JP4723742B2 - Developer transfer device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement of a developer transfer device used in an image forming apparatus such as an electrophotographic printer, a facsimile, or a copying machine using a two-component developer or a one-component developer. The present invention relates to an improvement in a developer transfer device that conveys the transferred toner after transfer to a developing device or a waste toner container, and a screw pump used therein.
[0002]
[Prior art]
In the image forming unit of the electrophotographic image forming apparatus, the electrostatic latent image formed on the photosensitive member is developed with toner supplied from the developing device to form a toner image, and the toner image is transferred onto a transfer sheet. The image is formed by fixing. When the amount of toner in the developing device decreases, toner is supplied into the developing device by the toner replenishing means. As the toner replenishing means, a toner cartridge having a relatively small capacity that is directly connected to the developing device is used, and a toner bottle having a relatively large capacity is located away from the developing device in terms of the layout of the device, particularly the developing device. It is often arranged at a lower position. There is also known a type capable of continuously performing a large amount of copy processing by using a toner bank as a large-capacity toner storing means regardless of whether inside or outside the apparatus main body.
In addition, a charging device, a developing device, a transfer device, a cleaning device, and the like are sequentially arranged around the photosensitive drum along the rotation direction. The cleaning device is a means for removing the toner remaining on the photoconductor after the toner image on the photoconductor drum is transferred onto the transfer paper by the transfer device. Recently, the cleaning device is removed by a cleaning device based on a request for toner recycling. Various toner recycling systems have been proposed and implemented in which the collected toner is re-supplied and reused without being discarded.
In any of the above cases, since the developing device and the toner supply source are separated from each other, it is necessary to transfer the toner by connecting with a pipe or the like between the supply source and the developing device.
[0003]
The following examples can be given as main methods for transferring the conventional developer and toner.
(1) A system in which a source and a destination are connected by a pipe, and developer and toner are transferred by a coil screw provided inside the pipe. This method is suitable for a straight conveyance path because of the nature of the coil screw, but has a drawback that it cannot be applied to a curved or bent path.
(2) A system in which the sending source and the sending destination are arranged in close proximity to each other, and are dropped and transferred mainly by gravity. This method has the disadvantages that the positional relationship between the source and destination is limited to a specific range, so that the degree of freedom in layout is low and the practicality is poor.
(3) A system in which a powder pump (uniaxial eccentric screw pump, commonly known as Mono pump) is used to transfer from a source to a destination arranged in a free positional relationship. This method is used as a means for supplying new toner and developer, a means for recycling collected toner, etc., and a flexible transfer tube can be used, so the positional relationship between the source and destination, the transfer route, etc. It has the advantage that the transfer route can be selected regardless of the obstacles inside. The powder pump allows the developer and toner to be transferred in the fixed rubber threaded female stator by the suction or discharge pressure generated by the rotation of the male threaded rotor, but the rotor and stator slide. Therefore, depending on certain conditions, the toner that has passed through the powder pump is rubbed and rarely aggregates, and when the toner aggregate is transferred as it is onto the image, there is a problem that an abnormal image is formed. . In particular, in a suction type powder pump used for sucking and transferring toner, if the rotor and the stator do not have a high sealing property, suction pressure is not generated and a conveying force cannot be obtained, so the amount of biting between the rotor and the stator is large. In many cases, the toner is more likely to be aggregated. Furthermore, when the usage environment is high temperature and high humidity or the original fluidity of the toner to be used is poor, the toner is likely to aggregate due to transfer by a powder pump, and the above problem is likely to occur.
[0004]
[Problems to be solved by the invention]
The present invention has been made in view of the above, and even when the powder pump is operated for a long time or when environmental conditions such as temperature and humidity are deteriorated, toner aggregates generated during the transfer of the developer and toner are displayed on the image. A developer transfer device capable of reliably preventing transfer to a toner is provided.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the invention of claim 1 is a powder pump comprising: a female screw type stator having a double pitch spiral groove therein; and a male screw type rotor rotatably fitted in the stator. Accordingly, a developer transfer device for transferring the developer to the developing apparatus, in the middle of the transport path from the powder pump to a developer supply port of the developing device, the particle diameter of toner to be replenished to the developing device In the developer transfer device provided with the mesh member to be regulated , the powder pump is a suction type screw pump provided in the vicinity of the developer supply port of the development device, and the mesh in the vicinity of the discharge port of the suction type screw pump. A drive shaft that is provided with a member and rotationally drives the suction type screw pump cleans the developer that comes in contact with and adheres to the mesh member by rotationally driving the drive shaft. That the this and features fitted with the cleaning member.
