed from the toner storage container 20 is provided upright on the set portion 50, and the toner storage container 20 is set to the setting portion 50 of the image forming apparatus main body 1 from above. The nozzle 40 provided in the set portion 50 is provided with a pointed member 44 formed in a conical cross section at the upper portion by integral molding or fixing, and the nozzle 40 serves also as an air supply path and a toner supply path following the pointed member 44. A passage 41 is provided. The inside of the nozzle 40 has a single tube structure, and the passage 41 is bent to the left in the drawing at the lower end of the nozzle 40, and a tip end thereof is provided with a toner connection port 42 to which the toner transfer tube 19 is connected. I have. The passage 41 is provided with an air connection port 43 which is bent to the right in the figure above the toner connection port 42.

  In the case of the present embodiment, the air connection port 43 is connected to the air pump 30 as an air supply means via the air transfer pipe 31. When the air pump 30 operates, air is blown from the pump into the toner container 20 via the air transfer pipe 31 and the passage 41. Then, the air blown into the toner storage container 20 is fluidized while diffusing the toner by passing through the toner layer.

  The toner storage container 20 is configured as a back-in-box type having a deformable toner bag 21 for storing toner and an outer box 22 for storing the toner bag 21 and having greater rigidity than the bag. . The toner bag 21 is made of a single layer or multiple layers of a flexible sheet made of resin or paper such as polyethylene or nylon having a size of about 80 μm to about 20 μm in a toner storage container. A base 23 made of resin or the like provided with a toner supply unit is fixed. The toner bag 21 has a hermetically sealed structure, and a base 23 at the bottom thereof is provided with a seal valve 24 made of an elastic body, preferably a foamed sponge, etc. as a self-closing valve. It is to be noted that performing aluminum vapor deposition on the front or back surface of the sheet of the toner bag 21 is effective for measures against static electricity and moisture.

  In the toner replenishing device configured as described above, when the toner storage container 20 is attached to and detached from the image forming apparatus main body 1, a nozzle 41 that is inserted into and removed from the container is provided with a passage 41 that doubles as an air supply path and a toner replenishment path. ing. Therefore, as compared with the case where the air supply path and the toner supply path are separately provided, the structure is simple, the manufacturing cost is greatly reduced, and the passage 41 itself has a large cross-sectional area, so that toner clogging is less likely to occur. Become. Further, in the present embodiment, since the air connection port 43 is provided above the toner connection port 42 in the nozzle 40, leakage of the toner to the air connection port can be reduced.

  By the way, when the nozzle 40 has a single tube structure, the movement of the toner and the supply of the air cannot be performed at the same time. Therefore, a control example will be described with reference to FIG. 4 while controlling so that toner movement and air supply are not performed simultaneously.

  In FIG. 4, the toner supply amount is determined by determining the ON time of the powder pump 11 based on the output of the T sensor for each print. When the determined toner replenishment is completed, the on-time of the powder pump 11 is integrated, and when the integrated time reaches a predetermined time, the air pump 30 is operated after the toner replenishment has reached the predetermined time, and the toner pump is operated. Air is supplied into the storage container 20. The supplied air amount is a fixed amount, and the accumulated time is reset.

By controlling the toner replenishment in this way, a stable toner replenishment performance can always be ensured even when the nozzle 40 has a single tube structure.
Further, when air is supplied to the toner storage container 20 by the air pump 30, if the nozzle 40 has a single tube structure, air may be sent to the developing device 10 via the toner transfer tube 19 and the powder pump 11. However, since the powder pump 11 is a single-axis eccentric screw pump, the toner transfer path is a closed path, and such a problem does not occur. Furthermore, when toner is sent by air pressure without using a powder pump, an on-off valve (not shown) may be provided in the toner transfer path instead of the powder pump. In this case, an air valve is also provided in the air passage of the air pump 30, and when supplying air to the toner storage container 20, the air valve is opened after closing the on-off valve to increase the internal pressure of the toner storage container to some extent. If the on-off valve is opened after the valve is closed, the toner can be replenished without sending the toner by the air pressure to the air pump side.

