EP1552347A2

EP1552347A2 - Method and device for the transport of toner material from a reservoir

Info

Publication number: EP1552347A2
Application number: EP03735451A
Authority: EP
Inventors: Bernd Schoch; Ursula SCHÄFER; Karl Zappe
Original assignee: Oce Printing Systems GmbH and Co KG
Current assignee: Canon Production Printing Germany GmbH and Co KG
Priority date: 2002-05-24
Filing date: 2003-05-23
Publication date: 2005-07-13
Anticipated expiration: 2023-05-23
Also published as: WO2003100530A2; US20060024101A1; DE10223231A1; WO2003100530A3; US7333756B2; DE50310621D1; EP1552347B1

Abstract

The invention relates to a method and device for the transport of toner material (12) from a container (16). A discharge opening on the container (16) is provided with toner material (12) which is transported away from the discharge area by means of an air flow. Air is supplied into the container (16) through at least one air-permeable section in a container wall. The invention further relates to a tubular line (132) for the transport of toner material (12) and a sealing element for sealing a reservoir container (16) containing toner material.

Description

description

Method and device for conveying toner material from a storage container

The invention relates to a method and a device for conveying toner material from a storage container, in which toner material is conveyed away from a removal opening of the container by an air flow. The invention further relates to a tubular line for conveying toner material and a closure device for closing a storage container, by means of which a simple removal of toner material from the storage container is possible.

In electrophotographic printers or copiers, a latent charge image is generated on a light-sensitive photoconductor material, a photoconductor drum or a photoconductor belt. This charge image is then colored with electrically charged toner in a developer station of the printer or copier. The colored toner image is then applied to a carrier material, e.g. Paper, transferred and fixed on it.

A one-component developer or a two-component developer is used to develop the latent charge image in the developer station. The one-component developer contains only toner particles; the two-component developer contains a mixture of toner particles and carrier particles. At the two-component developer, the toner particles are electrically charged by movements of the two-component developer mixture. In the one-component developer, the toner particles are charged by transporting a charge, for example from a carrier roller. The amount of toner required to generate the toner image must be fed to the developer station in order to be able to generate further toner images. In known printers or copiers, an intermediate store for toner material is provided near the developer station, from which toner material is conveyed into the developer station as needed or according to consumption.

In known printers or copiers, the intermediate store is filled with toner material from handy toner transport containers through an opening directly into the storage container or conveyed from a remote transport container into the intermediate store by a transport system. The buffer near the developer station has a fill level sensor in known printers or copiers. With a minimum fill level, toner material must be fed from the toner transport container to the buffer. This is done e.g. by emptying a transport container into the intermediate storage. In other known arrangements are closed with

Containers filled with toner material in the form of bottles or cartridges are adapted to an opening in the intermediate store. The bottle or cartridge is opened by pulling a slide and / or tearing open a tab, as a result of which the toner material can fall into the storage container.

However, with these solutions for refilling toner material into the intermediate store, there is a high risk of contamination for an operator and the surroundings of the intermediate store when filling in the toner material and when removing the emptied transport container. A low weight and a small size of the bottles and / or 'cartridges allows simple handling and safe handling when refilling the intermediate storage, but is associated with high toner consumption frequent refilling of the storage container necessary, which results in long machine downtimes and the operator is heavily used.

From documents US-A-4, 990, 964 and US-A-5, 074, 342 a toner container and a device for the contamination-free replacement of such a toner container in a toner conveying device of a printer or copier are known. If required, toner material is transported from a toner storage container located away from the developer station with the aid of suction air via a hose into the buffer store. A vertically movable suction nozzle dips through an opening in the top of the toner container and sucks out toner material. A special shape of the toner supply container and a vibrator on the side ensure that the container is almost completely emptied. To replace the storage container, the suction nozzle is pulled out of the container. The opening in the toner reservoir is always at the top, which prevents toner spillage. However, the delivery rate is heavily dependent on the level in the toner reservoir. With a reduction in the fill level, the delivery capacity of toner material also decreases, so that the printing process is interrupted when the toner fill level in the reservoir is low and the toner requirement in the developer station is high at the same time. The vibrator also causes disturbing noises.

From the document US-A-5, 915,154 and DE 196 52 860 AI an apparatus for conveying toner material from a storage container by means of a suction-pressure unit is known, which protrudes into the storage container. With the help of the suction-pressure unit, toner material is mixed with gas, so that the toner material to be sucked in is mixed into a powder-gas mixture, causing the fine powder to be sucked in Toner material from the reservoir is facilitated. However, this known device also has the problem that as the fill level in the storage container decreases, the conveying capacity decreases and the interruption in the printing process already described occurs as a result of insufficient conveyance of toner material.

From document US-A-5,884, 126 a device for conveying toner material is known, in which toner material is discharged from a storage container onto an inclined plane. The surface of the inclined plane contains porous elements through which air penetrates from below through the surface to the toner material and air permeates the toner material, thereby forming a liquid-like mixture of toner material and air. This mixture flows downwards into a toner buffer on the inclined plane. With such a known device, however, toner material can only be transported to lower positions, it also being necessary with this type of transport to provide further means to prevent contamination of the printer or copier during the transport of the toner material.

From document US-A-5, 727, 607 a device for removing toner material from a storage container is known. In this known device, air is forced into the toner reservoir by means of positive pressure through air-permeable areas of the removal device, whereby a toner-air mixture is created in the toner reservoir. The toner-air mixture falls down through a removal opening from the storage container into a collecting device.

The object of the invention is to provide a simple method and a simple arrangement for conveying toner material specify a container in which the container is almost completely emptied even when the toner material has solidified. Furthermore, a tubular line for transporting toner material and a closure device for closing a toner storage container are to be specified, from which the removal of toner material is easily possible.

The object is achieved for a method for conveying toner material from a container by the features of patent claim 1 and for a device for conveying toner material with the features of patent claim 12. Furthermore, the object is achieved by a tubular line for transporting toner material with the features of claim 13 and by a device for

Closing a toner reservoir with the features of claim 19 solved. Advantageous refinements of the invention are specified in the dependent claims.