According to a second aspect of the present invention, in the developer transfer device according to the first aspect, the cleaning member is a thin plate member, an elastic member, or a brush .
A third aspect of the present invention is the developer transfer device according to the first or second aspect, further comprising a discharge case provided with the developer replenishing port, and the discharge case includes a residue remaining on the mesh member. A discharge port and a storage case are provided for discharging and storing the container .
According to a fourth aspect of the present invention , a developer is developed by a powder pump having a female screw type stator having a double pitch spiral groove therein and a male screw type rotor rotatably fitted in the stator. And a mesh member that regulates the particle size of toner supplied to the developing device in the middle of the transfer path from the powder pump to the developer supply port of the developing device. The developer transfer device is characterized by further comprising an air supply unit that blows air onto the mesh member to remove foreign matters remaining on the mesh member .
According to a fifth aspect of the present invention, in the developer transfer device according to the fourth aspect of the present invention, a means for controlling the operation of the air supply means and a means for controlling the drive of the powder pump are provided separately, and the air supply means is It is operated when the powder pump is stopped .
According to a sixth aspect of the present invention, in the developer transfer device according to the fourth aspect of the present invention, a means for controlling the operation of the air supply means and a means for controlling the drive of the powder pump are provided separately, and the air supply means is The powder pump is operated immediately after the drive is stopped .
According to a seventh aspect of the present invention, in the developer transfer device according to the fourth aspect, the powder pump is a discharge screw pump provided at a position distant from the development device, and the discharge screw pump discharges the discharge pump screw. The mesh member is provided in the vicinity of the mouth .
According to an eighth aspect of the present invention, in the developer transfer apparatus according to any one of the first to seventh aspects, the mesh member is provided in a plurality of stages .
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to embodiments shown in the accompanying drawings.
First, FIG. 1 is an exploded sectional view showing a configuration of a discharge type developer transfer device. Note that the developer refers to carrier or toner, or a mixture of carrier and toner.
Reference numeral 1 denotes a screw pump type powder pump, which has a female thread type stator 2 in which a double pitch spiral groove made of an elastic member such as rubber is formed on an inner peripheral surface, and is rotatably inserted into the stator 2. And a male threaded rotor 3 made of metal, resin or the like. The rotor 3 is connected to the shaft of the transfer screw 310 on the upstream side by a spring pin 12 or the like, and is driven to rotate when the transfer screw 310 is rotated. A discharge pressure is generated at the discharge port 6 by rotating the rotor.
The periphery of the stator 2 is covered with a holder 4 fixed to a side plate, and a gap 5 is provided between the inner peripheral surface of the holder 4 and the outer peripheral surface of the stator 2. The gap 5 communicates with a developer discharge port 6 on the downstream side of the rotor 3. The holder 4 is provided with an air supply port 7 leading to the gap 5, and the air supply port 7 is fitted with an air supply tube 622 from the air pump 600 of FIG. 1. Air from the air pump 600 is supplied from the air supply port 7 through the gap 5 to the discharge port 6, fluidizes the developer, and smoothly and reliably moves the developer in the direction of the arrow by the discharge pressure of the powder pump. Exhale.
2 and 3 are views of a suction type toner replenishing device. 1 except that the shaft 11 is not provided with a transfer screw and the holder 4 does not have an air supply port. If the rotor 3 and the stator 2 are the same as the discharge type powder pump 1, the shaft 11 is rotated in the opposite direction to that of the discharge type (or by using a rotor or stator that is reversely wound to the discharge type), suction pressure is generated at the suction port 6, and the toner sucked from here is sucked into the suction shaft 11. Exhale in the direction.