  In this control, the operation time of the air pump 30 is shorter than the operation time of the powder pump 11. Therefore, when four image forming units 4 are provided as in the present embodiment, it is not necessary to provide the air pump 30 for each toner supply device, and only one air pump 30 is possible. FIGS. 5 and 6 show control examples of the control unit 30.

  FIG. 5 is a diagram showing the relationship between the air pump 30 and each of the toner storage containers 20M, 20C, 20Y, and 20Bk. The air supply tube 31 from the air pump 30 includes four toner storage containers 20M, 20C, and 20Y. , 20Bk, and is branched into four tubes 32M, 32C, 32Y, and 32Bk on the way. Each of the branched tubes 32M, 32C, 32Y, 32Bk is provided with an air valve 33M, 33C, 33Y, 33Bk, and the toner container 20M connected to the turned-on air valve 33M, 33C, 33Y, 33Bk. , 20C, 20Y, and 20Bk are supplied with air only.

  As shown in FIG. 6, the control of the configuration is such that the air pump 30 is turned on for a time corresponding to the total amount of air supplied to each of them, and when the air pump 30 is on, the amount of air supplied is The respective air valves 33M, 33C, 33Y, 33Bk are opened accordingly. At this time, by controlling not to turn on the two or more air valves 33M, 33C, 33Y, and 33Bk at the same time, a required amount of air can be supplied to each of the toner storage containers 20M, 20C, 20Y, and 20Bk.

  The toner replenishing device thus configured can reduce the cost as compared with the case where a plurality of air pumps are provided. Moreover, since air is not supplied to the two or more toner storage containers 20M, 20C, 20Y, and 20Bk at the same time, the required amount of air can be supplied to each container with high accuracy. Further, also in this control, since the toner supply and the air supply are not performed at the same time, the nozzle 40 functions sufficiently with a single tube structure.

FIG. 7 is a cross-sectional explanatory view showing another embodiment of the present invention. In the present embodiment, in the nozzle 40, the toner connection port 42 is provided above the air connection port 43.
With this configuration, clogging of the toner in the nozzle 40 can be prevented by the air flow. Further, by making the diameter of the air connection port 43 smaller than that of the toner connection port 42, it is possible to prevent toner from leaking into the toner through the air connection port 43.

FIG. 7 is a cross-sectional explanatory view showing another embodiment of the present invention. In the present embodiment, in the nozzle 40, the toner connection port 42 is provided above the air connection port 43.
With this configuration, clogging of the toner in the nozzle 40 can be prevented by the air flow. Further, by making the diameter of the air connection port 43 smaller than that of the toner connection port 42, it is possible to prevent toner from leaking into the toner through the air connection port 43.

  FIG. 8 is a sectional explanatory view showing still another embodiment of the present invention. In this embodiment, a branch pipe is provided at the lowest position from the nozzle 40 to the powder pump 11, in this example, in the middle of the toner transfer tube 19. The branch pipe 34 is connected to the tube 31 of the air pump 30.

  With this configuration, since the air from the air pump 30 is supplied from the lowest position in the toner transfer path, it is possible to reliably prevent the path from being clogged with the toner accumulated by its own weight at the lowest position.

As described above, the preferred embodiments of the present invention have been described, but the present invention is not limited to the above-described embodiments, and can be variously modified.
For example, the cross-sectional shape of the nozzle is preferably circular as in the above-described embodiment, but it is not necessary to limit the cross-sectional shape to a circular shape. The configuration of the developing device to which the toner is replenished is arbitrary, and the present invention can be applied to an apparatus using a one-component developer.