In the method with the features of claim 1, a container arrangement contains toner material which is removed from the container arrangement via a removal opening. The toner material is conveyed away from the removal opening by means of a tubular line connected at least to the removal opening. The toner material is transported through an air flow in the line. The air flow in the line creates a negative pressure at the discharge opening. The container arrangement contains at least one air-permeable area through which air flows into the container arrangement when a negative pressure is present.

The inflowing air creates a toner material-air mixture in at least one section of the container arrangement. mixed, which has liquid-like properties and which is therefore flowable. Such a liquid-like toner material-air mixture is also referred to as a fluidized toner material. This makes the toner material flowable and easier to convey. The toner material fluidized by the method according to the invention is very easy to convey from the container and can also be easily transported further in the printer or copier via the line connected to the removal opening. The fluidized toner material can simply be sucked off without toner swelling or toner deposits being formed in the container. Even solidified toner material, such as is present in the container after long periods of inactivity of the printer or copier, can be conveyed out of the container with the method according to the invention as easily as loose toner material.

In a development of the invention, the air-permeable section is arranged in the vicinity of the removal opening. As a result, the toner material in particular is permeated with air, which is present in the vicinity of the removal opening and is next sucked off through the removal opening. This ensures that the toner material to be transported and conveyed through the removal opening is fluidized and can easily flow through the removal opening.

In another development of the invention, the removal opening is arranged in a lower section of the container. This allows the toner material to slide out of an upper section of the container for removal by gravity towards and through the removal opening. It is also advantageous to transport the toner material to several developer stations using the line. By dosing the amount of air flowing past the removal opening, the amount of toner material to be conveyed can easily be set.

In another development of the invention, the container walls are arranged in a funnel shape at least in the vicinity of the removal opening. The toner material can thereby be almost completely conveyed out of the container. The toner material slides along the funnel-shaped container walls to the removal opening. There is no residue of toner in the container.

In a further advantageous embodiment of the invention, the air-permeable sections of the container wall are sealed airtight to the environment. Ambient air can be supplied to the isolated sections via a metering nozzle. As a result, the amount of air with which the toner material-air mixture is formed can be easily adjusted.

The method according to the invention can be carried out particularly easily if the air-permeable sections contain sintered material made of steel, iron and / or bronze. Alternatively or additionally, the air-permeable sections can contain a sieve or a filter medium. The air-permeable sections can thus be made easily toner-tight and air-permeable, while they are simple in construction and inexpensive materials are used.

A device according to the invention for conveying toner material has at least one container arrangement which contains toner material which is conveyed to the container arrangement via a device. opening is removable. The toner material can be conveyed away from the removal opening with the aid of a tubular line connected at least to the removal opening. An air flow is generated in the line, through which the toner material can be transported through the line. The air flow creates a negative pressure at the removal opening. The container arrangement has at least one air-permeable area through which air flows into the container arrangement when the negative pressure is present. With the help of the air flowing into the container arrangement, a toner material-air mixture is generated from the toner material present in the container. This toner material-air mixture is flowable. The flowable mixture is particularly easy to convey and transport. This makes it particularly easy to transport from the storage container to a developer station or to several developer stations.

A tubular line for transporting toner material according to the invention contains a first tubular element, the wall of which is at least partially permeable to air. Furthermore, the tubular line contains a second tubular element, in the interior of which the first tubular element is arranged. The second tubular element is essentially airtight. As a result, a flowable toner material-air mixture can be produced in the first tubular with toner material that is introduced into the first tubular element with the aid of compressed air that is introduced between the first and second tubular elements. Deposits of toner material in the first tubular element are prevented. Such a tubular line according to the invention can also be used to distribute the toner material to several developer stations of the printer or copier. Also bends on such a tubular line no toner material, which prevents clogging of the lines. With the help of such a tubular line, toner material can be transported particularly easily, particularly in a printer or copier.

It is advantageous if there is a distance between the outer wall of the first tubular element and the inner wall of the second tubular element in which at least one spacer is arranged. This ensures that the air introduced can flow through the first tubular element evenly along its length and that there are no areas in the first tubular element in which toner material is deposited.

In a device for closing a toner supply container, at least a section of the container wall is arranged obliquely towards the removal opening. A closure element is arranged in the container, which lies in a first position on the container wall near the removal opening in such a way that it closes the container towards the removal opening. In a second position of the closure element, there is a gap between the oblique container wall and the closure element. Toner material can be removed from the toner reservoir through this gap. The toner storage container can be easily closed with this device according to the invention, which prevents contamination from escaping toner when the storage container is removed. This device according to the invention can also be used to insert containers closed with the closure element into the printer or copier without toner material escaping. Additional closure elements, such as pull tabs or screw cap are necessary in the inventive device either for transporting ^'of the container or for insertion of the container. In a further development of this device, the closure element is pressed against the inside of the oblique container wall by means of a spring force. Due to the spring force, the removal opening of the container can be closed very easily. The container can then only be opened by moving the closure element against the spring force. It is also ensured that the spring force pushes the closure element back into the first position in which the removal opening of the container is closed when the storage container is removed from the printer or copier.

It is advantageous if the container wall is conical towards the removal opening and if the closure element has essentially the same conicity of at least a portion of the conical container wall. As a result, the removal opening of the container can be closed particularly easily by the closure element, since the closure element closes the container on a circumferential surface.

In another development of the invention, the closure element has an opening towards the removal opening of the container, through which compressed air can be fed into the interior of the closure element. The closure element has porous sections towards the interior of the toner reservoir through which the compressed air supplied flows into the interior of the reservoir. The toner material in the toner container is at least close to the

Closure element interspersed with air, creating a flowable toner material-air mixture. As a result, the toner material can flow past the closure element particularly easily through the gap. It is also achieved that the container is almost completely removed. can be emptied. Toner deposits or toner changes in the container cannot form even after prolonged downtimes of the printer or copier, since the flowable toner material-air mixture is formed from the toner material with the aid of the compressed air supplied.

In one embodiment of this development, there is a compressed air connection element which is connected in an airtight manner to the closure element in the operating state and presses the closure element into the second position.

As a result, when the container is inserted, the compressed air connection of the closure element can be established at the same time and the closure element can be pressed into the second position. Time-consuming operating procedures when inserting the storage container are not necessary.