There is also the idea that the suction pressure can be secured by increasing the amount of biting between the stator 2 and the rotor 3, but as the amount of biting into the dark clouds increases, the resulting torque increases and the temperature rises and passes through the powder pump. The toner tends to aggregate. On the other hand, if the amount of biting is reduced, the suction / conveyance force is reduced, but it is better in terms of torque, temperature increase, and toner aggregation degree. By setting the amount of biting in an appropriate range, the maximum suction pressure can be efficiently secured. Furthermore, it is desirable to appropriately select the range of biting amount in consideration of the toner to be used, conditions such as the lift, transfer distance, required operating time, and usage environment.
[0007]
In the transfer device provided with the suction-type powder pump 1 shown in FIGS. 2 and 3, the nozzle 510 serving as a toner passage connecting the toner cartridge 400 to the powder pump 1 and the transfer tube 301 are hermetically sealed. The suction force generated by the operation of the body pump 1 is transmitted to the toner 450 in the toner cartridge 400 via the transfer tube 301 and the nozzle 510, so that the toner can be transferred. At this time, air is supplied into the toner in the toner cartridge 400 through the nozzle 510 by the air pump (air supply means) 600. After the toner 450 near the nozzle 510 is sucked by the powder pump 1, a cross-linking phenomenon (a void is formed in the lost toner portion) occurs in the cartridge, and the toner replenishment amount becomes unstable or the toner remaining amount in the toner container However, by supplying air to the inside of the toner cartridge, the toner can be agitated and fluidized, and the above-mentioned toner cross-linking phenomenon can be prevented. Alternatively, since the crosslinked toner can be broken by the supplied air, it is possible to stabilize the toner replenishment amount and reduce the remaining amount of toner in the container. At this time, as shown in FIG. 3, the toner cartridge 400 may be provided with an air permeable filter 440 on the upper portion of the toner storage member 410, and thereby the cartridge is reversed by the air supplied from the air pump 600. It serves to depressurize the rise of the inside to a positive pressure.
[0008]
The sucked toner falls into the developing device from a toner introduction hole (developer supply port) 23 provided in a part of the developing container 200, and when using the two-component development method, the supplied toner ( The sucked toner) is agitated and mixed with the developer in the developing device 200 to obtain a uniform agent concentration and an appropriate charge amount.
The transfer member 310 is made of a rubber material (ex. Polyurethane, nitrile, EPDM, silicon, etc.) or plastic material (polyethylene, nylon, etc.) having a tube shape with an inner diameter of about 4 to 7 and flexible and excellent in toner resistance. Is very effective.
The container holder 500 holds the protective case 401 of the toner cartridge 400. The protective case 401 is made of a material such as rigid paper, cardboard, or plastic, and has a structure in which the periphery of the bag-like toner storage member 410 is wrapped and a part thereof is engaged with the base member 420. The bag-like toner storage member 410 is made like origami by making a flexible sheet made of a resin or paper sheet (thickness of about 80 to 200 μm) such as polyethylene or nylon into a single layer or multiple layers. It is made into a sealed bag-like container shape with no air inflow or outflow.
The base member 420 includes a case 421 made of resin, paper or the like and a seal 422 made of sponge or the like. The nozzle 510 has a toner discharge hole 512 at the tip and a toner discharge path 513 at the shaft core. In a state where the toner cartridge 400 is set in the container holder, the nozzle 510 is inserted into the seal 422 of the cap member, and the seal 422 is in close contact with the nozzle 510 to prevent toner leakage from the toner cartridge to the outside of the apparatus.
The difference in structure between the powder pumps of FIG. 2 and FIG. 3 is whether air is not put into the toner cartridge 400 by the air pump 600 (FIG. 2) or air is put (FIG. 3). 2 is a toner replenishing device in which the volume of the cartridge is reduced as it is discharged from the toner cartridge 400, and the cartridge can be taken out in a completely crushed state after use.
[0009]
Next, FIG. 4 shows an embodiment of an apparatus for conveying toner only by air. The same parts as those in the above embodiment will be described with the same reference numerals. By supplying air from the air pump 600 to the cartridge 400 via the nozzle 510, the toner 450 in the cartridge is agitated, and at the same time, a force to exhaust the air and toner to the outside of the cartridge by the pressure increase in the cartridge works. . This becomes the toner conveying force of the present apparatus, and the toner is conveyed through the conveying tube 301 connected to the nozzle and into the developing device 200 via the joint 270. At this time, if the developing device 200 that is the transfer path and the transfer destination is hermetically sealed or has low air permeability, the pressure in the developing device 200 increases due to the air supplied simultaneously with the toner, and eventually the air is supplied to the cartridge. However, the toner is not conveyed. For this purpose, the developing device 200 is provided with an air vent filter 251 so as to prevent the above problems.