FIG. 1 is a schematic diagram illustrating an overall configuration of a color image forming apparatus of the present invention. FIG. 2 is an explanatory diagram showing one image forming unit in the color image forming apparatus of FIG. 1 in an enlarged manner. FIG. 1 is an explanatory cross-sectional view illustrating an embodiment of a toner supply device of the present invention. 5 is a timing chart showing a control example of a powder pump and an air pump. It is explanatory drawing of the air supply path which shows other embodiment of this invention. 6 is a timing chart showing a control example of FIG. It is sectional drawing of the nozzle which shows other embodiment of this invention. FIG. 11 is an explanatory cross-sectional view of a toner replenishing device showing still another embodiment of the present invention.

Explanation of reference numerals

Reference Signs List 10 developing device 11 powder pump 20 toner container 30 air pump 40 nozzle 41 passage

Claims (17)

In a toner replenishing device for replenishing toner stored in a toner storage container to a developing device,
A tubular insertion / removal member to be inserted / removed into / from the toner storage container, and air supply means for supplying air into the toner storage container via the insertion / removal member; A toner passage that serves as an air passage through which air supplied to the inside passes and a toner passage through which toner discharged from the toner storage container passes.   2. The toner supply device according to claim 1, wherein an opening / closing unit that opens and closes the toner supply path is provided in a toner supply path from an air supply unit of the air supply unit to an entrance of the developing device. 3. To supply toner. In a toner replenishing device for replenishing toner stored in a toner storage container to a developing device,
A tubular insertion / removal member which is inserted into / removed from the toner storage container, air supply means for supplying air into the toner storage container via the insertion / removal member, and a developing device for supplying the toner stored in the toner storage container And a suction-type powder pump for replenishing the toner. The insertion / removal member has an air passage through which air supplied into the toner storage container passes, and a toner passage through which toner discharged from the toner storage container passes. A toner replenishing device comprising a passage that also serves as a toner supply device.   4. The toner supply device according to claim 3, wherein the powder pump also serves as an opening / closing unit that opens and closes a path provided in a toner supply path from an air supply unit of the air supply unit to an entrance of the developing device. A toner replenishing device.   5. The toner supply device according to claim 1, wherein when the air supply unit is operated, the toner supply path is closed by stopping the opening / closing unit or the powder pump. 6. Characteristic toner supply device.   6. The toner supply device according to claim 1, wherein the operation of the air supply unit is stopped when the toner supply path is opened by the operation of the opening / closing unit or the powder pump. A toner replenishing device characterized by the above-mentioned.   7. The toner replenishing device according to claim 3, wherein when the accumulated time of the toner replenishment time by the operation of the powder pump becomes equal to or longer than a predetermined time, the toner is supplied from the air supply unit to the toner storage container. A toner replenishing device, wherein air supply is performed.   The toner supply device according to claim 1, wherein an air supply unit and the toner supply unit are provided on the insertion / removal member, and the air supply unit is located above the toner supply unit. Characteristic toner supply device.   8. The toner supply device according to claim 1, wherein an air supply unit and the toner supply unit are provided on the insertion / removal member, and the toner supply unit is located above the air supply unit. 9. Characteristic toner supply device.   10. The toner replenishing device according to claim 1, wherein a diameter of an air supply unit from the air supply unit is smaller than a diameter of the toner replenishment unit.   The toner supply device according to claim 9, wherein the air supply from the air supply unit to the toner storage container is supplied from a lowermost position of the toner supply path.   9. The toner replenishing device according to claim 1, wherein the air supply from the air supply unit to the toner container is opened and closed by an air valve.   An image forming apparatus comprising the toner replenishing device according to claim 1.   14. The image forming apparatus according to claim 13, further comprising a plurality of toner containers, a toner replenishing device, and a developing device.   15. The image forming apparatus according to claim 14, wherein air is supplied to each toner container by a single air supply unit.   16. The image forming apparatus according to claim 15, wherein supply of air from the single air supply unit to each toner storage container is opened and closed by an air valve provided for each toner storage container.   17. The image forming apparatus according to claim 15, wherein control is performed such that two or more air supplies from the single air supply unit are not simultaneously supplied to the toner storage container.

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