The air-permeable sections are also suitable for a gas such as e.g. Let nitrogen, oxygen or a noble gas flow through, in which case a corresponding toner material-gas mixture is formed. However, air is currently frequently used as an inexpensive gas. To simplify the present application, the invention is described using air as a gas. However, the invention can also be carried out with any other gas.

Further features and advantages of the invention will become apparent from the following description, which in connection with the accompanying drawings explains the invention using exemplary embodiments. Show it:

FIG. 1 shows the schematic structure of a toner delivery system in a printer or copier, FIG. 2 shows the schematic structure of a second toner delivery system,

FIG. 3 shows an arrangement for conveying toner material out of a container,

FIG. 4 shows a second arrangement for conveying toner material from a container,

FIG. 5 shows a third arrangement for conveying toner material out of a container,

FIG. 6 shows an alternative embodiment to the arrangement according to FIG. 5,

FIG. 7 shows a further alternative embodiment to the arrangement shown in FIG. 5,

FIG. 8 shows the cross section of a tubular line for conveying toner material,

FIG. 9 shows an arrangement for conveying toner material from a container into several developer stations,

10 shows a container with a closure device, into which compressed air is fed with the aid of a compressed air supply, and

11 shows the container according to FIG. 10, with the closure element in a second position

Removal of toner material is arranged.

In Figure 1, a toner delivery system 10 of a printer or copier is shown. The toner delivery system 10 is used to feed toner material 12 into a developer station. tion 14. The toner material 12 is fed to the printer or copier, not shown, through a storage container 16 in which the toner material 12 is contained. An opening 18 serves for the removal of toner material 12. It is shown in a second, lower position, as will be explained further below. A closure device 20 is connected to the toner container 16 in a toner-tight manner in such a way that toner material 12 slips out of the storage container 16 into the closure device 20.

The closure device 20 contains a funnel 22, into which the toner material 12 slips out of the storage container 16. The funnel 22 has a funnel outlet 24 which is connected to a pipe system 26 in an airtight and toner-tight manner. The tube system 26 connects the funnel outlet 24 to an intermediate store 2, 8, which is arranged in the vicinity of the developer station 14 and is temporarily stored in the toner material 12 for further transport to the developer station 14. The intermediate store 28 contains a stirring bar 30, a fill level sensor 32 and a metering device 34 which contains a paddle wheel. A toner conveying pipe 36 having a toner conveying spiral 38 connects the latch 28 with the developer station 14 and delivers as needed toner material 12 from the intermediate memory 28, 14 to the developer station by means of the metering device ^'34 and / or the conveying pipe 36, which shown with a non each Drive device are connected, the amount of toner material 12 conveyed into the developer station 14 is adjusted and metered.

The stirrer 30 mixes the toner material 12 in the intermediate store 28. The intermediate store 28 is airtight, the airtight space of the intermediate store 28 being connected to a central vacuum line 44 via a pipe system 40 which contains a control valve 42. that is. A vacuum in the central vacuum line 44 is generated by a vacuum blower 46. The pipe system 40 is connected to an upper section of the intermediate store 28. A filter 50 is arranged below the connection point 48 towards the closed space. The intermediate store 28 is connected to the pipe system 26 below this filter 50. The control valve 42 regulates the negative pressure in the pipe system 40 and in the intermediate store 28 and in the pipe system 26 connected to it. This negative pressure ensures that toner material 12 is transported from the funnel outlet 24 of the closure device 20 into the space of the intermediate store 28 via the pipe system 26.

The amount of the conveyed toner material 12 can be adjusted in many positions by means of the control valve 42. However, in other exemplary embodiments, the control valve 42 can also be operated in two-point operation, the amount of toner material 12 then dependent on the negative pressure in the pipe system 44 and the opening time of the control valve 42. Funnel 22 has porous, air-permeable funnel walls. Due to the negative pressure at the funnel outlet 24, air is sucked into the funnel 22 from the closure device 20 through the funnel walls. As a result, a toner-air mixture is generated in the hopper 22, which has liquid-like, so-called fluid properties. Air is supplied to this via an opening 52 in the closure device 20, which air is drawn into the funnel 20 with the aid of the vacuum. The air supplied through the opening 52 can be controlled via a valve (not shown). The funnel outlet 24 is also connected to a pipe system 54 with a control valve 56, via which ambient air can be supplied to the pipe system 26. A check valve (not shown) is also contained in the control valve 56. - Solder that prevents leakage of toner material even in the case of unfavorable pressure conditions in the tube systems 44, 26, 54. The amount of toner material 12 which is conveyed from the container 16 into the intermediate store 28 can be regulated via the control valve 56.

The control valves 42 and 56 are electrically driven valves. With the help of the control valve 42, the vacuum conditions in the intermediate store 28 and in the pipe system 26 can be set exactly. The toner transport from the storage container 16 into the buffer store 28 is regulated in accordance with the signal from the fill level sensor 32. As already mentioned, the control valve 42 and the control valve 56 serve as control elements of the control. These suction valves 42, 56 are used to set the suction air required for the transport of the toner. The toner material 12 emerging from the funnel outlet 24 is entrained by the air flow in the pipe system 26, 54 and transported to the buffer store 28. The filter 50 in the intermediate storage 28 prevents the further transport of the toner material 12 into the pipe system 40.

After the valve 42 is closed, the clean air side of the filter 50 is vented to ambient pressure. As a result, there is at least a brief vacuum in the intermediate store 28 compared to the ambient pressure in the pipe system 40. During the subsequent pressure equalization between the pipe system 40 and the intermediate store, air flows from the pipe system 40 through the filter 50 into the intermediate store 28. The air flow during this pressure equalization is related to the air flow Sucking the toner material in the opposite direction. Toner material 12 attached to the filter 50 is released from the filter 50 by the air flow during pressure equalization and falls into the intermediate store 28. Any possible leakage of toner material 12 through the pipe system 54 is prevented by the Check valve 56 prevented. As already mentioned, the toner material 12 is transported from the buffer store 28 into the developer station 15 with the aid of a conveyor tube 36. The conveying tube 36 projects into the * developer station 14 at one end and has 57 wide openings on this bottom side through which the toner material 12 falls from the conveying tube 36 into the developer station 14.