FIG. 5 shows an embodiment of the present invention corresponding to the view of the powder pump unit portion of the developer transfer device of FIG. 2 or FIG. 6 is a perspective sectional view of FIG. As shown in the figure, a mesh member 30 is attached to the 23 part of the path (developer supply port) until the toner discharged from the powder pump 1 is supplied into the developing device 200 in the powder pump unit. Only the agglomerated toner can be removed from the toner discharged from the pump 1. In general, since the toner has a particle size of about 5 to 20 μm, it is desirable to use a mesh member having a mesh size of about 30 to 150 μm.
As described above, since the mesh member 30 is attached in the developer supply port 23 in the discharge case 20 and all the toner is sorted by the mesh member 30, the aggregated toner and other foreign matters are removed from the developing device. Intrusion to the side can be prevented.
[0010]
FIG. 7 shows an embodiment in which a cleaning member 32 for preventing clogging of the mesh member 30 is attached to the drive shaft 11 of the rotor in the toner replenishing device of FIG.
The cleaning member 32 whose one end edge is fixed to the drive shaft 11 is slidably contacted with the mesh member 30 when the drive shaft 11 rotates, and the material and dimensions thereof so that the toner aggregate remaining on the mesh member 30 can be scraped off. Is set. The cleaning member 32 can be made of a resin mylar such as polyethylene or polyurethane, or an elastic member such as polyurethane rubber or chloroprene rubber in a sheet shape, so that an excellent cleaning effect can be obtained at low cost.
According to this embodiment, the aggregated toner or the like that accumulates on the mesh member 30 is removed by the cleaning member 32. Therefore, when the aggregated toner or the like is captured by the filter function of the mesh member 30, the aggregated toner is formed on the upper surface of the mesh member 30. Can be effectively prevented from accumulating and causing clogging.
FIG. 8 is a modified example of the embodiment of FIG. 5 like FIG. 7, but is characterized in that the cleaning member 32 is a brush. That is, the manufacturing member 32 made of a brush is implanted on the outer periphery of the drive shaft 11 so that the tip thereof can be in sliding contact with the mesh member 30.
Compared with the sheet-like elastic member of FIG. 7, the manufacturing member 32 can remove the aggregates clogged into the mesh member more effectively by the brush hair entering the mesh of the mesh member 30.
[0011]
9A, 9B, and 9C are cross-sectional views orthogonal to the drive shaft 11, of the discharge case 20 portion of the powder pump unit of FIG. An agglomerate storage case 35 is arranged in communication with the side of the discharge case 20. When the cleaning member 32 is driven to rotate by the rotation of the drive shaft 11, the toner aggregate on the mesh member 30 is scraped and stored in the newly provided aggregate storage case 35. The toner aggregate TG is scraped off by the cleaning member 32 in the order shown in FIGS. 9A, 9B, and 9C when the drive shaft 11 rotates in the direction of, and eventually the cleaning member 32 opens the discharge port 34. When it passes, it is discharged from the discharge port 34 into the storage case 35. Accordingly, it is possible to prevent foreign matters such as aggregated toner removed from the mesh member 30 from remaining in the discharge case 20 and causing clogging.
FIG. 10 shows an embodiment in which a toner aggregate removing unit is provided in a powder pump unit of a developer transfer device using a discharge type powder pump similar to that shown in FIG. By attaching the mesh member 30 in the vicinity of the powder pump discharge port (downstream side) as shown in the figure in the holder 4 of the stator 2 of the powder pump 1, the aggregated toner after passing through the powder pump can be removed. In the case of the present embodiment, since the mesh member 30 is attached in the vicinity of the discharge port 6, the mesh member 30 is less likely to be clogged by the toner discharged vigorously by the discharge pressure of the powder pump 1. Furthermore, the air pump 600 is connected to the air supply port 7, and the air and the aggregates attached to the mesh member 30 are blown off by the air supplied from the air pump 600 being blown into the case from the air supply port 7. Can do.