The conveying spiral 38 contained in the conveying tube 36 has an incline so that it transports toner material 12 in the conveying tube 36 from the intermediate storage 28 to the developer station 14 in a manner similar to that in a screw conveying tube. As already mentioned, the conveyor spiral 38 is driven with the aid of a drive unit. The metering device 34 contains a roller similar to a paddle wheel, which is arranged between the intermediate store 28 and the delivery pipe. Such a metering device 34 is also referred to as a cellular wheel sluice. The paddle wheel-like roller seals the intermediate store 28 to the delivery pipe 36 in an almost airtight manner, so that air is sucked out of the pipe system 26 by means of the vacuum blower 46 when a negative pressure is generated. The paddle wheel-like roller is preferably driven in synchronism with the conveyor spiral 38, whereby upon rotation of the paddle wheel-like roller, which is also referred to as a cellular wheel, toner material falls from the intermediate store 28 into the paddle chambers or cells and is transported by the rotation downward to the conveying tube 36 ,

The conveying tube 36 has an opening below the metering device 34 at the top to the metering device 34, so that the toner material 12 falls downward out of the cells into the conveying tube 36. The stirring bar 30 in the interior of the intermediate store 28 is driven with the aid of a drive unit (not shown) and prevented by a Rotation forms a cave or change in the toner material 12 of the buffer store 28.

Figure 2 shows the schematic structure of a second To- nerfördersystems similar to the ^'toner conveying system 10 of Figure 1. Identical elements have the same reference numerals.

The storage container 16 contains toner material 12 which is conveyed into a developer station 14 with the aid of the schematically illustrated toner conveying system. A coupling device 58 is arranged on the storage container 16 and connects the storage container 16 to a discharge device 60. The coupling device 10 and the discharge device 60 are contained in the closure device 20. The structure of the discharge device 60 is explained in more detail below in connection with FIG. 3. With the aid of the discharge device 60, the toner material is fed from the storage container 16 to a T-shaped pipe section 64 which is further connected on one side to a check valve 62 and on the other side to a tubular toner delivery line 66. The toner material 12 supplied to the pipe section 64 is suctioned off via the toner delivery line 66.

A vacuum blower 84 creates a vacuum in a central vacuum line 44. A fine filter 82 and a coarse filter 78 are arranged between the vacuum line 44 and the vacuum blower 84. This prevents toner material 12 from being sucked into the blower 84. Furthermore, a residual toner container 80 is provided, in which the toner material 12 filtered out by the coarse filter 78 is collected. Further devices (not shown) of the printer or copier to be supplied with negative pressure are connected to the negative pressure line 44, such as, for example, another toner delivery system. The shown in Figure 2 The toner delivery system is connected to the central vacuum line 44 via a control valve 74. The control valve 74 has a ventilation device which serves to supply air to the tubular line 77 as required, in order to generate an overpressure in this tubular line 77 with respect to the vacuum line 44, for example at the level of the ambient pressure. A separating device 72 is provided on the upper side of the intermediate store 28 towards the tubular line 77. The separating device 72 can contain, for example, a filter medium and serves to separate the toner material 12 from a supplied toner material-air mixture.

The tubular line 66 is connected to the intermediate store 28 below the separating device 72. With the help of the negative pressure, a toner material-air mixture is generated through the tubular line 66, a so-called carrier air flow for transporting the toner material 12 supplied to the pipe section 64 being generated via the check valve 62. With the aid of the separating device 72, the toner material 12 is thus separated from the carrier air. The toner material is fed from the intermediate store 28 to the developer station 14 via a metering device 70 via an essentially air-tight lock 68, for example via a so-called cellular wheel lock. As already described in connection with FIG. 1, the tubular line 77 is repeatedly opened briefly to the ambient air with the aid of the ventilation element 76, so that the air flow in the tubular line 77 is briefly reversed and air via the ventilation element 76 through the tubular line 77 and flows through the separating device 72 to the buffer store 28. This toner material 12 which is adhered in the separator 72 to partition members is detached from the latter and fall within the intermediate _S PEICHER 28. This ensures that subsequently again a sufficiently large air flow can flow through the separating device 72 in order to generate the carrier air flow in the tubular line 66 for the transport of toner material 12. In a first operating phase, vacuum is drawn in via the vacuum line 44 via the control valve 74, as a result of which the carrier air flow for conveying toner material 12 is generated in the tubular line 66.

In a second operating phase, the control valve 74 is closed and the ventilation element 76 is opened. Due to the previously created negative pressure, a negative pressure is present in the pipe system 77 and the elements connected to it, such as the intermediate store 28 and the tubular line 66, with respect to the ventilation air supplied. As a result, an air flow is generated through the tubular line 77 to the intermediate store 28. As a result, air flows through the separating device 72 at least briefly in the opposite direction, as in the first operating phase. As a result, toner material 12, which adheres to separating elements, in particular to filter elements, is detached therefrom and falls into the intermediate store 28.

The amount of delivered toner can be dosed both with the aid of the discharge device 60 and with the aid of the control valve 74. The amount of toner to be conveyed, which is supplied to the tubular element 64, must be controlled in such a way that there is a sufficiently large air flow in the tubular line 66 in order to prevent blockage of the tubular line 66.

In Figure 3, the closure device 20 with the discharge device 60 is shown in a sectional view. As already explained in connection with FIGS. 1 and 2, the storage container 16 is with the opening facing downwards Coupling device 58 arranged in the printer or copier. The toner material 12 slips out of the storage container 16 through the coupling device 58 into the discharge device 60. The discharge device 60 contains a funnel 88, the funnel outlet of which opens into the pipe section 64. At the funnel outlet, a metering nozzle 90 is arranged towards the pipe section 64. The discharge device 60 is connected in an airtight manner to the storage container 16 via the coupling device 58.

The funnel walls of funnel 88 contain air-permeable sections. The discharge device 60 is closed off from the ambient air with the aid of airtight walls 92, 94. Ambient air can enter the interior of the discharge device 60 via supply air openings 96, 98

Follow the funnel walls. As already described in connection with FIGS. 1 and 2, a vacuum p _{σ is} generated in the tubular line 66 with the aid of a vacuum blower 84. A metering nozzle 100 for metering the carrier air flow V _{τ is} arranged toward the check valve 62, not shown in FIG.

The vacuum pu generates not only the air flow V _τ but also a metering air flow V _D. The metering air flow V _D and the carrier air flow V _τ are determined by the openings of the metering nozzles 90, 100 and by the negative pressure p _D and can also be controlled by the supply air openings 96, 98, on which, for example, a supply air throttle is arranged. The air of the metering air flow V _D thus flows in through the supply air openings 96, 98. This supply air flow penetrates into the toner material 12 through the air-permeable funnel walls, which contain, for example, sintered glass or sintered metal, the toner material 12 is penetrated by the metering air through this metering air flow V _D , so that a toner material / air mixture is formed. The dosing air thereby fluidizes the toner material 12. The toner material-air mixture is free-flowing, in contrast to the powdery toner material 12, whereby it can easily flow through the Dosierluftdüse 90 in the supporting air stream V _τ and Ström further in Tragluft- V _τ through the tubular conduit 66 can be transported.

In other embodiments, both the as pressed by the dispensing nozzle 90 in the Tragluftström V _τ toner material-air mixture formed may be applied p is ₀ also at the air inlets 96, 98, an overpressure relative to the ambient pressure, thereby.

In FIG. 4, as an alternative to the embodiment according to FIG. 3, a second arrangement for conveying toner material 12 from a container 16 is shown schematically, in which the toner material 12 is removed from the storage container 16 at the top. The storage container 16 is connected to a discharge device 102 via the coupling device 58, similar to the device according to FIG. 3. The discharge device 102 is connected to the container 16 in an airtight manner via the coupling element 58. Like the discharge device 60 according to FIG. 3, the discharge device 102 has funnel-shaped inner walls 104, 106 which contain a porous, air-permeable material. The outer wall 108 seals off the discharge device 102 from the surroundings in an airtight manner. An immersion tube 110 is passed through an overhead opening 112 of the storage container 16 into a lower section with funnel-shaped inner walls 104, 106 through the toner material 12. Via this immersion tube 110, a toner material-air mixture is conveyed or sucked through the tubular line 66 via a vacuum pu. The tubular line 66 and the dip tube 110 are each connected to the T-shaped pipe section 64. Due to the negative pressure in the immersion tube 110, toner material 12 is conveyed upward from the funnel-shaped section of the discharge device 102 into the tubular line 66. In the same way as already described in connection with FIG. 3, a carrier air stream is generated in the pipe section 64 via the metering nozzle 100. In the outer wall of the discharge device 102, supply air openings 114, 116 are provided, through which ambient air is supplied to generate a metering air flow 118. The inflowing ambient air penetrates through the inner walls 104, 106 of the discharge device 102 into the toner material 12 at least in the vicinity of the discharge device 102 and forms a toner material-air mixture. As already described, the toner material 12 is thereby fluidized and can flow upwards through the immersion tube 110 to the tube 64. Just as already described in connection with FIG. 3, supply air throttles can also be arranged on the supply air openings 114, 116. Furthermore, it is possible to provide only one supply air opening 114, 116. The supply air restrictors can be designed as an orifice or as a control valve.

In a first operating state in which no toner material is conveyed out of the container 16, ambient pressure is present between the inner walls 104, 106 and the outer wall 108. The volume between the inner walls 104, 106 and the outer wall 108 forms a buffer volume. With the aid of the additional air from the buffer volume, the metering air flow 118 is briefly increased in a second operating state, in particular at the start of toner delivery, as a result of which a large amount of the toner material / air mixture is generated relatively quickly in the region of the discharge device 102. In further operation, the dosing air flow 118 is limited by the inflowing amount of air flowing in through the supply air openings 114, 116. This has a favorable effect on the conveying properties of the toner material 12, particularly in the case of non-continuous operation of the toner delivery.

The inner walls 104, 106, 88 can have a funnel and / or channel shape both in the discharge device 60 according to FIG. 3 and in the discharge device 102 according to FIG. 4, or else form an inclined plane.

Arrangements with horizontally arranged air-permeable inner walls are also possible, with these arrangements at least the discharge device 60, 102 not being completely emptied of toner material 12. The inner walls 88, 104, 106 contain e.g. Sintered metal, sintered plastic, sieves and / or air filters and are therefore toner-tight and air-permeable. It is advantageous if these materials have a constant flow resistance. In other exemplary embodiments, the discharge device 60, 102 is part of the toner reservoir 16.

In other advantageous exemplary embodiments, the metering air nozzle 90 is equipped with a closure device which only opens when a negative pressure is set. The arrangement described for conveying toner material 12 is suitable for conveying pure toner material 12, for conveying a two-component mixture of toner material 12 and carrier particles and for conveying carrier particles for a two-component mixture.

FIG. 5 shows the schematic structure of a third arrangement for conveying toner material 12 from a storage container 16 with the aid of a discharge device 136. The discharge device 136 is via a Coupling device 58 hermetically connected to the reservoir 16. The discharge device 136 contains a horizontally arranged air-permeable plate 120, for example a porous metal plate, in the middle of which a funnel-shaped depression 88 is arranged. The toner material 12 from the container 16 can slide through an opening arranged at the bottom of the container 16 through the coupling device 58 into the discharge device 136 into the funnel 88. Compressed air, which has been generated by a compressed air generation unit, not shown, is fed into a pressure chamber 122 below the metal plate 120 via a pipe system 134.