[0012]
11 (a), 11 (b) and 11 (c) are cross-sectional views orthogonal to the drive shaft 11 of the discharge case 20 portion of the powder pump unit as in the examples of FIGS.
11 (a) and 11 (b), an air supply port 24 is provided in the upper part of the discharge case 20 of the powder pump unit according to the embodiment of FIG. 5, and an air tube (air supply means) 600 (not shown) is used as an air tube. Air is blown from the air supply port 24 via 624, and the toner and aggregate remaining on the mesh member 30 are blown away to prevent clogging of the mesh member.
11C is different from FIGS. 11A and 11B in that the air supply port 24 is provided at the lower side of the side surface of the discharge case 20, and the air supply port 24 is closer to the mesh member 30. Since air is supplied from the lateral direction, the toner and aggregates on the mesh member 30 can be more effectively removed.
In the embodiment shown in FIGS. 11A, 11B, and 11C, the air pump and the air supply port 24 constitute a cleaning means.
A means for controlling the operation of the air pump 600 and a means for controlling the driving of the powder pump 1 are separately provided so that the air pump is operated when the screw pump is stopped (when no suction force is generated). By doing so, clogging of the mesh member 30 can be reliably prevented. In other words, the clogging of the mesh member due to the removal of the agglomerated toner for a long time is prevented at any time, and the performance of the developer transfer device can be maintained for a longer time.
Further, when the means for controlling the operation of the air pump 600 and the means for controlling the driving of the powder pump are provided separately, if the air pump is operated immediately after the driving of the powder pump is stopped, the powder Foreign matter remaining on the mesh member after the body pump is stopped can be removed to reliably prevent clogging of the mesh member. Therefore, clogging of the mesh member due to the long-time aggregation toner removing operation is prevented at any time, and the performance of the developer transfer device can be maintained for a longer time.
In each of the above embodiments, a plurality of mesh members may be provided. In this way, clogging of the mesh member due to the long-time aggregation toner removing operation is prevented, and the performance of the developer transfer device can be maintained for a long time.
[0013]
【The invention's effect】
According to the invention 請 Motomeko 1, the drive shaft of the suction-type screw pump is a powder pump, since mounting a cleaning member for cleaning the developer contact attached to the mesh member by the rotation of the drive shaft, Foreign matter on the mesh member can be removed to prevent clogging. For this reason, clogging of the mesh member due to a long-time aggregation toner removing operation is prevented as needed, and the performance of the developer transfer device can be maintained for a long time .
According to the invention of claim 2, since the cleaning member is a thin plate member, an elastic member, or a brush attached to the drive shaft of the suction type screw pump, the clogging of the mesh member can be surely prevented. For this reason, clogging of the mesh member due to a long-time aggregation toner removing operation is prevented as needed, and the performance of the developer transfer device can be maintained for a long time .
According to the invention of claim 3, the discharge case provided with the developer replenishing port is provided with the discharge port and the storage case for discharging and storing the residue remaining on the mesh member. the residue was removed, prolonged use by preventing the discharge path by the foreign matter remaining on the mesh member is closed, the performance of the developer transfer device can be further maintained for a long time.
According to the invention of claim 4, since the air supply means for removing the foreign matter remaining on the mesh member by blowing air onto the mesh member is provided, it is possible to reliably prevent clogging of the mesh member. For this reason, clogging of the mesh member due to a long-time aggregation toner removing operation is prevented as needed, and the performance of the developer transfer device can be maintained for a long time.
According to the invention of claim 5, the means for controlling the operation of the air supply means and the means for controlling the drive of the powder pump are provided separately, and the air supply means is operated when the powder pump is stopped. Therefore, clogging of the mesh member can be reliably prevented. Therefore, clogging of the mesh member due to the long-time aggregation toner removing operation is prevented at any time , and the performance of the developer transfer device can be maintained for a longer time.
[0014]
According to a sixth aspect of the present invention, the air supply means and the powder pump are separately controlled, and the air supply means is operated immediately after the powder pump is stopped. As a result, it is possible to reliably prevent clogging of the mesh member. Further, clogging of the mesh member due to long-time aggregation toner removal is prevented at any time, and the performance of the apparatus can be maintained for a longer time .