The amount of compressed air supplied is set using a throttle 124. The pressure in the pipe system 134 after the throttle 124 is determined with the aid of a pressure sensor 128. The pressure in the compressed air supply line of the pipe system 134 is determined with the aid of a second pressure sensor 130. The compressed air supplied penetrates through the air-permeable plate 120 and through air-permeable walls of the funnel-shaped depression 88 into the toner material 12 and forms, together with the toner material 12, a toner material-air mixture which is flowable. The flowable toner material-air mixture is forced through the funnel outlet into a tubular line 132 by gravity and with the aid of a metering delivery flow generated by the compressed air. The tubular line 132 has an inner tubular element 138, which contains toner-tight and air-permeable elements, and an outer tubular, air-tight element 140. The compressed air supply line 134 becomes a space between the inner tubular element 138 and the outer one via a second throttle 126 tubular element 140 of the tubular line 132 is fed with compressed air. This compressed air penetrates the entire length of line 132 through the interior tubular element 138 and continuously forms a toner material-air mixture inside the tubular element 138. Thus, the toner material 12 is placed in a fluid state along the entire length of the line 132. In the pressure chamber 122 arranged below the porous metal plate 120 and next to the funnel-shaped depression 88, a pressure of about 20 millibars above ambient pressure is set by the throttle 124 when the reservoir 16 is full. The space between the first tubular element 138 and the second tubular element 140 of the tubular line 132 is preset by the throttle 126 to approximately 10 millibars above ambient pressure.

As already mentioned, the pressure sensor 128 determines the pressure in the pressure chamber 122. As the fill level of the toner material 12 in the reservoir 16 decreases, the pressure in the pressure chamber 122 decreases continuously with the throttle setting of the throttle 124 remaining the same. The throttle 124 only limits the flow rate. With

The pressure of the supplied compressed air is determined with the aid of the pressure sensor 130. The measurement results of the pressure sensor 128 are compared with the aid of the measurement results of the pressure sensor 130, as a result of which fluctuations in the pressure conditions in the supply air are compensated for when determining the fill level present in the storage container 16. The pressure fluctuations in the supply air lead to proportional pressure fluctuations in the pressure sensor 128, which are independent of the fill level. To determine the fill level in the storage container 16, the difference can be formed from the measured values of the pressure sensors 130 and 128, this pressure difference being a measure of the fill level in the storage container 16. A specific value for the fill level and / or for the amount of toner material 12 that is located in the storage container 16 is determined with the help of a control unit (not shown). provides) determined to which the measured values of the pressure sensors 128, 130 are supplied. The determined fill level value can be displayed on a display unit of the printer or copier, and signaling can also take place when a preset value is exceeded.

FIG. 6 schematically shows an embodiment of the toner conveying system according to FIG. 5, in which toner material is conveyed from a storage container 16 into a tubular line with the aid of excess pressure. The storage container 17 is connected in an airtight manner to an intermediate store 42 via the coupling device 58. The toner material 12 slips out of the storage container 16 into the intermediate storage 142. The size relationships of the storage container 16 and the intermediate storage 142 shown in FIG. 6 can also be such in a specific embodiment in a printer or copier that the intermediate storage 142 has only a small fraction of the volume of the storage container 16. A porous metal plate 144 is arranged approximately horizontally in the storage container 144. For example, the porous metal plate 142 is a chrome-nickel steel sintered plate with a pore size of approximately 2 μm. Such a metal plate 144 is permeable to air, but neither toner material 12 nor carrier particles can pass through this metal plate 144.

The inner tubular element 138 of the tubular line 132 is connected in a toner-tight manner to an opening 146 in the metal plate 144, which is arranged approximately in the middle of the metal plate 144. The toner material 12 slides out of the intermediate storage 142 into the tubular line 132 via the removal opening 146. A pressure chamber 154 is arranged below this opening 146 and around this opening 146 Compressed air is supplied. The amount of compressed air supplied is dimensioned such that a pressure of approximately 20 millibars above ambient pressure builds up in this pressure chamber 154. The pressure chamber 154 is connected in an airtight manner to the outer tube element 140 of the tubular line 132 in such a way that the compressed air supplied with the aid of the compressed air line 156 can get into the intermediate line between the inner tube element 138 and the outer tube element 140 into the tubular line 132.

As already mentioned in connection with FIG. 5, the inner tubular element 138 is porous air-permeable, as a result of which the air fed into the pressure chamber 154 is pressed not only through the porous metal plate 144 into the toner material 12 in the intermediate storage 142, but also along the length of the tubular one Line 132 through the wall of the inner tubular element 138 into this. As a result, not only is the toner material-air mixture formed in the intermediate store 142, but the toner material-air mixture conveyed into the tubular line 132 also remains contained in this line 132 as a flowable mixture. This prevents blockages in the tubular line 132. Such a tubular line 132 can also have bending points without toner accumulations occurring at these bending points, which lead to a blockage of the tubular line 132. A second pressure chamber 148 is arranged below the metal plate 144 around the pressure chamber 154.

The pressure chamber 148 is fed via a pressure line 150, which contains a valve 152. The amount of compressed air supplied to the pressure chamber 148 can be adjusted by the valve 152. The valve 152 can be designed, for example, as a solenoid valve that can be controlled in an open and a closed position. Depending on the density of the toner material rials 12 is supplied to the pressure chamber 148 for conveying toner material 12. Compressed air "does not necessarily have to be supplied to the pressure chamber 148 up to a density of about 0.46 g / cm ³ , since up to this density the pressure via the pressure chamber 148 afterflowing ^'ambient air is sufficient to form at least in the region of the removal opening 146, a toner material-air mixture. the toner conveying system shown in Figure 6 is preferably located above a developer station 14. This makes it possible, even large-volume reservoir 16 with a volume of toner material 12 in the range between 5 kg and 20 kg The transport of the toner material 12 through the tubular line 132 is favored by gravity.

The arrows 148 indicate the direction of flow of the ambient or compressed air fed through the porous metal plate 144 to the intermediate store 142, a toner material / air mixture also being generated by this air in regions of the storage container 16. The intermediate store 142, the pressure chambers 146, 148 and the tubular line 132 are shown in a sectional illustration in FIG. 6.

FIG. 7 shows a further embodiment of the toner delivery system according to FIG. 5. In contrast to the toner conveying system according to Figure 6, the ^porous' metal plate 144 is funnel-shaped in the system of FIG. 7 The inner tubular element 138 is arranged at the funnel outlet and connected to it in a toner-tight manner. Compressed air is supplied to the pressure chamber 154 with the aid of the compressed air line 146. The pressure chamber 154 is arranged around the funnel-shaped metal plate 154. The toner material 12 slips out of the storage container 16 into the funnels formed by the porous metal plate 144.

The compressed air fed into the pressure chamber 154 is pressed through the porous metal plate 144 into the toner material 12, whereby a toner material-air mixture is generated. The toner material-air mixture then slides or flows through the outlet opening of the funnel into the inner tubular element 138 of the tubular line 132. The outer tubular member 140 of the tubular conduit 132 is airtightly connected to the pressure chamber 154 so that compressed air is supplied into the space between the inner tubular member 138 and the outer tubular member 140. As a result, the toner material-air mixture is also retained in the tubular line 132 and can simply be conveyed to the developer station 14 through the tubular line 132. In the developer station 14, the toner material-air mixture flows out of the inner tubular element and falls into the developer station 14. Via a coupling device 58, the pressure chamber 154 and the intermediate store 142 are connected to the reservoir 16 in an airtight manner.

FIG. 8 shows a cross section of the tubular line 132. The outer tubular member 140 is airtight and is spaced 160 from the outer wall of the inner tubular member 138. Spacers, one of which is designated 162, ensure that compressed air fed into the space 160 is internal tubular element 138 is supplied evenly on all sides. The spacers. 162 also ensure that when the tubular conduit 132 is bent over the entire circumference and the entire length of the first tubular element 138, compressed air is supplied to it. As mentioned above, the inner tubular member 138 comprises air-permeable material, whereby compressed air from the space 160, the inner tubular member 138 penetrates through ^'in DES sen interior. A toner material-air mixture is formed with the toner material, which is located inside the inner tubular element 138, by the inflowing compressed air. In other embodiments of the tubular line 132, it is also possible to dispense with spacers 162 if, for example, relatively rigid tubular elements 138, 140 are used and only a few points of contact between the inner tubular element 138 and the outer tubular element 140 are to be expected. When designing the tubular elements 138, 140 as flexible hoses, however, it is advantageous to use spacers 162, since otherwise no toner material / air mixture is formed in sections of the line 132.

At the outlet opening of the tubular line 132, the inner tube element 138 is connected to the outer tube element 140 in an airtight manner. This prevents the compressed air from simply escaping from the interspace 160 between the inner tube element 138 and the outer tube element 140 and as a result from which insufficient air is no longer forced through the inner air-permeable tube element 138.

FIG. 9 schematically shows an arrangement for conveying toner material from a container 16 into several developer stations 14a, 14b in electrophotographic printers or copiers. Toner material 12 is fed from a storage container 16 to an intermediate storage 142. From this buffer 142, a toner material-air mixture is fed through a tubular line 132a to a first developer station 14a. Via a second pipe conveyor Line 132b is also fed from the buffer 142 to a second developer station 14b, a toner material-air mixture. The supply of the toner material 12 to the developer station 14a and 14b takes place alternately one after the other. With the help of the valves 164, 166 arranged in the tubular lines 132a, 132b, the tubular lines 132a and 132b can optionally be closed. This arrangement is particularly advantageous if two printing units, each with a developer station, are provided in an electrophotographic printer or copier, for example for printing a front and a back on a carrier material. However, the buffer 142 can also be used to supply developer stations 14a, 14b with toner material 12 which are arranged in different electrophotographic printers or copiers.

FIG. 10 shows a storage container 16 with a closure device 164. The storage container 16 has a conical section 168 towards a removal opening 180. A closure element 166 is arranged in the interior of the storage container 16. The closure element 166 also has conically shaped walls on the outside in the section of the conical container walls 168, the conicalities roughly matching. The closure element 166 is pressed toward the removal opening 180 by a spring 176. The conical outer walls of the closure element 166 are pressed against the conical inner walls 168 of the storage container 16, so that no toner material 12 reaches the removal opening 180. The spring 176 is biased by a spring holder 178, whereby the closure element 166 is pressed against the conical container walls 168. The closure element 166 thus forms a plug in front of the removal opening 180. element 166 has porous air-permeable sections 170, 171 towards the interior of the storage container 16.

To remove toner material 12 from the storage container 16, a compressed air nozzle 174 is inserted into a compressed air inlet 172 of the closure element 166. The compressed air nozzle 174 is guided through the removal opening 180 of the storage container 16. The compressed air nozzle 174 is inserted so far into the storage container 16 that the closure element 166 is pressed away from the removal opening 180 into the interior of the storage container 16 against the spring force, as a result of which a gap is formed in the conical section 168 of the container 16.

FIG. 11 shows the storage container 16 according to FIG. 10 in the open state for the removal of toner material 12 from the container 16. As already described in connection with FIG. 10, the closure element 166 is pushed into the container 16 in the direction of the arrow P3 with the aid of the compressed air connection 174. The spring 176 is further biased. By pushing the closure element 166 into the container 16, a gap 182 is formed between the conical container wall 168 and the closure element 166, through which the toner material 12 can slide down to the removal opening 180. With the aid of the compressed air connection 174, compressed air is fed into the interior of the closure element 166. The compressed air is pressed into the toner material 12 through the porous air-permeable sections 170, 171 of the closure element 166. Arrows show the flow through the air-permeable sections 170, 171 when compressed air is supplied. This compressed air flows through the toner material 12, as a result of which a flowable toner material-air mixture is formed. This allows the toner material-air mixture to pass through the gap very easily 182 flow to the discharge opening 180 and exit through it.

In this context, reference is also made to the patent applications with the internal file numbers 20010510 and 200E0511, which were filed at the same time as this patent application and which contain a method and a device for conveying toner material from a storage container and a device and a method for dosing of toner in an electrographic printer or copier. Both of these patent applications are hereby incorporated by reference into the present description.