According to the invention of claim 7, the powder pump is a discharge screw pump provided at a position away from the developing device, and the mesh member is provided in the vicinity of the discharge port of the discharge screw pump. The aggregated toner generated by passing through the discharge type powder pump can be efficiently removed. Accordingly, it is possible to prevent abnormal images due to the transfer of the aggregated toner generated by passing through the discharge type powder pump onto the paper .
According to the invention of claim 8, since the mesh member is provided in a plurality of stages, clogging of the mesh member can be more effectively prevented. Therefore, clogging of the mesh member due to the removal of the aggregated toner for a long time is prevented, and the performance of the developer transfer device can be maintained for a longer time.
[Brief description of the drawings]
FIG. 1 is an exploded cross-sectional view illustrating a configuration of a discharge type developer transfer device.
FIG. 2 is an explanatory diagram of a suction type toner supply device.
FIG. 3 is an explanatory diagram of a suction-type toner supply device.
FIG. 4 is a diagram illustrating an embodiment of an apparatus that conveys toner using only air.
5 is an explanatory diagram of a powder pump unit portion of the developer transfer device of FIG. 2 or FIG. 3;
6 is a perspective view of FIG. 5. FIG.
FIG. 7 is a main part configuration diagram of a developer transfer device according to another embodiment of the present invention.
FIG. 8 is a main part configuration diagram of a developer transfer device according to another embodiment of the present invention.
FIG. 9 is a cross-sectional view showing the configuration and operation of a developer transfer device according to another embodiment of the present invention.
FIG. 10 is a diagram illustrating the configuration and operation of a developer transfer device according to another embodiment of the invention.
FIG. 11 is a diagram illustrating the configuration and operation of a developer transfer device according to another embodiment of the invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Powder pump, 2 internal thread type stator, 3 external thread type rotor, 4 holder, 5 clearance, 6 discharge port, 7 air supply port, 11 axis | shaft, 20 discharge case, 30 mesh member, 32 cleaning member, 32 cleaning member, 34 Discharge port, 600 air pump.

Claims (8)

A developer transfer device that transfers the developer to the developing device by a powder pump having a female screw type stator having a double pitch spiral groove therein and a male screw type rotor that is rotatably fitted in the stator. In the developer transfer device provided with a mesh member for regulating the particle size of the toner supplied to the developing device in the transfer path from the powder pump to the developer supply port of the developing device ,
The powder pump is a suction-type screw pump provided near the developer supply port of the developing device, and the mesh member is provided near the discharge port of the suction-type screw pump, and the suction-type screw pump is driven to rotate. A developer transfer device, wherein a cleaning member for cleaning the developer that comes in contact with and adheres to the mesh member when the drive shaft is rotationally driven is attached to the drive shaft . The developer transfer device according to claim 1 , wherein the cleaning member is a thin plate member, an elastic member, or a brush . A discharge case provided with the developer replenishing port, wherein the discharge case is provided with a discharge port and a storage case for discharging and storing the residue remaining on the mesh member; The developer transfer device according to claim 1 or 2 . A developer transfer device that transfers the developer to the developing device by a powder pump having a female screw type stator having a double pitch spiral groove therein and a male screw type rotor that is rotatably fitted in the stator. In the developer transfer device provided with a mesh member for regulating the particle size of the toner supplied to the developing device in the transfer path from the powder pump to the developer supply port of the developing device,
A developer transfer device comprising air supply means for blowing air onto the mesh member to remove foreign matter remaining on the mesh member . The means for controlling the operation of the air supply means and the means for controlling the drive of the powder pump are separately provided, and the air supply means is operated when the powder pump is stopped . Developer transfer device. 5. The apparatus according to claim 4 , wherein means for controlling the operation of the air supply means and means for controlling the drive of the powder pump are separately provided, and the air supply means is operated immediately after the drive of the powder pump is stopped. The developer transfer device as described. 5. The powder pump is a discharge screw pump provided at a position away from the developing device, and the mesh member is provided in the vicinity of a discharge port of the discharge screw pump. The developer transfer device according to 1. The developer transfer device according to claim 1, wherein a plurality of mesh members are provided .

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