LIST OF REFERENCE NUMBERS

10 toner delivery system

12 toner material

14 developer station 16 storage container

18 opening

20 locking device

22 fluid funnels

24 funnel outlet 26 pipe system

28 buffers

30 stirrers

32 level sensor

34 Cell wheel lock 36 Toner delivery tube 8 Conveyor spiral

40 pipe system

42 control valve

44 vacuum line 6 vacuum blower 8 connection point 0 filter 2 opening 4 pipe system 6 control valve 7 bottom 8 coupling device 0 discharge device 2 check valve 4 pipe section 6, 67 tubular line 8 sluice 0 metering device 2 separating device 4 control valve 76 ventilation element

78 filters ^"

80 waste toner containers

82 Fine filter 84 Vacuum blower

86 vacuum distribution

88 funnels

90, 100 dosing nozzle

92, 92 walls 96, 98 supply air openings

102 discharge device

104, 106 inner walls

108 outer wall

110 dip tube 112 opening

114, 116 supply air openings

118 dosing air flow

120 porous plate

122 pressure chamber 124, 126 throttle

128, 130 pressure measuring sensors

132 tubular conduit

134 compressed air supply

136 discharge device 138 inner tube element

140 outer tubular element

142 buffers

144 porous metal plate

146 Discharge opening 148 pressure chamber

150 compressed air line

152 valve

154 pressure chamber

156 pressure line 158 fluid air 160 space

162 spacers

164 closure device

166 closure element

168 conical section

170, 171 porous air-permeable sections

172 compressed air inlet

174 compressed air nozzle

176 feather

178 feather holder

180 removal opening

182 gap

184 compressed air outlet

Claims

Expectations

1. method for conveying toner material from a container,

in which a container arrangement contains toner material (12) which is removed from the container arrangement via a removal opening (24),

the toner material (12) is conveyed away from the removal opening (24) with the aid of a tubular line (26) connected at least to the removal opening (24), the toner material (12) being transported by an air flow in the line (26),

a vacuum is generated at the removal opening (24) by the air flow in the line (26), and in which the container arrangement has at least one air-permeable area (22) through which air flows into the container arrangement when the vacuum is present.

2. The method according to claim 1, characterized in that the container arrangement contains a toner reservoir (16) and a closure device (20).

3. The method according to any one of the preceding claims, characterized in that the air flow in the line is generated by a negative pressure and / or by an excess pressure, which is respectively applied to one end of the line.

4. The method according to any one of the preceding claims, characterized in that the air-permeable section (22) in the vicinity of the removal opening (24) is ordered.

5. The method according to any one of the preceding claims, characterized in that air is drawn through the air-permeable section (22) into the container arrangement by the air flow, whereby a toner material-air mixture is generated with the aid of the supplied air at least in a part of the container arrangement ,

6. The method according to any one of the preceding claims, characterized in that the removal opening (24) is arranged in a section of the container (16) lying at the bottom in the removal position.

7. The method according to any one of claims 1 to 5, characterized in that the removal opening is arranged in the removal position above, and that the toner material (12) is sucked up through the container (16).

8. The method according to any one of the preceding claims, characterized in that the toner material (12) slides through funnel-shaped container walls (22) to the removal opening (24).

9. The method according to any one of the preceding claims, characterized in that at least the air-permeable sections are sealed airtight to the environment, ambient air being supplied to the sealed-off sections (22) through a metering nozzle (52).

10. The method according to any one of the preceding claims, characterized in that the air-permeable Ab- cut (22) contain sintered materials made of steel, iron and / or bronze.

11. The method according to any one of the preceding claims, characterized in that the air-permeable section (22) contain a sieve or a filter medium.

12. Device for conveying toner material,

with a container arrangement which contains toner material (12) which can be removed from the container arrangement via a removal opening (24),

with a tubular line (26) connected at least to the removal opening (24), through which the toner material (12) can be conveyed away from the removal opening,

with means for generating an air flow in the

Line (26) through which the toner material (12) can be transported through line (26), the air flow at the removal opening (24) generating a negative pressure,

and wherein the container arrangement has at least one air-permeable area (22) through which air flows into the container arrangement when the negative pressure is present.

13. line (132) for transporting toner material (12), which contains a first tubular element (138), the wall of which is at least partially permeable to air,

wherein a second tubular element (140) is provided, in the interior of which the first tubular element element (138) is arranged, wherein the second tubular element (140) is substantially airtight.

14. Line according to claim 13, characterized in that between the outer wall of the first tubular

Element (138) and the inner wall of the second tubular element (140) is a distance.

15. Pipe according to claim 14, characterized in that between the outer wall of the first tubular

Element (138) and the inner wall of the second tubular element (140) at least one spacer (162) is provided.

16. Line according to one of claims 13 to 15, characterized in that compressed air can be fed to the second tubular element (140).

17. Line according to one of claims 13 to 16, characterized in that the compressed air supplied to the second tubular element (140) can be fed into the distance (160) between the first and second tubular elements, the compressed air being passed through the wall of the first tubular member (138) enters the interior of the first tubular member (138).

18. Line according to one of claims 13 to 17, characterized in that toner material (12) is conveyed inside the first tubular element (138).

19. Device for closing a toner reservoir,

at the one removal opening (180) in a lower one Section of a toner reservoir (16) is arranged j

at least one section (168) of the container wall is arranged obliquely towards the removal opening (180), ^■

a closure element (166) is provided in the container (16) which, in a first position, bears against the container wall in the vicinity of the removal opening (180) in such a way that it closes the container (16) towards the removal opening (180),

in a second position of the closure element (166) there is a gap between the inclined container wall (168) and closure element (166) through which the toner material (12) present in the toner reservoir (16) can be removed.

20. The apparatus according to claim 19, characterized in that the closure element (166) is pressed by means of a spring force against the inside of the oblique container wall (168).

21. Device according to one of claims 19 or 20, characterized in that the container wall is conical towards the removal opening (180) and that the closure element (166) essentially the same conicity of at least a portion (168) of the conical container wall Has.

22. Device according to one of claims 19 to 21, characterized in that the closure element (166) has an opening to the removal opening (180) through which compressed air can be supplied to the closure element (166), and in that the closure element (166) to the Toner storage container (16) has at least one air-permeable section (170, 171) through which the supplied compressed air can be fed into the interior of the toner storage container (16), whereby the toner material (12) present in the toner storage container (16) at least in one area a flowable toner-air mixture is generated.

23. Device according to one of claims 19 to 22, characterized in that a compressed air connection element (174) is present, which in the operating state is connected airtight to the closure element (166), the compressed air connection element (174) closing element (166) in presses the second position.